Heart Failure

Heart failure is the pathophysiologic state in which the heart, via an abnormality of cardiac function (detectable or not), fails to pump blood at a rate commensurate with the requirements of the metabolizing tissues or is able to do so only with an elevated diastolic filling pressure.

Heart failure (see the images below) may be caused by myocardial failure but may also occur in the presence of near-normal cardiac function under conditions of high demand. Heart failure always causes circulatory failure, but the converse is not necessarily the case, because various noncardiac conditions (eg, hypovolemic shock, septic shock) can produce circulatory failure in the presence of normal, modestly impaired, or even supranormal cardiac function. To maintain the pumping function of the heart, compensatory mechanisms increase blood volume, cardiac filling pressure, heart rate, and cardiac muscle mass. However, despite these mechanisms, there is a progressive decline in the ability of the heart to contract and relax, resulting in worsening heart failure.

Heart Failure. This chest radiograph shows an enlarged cardiac silhouette and edema at the lung bases, signs of acute heart failure.

Heart Failure. A 28-year-old woman presented with acute heart failure secondary to chronic hypertension. The enlarged cardiac silhouette on this anteroposterior (AP) radiograph is caused by acute heart failure due to the effects of chronic high blood pressure on the left ventricle. The heart then becomes enlarged, and fluid accumulates in the lungs (ie, pulmonary congestion).

Signs and symptoms of heart failure include tachycardia and manifestations of venous congestion (eg, edema) and low cardiac output (eg, fatigue). Breathlessness is a cardinal symptom of left ventricular (LV) failure that may manifest with progressively increasing severity.

Heart failure can be classified according to a variety of factors (see Heart Failure Criteria, Classification, and Staging). The New York Heart Association (NYHA) classification for heart failure comprises four classes, based on the relationship between symptoms and the amount of effort required to provoke them, as follows[2] :

• Class I patients have no limitation of physical activity
• Class II patients have slight limitation of physical activity
• Class III patients have marked limitation of physical activity
• Class IV patients have symptoms even at rest and are unable to carry on any physical activity without discomfort

The American College of Cardiology/American Heart Association (ACC/AHA) heart failure guidelines complements the NYHA classification to reflect the progression of disease, divided into four stages, as follows[3] :

• Stage A patients are at high risk for heart failure but have no structural heart disease or symptoms of heart failure
• Stage B patients have structural heart disease but have no symptoms of heart failure
• Stage C patients have structural heart disease and have symptoms of heart failure
• Stage D patients have refractory heart failure requiring specialized interventions

More recently, the ACC/AHA and Heart Failure Society of America (HFSA) introduced additional disease-staging terminology to characterize the syndrome of heart failure as a continuum, as follows[4, 5, 6, 7] :

• "At risk for HF" for stage A: Applied to asymptomatic patients with risk factors such as diabetes or hypertension but no known cardiac changes
• "Pre-HF" for stage B: Adds cardiac structural changes or elevated natriuretic peptides, still in the absence of symptoms
• "Symptomatic HF" for stage C: Structural disease with current or previous symptoms
• "Advanced HF" for stage D: Characterized by severe debilitating symptoms or repeated hospitalizations even with guideline-directed medical therapy (GDMT)

Laboratory studies for heart failure should include a complete blood count (CBC), electrolyte levels, and hepatorenal function studies. Imaging studies such as chest radiography and two-dimensional echocardiography are recommended in the initial evaluation of patients with known or suspected heart failure. B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels can be useful in differentiating cardiac and noncardiac causes of dyspnea. (See Workup for more information.)

In acute heart failure, patient care consists of stabilizing the patient's clinical condition; establishing the diagnosis, etiology, and precipitating factors; and initiating therapies to provide rapid symptom relief and survival benefit. Surgical options for heart failure include revascularization procedures, electrophysiologic intervention, cardiac resynchronization therapy (CRT), implantable cardioverter-defibrillators (ICDs), valve replacement or repair, ventricular restoration, heart transplantation, and ventricular assist devices (VADs). (See Treatment for more information.)

The goals of pharmacotherapy are to increase survival and to prevent complications. Along with oxygen, medications assisting with symptom relief include diuretics, digoxin, inotropes, and morphine. Drugs that can exacerbate heart failure should be avoided (nonsteroidal anti-inflammatory drugs [NSAIDs], calcium channel blockers [CCBs], and most antiarrhythmic drugs). (See Medication for more information.)

For further information, see the Medscape Drugs & Diseases articles Pediatric Congestive Heart Failure, Congestive Heart Failure Imaging, Heart Transplantation, Pediatric Heart Transplantation, Coronary Artery Bypass Grafting, and Implantable Cardioverter-Defibrillators.

The common pathophysiologic state that perpetuates the progression of heart failure is extremely complex, regardless of the precipitating event. Compensatory mechanisms exist on every level of organization, from the subcellular all the way through to organ-to-organ interactions. Only when this network of adaptations becomes overwhelmed does heart failure ensue.[11, 12, 13, 14, 15]

Adaptations

Most important among the adaptations are the following[16] :

• The Frank-Starling mechanism, in which an increased preload helps to sustain cardiac performance
• Alterations in myocyte regeneration and death
• Myocardial hypertrophy with or without cardiac chamber dilatation, in which the mass of contractile tissue is augmented
• Activation of neurohumoral systems

The release of norepinephrine by adrenergic cardiac nerves augments myocardial contractility and includes activation of the renin-angiotensin-aldosterone system [RAAS], the sympathetic nervous system [SNS], and other neurohumoral adjustments that act to maintain arterial pressure and perfusion of vital organs.

In acute heart failure, the finite adaptive mechanisms that may be adequate to maintain the overall contractile performance of the heart at relatively normal levels become maladaptive when trying to sustain adequate cardiac performance.[17]

The primary myocardial response to chronic increased wall stress is myocyte hypertrophy, death/apoptosis, and regeneration.[18] This process eventually leads to remodeling, usually the eccentric type. Eccentric remodeling further worsens the loading conditions on the remaining myocytes and perpetuates the deleterious cycle. The idea of lowering wall stress to slow the process of remodeling has long been exploited in treating heart failure patients.[19]

The reduction of cardiac output following myocardial injury sets into motion a cascade of hemodynamic and neurohormonal derangements that provoke activation of neuroendocrine systems, most notably the above-mentioned adrenergic systems and RAAS.[20]

The release of epinephrine and norepinephrine, along with the vasoactive substances endothelin-1 (ET-1) and vasopressin, causes vasoconstriction, which increases calcium afterload and, via an increase in cyclic adenosine monophosphate (cAMP), causes an increase in cytosolic calcium entry. The increased calcium entry into the myocytes augments myocardial contractility and impairs myocardial relaxation (lusitropy).

The calcium overload may induce arrhythmias and lead to sudden death. The increase in afterload and myocardial contractility (known as inotropy) and the impairment in myocardial lusitropy lead to an increase in myocardial energy expenditure and a further decrease in cardiac output. The increase in myocardial energy expenditure leads to myocardial cell death/apoptosis, which results in heart failure and further reduction in cardiac output, perpetuating a cycle of further increased neurohumoral stimulation and further adverse hemodynamic and myocardial responses.

In addition, the activation of the RAAS leads to salt and water retention, resulting in increased preload and further increases in myocardial energy expenditure. Increases in renin, mediated by a decreased stretch of the glomerular afferent arteriole, reduce delivery of chloride to the macula densa and increase beta1-adrenergic activity as a response to decreased cardiac output. This results in an increase in angiotensin II (Ang II) levels and, in turn, aldosterone levels, causing stimulation of the release of aldosterone. Ang II, along with ET-1, is crucial in maintaining effective intravascular homeostasis as mediated by vasoconstriction and aldosterone-induced salt and water retention.

The concept of the heart as a self-renewing organ is a relatively recent development.[21] This paradigm for myocyte biology created an entire field of research aimed directly at augmenting myocardial regeneration. The rate of myocyte turnover has been shown to increase during times of pathologic stress.[18] In heart failure, this mechanism for replacement becomes overwhelmed by an even faster increase in the rate of myocyte loss. This imbalance of hypertrophy and death over regeneration is the final common pathway at the cellular level for the progression of remodeling and heart failure.

Angiotensin II

Research indicates that local cardiac Ang II production (which decreases lusitropy, increases inotropy, and increases afterload) leads to increased myocardial energy expenditure. Ang II has also been shown in vitro and in vivo to increase the rate of myocyte apoptosis.[22] In this fashion, Ang II has similar actions to norepinephrine in heart failure.

Ang II also mediates myocardial cellular hypertrophy and may promote progressive loss of myocardial function. The neurohumoral factors above lead to myocyte hypertrophy and interstitial fibrosis, resulting in increased myocardial volume and increased myocardial mass, as well as myocyte loss. As a result, the cardiac architecture changes which, in turn, leads to further increase in myocardial volume and mass.

Myocytes and myocardial remodeling

In the failing heart, increased myocardial volume is characterized by larger myocytes approaching the end of their life cycle.[23] As more myocytes drop out, an increased load is placed on the remaining myocardium, and this unfavorable environment is transmitted to the progenitor cells responsible for replacing lost myocytes.

Progenitor cells become progressively less effective as the underlying pathologic process worsens and myocardial failure accelerates. These features—namely, the increased myocardial volume and mass, along with a net loss of myocytes—are the hallmark of myocardial remodeling. This remodeling process leads to early adaptive mechanisms, such as augmentation of stroke volume (Frank-Starling mechanism) and decreased wall stress (Laplace law) and, later, to maladaptive mechanisms such as increased myocardial oxygen demand, myocardial ischemia, impaired contractility, and arrhythmogenesis.

As heart failure advances, there is a relative decline in the counterregulatory effects of endogenous vasodilators, including nitric oxide (NO), prostaglandins (PGs), bradykinin (BK), atrial natriuretic peptide (ANP), and B-type natriuretic peptide (BNP). This decline occurs simultaneously with the increase in vasoconstrictor substances from the RAAS and the adrenergic system, which fosters further increases in vasoconstriction and thus preload and afterload. This results in cellular proliferation, adverse myocardial remodeling, and antinatriuresis, with total body fluid excess and worsening of heart failure symptoms.

Systolic and diastolic failure

Systolic and diastolic heart failure each result in a decrease in stroke volume.[24, 25] This leads to activation of peripheral and central baroreflexes and chemoreflexes that are capable of eliciting marked increases in sympathetic nerve traffic.

Although there are commonalities in the neurohormonal responses to decreased stroke volume, the neurohormone-mediated events that follow have been most clearly elucidated for individuals with systolic heart failure. The ensuing elevation in plasma norepinephrine directly correlates with the degree of cardiac dysfunction and has significant prognostic implications. Norepinephrine, while directly toxic to cardiac myocytes, is also responsible for a variety of signal-transduction abnormalities, such as downregulation of beta1-adrenergic receptors, uncoupling of beta2-adrenergic receptors, and increased activity of inhibitory G-protein. Changes in beta1-adrenergic receptors result in overexpression and promote myocardial hypertrophy.

Atrial natriuretic peptide and B-type natriuretic peptide

ANP and BNP are endogenously generated peptides activated in response to atrial and ventricular volume/pressure expansion. ANP and BNP are released from the atria and ventricles, respectively, and both promote vasodilation and natriuresis. Their hemodynamic effects are mediated by decreases in ventricular filling pressures, owing to reductions in cardiac preload and afterload. BNP, in particular, produces selective afferent arteriolar vasodilation and inhibits sodium reabsorption in the proximal convoluted tubule. It also inhibits renin and aldosterone release and, therefore, adrenergic activation. ANP and BNP are elevated in chronic heart failure. BNP especially has potentially important diagnostic, therapeutic, and prognostic implications.

For more information, see the Medscape Drugs & Diseases article Natriuretic Peptides in Congestive Heart Failure.

Other vasoactive systems

Other vasoactive systems that play a role in the pathogenesis of heart failure include the ET receptor system, the adenosine receptor system, vasopressin, and tumor necrosis factor-alpha (TNF-alpha).[26] ET, a substance produced by the vascular endothelium, may contribute to the regulation of myocardial function, vascular tone, and peripheral resistance in heart failure. Elevated levels of ET-1 closely correlate with the severity of heart failure. ET-1 is a potent vasoconstrictor and has exaggerated vasoconstrictor effects in the renal vasculature, reducing renal plasma blood flow, glomerular filtration rate (GFR), and sodium excretion.

TNF-alpha has been implicated in response to various infectious and inflammatory conditions. Elevations in TNF-alpha levels have been consistently observed in heart failure and seem to correlate with the degree of myocardial dysfunction. Some studies suggest that local production of TNF-alpha may have toxic effects on the myocardium, thus worsening myocardial systolic and diastolic function.

In individuals with systolic dysfunction, therefore, the neurohormonal responses to decreased stroke volume result in temporary improvement in systolic blood pressure and tissue perfusion. However, in all circumstances, the existing data support the notion that these neurohormonal responses contribute to the progression of myocardial dysfunction in the long term.

Heart failure with preserved ejection fraction

In diastolic heart failure (heart failure with preserved ejection fraction [HFpEF]), the same pathophysiologic processes occur that lead to decreased cardiac output in systolic heart failure, but they do so in response to a different set of hemodynamic and circulatory environmental factors that depress cardiac output.[27]

In HFpEF, altered relaxation and increased stiffness of the ventricle (due to delayed calcium uptake by the myocyte sarcoplasmic reticulum and delayed calcium efflux from the myocyte) occur in response to an increase in ventricular afterload (pressure overload). The impaired relaxation of the ventricle then leads to impaired diastolic filling of the left ventricle (LV).

Morris et al found that right venticular (RV) subendocardial systolic dysfunction and diastolic dysfunction, as detected by echocardiographic strain rate imaging, are common in patients with HFpEF. This dysfunction is potentially associated with the same fibrotic processes that affect the subendocardial layer of the LV and, to a lesser extent, with RV pressure overload. It may play a role in the symptomatology of patients with HFpEF.[28]

LV chamber stiffness

An increase in LV chamber stiffness occurs secondary to any one, or any combination, of the following three mechanisms:

• Rise in filling pressure
• Shift to a steeper ventricular pressure-volume curve
• Decrease in ventricular distensibility

A rise in filling pressure is the movement of the ventricle up along its pressure-volume curve to a steeper portion, as may occur in conditions such as volume overload secondary to acute valvular regurgitation or acute LV failure due to myocarditis.

A shift to a steeper ventricular pressure-volume curve results, most commonly, not only from increased ventricular mass and wall thickness (as observed in aortic stenosis and long-standing hypertension) but also from infiltrative disorders (eg, amyloidosis), endomyocardial fibrosis, and myocardial ischemia.

Parallel upward displacement of the diastolic pressure-volume curve is generally referred to as a decrease in ventricular distensibility. This is usually caused by extrinsic compression of the ventricles.

Concentric LV hypertrophy

Pressure overload that leads to concentric LV hypertrophy (LVH), as occurs in aortic stenosis, hypertension, and hypertrophic cardiomyopathy, shifts the diastolic pressure-volume curve to the left along its volume axis. As a result, ventricular diastolic pressure is abnormally elevated, although chamber stiffness may or may not be altered.

Increases in diastolic pressure lead to an increased myocardial energy expenditure, remodeling of the ventricle, increased myocardial oxygen demand, myocardial ischemia, and eventual progression of the maladaptive mechanisms of the heart that lead to decompensated heart failure.

Arrhythmias

Although life-threatening rhythms are more common in ischemic cardiomyopathy, arrhythmia imparts a significant burden in all forms of heart failure. In fact, some arrhythmias even perpetuate heart failure. The most significant of all rhythms associated with heart failure are the life-threatening ventricular arrhythmias. Structural substrates for ventricular arrhythmias that are common in heart failure, regardless of the underlying cause, include ventricular dilatatation, myocardial hypertrophy, and myocardial fibrosis.

At the cellular level, myocytes may be exposed to increased stretch, wall tension, catecholamines, ischemia, and electrolyte imbalance. The combination of these factors contributes to an increased incidence of arrhythmogenic sudden cardiac death in patients with heart failure.

Most patients who present with significant heart failure do so because of an inability to provide adequate cardiac output in that scenario. This is often a combination of the causes listed below in the setting of an abnormal myocardium. The list of causes responsible for presentation of a patient with heart failure exacerbation is very long, and searching for the proximate cause to optimize therapeutic interventions is important.

From a clinical standpoint, classifying the causes of heart failure into the following four broad categories is useful:

• Underlying causes: Underlying causes of heart failure include structural abnormalities (congenital or acquired) that affect the peripheral and coronary arterial circulation, pericardium, myocardium, or cardiac valves, thus leading to increased hemodynamic burden or myocardial or coronary insufficiency
• Fundamental causes: Fundamental causes include biochemical and physiologic mechanisms, through which either an increased hemodynamic burden or a reduction in oxygen delivery to the myocardium results in impairment of myocardial contraction
• Precipitating causes: Overt heart failure may be precipitated by progression of the underlying heart disease (eg, further narrowing of a stenotic aortic valve or mitral valve) or various conditions (fever, anemia, infection) or medications (chemotherapy, nonsteroidal anti-inflammatory drugs [NSAIDs]) that alter the homeostasis of heart failure patients
• Genetics of cardiomyopathy: Dilated, arrhythmic right ventricular and restrictive cardiomyopathies are known genetic causes of heart failure

Underlying causes

Specific underlying factors cause various forms of heart failure, such as systolic heart failure (most commonly, left vetricular [LV] systolic dysfunction), heart failure with preserved LV ejection fraction (LVEF), acute heart failure, high-output heart failure, and right heart failure.

Underlying causes of systolic heart failure include the following:

• Coronary artery disease
• Diabetes mellitus
• Hypertension
• Valvular heart disease (stenosis or regurgitant lesions)
• Arrhythmia (supraventricular or ventricular)
• Infections and inflammation (myocarditis)
• Peripartum cardiomyopathy
• Congenital heart disease
• Drugs (either recreational, such as alcohol and cocaine, or therapeutic drugs with cardiac side effects, such as doxorubicin)
• Idiopathic cardiomyopathy
• Rare conditions (endocrine abnormalities, rheumatologic disease, neuromuscular conditions)

Underlying causes of diastolic heart failure include the following:

• Coronary artery disease
• Diabetes mellitus
• Hypertension
• Valvular heart disease (aortic stenosis)
• Hypertrophic cardiomyopathy
• Restrictive cardiomyopathy (amyloidosis, sarcoidosis)
• Constrictive pericarditis

Underlying causes of acute heart failure include the following:

• Acute valvular (mitral or aortic) regurgitation
• Myocardial infarction (MI)
• Myocarditis
• Arrhythmia
• Drugs (eg, cocaine, calcium channel blockers, or beta-blocker overdose)
• Sepsis

Underlying causes of high-output heart failure include the following:

• Anemia
• Systemic arteriovenous fistulas
• Hyperthyroidism
• Beriberi heart disease
• Paget disease of bone
• Albright syndrome (fibrous dysplasia)
• Multiple myeloma
• Pregnancy
• Glomerulonephritis
• Polycythemia vera
• Carcinoid syndrome

Underlying causes of right heart failure include the following:

• LV failure
• Coronary artery disease (ischemia)
• Pulmonary hypertension
• Pulmonary valve stenosis
• Pulmonary embolism
• Chronic pulmonary disease
• Neuromuscular disease

Precipitating causes of heart failure

A previously stable, compensated patient may develop heart failure that is clinically apparent for the first time when the intrinsic process has advanced to a critical point, such as with further narrowing of a stenotic aortic valve or mitral valve. Alternatively, decompensation may occur as a result of the failure or exhaustion of the compensatory mechanisms but without any change in the load on the heart in patients with persistent, severe pressure or volume overload. In particular, consider whether the patient has underlying coronary artery disease or valvular heart disease.

The most common cause of decompensation in a previously compensated patient with heart failure is inappropriate reduction in the intensity of treatment, such as dietary sodium restriction, physical activity reduction, or drug regimen reduction. Uncontrolled hypertension is the second most common cause of decompensation, followed closely by cardiac arrhythmias (most commonly, atrial fibrillation). Arrhythmias, particularly ventricular arrhythmias, can be life threatening. Also, patients with one form of underlying heart disease that may be well compensated can develop heart failure when a second form of heart disease ensues. For example, a patient with chronic hypertension and asymptomatic LV hypertrophy (LVH) may be asymptomatic until an MI develops and precipitates heart failure.

Systemic infection or the development of unrelated illness can also lead to heart failure. Systemic infection precipitates heart failure by increasing total metabolism as a consequence of fever, discomfort, and cough, increasing the hemodynamic burden on the heart. Septic shock, in particular, can precipitate heart failure by the release of endotoxin-induced factors that can depress myocardial contractility.

Cardiac infection and inflammation can also endanger the heart. Myocarditis or infective endocarditis may directly impair myocardial function and exacerbate existing heart disease. The anemia, fever, and tachycardia that frequently accompany these processes are also deleterious. In the case of infective endocarditis, the additional valvular damage that ensues may precipitate cardiac decompensation.

Patients with heart failure, particularly when confined to bed, are at high risk of developing pulmonary emboli, which can increase the hemodynamic burden on the right ventricle (RV) by further elevating RV systolic pressure, possibly causing fever, tachypnea, and tachycardia.

Intense, prolonged physical exertion or severe fatigue, such as may result from prolonged travel or emotional crisis, is a relatively common precipitant of cardiac decompensation. The same is true of exposure to severe climate change (ie, the individual comes in contact with a hot, humid environment or a bitterly cold one).

Excessive intake of water and/or salt and the administration of cardiac depressants or drugs that cause salt retention are other factors that can lead to heart failure. At the European Society of Cardiology 2017 Congress, investigators presented a study comprising more than 4630 people that indicated high daily salt intake (>13.7 g) is associated with a substantial increased risk of developing heart failure, independent of other risk factors.[29, 30]

Because of increased myocardial oxygen consumption and demand beyond a critical level, the following high-output states can precipitate the clinical presentation of heart failure:

• Profound anemia
• Thyrotoxicosis
• Myxedema
• Paget disease of bone
• Albright syndrome
• Multiple myeloma
• Glomerulonephritis
• Cor pulmonale
• Polycythemia vera
• Obesity
• Carcinoid syndrome
• Pregnancy
• Nutritional deficiencies (eg, thiamine deficiency, beriberi)

Longitudinal data from the Framingham Heart Study has suggested that antecedent subclinical LV systolic or diastolic dysfunction is associated with an increased incidence of heart failure, supporting the notion that heart failure is a progressive syndrome.[31, 32] Another analysis of over 36,000 patients undergoing outpatient echocardiography reported that moderate or severe diastolic dysfunction, but not mild diastolic dysfunction, is an independent predictor of mortality.[33]

Genetics of cardiomyopathy

Autosomal dominant inheritance has been demonstrated in dilated cardiomyopathy and in arrhythmic right ventricular cardiomyopathy. Restrictive cardiomyopathies are usually sporadic and associated with the gene for cardiac troponin I. Genetic tests are available at major genetic centers for cardiomyopathies.[34]

In families with a first-degree relative who has been diagnosed with a cardiomyopathy leading to heart failure, the at-risk patient should be screened and followed.[34] The recommended screening consists of an electrocardiogram and an echocardiogram. If the patient has an asymptomatic LV dysfunction, it should be documented and treated.[34]

United States statistics

According to 2017 American Heart Association (AHA) data, heart failure affects an estimated 6.5 million Americans aged 20 years and older.[35]  With improved survival of patients with acute myocardial infarction and with a population that continues to age, heart failure will continue to increase in prominence as a major health problem in the United States. The AHA projects a 46% increase of heart failure prevalence from year 2012 to year 2030, resulting in 8 million or more Americans aged 18 years or older with heart failure.[35]  

Despite a more than decade-long decrease (2000-2012) in the the incidence of heart failure–related deaths in the United States, such deaths are on the rise again, particularly among men and non-Hispanic black populations, according to 2000-2014 data (the most recent data available) released by the Centers for Disease Control and Prevention (CDC) in December 2015.[36, 37]  The crude rate for heart failure-related deaths decreased from 103.1 deaths per 100,000 population in 2000 to 89.5 in 2009; it then increased to 96.9 in 2014. The age-adjusted rate for heart failure-related deaths decreased from 105.4 deaths per 100,000 standard population in 2000 to 81.4 in 2012; it then increased to 83.4 in 2013 and to 84.0 in 2014.[36]  The trend appears to represent a shift from coronary heart disease as the underlying cause of heart failure deaths toward other cardiovascular and noncardiovascular causes, including malignancies, diabetes, chronic lower respiratory diseases, and renal disease.

Analysis of national and regional trends in hospitalization and mortality among Medicare beneficiaries from 1998-2008 showed a relative decline of 29.5% in heart failure hospitalizations[35, 38] ; however, wide variations were noted between states and races, with black men having the slowest rate of decline. A relative decline of 6.6% in mortality was also observed, although the rate was uneven across states. The length of stay decreased from 6.8 days to 6.4 days, despite an overall increase in the comorbid conditions.[38]

Heart failure statistics for the United States are as follows[35] :

• Heart failure is the primary cause of hospitalization in the elderly. ^{[39, 40]}
• An estimated one in eight deaths is from heart failure (about 309,000 deaths caused by heart failure each year)
• Heart failure accounts for 8.5% of cardiovascular-related deaths
• Approximately 960,000 new cases of heart failure are diagnosed each year
• The annual incidence of heart failure in patients older than 65 years is 21 per 1,000 population
• Rehospitalization rates during the 6 months following discharge are as much as 50% ^[41]
• In 2012, the estimated total cost of heart failure in the United States was $30.7 billion (68% of which were direct medical costs); by 2030, the total cost is projected to rise to $69.7 billion, a nearly 127% increase.

The incidence and prevalence of heart failure are higher in black persons, Hispanics, Native Americans, and recent immigrants from developing nations, Russia, and the former Soviet republics. The higher prevalence of heart failure in blacks, Hispanics, and Native Americans is directly related to the higher incidence and prevalence of hypertension and diabetes. This problem is particularly exacerbated by a lack of access to health care and by substandard preventive health care available to the most indigent of individuals in these and other groups; in addition, many persons in these groups do not have adequate health insurance.

The higher incidence and prevalence of heart failure in recent immigrants from developing nations are largely due to a lack of prior preventive health care, a lack of treatment, or substandard treatment for common conditions, such as hypertension, diabetes, rheumatic fever, and ischemic heart disease.

Men and women have a similar incidence and prevalence of heart failure. However, many differences remain between men and women with heart failure, such as the following:

• Whereas the incidence of heart failure in men approximately doubles with each 10-year age increase between 65 and 85 years, it triples for women between ages 65 to 74 years and 75 to 85 years ^[35]
• Women tend to develop heart failure later in life than men do
• Women are more likely than men to have preserved systolic function
• Women develop depression more commonly than men do
• Women have signs and symptoms of heart failure similar to those of men, but they are more pronounced in women
• Women survive longer with heart failure than men do

The prevalence of heart failure increases with age.[40] The prevalence is 1-2% of the population younger than 55 years and increases to a rate of 10% for persons older than 75 years. Nonetheless, heart failure can occur at any age, depending on the cause.

International statistics

Heart failure is a worldwide problem. The most common cause of heart failure in industrialized countries is ischemic cardiomyopathy, with other causes, including Chagas disease and valvular cardiomyopathy, assuming a more important role in developing countries. However, in developing nations that have become more urbanized and more affluent, eating a more processed diet and leading a more sedentary lifestyle have resulted in an increased rate of heart failure, along with increased rates of diabetes and hypertension. This change was illustrated in a population study in Soweto, South Africa, where the community transformed into a more urban and westernized city, followed by an increase in diabetes, hypertension, and heart failure.[42]

In terms of treatment, one study showed few important differences in uptake of key therapies in European countries with widely differing cultures and varying economic status for patients with heart failure. In contrast, studies of sub-Saharan Africa, where healthcare resources are more limited, have shown poor outcomes in specific populations.[43, 44] For example, in some countries, hypertensive heart failure carries a 25% 1-year mortality, and human immunodeficiency virus (HIV)–associated cardiomyopathy generally progresses to death within 100 days of diagnosis in patients who are not treated with antiretroviral drugs.

Although data regarding developing nations are not as robust as studies of Western society, the following trends in developing nations are apparent:

• Causes tend to be largely nonischemic
• Patients tend to present at a younger age
• Outcomes are largely worse where healthcare resources are limited
• Isolated right heart failure tends to be more prominent, with a variety of causes having been postulated, ranging from tuberculous pericardial disease to lung disease and pollution

In general, the mortality following hospitalization for patients with heart failure is 10.4% at 30 days, 22% at 1 year, and 42.3% at 5 years, despite marked improvement in medical and device therapy.[35, 45, 46, 47, 48, 49]

Mortality is greater than 50% for patients with New York Heart Association (NYHA) class IV, American College of Cardiology/American Heart Association (ACC/AHA) stage D heart failure. Heart failure associated with acute myocardial infarction (MI) has an inpatient mortality of 20-40%; mortality approaches 80% in patients who are also hypotensive (eg, cardiogenic shock). (See Heart Failure Criteria, Classification, and Staging).

Heart failure related to systolic dysfunction has an associated mortality of 50% after 5 years.[24]

Numerous demographic, clinical and biochemical variables have been reported to provide important prognostic value in patients with heart failure, and several predictive models have been developed.[50]

A study by van Diepen et al suggested that patients with heart failure or atrial fibrillation have a significantly higher risk of noncardiac postoperative mortality than patients with coronary artery disease; this risk should be considered even if a minor procedure is planned.[51]

Bursi et al found that among community patients with heart failure, pulmonary artery systolic pressure (PASP), as assessed by Doppler echocardiography, can strongly predict death and can provide incremental and clinically significant prognostic information independent of known outcome predictors.[52]

In the Framingham Offspring Cohort, higher concentrations of galectin-3, a marker of cardiac fibrosis, were associated with an increased risk for incident heart failure (hazard ratio: 1.28 per 1 standard deviation increase in log galectin-3). Galectin-3 was also associated with an increased risk for all-cause mortality (multivariable-adjusted hazard ratio: 1.15).[53]

A more recent, retrospective study that evaluated data from the 2010 Nebraska Hospital Discharge files for 4319 hospitalizations of 3521 heart failure patients admitted to 79 in-state hospitals reported that risk factors for in-hospital mortality in these patients were increasing age, the presence of comordities, and length of hospital day.[54]

To help prevent recurrence of heart failure in patients in whom heart failure was caused by dietary factors or medication noncompliance, counsel and educate such patients about the importance of proper diet and the necessity of medication compliance.

Dunlay et al examined medication use and adherence among community-dwelling patients with heart failure and found that medication adherence was suboptimal in many patients, often because of cost.[55] A randomized controlled trial of 605 patients with heart failure reported that the incidence of all-cause hospitalization or death was not reduced in patients receiving multisession self-care training compared to those receiving a single-session intervention.[56] The optimum method for patient education remains to be established. It appears that more intensive interventions are not necessarily better.[56]

For patient education information, see the Heart Health Center, Cholesterol Center, and Diabetes Center, as well as Congestive Heart Failure Symptoms, Causes, and Life Expectancy, High Cholesterol, Chest Pain, Arrhythmias (Heart Rhythm Disorders), Heart Disease (Coronary Heart Disease), and Heart Attack.

In evaluating patients with heart failure, the clinician should ask about the following comorbidities and/or risk factors:

• Myopathy
• Previous myocardial infarction
• Valvular heart disease, familial heart disease
• Alcohol use
• Hypertension
• Diabetes
• Dyslipidemia
• Coronary/peripheral vascular disease
• Sleep-disordered breathing
• Collagen vascular disease, rheumatic fever
• Pheochromocytoma
• Thyroid disease
• Substance abuse (previous/current history)
• History of chemotherapy/radiation to the chest

The New York Heart Association (NYHA) classification of heart failure is widely used in practice and in clinical studies to quantify clinical assessment of heart failure (see Heart Failure Criteria, Classification, and Staging). Breathlessness, a cardinal symptom of left ventricular (LV) failure, may manifest with progressively increasing severity as the following:

• Exertional dyspnea
• Orthopnea
• Paroxysmal nocturnal dyspnea
• Dyspnea at rest
• Acute pulmonary edema

Other cardiac symptoms of heart failure include chest pain/pressure and palpitations. Common noncardiac signs and symptoms of heart failure include anorexia, nausea, weight loss, bloating, fatigue, weakness, oliguria, nocturia, and cerebral symptoms of varying severity, ranging from anxiety to memory impairment and confusion. Findings from the Framingham Heart Study suggested that subclinical cardiac dysfunction and noncardiac comorbidities are associated with increased incidence of heart failure, supporting the idea that heart failure is a progressive syndrome and that noncardiac factors are extremely important.[31, 32, 57]

Older patients with heart failure frequently have preserved ejection fraction and an atypical and/or delayed presentation.[58]

Exertional dyspnea

The principal difference between exertional dyspnea in patients who are healthy and exertional dyspnea in patients with heart failure is the degree of activity necessary to induce the symptom. As heart failure first develops, exertional dyspnea may simply appear to be an aggravation of the breathlessness that occurs in healthy persons during activity, but as LV failure advances, the intensity of exercise resulting in breathlessness progressively declines; however, subjective exercise capacity and objective measures of LV performance at rest in patients with heart failure are not closely correlated. Exertional dyspnea, in fact, may be absent in sedentary patients.

Orthopnea

Orthopnea is an early symptom of heart failure and may be defined as dyspnea that develops in the recumbent position and is relieved with elevation of the head with pillows. As in the case of exertional dyspnea, the change in the number of pillows required is important. In the recumbent position, decreased pooling of blood in the lower extremities and abdomen occurs. Blood is displaced from the extrathoracic compartment to the thoracic compartment. The failing LV, operating on the flat portion of the Frank-Starling curve, cannot accept and pump out the extra volume of blood delivered to it without dilating. As a result, pulmonary venous and capillary pressures rise further, causing interstitial pulmonary edema, reduced pulmonary compliance, increased airway resistance, and dyspnea.

Orthopnea occurs rapidly, often within a minute or two of recumbency, and develops when the patient is awake. Orthopnea may occur in any condition in which the vital capacity is low. Marked ascites, regardless of its etiology, is an important cause of orthopnea. In advanced LV failure, orthopnea may be so severe that the patient cannot lie down and must sleep sitting up in a chair or slumped over a table.

Cough, particularly during recumbency, may be an "orthopnea equivalent." This nonproductive cough may be caused by pulmonary congestion and is relieved by the treatment of heart failure.

Paroxysmal nocturnal dyspnea

Paroxysmal nocturnal dyspnea usually occurs at night and is defined as the sudden awakening of the patient, after a couple of hours of sleep, with a feeling of severe anxiety, breathlessness, and suffocation. The patient may bolt upright in bed and gasp for breath. Bronchospasm increases ventilatory difficulty and the work of breathing and is a common complicating factor of paroxysmal nocturnal dyspnea. On chest auscultation, the bronchospasm associated with a heart failure exacerbation can be difficult to distinguish from an acute asthma exacerbation, although other clues from the cardiovascular examination should lead the examiner to the correct diagnosis. Both types of bronchospasm can be present in a single individual.

In contrast to orthopnea, which may be relieved by immediately sitting up in bed, paroxysmal nocturnal dyspnea may require 30 minutes or longer in this position for relief. Episodes may be so frightening that the patient may be afraid to resume sleeping, even after the symptoms have subsided.

Dyspnea at rest

Dyspnea at rest in heart failure is the result of the following mechanisms:

• Decreased pulmonary function secondary to decreased compliance and increased airway resistance
• Increased ventilatory drive secondary to hypoxemia due to increased pulmonary capillary wedge pressure (PCWP); ventilation/perfusion (V/Q) mismatching due to increased PCWP and low cardiac output; and increased carbon dioxide production
• Respiratory muscle dysfunction, with decreased respiratory muscle strength, decreased endurance, and ischemia

Pulmonary edema

Acute pulmonary edema is defined as the sudden increase in PCWP (usually >25 mm Hg) as a result of acute and fulminant LV failure. It is a medical emergency and has a very dramatic clinical presentation. The patient appears extremely ill, poorly perfused, restless, sweaty, tachypneic, tachycardic, hypoxic, and coughing, with an increased work of breathing and using respiratory accessory muscles and with frothy sputum that on occasion is blood tinged.

Chest pain/pressure and palpitations

Chest pain/pressure may occur as a result of either primary myocardial ischemia from coronary disease or secondary myocardial ischemia from increased filling pressure, poor cardiac output (and, therefore, poor coronary diastolic filling), or hypotension and hypoxemia.

Palpitations are the sensation a patient has when the heart is racing. It can be secondary to sinus tachycardia due to decompensated heart failure, or more commonly, it is due to atrial or ventricular tachyarrhythmias.

Fatigue and weakness

Fatigue and weakness are often accompanied by a feeling of heaviness in the limbs and are generally related to poor perfusion of the skeletal muscles in patients with a lowered cardiac output. Although they are generally a constant feature of advanced heart failure, episodic fatigue and weakness are also common in earlier stages.

Nocturia and oliguria

Nocturia may occur relatively early in the course of heart failure. Recumbency reduces the deficit in cardiac output in relation to oxygen demand, renal vasoconstriction diminishes, and urine formation increases. Nocturia may be troublesome for patients with heart failure because it may prevent them from obtaining much-needed rest. Oliguria is a late finding in heart failure, and it is found in patients with markedly reduced cardiac output from severely reduced LV function.

Cerebral symptoms

The following may occur in elderly patients with advanced heart failure, particularly in those with cerebrovascular atherosclerosis:

• Confusion
• Memory impairment
• Anxiety
• Headaches
• Insomnia
• Bad dreams or nightmares
• Rarely, psychosis with disorientation, delirium, or hallucinations

Patients with mild heart failure appear to be in no distress after a few minutes of rest, but they may be obviously dyspneic during and immediately after moderate activity. Patients with left ventricular (LV) failure may be dyspneic when lying flat without elevation of the head for more than a few minutes. Those with severe heart failure appear anxious and may exhibit signs of air hunger in this position.

Patients with a recent onset of heart failure are generally well nourished, but those with chronic severe heart failure are often malnourished and sometimes even cachectic. Chronic marked elevation of the systemic venous pressure may produce exophthalmos and severe tricuspid regurgitation, and it may lead to visible pulsation of the eyes and of the neck veins. Central cyanosis, icterus, and malar flush may be evident in patients with severe heart failure.

In mild or moderate heart failure, stroke volume is normal at rest; in severe heart failure, it is reduced, as reflected by a diminished pulse pressure and a dusky discoloration of the skin. With very severe heart failure, particularly if cardiac output has declined acutely, systolic arterial pressure may be reduced. The pulse may be weak, rapid, and thready; the proportional pulse pressure (pulse pressure/systolic pressure) may be markedly reduced. The proportional pulse pressure correlates reasonably well with cardiac output. In one study, when pulse pressure was less than 25%, it usually reflected a cardiac index of less than 2.2 L/min/m2.[59]

Ascites occurs in patients with increased pressure in the hepatic veins and in the veins draining into the peritoneum; it usually reflects long-standing systemic venous hypertension. Fever may be present in severe decompensated heart failure because of cutaneous vasoconstriction and impairment of heat loss.

Increased adrenergic activity is manifested by tachycardia, diaphoresis, pallor, peripheral cyanosis with pallor and coldness of the extremities, and obvious distention of the peripheral veins secondary to venoconstriction. Diastolic arterial pressure may be slightly elevated.

Rales heard over the lung bases are characteristic of heart failure that is of at least moderate severity. With acute pulmonary edema, rales are frequently accompanied by wheezing and expectoration of frothy, blood-tinged sputum. The absence of rales does not exclude elevation of pulmonary capillary pressure due to LV failure.

Systemic venous hypertension is manifested by jugular venous distention. Normally, jugular venous pressure declines with respiration; however, it increases in patients with heart failure, a finding known as the Kussmaul sign (also found in constrictive pericarditis). This reflects an increase in right atrial pressure and, therefore, right-sided heart failure. In general, elevated jugular venous pressure is the most reliable indicator of fluid volume overload in older patients, and thorough evaluation is needed.[58]

The hepatojugular reflux is the distention of the jugular vein induced by applying manual pressure over the liver; the patient's torso should be positioned at a 45° angle. The hepatojugular reflux occurs in patients with elevated left-sided filling pressures and reflects elevated capillary wedge pressure and left-sided heart failure.

Although edema is a cardinal manifestation of heart failure, it does not correlate well with the level of systemic venous pressure. In patients with chronic LV failure and low cardiac output, extracellular fluid volume may be sufficiently expanded to cause edema in the presence of only slight elevations in systemic venous pressure. Usually, a substantial gain of extracellular fluid volume (ie, a minimum of 5 L in adults) must occur before peripheral edema develops. Edema in the absence of dyspnea or other signs of LV or right ventricular (RV) failure is not solely indicative of heart failure and can be observed in many other conditions, including chronic venous insufficiency, nephrotic syndrome, or other syndromes of hypoproteinemia or osmotic imbalance.

Hepatomegaly is prominent in patients with chronic right-sided heart failure, but it may occur rapidly in acute heart failure. When hepatomegaly occurs acutely, the liver is usually tender. In patients with considerable tricuspid regurgitation, a prominent systolic pulsation of the liver, attributable to an enlarged right atrial V wave, is often noted. A presystolic pulsation of the liver, attributable to an enlarged right atrial A wave, can occur in tricuspid stenosis, constrictive pericarditis, restrictive cardiomyopathy involving the right ventricle, and pulmonary hypertension (primary or secondary).

Hydrothorax is most commonly observed in patients with hypertension involving both the systemic and pulmonary circulation. It is usually bilateral, although when unilateral, it is usually confined to the right side of the chest. When hydrothorax develops, dyspnea usually intensifies because of further reductions in vital capacity.

Cardiac findings

Protodiastolic (S3) gallop is the earliest cardiac physical finding in decompensated heart failure in the absence of severe mitral or tricuspid regurgitation or left-to-right shunts. The presence of an S3 gallop in adults is important, pathologic, and often the most apparent finding on cardiac auscultation in patients with significant heart failure.

Cardiomegaly is a nonspecific finding that nonetheless occurs in most patients with chronic heart failure. Notable exceptions include heart failure from acute myocardial infarction, constrictive pericarditis, restrictive cardiomyopathy, valve or chordae tendineae rupture, or heart failure due to tachyarrhythmias or bradyarrhythmias.

Pulsus alternans (during pulse palpation, this is the alternation of one strong and one weak beat without a change in the cycle length) occurs most commonly in heart failure due to increased resistance to LV ejection, as occurs in hypertension, aortic stenosis, coronary atherosclerosis, and dilated cardiomyopathy. Pulsus alternans is usually associated with an S3 gallop, signifies advanced myocardial disease, and often disappears with treatment of heart failure.

Accentuation of the P2 heart sound is a cardinal sign of increased pulmonary artery pressure; it disappears or improves after treatment of heart failure. Mitral and tricuspid regurgitation murmurs are often present in patients with decompensated heart failure because of ventricular dilatatation. These murmurs often disappear or diminish when compensation is restored. Note that the correlation is poor between the intensity of the murmur of mitral regurgitation and its significance in patients with heart failure. Severe mitral regurgitation may be accompanied by an unimpressively soft murmur.

Cardiac cachexia is found in long-standing heart failure, particularly of the RV, because of anorexia from hepatic and intestinal congestion and sometimes because of digitalis toxicity. Occasionally, impaired intestinal absorption of fat occurs and, rarely, protein-losing enteropathy occurs. Patients with heart failure may also exhibit increased total metabolism secondary to augmentation of myocardial oxygen consumption, excessive work of breathing, low-grade fever, and elevated levels of circulating tumor necrosis factor (TNF).

Ascites, congestive hepatomegaly, and anasarca due to elevated right-sided heart pressures transmitted backward into the portal vein circulation may result in increased abdominal girth and epigastric and right upper quadrant (RUQ) abdominal pain. Other gastrointestinal symptoms, caused by congestion of the hepatic and gastrointestinal venous circulation, include anorexia, bloating, nausea, and constipation. In preterminal heart failure, inadequate bowel perfusion can cause abdominal pain, distention, and bloody stools. Distinguishing right-sided heart failure from hepatic failure is often clinically difficult.

Dyspnea, prominent in left ventricular failure, becomes less prominent in isolated right-sided heart failure because of the absence of pulmonary congestion. However, when cardiac output becomes markedly reduced in patients with terminal right-sided heart failure (as may occur in isolated right ventricular infarction and in the late stages of primary pulmonary hypertension and pulmonary thromboembolic disease), severe dyspnea may occur as a consequence of the reduced cardiac output, poor perfusion of respiratory muscles, hypoxemia, and metabolic acidosis.

In children, manifestations of heart failure vary with age.[60] Signs of pulmonary venous congestion in an infant generally include tachypnea, respiratory distress (retractions), grunting, and difficulty with feeding. Often, children with heart failure have diaphoresis during feedings, which is possibly related to a catecholamine surge that occurs when they are challenged with eating while in respiratory distress.

Right-sided venous congestion is characterized by hepatosplenomegaly and, less frequently, with edema or ascites. Jugular venous distention is not a reliable indicator of systemic venous congestion in infants, because the jugular veins are difficult to observe. Also, the distance from the right atrium to the angle of the jaw may be no more than 8-10 cm, even when the infant is sitting upright. Uncompensated heart failure in an infant primarily manifests as a failure to thrive. In severe cases, failure to thrive may be followed by signs of renal and hepatic failure.

In older children, left-sided venous congestion causes tachypnea, respiratory distress, and wheezing (cardiac asthma). Right-sided congestion may result in hepatosplenomegaly, jugular venous distention, edema, ascites, and/or pleural effusions. Uncompensated heart failure in older children may cause fatigue or lower-than-usual energy levels. Patients may complain of cool extremities, exercise intolerance, dizziness, or syncope.

For more information, see the Medscape Drugs & Diseases article Pediatric Congestive Heart Failure.

Framingham system for diagnosis of heart failure

In the Framingham system, the diagnosis of heart failure requires that either two major criteria or one major and two minor criteria be present concurrently, as shown in Table 1 below.[1] Minor criteria are accepted only if they cannot be attributed to another medical condition.

Table 1. Framingham Diagnostic Criteria for Heart Failure (Open Table in a new window)

Stage A

American College of Cardiology/American Heart Association (ACC/AHA) stage A patients are at high risk for heart failure; thus, this stage is now also known as "at risk for heart failure."[4, 5, 6, 7]  Patients in this stage do not have structural heart disease or symptoms of heart failure. Thus, management in these cases focuses on prevention, through reduction of risk factors. Measures include the following[3] :

• Treat hypertension (optimal blood pressure: < 130/80 mm Hg ^[61] )
• Encourage smoking cessation
• Treat lipid disorders
• Encourage regular exercise
• Discourage alcohol intake and illicit drug use

Patients who have a family history of dilated cardiomyopathy should be screened with a comprehensive history and physical examination together with echocardiography and transthoracic echocardiography every 2-5 years.[8]

Stage B

ACC/AHA stage B patients are now also designated as "pre-heart failure..[4, 5, 6, 7]  These individuals are asymptomatic, with left ventricular (LV) dysfunction from previous myocardial infarction (MI), LV remodeling from LV hypertrophy (LVH), and asymptomatic valvular dysfunction, which includes patients with New York Heart Association (NYHA) class I heart failure (see Heart Failure Criteria, Classification, and Staging for a description of NYHA classes).[3] In addition to the heart failure education and aggressive risk factor modification used for stage A, treatment with an angiotensin-converting enzyme inhibitor/angiotensin-receptor blocker (ACEI/ARB) and/or beta-blockade is indicated.

Evaluation for coronary revascularization either percutaneously or surgically, as well as correction of valvular abnormalities, may be indicated.[3] Treatment with an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden death in patients with an LV ejection fraction (LVEF) below 30% that is more than 40 days post-MI is reasonable if the expected survival is more than 1 year.

There is less evidence for implantation of an ICD in patients with nonischemic cardiomyopathy, an LVEF less than 30%, and no heart failure symptoms. There is no evidence for use of digoxin in these populations.[62] Aldosterone receptor blockade with eplerenone is indicated for post-MI LV dysfunction.

Stage C

ACC/AHA stage C patients have structural heart disease and current or previous symptoms of heart failure; they are therefore designated as having "symptomatic heart failure."[4, 5, 6, 7]  ACC/AHA stage C corresponds with NYHA class I-IV heart failure. The preventive measures used for stage A disease are indicated, as is dietary sodium restriction.

Drugs routinely used in these patients include ACEI/ARBs, beta-blockers, or angiotensin receptor–neprilysin inhibitors (ARNIs), in conjunction with evidence-based beta-blockers, and loop diuretics for fluid retention.[3, 61, 63] For selected patients, therapeutic measures include aldosterone receptor blockers, hydralazine and nitrates in combination, and cardiac resynchronization with or without an ICD (see Electrophysiologic Intervention).[3, 61, 63]

A meta-analysis performed by Badve et al suggested that the survival benefit of treatment with beta-blockers extends to patients with chronic kidney disease and systolic heart failure (risk ratio 0.72).[64]

The 2016 and 2017 ACC/AHA focused updates to the 2013 guidelines added a class IIa recommendation for ivabradine, a sinoatrial node modulator, in patients with stage C heart failure.[61, 63]  They indicate that ivabradine may reduce hospitalization for patients with symptomatic (NYHA class II-III) stable chronic heart failure with reduced ejection fraction (LVEF ≤35%) who are receiving recommended therapy, including a beta blocker at the maximum tolerated dose, and who are in sinus rhythm with a heart rate of 70 bpm or greater at rest.[61, 63]

Stage D

ACC/AHA stage D patients have refractory heart failure (NYHA class IV) that requires specialized interventions; they are in "advanced heart failure."[4, 5, 6, 7] Therapy includes all the measures used in stages A, B, and C. Treatment considerations include heart transplantation or placement of an LV assist device in eligible patients; pulmonary catheterization; and options for end-of-life care.[3] For palliation of symptoms, continuous intravenous infusion of a positive inotrope may be considered.

Careful evaluation of the patient's history and physical examination (including signs of congestion, such as jugular venous distention) can provide important information about the underlying cardiac abnormality in heart failure (HF).[3] However, other studies and/or tests may be necessary to identify structural abnormalities or conditions that can lead to or exacerbate HF.[3]

Endomyocardial biopsy is indicated only when a specific diagnosis is suspected that would influence therapy in patients presenting with HF (see the image below).

Heart Failure. Transesophageal echocardiogram with continuous wave Doppler interrogation across the mitral valve. An increased mean gradient of 16 mmHg is revealed, consistent with severe mitral stenosis.

2022 ACC/AHA/HFSA guidelines

The American College of Cardiology, American Heart Association, and Heart Failure Society of America (ACC/AHA/HFSA) guidelines recommend the following for the diagnosis of HF[4] :

• Levels of: B-type natriuretic peptide/N-terminal BNP (BNP/NT-proBNP), urea and electrolytes, fasting glucose and HbA1c, lipids
• 12-Lead electrocardiography (ECG)
• Transthoracic echocardiography (TTE)
• Chest radiography
• Complete blood cell (CBC) count
• Thyroid function tests
• Iron studies (transferrin saturation and ferritin)

Cardiac magnetic resonance imaging (CMRI) is recommended for the following[4] :

• Evaluation of myocardial structure and function in patients with poor echocardiogram acoustic windows
• Characterization of myocardial in suspected infiltrative disease, Fabry disease, myocarditis, noncompacted left ventricle (LV), amyloid, sarcoidosis, iron overload/hemochromatosis

In patients with angina despite pharmacotherapy or who have symptomatic ventricular arrhythmias, invasive coronary angiography is recommended.

For those being evaluated for heart transplantation or mechanical circulatory support (MCS), cardiopulmonary exercise testing is recommended; in those with severe HF undergoing the evaluation for heart transplantation or MCS, right heart catheterization is recommended.

2021 ESC guidelines

The European Society of Cardiology (ESC) recommendations on the diagnosis of HF include the following[68] :

• HFpEF (heart failure with preserved ejection fraction) diagnosis requires evidence of cardiac structural or functional abnormalities as well as elevated plasma NP (natriuretic peptide) concentrations consistent with LV diastolic dysfunction and increased LV filling pressures. A diastolic stress test is recommended if these markers are equivocal.

• A chest x-ray is recommended to identify other potential causes of breathlessness, such as pulmonary disease.

• If the patient has a normal ECG, the diagnosis of HF is unlikely. The ECG may reveal abnormalities such as AF, Q waves, LV hypertrophy (LVH), and a widened QRS complex, which increase the likelihood of HF.

• Basic tests such as serum urea and electrolytes, creatinine, full blood count, and liver and thyroid function tests are recommended to differentiate HF from other conditions, to provide prognostic information, and to guide potential therapy.

• Echocardiography is recommended as the key investigative tool to assess cardiac function and provide information on other parameters such as chamber size, eccentric or concentric LVH, regional wall motion abnormalities, RV function, pulmonary hypertension, valvular function, and markers of diastolic function.

Laboratory studies should include a complete blood cell (CBC) count, serum electrolyte levels (including calcium and magnesium), and renal and liver function studies. Other tests may be indicated in specific patients. The CBC aids in the assessment of severe anemia, which may cause or aggravate heart failure.[69, 70] Leukocytosis may signal underlying infection. Otherwise, CBCs are usually of little diagnostic help.

An assessment for iron deficiency should be considered; about one third of heart failure patients are also iron deficient, which is associated with poor cardiac function and can worsen outcomes in these individuals.[71, 72, 73]  Iron deficiency appears to impair contractility of human cardiomyocytes by impairing mitochondrial respiration and reducing contractility and relaxation; these effects can be reversed by restoring intracellular iron levels.[72]

In a study that sought to define biomarker-based iron deficiency in heart failure based on bone marrow iron staining as the gold standard, as well as evaluate the prognostic value of the optimized definition, investigators found that a transferrin saturation (TSAT) up to 19.8% or a serum iron level up to 13 μmol/L had the best results in selecting patients with iron deficiency as well as identifying heart patients with the greatest mortality risk.[70]  These TSAT and serum iron values not only achieved a 94% sensitivity, and a respective 84% and 88% specificity (ie, specificity of 84% for TSAT ≤19.8% and 88% for serum iron ≤13 μmol/L), but both measures were also independent prognostic factors for mortality.[70]

Serum electrolyte values are generally within reference ranges in patients with mild to moderate heart failure before treatment. In cases of severe heart failure, however, prolonged, rigid sodium restriction, coupled with intensive diuretic therapy and the inability to excrete water, may lead to dilutional hyponatremia, which occurs because of a substantial expansion of extracellular and intravascular fluid volume and a normal or increased level of total body sodium.

Potassium levels are usually within reference ranges, although the prolonged administration of diuretics may result in hypokalemia. Hyperkalemia may occur in patients with severe heart failure who show marked reductions in glomerular filtration rate (GFR) and inadequate delivery of sodium to the distal tubular sodium-potassium exchange sites of the kidney, particularly if they are receiving potassium-sparing diuretics and/or angiotensin-converting enzyme inhibitors (ACEIs).

Pulmonary function testing is generally not helpful in the diagnosis of heart failure. However, such testing may demonstrate or exclude respiratory causes of dyspnea and help in the assessment of any pulmonary causes of dyspnea.

Renal function tests

Blood urea nitrogen (BUN) and creatinine levels can be within reference ranges in patients with mild to moderate heart failure and normal renal function, although BUN levels and BUN/creatinine ratios may be elevated.

Patients with severe heart failure, particularly those on large doses of diuretics for long periods, may have elevated BUN and creatinine levels indicative of renal insufficiency owing to chronic reductions of renal blood flow from reduced cardiac output. Diuresing this group of patients is complex. In some individuals, diuretics will improve renal congestion and renal function, whereas in others, overaggressive diuresis may aggravate renal insufficiency due to volume depletion.

Liver function tests

Congestive hepatomegaly and cardiac cirrhosis are often associated with impaired hepatic function, which is characterized by abnormal values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and other liver enzymes. Hyperbilirubinemia secondary to an increase in the directly and indirectly reacting bilirubin is common. In severe cases of acute right ventricular (RV) or left ventricular (LV) failure, frank jaundice may occur.

Acute hepatic venous congestion can result in severe jaundice, with a bilirubin level as high as 15-20 mg/dL, elevation of AST to more than 10 times the upper reference range limit, elevation of the serum alkaline phosphatase level, and prolongation of the prothrombin time. The clinical and laboratory pictures may resemble viral hepatitis, but the impairment of hepatic function is rapidly resolved by successful treatment of heart failure. In patients with long-standing heart failure, albumin synthesis may be impaired, leading to hypoalbuminemia and intensifying the accumulation of fluid. Fulminant hepatic failure is an uncommon, late, and sometimes terminal complication of cardiac cirrhosis.

Clinical findings and routine diagnostic tests are not always sufficient to diagnose heart failure. In such ambiguous cases, rapid measurement of B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) levels can aid clinicians in differentiating between cardiac and noncardiac causes of dyspnea.[3, 4, 8, 9, 65, 66, 74, 75] That is, BNP is mostly limited to the differentiation of heart failure versus other causes of dyspnea in patients with an atypical presentation.

BNP is a 32-amino-acid polypeptide containing a 17-amino-acid ring structure common to all natriuretic peptides. The major source of plasma BNP is the cardiac ventricles, and the release of BNP appears to be in direct proportion to ventricular volume and pressure overload. BNP is an independent predictor of high LV end-diastolic pressure, and it is more useful than atrial natriuretic peptide (ANP) or norepinephrine levels for assessing mortality risk in patients with heart failure.[76, 77, 78, 79]

Although BNP has been determined to be the strongest predictor of systolic versus nonsystolic heart failure (followed by oxygen saturation, history of myocardial infarction, and heart rate), BNP does not reliably differentiate between heart failure with preserved ejection fraction and heart failure with reduced ejection fraction.[74] Increased NT-proBNP was found to be the strongest independent predictor of a final diagnosis of acute heart failure.[80, 81, 82]

Measurement of BNP and its precursor NT-proBNP in the urgent care setting can be used to establish the diagnosis of heart failure when the clinical presentation is ambiguous or when confounding comorbidities are present.[3, 8, 9] BNP and NT-proBNP assays have different cutoff values for ruling in and ruling out heart failure.[61, 63, 83, 84, 85]

BNP levels correlate closely with the New York Heart Association (NYHA) classification of heart failure.[86, 87] BNP levels greater than 100 pg/mL have a specificity greater than 95% and a sensitivity greater than 98% when comparing patients without heart failure to all patients with heart failure.[88] Even BNP levels greater than 80 pg/mL have a specificity greater than 95% and a sensitivity greater than 98% in the diagnosis of heart failure.[83]

Table of cutoff values

Table 2, below, summarizes the evidence-based cutoff values of BNP and NT-proBNP for ruling in and ruling out the diagnosis of heart failure in the dyspneic patient presenting to the emergency department.

Table 2. Evidence-Based BNP and NT-proBNP Cutoff Values for Diagnosing HF (Open Table in a new window)

BNP and NT-proBNP levels are higher in older patients,[89] women,[89] and patients with renal dysfunction[90] or sepsis. Atrial fibrillation has also been associated with increased BNP levels in the absence of acute heart failure. However, BNP levels may be disproportionately lower in patients who are obese due to fat metabolism or who have hypothyroidism or advanced end-stage heart failure (the latter due to increased fibrosis). NT-proBNP plasma levels are also lower in obese heart failure patients relative to nonobese patients with heart failure, regardless of whether the etiology is ischemic or nonischaemic.[91]

However, NT-proBNP may be elevated in severely obese patients (BMI >40 kg/m2) owing to an increased cardiac burden in these individuals.[92] NT-pro-BNP may be a better marker for detecting cardiac dysfunction than BNP, because its chemical stability is better in circulating blood than that of BNP, and it is a sensitive marker of cardiac function even in early cardiac decompensation.[93]

BNP measurement not indicated with nesiritide therapy

Nesiritide is a synthetic BNP analogue; therefore, the measurement of BNP is not indicated in patients who are receiving nesiritide. If BNP is used as a diagnostic marker to rule in heart failure, the level must be determined before nesiritide therapy is started.[94, 95, 96, 97]

In a study by Miller et al, levels of NT-proBNP and BNP decreased in patients with advanced heart failure after therapy with nesiritide, but the majority of the patients did not have biochemically significant decreases in these markers even with a clinical response.[98] The investigators were unable to give a definitive reason for their results, and they indicated that nesiritide therapy should not be guided by the use of levels of both markers.[98] Fitzgerald et al also found decreased levels of both natriuretic peptides following nesiritide therapy in patients with decompensated heart failure.[99]

For more information, see the Medscape Drugs & Diseases article Natriuretic Peptides in Congestive Heart Failure.

Cardiomyopathy phenotypes that have known genetic cause(s) include hypertrophic (HCM), dilated (DCM), restrictive (RCM), arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), and left ventricular noncompaction (LVNC). Because most cases of cardiomyopathy are treatable—which is not the case in many genetic diseases—and screening for genetic risk of cardiomyopathy before the onset of disease can guide the recommendations for early detection of disease and therapy (see Presentation, History),[9, 34] it is recommended that consideration be given for patients with cardiomyopathy to be referred to centers with expertise in these matters and in family-based management.[9] These specialized centers will have a better understanding of the complexities involved in genetic evaluation, testing, and counseling of patients with cardiomyopathy.

To establish specific gene testing and laboratories offering tests, please see GeneReviews for further information and larger reviews.

Genetic testing has the highest yield in three types of cardiomyopathy: DCM, HCM, and autosomal dominant ARVD/C. The diagnosis must be established using the specific criteria for each type of cardiomyopathy, as the genetic testing is different for each type.

Dilated cardiomyopathy

It is thought that approximately 20-50% of idiopathic dilated cardiomyopathy (IDC) may have a genetic basis. Screening first-degree relatives of a proband with IDC by echocardiography and electrocardiography (ECG) reveals that 20-48% of probands have affected relatives, consistent with a diagnosis of familial dilated cardiomyopathy (FDC).[100, 101, 102]

Molecular genetic testing of the proband for an LMNA mutation is probably indicated, particularly if significant conduction system disease is present in the family. It should be noted that although the analytical sensitivity for detecting LMNA gene mutations is quite high, the clinical sensitivity (likelihood of identifying a mutation in a person with the disorder) is approximately 8% for FDC. Because molecular genetic testing for MYH7 has comparable clinical sensitivity, testing for mutations in MHY7 may also be considered.

Hypertrophic cardiomyopathy

HCM, caused by mutation in one of the genes currently known to encode different components of the sarcomere, is characterized by left ventricular (LV) hypertrophy (LVH) in the absence of predisposing cardiac conditions (eg, aortic stenosis) or cardiovascular conditions (eg, long-standing hypertension). Most often, the LVH of HCM becomes apparent during adolescence or young adulthood, although it may also develop late in life, in infancy, or in childhood.

Molecular genetic testing of any of the 14 genes currently known to encode different components of the sarcomere is clinically available. A detailed 3- to 4-generation family history should be obtained from relatives to assess the possibility of familial HCM. Attention should be directed to a history of any of the following in relatives: heart failure, HCM, cardiac transplantation, unexplained sudden death, unexplained cardiac conduction system disease and/or arrhythmia, or unexplained stroke or other thromboembolic disease.

Autosomal dominant arrhythmogenic right ventricular dysplasia/cardiomyopathy

ARVD/C is characterized by progressive fibrofatty replacement of the myocardium that predisposes to ventricular tachycardia and sudden death in young individuals and athletes. It primarily affects the RV; with time, it may also involve the LV. The presentation of disease is highly variable even within families, and affected individuals may not meet the established clinical criteria. The mean age at diagnosis is 31 years (±13 y; range, 4-64 y).

Genetic testing should be considered in individuals who have a clinical diagnosis of ARVD based on the diagnostic criteria. A case can be made to offer genetic testing to all with a clinical diagnosis of ARVD with a negative family history based on the high rate of reduced penetrance thus far identified with the ARVD genes. Molecular genetic testing is available on a clinical basis for TGFB3, RYR2, TMEM43, DSP, PKP2, DSG2, DSC2, and JUP.[103]

For more information regarding genetic testing and cardiomyopathy, please see HFSA Guideline Approach to Medical Evidence for Genetic Evaluation of Cardiomyopathy, as well as Murphy RT, Starling RC. Genetics and cardiomyopathy: where are we now? Cleve Clin J Med. Jun 2005;72(6):465-6, 469-70, 472-3 passim.[34]

Arterial and venous blood gases

Although arterial blood gas (ABG) measurement is more accurate than pulse oximetry for measuring oxygen saturation, it is unclear if ABG results add any clinical utility to pulse oximetry. In the setting of acute heart failure, ABG measurement is rarely performed. Indications include severe respiratory distress, documented hypoxemia by pulse oximetry not responsive to supplemental oxygen, and evidence of acidosis by serum chemistry findings or elevated lactate levels.

In general, heart failure patients who do not have comorbid lung disease do not manifest hypoxemia except in severe acute decompensation. Patients with severe heart failure may have signs and symptoms ranging from severe hypoxemia, or even hypoxia, along with hypercapnia, to decreased vital capacity and poor ventilation.

ABG measurement helps assess the presence of hypercapnia, a potential early marker for impending respiratory failure. Hypoxemia and hypocapnia occur in stages 1 and 2 of pulmonary edema because of a ventilation/perfusion (V/Q) mismatch. In stage 3 of pulmonary edema, right-to-left intrapulmonary shunt develops secondary to alveolar flooding and further contributes to hypoxemia. In more severe cases, hypercapnia and respiratory acidosis are usually observed. The decision regarding intubation and the use of mechanical ventilation is frequently based on many clinical parameters, including oxygenation, ventilation, and mental status. ABG values in isolation are rarely useful, but they may add to the entire clinical picture.

Mixed venous oxygen saturation (obtained from the main pulmonary artery in the absence of an intracardiac shunt) is a good marker of the blood circulation time and thus of the cardiac output and cardiac performance. Patients who have advanced heart failure have low cardiac output and slower circulation time, which translate into an increased oxygen extraction by the tissues and therefore lower oxygen (< 60% saturation).

Pulse oximetry

Pulse oximetry is highly accurate at assessing the presence of hypoxemia and, therefore, the severity of acute heart failure presentations. Patients with mild to moderate acute heart failure may show modest reductions in oxygen saturation, whereas patients with severe heart failure may have severe oxygen desaturation, even at rest. Pulse oximetry is also useful for monitoring the patient's response to supplemental oxygen and other therapies.

Patients with mild to moderate heart failure may have normal oxygen saturations at rest, but they may exhibit marked reductions in oxygen saturations during physical exertion or recumbency. In general, arterial desaturation during exercise is not expected in heart failure and suggests the presence of comorbid lung disease. The use of continuous oxygen may be needed until compensation returns oxygen saturation to normal during exertion and recumbency or on a permanent basis if oxygen desaturation during exertion and/or recumbency exists during compensated severe chronic heart failure.

A screening electrocardiogram (ECG) is reasonable in patients with symptoms suggestive of heart failure. The presence of left atrial enlargement and left ventricular (LV) hypertrophy (LVH) is sensitive (although nonspecific) for chronic LV dysfunction. It is unlikely that an ECG would be completely normal in the presence of heart failure; therefore, an alternative diagnosis should be sought in such cases.[8, 9]

Electrocardiography may suggest an acute tachyarrhythmia or bradyarrhythmia as the cause of heart failure. It may also aid in the diagnosis of acute myocardial ischemia or infarction as the cause of heart failure, or it may suggest the likelihood of a prior myocardial infarction or the presence of coronary artery disease as the cause of heart failure.[3, 9]

Heart failure can have multiple and diverse presentations on ECGs (see the images below).

Heart Failure. This electrocardiogram (ECG) is from a 32-year-old female with recent-onset congestive heart failure and syncope. The ECG demonstrates a tachycardia with a 1:1 atrial:ventricular relationship. It is not clear from this tracing whether the atria are driving the ventricles (sinus tachycardia) or the ventricles are driving the atria (ventricular tachycardia [VT]). At first glance, sinus tachycardia in this ECG might be considered with severe conduction disease manifesting as marked first-degree atrioventricular block with left bundle branch block. On closer examination, the ECG morphology gives clues to the actual diagnosis of VT. These clues include the absence of RS complexes in the precordial leads, a QS pattern in V6, and an R wave in aVR. The patient proved to have an incessant VT associated with dilated cardiomyopathy.

Heart Failure. Electrocardiogram depicting ventricular fibrillation in a patient with a left ventricular assist device (LVAD). Ventricular fibrillation is often due to ischemic heart disease and can lead to myocardial infarction and/or sudden death.

Heart Failure. This electrocardiogram (ECG) shows evidence of severe left ventricular hypertrophy (LVH) with prominent precordial voltage, left atrial abnormality, lateral ST-T abnormalities, and a somewhat leftward QRS axis (–15º). The patient had malignant hypertension with acute heart failure, accounting also for the sinus tachycardia (blood pressure initially 280/180 mmHg). The ST-T changes seen here are nonspecific and could be due to, for example, LVH alone or coronary artery disease. However, the ECG is not consistent with extensive inferolateral myocardial infarction. Image courtesy of http://ecg.bidmc.harvard.edu.

Heart Failure. This electrocardiogram shows an extensive acute/evolving anterolateral myocardial infarction pattern, with ST-T changes most apparent in leads V2-V6, I, and aVL. Slow R-wave progression is also present in leads V1-V3. The rhythm is borderline sinus tachycardia with a single premature atrial complex (PAC) (fourth beat). Note also the low limb-lead voltage and probable left atrial abnormality. Left ventriculography showed diffuse hypokinesis as well as akinesis of the anterolateral and apical walls, with an ejection fraction estimated at 33%. Image courtesy of http://ecg.bidmc.harvard.edu.

Heart Failure. This electrocardiogram shows a patient is having an evolving anteroseptal myocardial infarction secondary to cocaine. There are Q waves in leads V2-V3 with ST-segment elevation in leads V2-V5 associated with T-wave inversion. Also noted are biphasic T waves in the inferior leads. These multiple abnormalities suggest occlusion of a large left anterior descending artery that wraps around the apex of the heart (or multivessel coronary artery disease). Image courtesy of http://ecg.bidmc.harvard.edu.

Electrocardiography is of limited help when an acute valvular abnormality or LV systolic dysfunction is considered to be the cause of heart failure; however, the presence of left bundle branch block (LBBB) on an ECG is a strong marker for diminished LV systolic function.

Chest radiographs (see the images below) are used in cases of heart failure to assess heart size, pulmonary congestion, pulmonary or thoracic causes of dyspnea, and the proper positioning of any implanted cardiac devices.[3, 8, 9]  Posterior-anterior and lateral views are recommended.[9]

Heart Failure. This chest radiograph shows an enlarged cardiac silhouette and edema at the lung bases, signs of acute heart failure.

Heart Failure. A 28-year-old woman presented with acute heart failure secondary to chronic hypertension. The enlarged cardiac silhouette on this anteroposterior (AP) radiograph is caused by acute heart failure due to the effects of chronic high blood pressure on the left ventricle. The heart then becomes enlarged, and fluid accumulates in the lungs (ie, pulmonary congestion).

Although up to 50% of patients with heart failure and documented elevation of pulmonary capillary wedge pressure (PCWP) do not manifest typical radiographic findings of pulmonary congestion, two principal features of chest radiographs are useful in the evaluation of patients with heart failure: (1) the size and shape of the cardiac silhouette and (2) edema at the lung bases.

Two-dimensional (2-D) echocardiography is recommended in the initial evaluation of patients with known or suspected heart failure.[3, 8, 9] Ventricular function may be evaluated, and primary and secondary valvular abnormalities may be accurately assessed.[104, 105, 106, 107, 108, 109]

Doppler echocardiography, along with 2-D echocardiography, may play a valuable role in determining diastolic function and in establishing the diagnosis of diastolic heart failure. Approximately 30-40% of patients presenting with heart failure have normal systolic function but abnormal diastolic relaxation. The primary finding to differentiate diastolic heart failure is the presence of a normal ejection fraction; however, note that findings of diastolic dysfunction are common in the elderly and may not be associated with clinical heart failure. Because the therapy for this condition is distinctly different from that for systolic dysfunction, establishing the appropriate etiology and diagnosis is essential.

Doppler and 2-D echocardiography may also be used to determine both systolic and diastolic left ventricular (LV) performance, cardiac output (ejection fraction), and pulmonary artery and ventricular filling pressures. In addition, echocardiography may be used to identify clinically important valvular disease (see the images below).

Heart Failure. Cervicocephalic fibromuscular dysplasia (FMD) can lead to complications such as hypertension and chronic kidney failure, which can lead to heart failure. In this color Doppler and spectral Doppler ultrasonographic examination of the left internal carotid artery (ICA) in a patient with cervicocephalic FMD, stenoses of about 70% is seen in the ICA.

Heart Failure. Cervicocephalic fibromuscular dysplasia (FMD) can lead to complications such as hypertension and chronic kidney failure, which, in turn, can lead to heart failure. Nodularity in an artery is known as the "string-of-beads sign," and it can be seen this color Doppler ultrasonographic image from a 51-year-old patient with low-grade stenosing FMD of the internal carotid artery (ICA).

Heart Failure. Echocardiogram of a patient with severe pulmonic stenosis. This image shows a parasternal short-axis view of a thickened pulmonary valve. Pulmonic stenosis can lead to pulmonary hypertension, which can result in hepatic congestion and in right-sided heart failure.

The following video is from a patient with arrhythmogenic right ventricular dysplasia (ARVD), a congenital cardiomyopathy that can lead to heart failure.

Transesophageal echocardiography

Transesophageal echocardiography (TEE) is particularly useful in patients who are on mechanical ventilation or are morbidly obese and in patients whose transthoracic echocardiogram is suboptimal in its imaging.[8, 110] It is an easy and safe alternative to conventional transthoracic echocardiography (TTE) and provides better imaging quality (see the following video). Transesophageal echocardiography also has the potential to be a noninvasive alternative to pulmonary artery catherization (Swan-Gantz catheterization) for hemodynamic monitoring, as it also allows the measurement of central venous, pulmonary arterial, and pulmonary capillary wedge pressures, as well as pulmonary and systemic vascular resistance, and stroke volume and cardiac output.[110]

Stress echocardiography

Stress echocardiography, also known as dobutamine or exercise echocardiography, has several uses; however, in heart failure, this technique is used mainly to assess coronary artery disease. This imaging modality may be used to detect ventricular dysfunction caused by ischemia, evaluate myocardial viability in the presence of marked hypokinesis or akinesis, identify myocardial stunning and hibernation, and relate heart failure symptoms to valvular abnormalities.[8] However, stress echocardiography may have a lower sensitivity and specificity in heart failure patients because of LV dilatation or because of the presence of bundle branch block.

Computed tomography (CT) scanning or magnetic resonance imaging (MRI) may be useful in evaluating cardiac chamber size and ventricular mass, cardiac function, and wall motion; delineating congenital and valvular abnormalities; and demonstrating the presence of pericardial disease.[3] However, cardiac CT scanning is usually not required in the routine diagnosis and management of heart failure, and echocardiography and MRI may provide similar information without exposing the patient to ionizing radiation.

The benefits of cardiac MRI (cMRI) include the ability to obtain a great deal of information with a noninvasive test. This modality provides detailed functional and morphologic information; can be used to assess ischemic versus nonischemic disease, infiltrative disease, and hypertrophic disease; and can be employed to determine viability. It is used principally for the delineation of congenital cardiac abnormalities and for the assessment of valvular heart disease, and it is the gold standard for evaluating right ventricular (RV) function (see the video below).

MRI has become particularly useful for evaluating abnormalities in wall motion and viable myocardium, and MRI findings can help predict the success of revascularization in patients with low ejection fractions.[111] However, the detailed information obtained by MRI must be balanced by its high costs and the fact that this imaging modality cannot be performed in patients with implantable defibrillators.

Radionuclide multiple-gated acquisition scanning

Radionuclide multiple-gated acquisition (MUGA) scan is a reliable imaging technique for the evaluation of left ventricular (LV) and right ventricular (RV) function and wall motion abnormalities. Because of its reliability, LV ejection fraction (LVEF), as determined by MUGA scanning, is often used for serial assessment of postchemotherapy LV function.[112]

Electrocardiogram-gated myocardial perfusion imaging

The high photon flux of compounds labeled with technetium-99m (99mTc) makes it feasible to acquire myocardial perfusion images in an electrocardiogram (ECG)-gated mode. ECG-gated single-photon emission computed tomography (SPECT) images allow for the assessment of the global LVEF, regional wall motion, and regional wall thickening at rest in patients with documented stress-induced wall motion and perfusion abnormalities.

In general, LVEF from gated SPECT scanning agrees well with resting LVEF determined by other modalities. Quality assurance is important, however, because determinations of LVEF with gated SPECT scanning may be less accurate, even invalidated, in the presence of an irregular heart rate, low count density, intense extracardiac radiotracer uptake adjacent to the LV, or a small LV.

Combined interpretation of perfusion and function on ECG-gated images substantially increases the confidence of the interpretation. Taillefer and associates reported that the interpretation of stress and rest end-diastolic section, rather than summed ungated sections, may enhance the overall sensitivity for the detection of mild coronary artery disease.[113]

ECG-gated images are also useful for recognizing artifactual defects caused by attenuation (breast and diaphragm) and thus are useful in the quality control of SPECT imaging. ECG-gated SPECT imaging is considered state of the art of radionuclide myocardial perfusion imaging.

Three important practical issues need to be addressed in the evaluation of patients with presumed ischemic dysfunction, as follows:

• Assessment of the relative regional myocardial uptake of thallium-201 ( ²⁰¹Tl; often after rest reinjection), ^99mTc-sestamibi, or ^99m Tc-tetrofosmin (often after rest administration of nitroglycerin); when the resting uptake of radiotracer is greater than 50% of normal, expect recovery of function after revascularization
• Assessment of the presence of demonstrable ischemia (eg, partially reversible defect) in a myocardial segment with decreased uptake, even if the resting uptake is less than 50%
• Data reported in 2011 from a STICH viability substudy failed to demonstrate a significant impact on survival based on the extent of the viable myocardium in patients with coronary artery disease and LV dysfunction treated surgically or medically ^[114]

Equilibrium radionuclide angiocardiography

Equilibrium radionuclide angiocardiography (ERNA) uses ECG events to define the temporal relationship between the acquisition of nuclear data and the volumetric components of the cardiac cycle. Sampling is performed repetitively over several hundred heartbeats, with physiologic segregation of the nuclear data in accordance with their occurrence within the cardiac cycle.

Data are quantified and displayed in an endless-loop, cinegraphic format for additional qualitative visual interpretation and analysis. Equilibrium blood-pool labeling is achieved by use of 99mTc. Data are analyzed by use of a computer, generally with some operator interaction.

Analysis may be obtained in either the frame or list mode. Radionuclide data are collected and segregated temporally. The process generally requires 3-10 minutes for completion of each view. Following data acquisition, data from the several hundred individual beats are summed, processed, and displayed as a single representative cardiac cycle.

Data from the left anterior oblique (LAO) view are also used for qualitative analysis of global LV function. On this view, overlap of the two ventricles is minimal. In a count-based approach, LVEF and other indices of filling and ejection are calculated from the LV radioactivity preset at various points throughout the cardiac cycle.

Right ventricular (RV) function is best evaluated by first-pass techniques. The LAO view provides qualitative information concerning contraction of the septal, inferoapical, and lateral walls. The anterior view provides data concerning the regional motion of the anterior and apical segments. The left lateral or left posterior oblique view provides optimal qualitative information concerning contraction of the inferior wall and posterobasal segment.

ERNA may easily be combined with additional physiologic stress testing or provocation, which may be in the form of either physiologic stress, such as exercise; pharmacologic stress, with the use of positive inotropic agents, such as dobutamine or isoproterenol; or psychological stress. The degree of confidence with ERNA is moderately high. False-positive and false-negative findings are infrequent.

Radionuclide ventriculography

Radionuclide ventriculography is most often performed as part of a myocardial perfusion scan to obtain accurate measurements of LV function and RV ejection fraction (RVEF),[3, 8]  but it is unable to directly assess valvular abnormalities or cardiac hypertrophy and has limited value for assessing volumes or more subtle indices of systolic or diastolic function.

Iobenguane scanning for cardiac risk evaluation

The scintigraphic imaging agent iobenguane I 123 injection (AdreView) is used for the evaluation of myocardial sympathetic innervation in patients with New York Heart Association (NYHA) class 2-3 heart failure with an LVEF of 35% or less.[10] This radionuclide tracer, which functions molecularly as a norepinephrine analogue, can show relative levels of norepinephrine uptake in the cardiac sympathetic nervous system and contribute to risk stratification in heart failure patients. Improved reuptake of norepinephrine is associated with a better prognosis.[10]

In patients with a nonischemic cardiomyopathy, perfusion deficits and segmental wall-motion abnormalities suggestive of coronary artery disease are commonly present on noninvasive imaging.[3] Only coronary angiography, however, can reliably demonstrate or exclude the presence of obstructed coronary vessels (see the following image).[3]

Heart Failure. A color-enhanced angiogram of the left heart shows a plaque-induced obstruction (top center) in a major artery, which can lead to myocardial infarction (MI). MIs can precipitate heart failure.

The procedures are frequently indicated when systolic dysfunction of unexplained cause is present on noninvasive testing or when normal systolic function with episodic heart failure suggests ischemically mediated left ventricular (LV) dysfunction. However, although coronary angiography may be indicated in young patients to exclude the presence of congenital coronary anomalies, this procedure may not be as useful in older patients, because revascularization has not been shown to improve clinical outcomes in patients without angina.[3] Despite this, because revascularization may improve LV function, some experts suggest that coronary artery disease should be excluded whenever possible, especially in patients with diabetes mellitus or other states associated with silent myocardial ischemia.[3] The degree of confidence is moderately high.

Right-sided heart catheterization

Right heart catheterization is useful in providing important hemodynamic information about filling pressures, vascular resistance, and cardiac output when there is doubt about the patient's fluid status; in heart failure refractory to initial therapy; in the presence of significant hypotension (systolic blood pressure typically < 90 mm Hg or symptomatic low systolic blood pressure) and/or worsening renal function during initial treatment; and when heart transplantation or placement of a mechanical circulatory support device is being considered.[3] However, it plays a limited role in the diagnosis of heart failure, as studies evaluating right heart catheterization and overall improved outcomes have been essentially neutral.[115]

Normal right-sided hemodynamics include a right atrial pressure less than 7 mm Hg, right ventricular (RV) pressure below 30/7 mm Hg, pulmonary pressure less than 30/18 mm Hg, pulmonary capillary wedge pressure (PCWP) below 18 mm Hg, and cardiac index (CI) above 2.2 L/min/m2.

PCWP can be measured by using a pulmonary arterial catheter (Swan-Ganz catheter). This helps to differentiate cardiogenic causes of decompensated heart failure from noncardiogenic causes, such as acute respiratory distress syndrome (ARDS), which occurs secondary to injury to the alveolar-capillary membrane rather than to alteration in Starling forces. A PCWP exceeding 18 mm Hg in a patient not known to have chronically elevated left atrial pressure is indicative of cardiogenic decompensated heart failure. In patients with chronic pulmonary capillary hypertension, capillary wedge pressures exceeding 25 mm Hg are generally required to overcome the pumping capacity of the lymphatics and produce pulmonary edema.

Large V waves may be observed in the PCWP tracing in patients with significant mitral regurgitation because large volumes of blood regurgitate into a poorly compliant left atrium. This raises the pulmonary venous pressure and may cause pulmonary edema.

Left-sided heart catheterization

Left-sided heart catheterization and coronary angiography should be undertaken when the etiology of heart failure cannot be determined by clinical or noninvasive imaging methods or when the etiology is likely to be due to acute myocardial ischemia or infarction. Coronary angiography is particularly helpful in patients with LV systolic dysfunction and known or suspected coronary artery disease in whom myocardial ischemia is thought to play a dominant role in the reduction of LV systolic function and the worsening of heart failure.

Cardiopulmonary stress testing (maximal exercise stress testing with measurement of respiratory gas exchange) can help in the assessment of a patient’s chance of survival within the next year, as well as determine the need for referral for either cardiac transplantation or implantation of mechanical circulatory support.  A 6-minute walk test evaluates the distance walked, dyspnea index on a Borg scale from 0 to 10, oxygen saturation, and heart rate response to exercise. A normal value is walking more than 1500 feet. Patients who walk less than 600 feet have severe cardiac dysfunction and a worse short- and long-term prognosis.[8]

Medical care for heart failure (HF) includes a number of nonpharmacologic, pharmacologic, and invasive strategies to limit and reverse its manifestations.[3, 8, 116] Depending on the severity of the illness, nonpharmacologic therapies include dietary sodium and fluid restriction; physical activity as appropriate; and attention to weight gain. Pharmacologic therapies include the use of diuretics, vasodilators, inotropic agents, anticoagulants, beta blockers, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), digoxin, nitrates, B-type natriuretic peptides (BNPs), I(f) inhibitors, angiotensin receptor-neprilysin inhibitors (ARNIs), soluble guanylate cyclase stimulators, sodium-glucose cotransporter-2 inhibitors (SGLT2Is), and mineralocorticoid receptor antagonists (MRAs).

2022 ACC/AHA/HFSA Guidelines

Updated and revised guidelines on the management of HF were published in May 2022 by the American College of Cardiology, American Heart Association, and Heart Failure Society of America (ACC/AHA/HFSA).[4, 5, 6, 7] These guidelines replace the 2013 and 2017 recommendations with significant and paradigm-shifting additional treatment options that include new/repurposed drug therapies that benefit almost without regard to ejection fraction (EF); additional disease-staging terminology that characterizes HF as a continuum; updated recommendations for advanced HF, acute HF, and comorbidities; as well as other guidance.

Top 10 key points

• Four core foundational medication classes (SGLT2Is, beta blockers, MRAs, and renin-angiotensin system [RAF] inhibitors) are now included in guideline-directed medical therapy (GDMT) for HF with reduced EF (HFrEF). ARNIs, ACEIs, or ARBs are recommended as first-line agents in HFrEF.
• SGLT2Is are a class 2a (moderate) recommendation in HF with mildly reduced ejection fraction (HFmrEF), whereas ARNIs, ACEIs, ARBs, MRAs, and beta blockers are class 2b (weak) recommendations for this patient population.
• There are new recommendations for HF with preserved EF (HFpEF) for SGLT2Is (class 2a), MRAs (class 2b), and ARNIs (class 2b). Renewed recommendations include those for treatment of hypertension (class 1 [strong]) and of atrial fibrillation (AF) (class 2a); use of ARBs (class 2b); as well as avoidance of the routine use of nitrates or phosphodiesterase-5 (PDE5) inhibitors (class 3 [no benefit]).
• Patients with previous HFrEF who now have an left ventricular (LV) EF above 40% should be referred to as having improved LVEF; they should continue their HFrEF treatment.
• The ACC/AHA/HFSA created value statements for select recommendations in which there are high-quality, cost-effectiveness studies of the intervention published.
• New amyloid heart disease treatment recommendations include screening for serum and urine monoclonal light chains, bone scintigraphy, genetic sequencing, tetramer stabilizer therapy, and anticoagulation.
• It is important for evidence to support increased filling pressures for the diagnosis of HF if the LVEF is over 40%. Such evidence can be obtained from noninvasive (eg, natriuretic peptide, diastolic function on imaging) or invasive testing (eg, hemodynamic measurement).
• Refer those with advanced HF who desire prolonged survival to a team that specializes in HF. These teams review HF management, assess candidacy for advanced HF therapies, and use palliative care such as palliative inotropes when it is consistent with the patient’s goals of care.
• Primary prevention is crucial for those at risk for HF (stage A) or pre-HF (stage B). The revised stages of HF emphasize the new terminologies of “at risk” for HF for stage A and pre-HF for stage B.
• Updated and new recommendations cover select patients with HF and iron deficiency, anemia, coronary artery disease (CAD), AF, valvular heart disease, cardiomyopathy, hypertension, type 2 diabetes, sleep disorders, and malignancy.

2021 ESC Guidelines

Clinical practice guidelines on the management of heart failure were also published by the European Society of Cardiology (ESC) in August 2021. Recommendations include the following[68] :

• Treatment of acute HF is based on the use of diuretics for congestion, inotropes, and short-term MCS (mechanical circulatory support) for peripheral hypoperfusion.

• ACEI or ARNI, beta blockers, MRA, and SGLT2Is are recommended for patients with HFrEF. ARNI remains a recommended replacement for ACEI in appropriate patients with persistent symptoms while on ACEIs, beta-blockers, and MRAs. ARNI may be considered as a first-line therapy in place of an ACEI.

• Right heart catheterization should be considered in all patients in whom HF is thought to be due to constrictive pericarditis, restrictive cardiomyopathy, congenital heart disease, and high output stress.

• Dapagliflozin or empagliflozin is recommended for patients with HFrEF to reduce the risk of hospitalization and death due to HF.

• Heart transplantation is recommended for patients who have advanced HF that is refractory to medical/device therapy and who do not have absolute contraindications.SGLT2 inhibitors (canagliflozin, dapagliflozin, empagliflozin, etrugliflozin, sotagliflozin) are recommended in patients with type 2 diabetes mellitus who are at risk for cardiovascular events, to reduce hospitalizations for HF, major cardiac events, end-stage renal dysfunction, and cardiovascular death.

Invasive therapies for HF include electrophysiologic intervention such as cardiac resynchronization therapy (CRT), pacemakers, and implantable cardioverter-defibrillators (ICDs); revascularization procedures such as coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI); valve replacement or repair; and ventricular restoration.[3, 8, 61, 63, 116]

Heart transplantation has been the criterion standard for therapy when progressive end-stage heart failure occurs despite maximal medical therapy, when the prognosis is poor, and when there is no viable therapeutic alternative.[3, 8, 9] However, mechanical circulatory devices such as ventricular assist devices (VADs) and total artificial hearts (TAHs) can bridge the patient to transplantation; in addition, VADs are increasingly being used as permanent therapy.[8]

Comorbidities to consider

Coronary artery disease

Patients with heart failure should be evaluated for coronary artery disease, which can lead to heart failure (see Etiology). Not only may this condition be the underlying cause in up to two thirds of heart failure patients with low ejection fraction, but coronary artery disease may also play a role in the progression of heart failure through mechanisms such as endothelial dysfunction, ischemia, and infarction, among others.[3]

Patients with coronary artery disease with modestly reduced ejection fraction and angina have demonstrated symptomatic and survival improvement with CABG in studies; however, the trials did not include individuals with heart failure or those with severely reduced ejection fractions.[3] In patients with angina and ventricular dysfunction, evaluation with coronary angiography should not be delayed (see Catheterization and Angiography). Noninvasive cardiac testing is not recommended in patients with significant ischemic chest pain, as revascularization is advised in these patients independent of their degree of ischemia/viability.[3]

Although there are no reports of controlled trials evaluating heart failure without angina and their outcomes with coronary revascularization, surgical revascularization is recommended in those with significant left main stenosis and in those with extensive noninfarcted but hypoperfused and hypocontractile myocardium on noninvasive testing.[3] In patients with heart failure and reduced LVEF but without angina, it has not yet been determined whether routine evaluation of possible myocardial ischemia/viability and coronary artery disease should be performed.[3]

For patients with heart failure from LV dysfunction without chest pain and without a history of coronary artery disease, coronary angiography may be useful in young patients to exclude congenital coronary anomalies. However, because clinical outcomes have not been shown to improve in patients without angina, coronary angiography may not be as useful in older patients for evaluating the presence of coronary artery disease.[3] Some experts nonetheless suggest excluding coronary artery disease whenever possible, particularly in the presence of diabetes or other conditions associated with silent myocardial ischemia, because LV function may show improvement with revascularization.[3]

In general, if coronary artery disease has already been excluded as the cause of abnormalities in LV function, it is not necessary to perform repeated evaluations for ischemia (invasive or noninvasive) provided the patient’s clinical status has not changed to suggest the development of ischemic disease.[3]

For more information, see the Medscape Drugs & Diseases articles Primary and Secondary Prevention of Coronary Artery Disease, Risk Factors for Coronary Artery Disease, and Coronary Artery Atherosclerosis.

Valvular heart disease

Valvular heart disease may be the underlying etiology or an important aggravating factor in heart failure.[3, 8, 9]

Sleep apnea

Sleep apnea has an increased prevalence in patients with heart failure and is associated with increased mortality[8] due to further neurohormonal activation, although randomized, controlled data are lacking. Patients with heart failure and suspected sleep-disordered breathing or excessive daytime sleepiness should undergo a formal sleep assessment.[61] ​[116]

Sleep apnea should be treated aggressively in heart failure patients. Guidelines recommend providing oxygen supplementation and continuous positive airway pressure (CPAP).[4, 5, 8, 61, 116]  However, the recommendations differ on the use of adaptive servo-ventilation (ASV): The 2017 focused update guideline of the 2013 American College of Cardiology/American Heart Association/Heart Failure Society of America (ACC/AHA/HFSA) guidelines indicates ASV causes harm in patients with New York Heart Association (NYHA) class II-IV heart failure with reduced ejection fraction (HFpEF) and central sleep apnea,[61] whereas the 2016 European Society of Cardiology (ESC) indicates that ASV may be considered for treating noctural hypoxemia in those with heart failure and sleep apnea.[8]

A long-term study involving 283 heart failure patients who had an implanted cardiac resynchronization device with cardioverter-defibrillator concluded that obstructive sleep apnea (OSA) and/or central sleep apnea (CSA) are independently associated with an increased risk for ventricular arrhythmias requiring cardioverter-defibrillator therapies.[117]

Anemia

Anemia is also common in chronic heart failure. Whether anemia is a reflection of the severity of the heart failure or contributes to worsening heart failure is not clear. Potential etiologies of anemia in heart failure involve poor nutrition, angiotensin-converting enzyme inhibitors (ACEIs), the renin-angiotensin-aldosterone system (RAAS), inflammatory cytokines, hemodilution, and renal dysfunction. Anemia in heart failure is associated with increased mortality.[69]

The 2010 HFSA,[9] 2013 ACC Foundation (ACCF)/AHA,[3] 2016 ACC/AHA/HFSA,[63] and 2016 ESC guidelines[8] ​ made no recommendations regarding the administration of iron to patients with heart failure, although the ACC/AHA noted that several small studies suggested a benefit in mild anemia and heart failure,[3] and the ESC observed that intravenous (IV) ferric carboxymaltose may potentially lead to sustainable improvements in function, symptoms, and quality of life.[8] However, the ACC/AHA's 2017 focused update to the 2013 guidelines has a class IIb recommendation for IV iron replacement for patients with NYHA class II and III heart failure and iron deficiency (ferritin < 100 ng/mL or 100-300 ng/mL if transferrin saturation < 20%).[61] In addition, their class III recommendation is to avoid using erythropoietin-stimulating agents in patients with heart failure and anemia to improve morbidity and mortality owing to a lack of benefit.[4, 5, 61]

The 2022 ACC/AHA/HFSA HF guidelines update indicates IV iron replacement is reasonable for improvement of functional status and quality of life in those with HFrEF with/without anemia.[4, 5]  

Cardiorenal syndrome

Cardiorenal syndrome reflects advanced cardiorenal dysregulation manifested by acute heart failure, worsening renal function, and diuretic resistance. It is equally prevalent in patients with HFpEF and those with LV systolic dysfunction. Worsening renal function is one of the three predictors of increased mortality in hospitalized patients with heart failure regardless of the LVEF.

Cardiorenal syndrome can be classified into the following five types[118] :

• CR1: Rapid worsening of cardiac function leading to acute kidney injury (HFpEF, acute heart failure, cardiogenic shock, and right ventricular [RV] failure)
• CR2: Worsening renal function due to progression of chronic heart failure
• CR3: Abrupt and primary worsening of kidney function leading to acute cardiac dysfunction (heart failure, arrhythmia, ischemia)
• CR4: Chronic kidney disease leading to progressive cardiac dysfunction, LV hypertrophy (LVH), and diastolic dysfunction
• CR5: Combination of cardiac and renal dysfunction due to acute and chronic systemic conditions

The pathophysiology of CR1 and CR2 is complex and multifactorial, involving neurohormonal activation (RAAS, sympathetic nervous system, arginine vasopressin, natriuretic peptides, adenosine receptor activation), low arterial pressure, and high central venous pressure, leading to lower transglomerular perfusion pressure and decreased availability of diuretics to the proximal nephron. This results in an increased reabsorption of sodium and water and poor diuretic response—hence, diuretic resistance despite escalating doses of oral or IV diuretics.

Treatment of cardiorenal syndrome in patients with heart failure is largely empirical, but it typically involves the use of combination diuretics, vasodilators, and inotropes as indicated.[119] Ultrafiltration is recommended for symptomatic relief by the ACC/AHA guidelines for patients with heart failure that is refractory to diuretic therapy.[3, 61] The 2017 ACC/AHA focused update noted the following five criteria may be indications for renal replacement therapy in these patients[61] :

• Oliguria unresponsive to fluid resuscitation measures
• Severe hyperkalaemia (potassium level >6.5 mmol/L)
• Severe acidemia (pH < 7.2)
• Serum urea level above 25 mmol/L (150 mg/dL)
• Serum creatinine over 300 µmol/L (>3.4 mg/dL)

A sudden increase in creatinine levels can be seen after the initiation of diuretic therapy, and it is often mistakenly considered evidence of overdiuresis or intravascular depletion (even in the presence of fluid overload). A common error in this situation is to decrease the dose of ACEIs, angiotensin-receptor blockers (ARBs), and/or diuretics, or to even withdraw one of these agents. In fact, when diuresis or ultrafiltration is continued, patients demonstrate improved renal function, decreased total body fluid, and increased response to diuretics, as central venous pressure falls.

Low-dose dopamine has been used in combination with diuretic therapy, on the supposition that it can increase kidney perfusion. Data have been contradictory, however. In a randomized controlled study, Giamouzis et al found that the combination of low-dose furosemide and low-dose dopamine was equally as effective as high-dose furosemide for kidney function in patients with acute decompensated heart failure.[120] In addition, patients who received dopamine and furosemide were less likely to have worsened renal function or hypokalemia at 24 hours.[120]

Use of nesiritide, a synthetic natriuretic peptide, to increase diuresis in these cases has not been studied. A meta-analysis of several trials using nesiritide suggested the potential of worsening renal function, although this has not been demonstrated in prospective trials. Results of the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial suggested that, although nesiritide is safe, it does not provide additional efficacy when added to standard therapy.[121] In another large study comprising 7141 patients with decompensated heart failure, the use of nesiritide did not have an effect on renal function, rehospitalization, and mortality, albeit there was a small but nonsignificant impact on dyspnea when used in conjunction with other therapies.[122]

The Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial showed that the addition of the vasopressin antagonist tolvaptan to diuretic therapy facilitates diuresis in acute heart failure. However, tolvaptan had no impact on mortality or hospitalizations in this setting.[123]

Adenosine receptor antagonists have been proposed for protecting renal function in acute heart failure. However, in a double-blind, placebo-controlled trial, the adenosine A1−receptor antagonist rolofylline demonstrated no benefit for patients hospitalized for acute heart failure with impaired renal function.[124]

A meta-analysis performed by Badve et al suggested that treatment with beta-blockers reduced all-cause mortality in patients with chronic kidney disease and systolic heart failure (risk ratio, 0.72).[125]

Atrial fibrillation

Many patients with heart failure also have atrial fibrillation, and the two conditions can adversely affect each other. However, in the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial, there was no difference in stroke, heart failure exacerbation, or cardiovascular mortality in patients treated with rhythm control (amiodarone) and patients treated with rate control.[126] All of these patients require anticoagulation for stroke prevention, which can be achieved by using warfarin or a direct thrombin inhibitor (no need to follow protime).

Administer chronic anticoagulant therapy to patients with chronic HF who have permanent persistent-paroxysmal AF and a CHA2DS2-VASc (congestive HF, hypertension, age ≥75 y, diabetes mellitus, stroke or transient ischemic attack [TIA], vascular disease, age 65-74 y, sex category) score of ≥2 (men) and ≥3 (women).[4, 5]  Such therapy is also reasonable in those with chronic HF who have permanent persistent-paroxysmal AF who do not have additional risk factors.

Administer a direct-acting anticoagulant over warfarin in the setting of eligible patients with chronic HF who have permanent persistent-paroxysmal AF. For those with HF and symptoms due to atrial fibrillation, it is reasonable to perform atrial fibrillation ablation for symptomatic and quality-of-life improvement.[4, 5]

Atrioventricular nodal ablation with implantation of a cardiac resynchronization therapy (CRT) device is reasonable for patients with atrial fibrillation and an LVEF ≤ 50% in whom a rhythm control strategy is ineffective or is not desired and in whom rapid ventricular rates are refractory to medical therapy.[4, 5]

A meta-analysis found that patients with LV systolic dysfunction who underwent catheter ablation for atrial fibrillation demonstrated significant improvements in LVEF, and their risk for recurrent atrial fibrillation or atrial tachycardia after catheter ablation was similar to that in patients with normal LV function after ablation.[127] However, patients with LV systolic dysfunction were more likely to require repeat procedures.

In contrast, MacDonald et al reported that in patients with advanced heart failure and severe LV systolic dysfunction, radiofrequency ablation for persistent atrial fibrillation resulted in long-term restoration of sinus rhythm in only 50% of cases.[128] Radiofrequency ablation also failed to improve such secondary outcomes as walking distance or quality of life, and the rate of related serious complications was 15%.

Patients with heart failure can benefit from attention to exercise, diet, and nutrition.[3, 9] Restriction of activity promotes physical deconditioning, so physical activity should be encouraged. However, limitation of activity is appropriate during acute heart failure exacerbations and in patients with suspected myocarditis. Most patients should not participate in heavy labor or exhaustive sports.

A meta-analysis showed that aerobic exercise training, particularly over the long term, can reverse left ventricular remodeling in clinically stable heart failure patients, whereas strength training had no effect on remodeling.[129]

Because nonadherence to diet and medication can have rapid and profound adverse effects on patients’ clinical status, close observation and follow-up are important aspects of care.[3, 8] Patient education and close supervision, including surveillance by the patient and family, can improve adherence. These measures also facilitate early detection of weight gain or slightly worsened symptoms, which often occur several days before major clinical episodes that require emergency care or hospitalization. Patients can then alert their clinicians, who may be able to prevent such episodes through prompt intervention.

Dietary sodium restriction to 2-3 g/day is recommended. Fluid restriction to 2 L/day is recommended for patients with evidence of hyponatremia (Na < 130 mEq/dL) and for those whose fluid status is difficult to control despite sodium restriction and the use of high-dose diuretics. Caloric supplementation is recommended for patients with evidence of cardiac cachexia.

An analysis of concentrations of plasma eicosapentaenoic acid (EPA), a long-chain omega-3 fatty acid, in the Cardiovascular Health Study identified plasma phospholipid EPA concentration as being inversely related to incident congestive heart failure.[130] These results support additional studies on the potential benefits of omega-3 fatty acids for primary prevention of heart failure.

The GISSI-HF (Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico) trial, which included nearly 7000 patients with systolic heart failure (any LV ejection fraction) who received either 1 g of omega-3 polyunsaturated fatty acids (PUFAs) or placebo daily, demonstrated that the PUFA regimen had a small but significant reduction in both all-cause mortality and all-cause mortality/hospitalization for cardiovascular causes.[131]

Pharmacologic therapy for heart failure (HF) includes but is not limited to the following[3, 8, 9, 63] :

• Diuretics (to reduce edema by reduction of blood volume and venous pressures) and salt restriction (to reduce fluid retention) in patients with current or previous heart failure symptoms and reduced left ventricular (LV) ejection fraction (EF) for symptomatic relief

• Angiotensin-converting enzyme inhibitors (ACEIs) for neurohormonal modification, vasodilatation, improvement in LVEF, and survival benefit

• Angiotensin receptor blockers (ARBs) for neurohormonal modification, vasodilatation, improvement in LVEF, and survival benefit

• Angiotensin receptor-neprilysin inhibitors (ARNIs) for neurohormonal modification and neprilysin inhibition, reduction in hospitalization for heart failure, and survival benefit

• Hydralazine and nitrates to improve symptoms, ventricular function, exercise capacity, and survival in patients who cannot tolerate an ACEI/ARB or as an add-on therapy to ACEI/ARB and beta-blockers in the black population for survival benefit

• Beta-adrenergic blockers for neurohormonal modification, improvement in symptoms and LVEF, survival benefit, arrhythmia prevention, and control of ventricular rate

• Aldosterone antagonists, as an adjunct to other drugs for additive diuresis, heart failure symptom control, improved heart rate variability, decreased ventricular arrhythmias, reduction in cardiac workload, improved LVEF, and increase in survival

• Digoxin, which can lead to a small increase in cardiac output, improvement in heart failure symptoms, and decreased rate of heart failure hospitalizations

• Anticoagulants to decrease the risk of thromboembolism

• Inotropic agents to restore organ perfusion and reduce congestion

• Soluble guanylate cyclase (sGC) stimulators to augment smooth muscle relaxation and vasodilation

• Selective sodium-glucose cotransporter-2 (SGLT2) or dual SGLT1/SGLT2 inhibitors to reduce the risk of cardiovascular death

2022 ACC/AHA/HFSA Guidelines

As noted earlier, the updated American College of Cardiology, American Heart Association, and Heart Failure Society of America (ACC/AHA/HFSA) guidelines include four core foundational medication classes (SGLT2Is, beta blockers, mineralocorticoid receptor antagonists [MRAs], and renin-angiotensin system [RAF] inhibitors) in guideline-directed medical therapy (GDMT) for HF with reduced EF (HFrEF).[4, 5, 6, 7]

HFrEF

Renin-angiotensin system inhibition with ACEI or ARB or ARNI (class 1 recommendations)

• Patients with HFrEF and New York Heart Association (NYHA) class II-III symptoms: Use ARNI for reduction of morbidity/mortality
• Patients with previous/current symptoms of chronic HFrEF: When ARNI is not feasible, ACEI is of benefit for reduction of morbidity/mortality
• Patients with previous/current symptoms of chronic HFrEF and intolerant of ACEI due to cough or angioedema and when ARNI is infeasible: Use ARB for reduction of morbidity/mortality
• Patients with chronic symptomatic HFrEF NYHA class II/III tolerant of ACEI/ARB: Replace with an ARNI for further reduction of morbidity/mortality

Prior to hospital discharge, ARNIs are recommended as de novo treatment in patients with acute HF for improvement in health status, lower N-terminal pro-brain natriuretic peptide (NT-proBNP), and improved LV remodeling parameters relative to ACEIs/ARBs.

Beta blockers (class 1 recommendation)

Patients with HFrEF, with previous/current symptoms: Use one of three beta blockers with proven mortality reduction (eg, bisoprolol, carvedilol, sustained-release metoprolol succinate) to lower mortality and hospitalizations.

MRAs (class 1 recommendation)

Patients with HFrEF and NYHA class II-IV symptoms: Use an MRA (spironolactone or eplerenone) to reduce morbidity/mortality, if the estimated glomerular filtration rate is >30 mL/min/1.73 m2 and serum potassium is < 5.0 mEq/L. Minimize the risk of hyperkalemia and renal insufficiency by closely monitoring potassium levels, renal function, and diuretic dosing at initiation and thereafter.

SGLT2Is (class 1 recommendation)

Patients with symptomatic chronic HFrEF: Irrespective of the presence of type 2 diabetes, use SGLT2Is for reduction of hospitalization for HF and cardiovascular mortality.

HF with mildly reduced EF (HRmrEF)

Patients with HFmrEF: SGLT2Is can provide benefit in reducing HF hospitalizations and cardiovascular morbidity (class 2a).

Patients with previous/current symptomatic HFmrEF (LVEF: 41-49%) taking evidence-based beta blockers for HFrEF: Consider ARNIs, ACEIs or ARBs, and MRAs to lower the risk of HF hospitalizations and cardiovascular mortality (especially among patients with LVEF on the lower end) (class 2b).

HF with preserved EF (HFpEF)

(New) Patients with HFpEF: SGLT2Is can provide benefit in reducing HF hospitalizations and cardiovascular morbidity (class 2a).

(New) In select patients with HFpEF: Consider MRAs or ARNIs to lower hospitalizations (especially among patients with LVEF on the lower end) (class 2b)

(Renewed) Patients with HFpEF and hypertension: To prevent morbidity, titrate medication to achieve blood pressure goals as laid out in pubished clinical practice guidelines (class 1).

(Renewed) Patients with HFpEF and atrial fibrillation (AF): Management of AF can be useful for symptomatic improvement (class 2a).

(Renewed) Selected patients with HFpEF: Consider ARBs to lower hospitalizations (especially among patients with LVEF on the lower end) (class 2b).

(Renewed) In patients with HFpEF, there is no benefit to the routine use of nitrates or phosphodiesterase-5 (PDE5) inhibitors to increase activity or quality of life (class 3).

HF with improved EF (HFimpEF)

Patients with posttreatment HFimpEF: Continue guideline-directed medical therapy (GDMT) to prevent relapse of HF and LV dysfunction, even in those who may become asymptomatic (class 1).

FDA drug approvals and studies

Soluble guanylate cyclase stimulators

The FDA approved vericiguat (Verquvo), a sGC stimulator, in 2021. Vericiguat stimulates sGC, the intracellular receptor for endogenous nitric oxide (NO), which catalyzes cyclic guanosine monophosphate (cGMP) production. Heart failure is associated with impaired NO synthesis and decreased sGC activity, which may contribute to myocardial and vascular dysfunction. This agent is indicated to reduce the risk of cardiovascular death and HF hospitalization in adults following a hospitalization for HF or need for outpatient IV diuretics, who have symptomatic chronic HF and ejection fraction below 45%.

Approval of vericiguat was based on the multinational Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction (VICTORIA) involving 5,050 patients with CHF who had evidence of clinical worsening. At a median of 10.8 months, incidence of death from cardiovascular causes or hospitalization for HF was significantly lower among those who received vericiguat compared with those who received placebo (P = 0.02).[132]

I(f) current inhibitors

The I(f) "funny current" inhibitor, ivabradine (Corlanor) received FDA approval in 2015 to reduce the risk of hospitalization for worsening heart failure in patients with stable, symptomatic chronic heart failure with an LVEF of 35% or lower, who are in sinus rhythm with a resting heart rate of 70 bpm or higher, and who are either on maximally tolerated doses of beta-blockers or have a contraindication to beta-blocker use.[133, 134] This drug blocks the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel responsible for the cardiac pacemaker I(f) "funny" current, which regulates heart rate without any effect on ventricular repolarization or myocardial contractility.

Approval for ivabradine was based on the international, placebo-controlled Systolic Heart failure treatment with the If inhibitor ivabradine Trial (SHIFT) published in 2010, which randomized more than 6500 patients with New York Heart Association (NYHA) class II-IV heart failure and an LVEF of 35% or lower.[133, 134] The trial saw a highly significant 18% drop in risk for cardiovascular death or hospitalization for worsening heart failure over an average of 23 months in patients treated with ivabradine.

Angiotensin receptor-neprilysin inhibitors (ARNIs)

The FDA approved the combination tablet sacubitril/valsartan (Entresto) in 2015 to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with NYHA class II-IV heart failure and reduced ejection fraction.[135] The combination drug is the first approved agent in the angiotensin receptor-neprilysin inhibitor (ARNI) class and consists of the ARB valsartan affixed to the neprilysin inhibitor sacubitril. The cardiovascular and renal effects of sacubitril’s active metabolite (LBQ657) in heart failure are attributed to the increased levels of peptides that are degraded by neprilysin (eg, natriuretic peptide). Administration results in increased natriuresis, increased urine cGMP, and decreased plasma mid-regional proatrial natriuretic peptide (MR-proANP) and NT-proBNP. In 2021, this indication was expanded to include heart failure in adults with preserved ejection fraction (HFpEF) based on the PARAGON-HF study.[136]

The approval was based on the Prospective Comparison of ARNI with ACE-I to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial.[135] PARADIGM-HF studied 8442 patients with chronic heart failure treated with either valsartan/sacubitril or enalapril. The combination significantly reduced cardiovascular death or heart-failure hospitalizations (the study's primary end point) by 20% compared with treatment with enalapril alone. All-cause mortality, a secondary end point, was also significantly reduced with the ARNI when compared with enalapril.[135]

The Prospective Comparison of ARNI with ARB on Management of Heart Failure with Preserved Ejection Fraction (PARAMOUNT) trial compared reduction of NP-proBNP levels with sacubitril plus valsartan and valsartan alone over 12 weeks in 149 patients with LVEF of 45% or greater. Sacubitril/valsartan reduced NT-proBNP levels to a significantly greater extent (783 pg/mL at baseline and 605 pg/mL at 12 weeks) compared with valsartan alone (862 pg/mL at baseline and 835 pg/mL at 12 weeks).[137]

In the PARADIGM-HF trial, sacubitril/valsartan improved outcomes and reduced NT-proBNP in adults. The effect on NT-proBNP was considered a reasonable basis to infer cardiovascular outcomes in pediatric patients.[138]

Selective sodium-glucose transporter-2 (SGLT2) inhibitors

The SGLT2 inhibitors empagliflozin and dapagliflozin are indicated to reduce the risk of cardiovascular death and hospitalization in patients with heart failure. They are also indicated to reduce the risk of hospitalization for heart failure in patients with type 2 diabetes mellitus who have either established cardiovascular disease or multiple cardiovascular risk factors.

HFrEF

The Empagliflozin Outcome Trial in Patients with Chronic Heart Failure and a Reduced Ejection Fraction (EMPEROR-Reduced) and the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure (DAPA-HF) phase 3 clinical trials noted that empagliflozin and dapagliflozin reduced the risk of cardiovascular death plus hospitalization for heart failure in adults with HFrEF.[139, 140]

HFpEF

In the EMPEROR-Preserved trial, empagliflozin plus standard therapy reduced the combined risk of cardiovascular death or hospitalization for heart failure in patients with HFpEF, regardless of the presence or absence of diabetes.[141]

The Dapagliflozin Evaluation to Improve the Lives of Patients with Preserved Ejection Fraction Heart Failure (DELIVER) trial compared outcomes of worsening heart failure (unplanned hospitalization or urgent visit for heart failure) or cardiovascular death in patients taking usual therapy plus dapagliflozin or placebo. Results showed dapagliflozin reduced the combined risk of worsening heart failure or cardiovascular death among patients with heart failure and a mildly reduced or preserved ejection fraction compared with placebo.[142]

SGLT1/SGLT2 Inhibitors

Sotagliflozin, a dual SGLT1/SGLT2 inhibitor was approved in 2023 and is indicated to reduce the risk of cardiovascular death, hospitalization, and urgent clinic visits for heart failure in adults with heart failure, type 2 diabetes mellitus, chronic kidney disease, or other cardiovascular risk factors.

Approval for sotagliflozin was supported by the SOLOIST-WHF (Effect of Sotagliflozin on Cardiovascular Events in Participants With Type 2 Diabetes Post Worsening Heart Failure) and SCORED (Effect of Sotagliflozin on Cardiovascular and Renal Events in Patients with Type 2 Diabetes and Moderate Renal Impairment Who Are at Cardiovascular Risk) trials. Results from SOLOIST-WHF showed that among patients recently hospitalized for worsening heart failure, sotagliflozin initiated before or shortly after hospital discharge led to significant reduction in risk of the composite of hospitalizations for heart failure, urgent visits for heart failure, and cardiovascular death compared with patients taking placebo.[143]

The SCORED trial included 10,584 patients with type 2 diabetes mellitus, chronic kidney disease, or cardiovascular risks randomized 1:1 to receive sotagliflozin or placebo.[144] Patients randomized to sotagliflozin had a lower risk of the composite of deaths from cardiovascular causes, hospitalizations for heart failure, and urgent visits for heart failure relative to patients with diabetes mellitus and chronic kidney disease, with or without albuminuria, who received placebo.[144]

Anticoagulation

Patients with heart failure and depressed LVEF are thought to have an increased risk of thrombus formation due to low cardiac output.[3, 8, 10] Anticoagulation with an international normalized ratio (INR) goal of 2-3 is indicated in the presence of LV thrombus, thromboembolic event with or without evidence of an LV thrombus, and paroxysmal or chronic atrial arrhythmias.[9]

Routine anticoagulation with warfarin in patients with normal sinus rhythm, heart failure, and LV dysfunction has not proven to be superior to aspirin alone in decreasing death, myocardial infarction (MI), and stroke, and it was associated with an increased risk of bleeding in the warfarin arm of the WATCH (warfarin and antiplatelet therapy in chronic heart failure) trial.[145]

Precautions

The use of regularly scheduled intermittent intravenous infusions of positive inotropic drugs in a supervised outpatient setting was previously proposed, but the 2013 ACCF/AHA/HFSA guidelines advised against this, given the lack of evidence to support efficacy and concerns about toxicity with an increase in mortality. Rather, the guidelines recommended infusion of a positive inotrope only as palliation in patients with end-stage disease who cannot be stabilized with standard medical treatment.[3]

Nonsteroidal anti-inflammatory drugs (NSAIDs), calcium channel blockers, and most antiarrhythmic agents may exacerbate heart failure and should be avoided in most patients.[3, 8] NSAIDs can cause sodium retention and peripheral vasoconstriction and can attenuate the efficacy and enhance the toxicity of diuretics and ACEIs.

Antiarrhythmic agents can have cardiodepressant effects and may promote arrhythmia; only amiodarone and dofetilide have been shown not to adversely affect survival. Calcium channel blockers can worsen heart failure and may increase the risk of cardiovascular events; only the vasoselective calcium channel blockers have been shown not to adversely affect survival.[3, 8]

In a community-based cohort study of 2891 digoxin-naive adults with newly diagnosed systolic heart failure, 18% of whom initiated treatment with digoxin, incident digoxin use was associated with significantly higher rates of death (14.2 vs 11.3 per 100 person-years) during a median of 2.5 years of follow-up.[146] Digoxin use was not associated with a significant difference in the risk of hospitalization for heart failure. Results were similar when the analyses were stratified by sex and use of beta-blockers. Digoxin currently occupies places in both US and European guidelines as no more than a second-line agent for systolic heart failure.

In a review of the safety and efficacy of digoxin in heart failure patients with a reduced EF, Konstantinou et al suggest that digoxin may still have a role in the setting of severe heart failure with evidence of congestion in patients unable to tolerate high doses of disease-modifying agents because of borderline blood pressure/renal function.[147] The investigators indicate the goal of digoxin use should be a reduction in hospital readmissions, and that clinicians should closely monitor levels of serum digoxin, creatinine, and potassium.[147]

Most patients who present with acute heart failure have exacerbation of chronic heart failure, with only 15-20% having acute de novo heart failure. Approximately 50% of patients with acute heart failure have a preserved left ventricular (LV) ejection fraction (EF) (>40%).[148, 149] Less than 5% of patients presenting with acute heart failure are hypotensive and require inotropic therapy.[150] Pulmonary edema is a medical emergency, but it is only one of the many presentations of acute heart failure.

A systematic and expeditious approach to management of acute heart failure is required, starting in the outpatient setting (eg, emergency department, urgent care center, office), continuing during hospitalization, and extending after discharge to the outpatient setting. The clinician’s agenda in these cases is three-fold:

• Stabilize the patient's clinical condition
• Establish the diagnosis, etiology, and precipitating factors
• Initiate therapies to rapidly provide symptomatic relief

Administration of oxygen, if oxygen saturation is less than 90%, and noninvasive positive pressure ventilation (NIPPV) provides patients with respiratory support to avoid intubation. NIPPV has been shown to decrease the rate of intubation, hospital morality, and mechanical ventilation.[151, 152, 153, 154, 155] No difference has been noted between continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP). A prospective randomized trial that compared the use of noninvasive ventilation (NIV) and standard therapy with the use of standard therapy alone suggested that although NIV may improve dyspnea and respiratory acidosis, it does not appear to improve mortality.[156]

Medical therapy for heart failure patients, the majority who present with normal perfusion and evidence of congestion, focuses on the following goals:

• Preload and afterload reduction for symptomatic relief using vasodilators (nitrates, hydralazine, nipride, nesiritide, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers [ACEI/ARB]) and diuretics

• Inhibition of deleterious neurohormonal activation (renin-angiotensin-aldosterone system [RAAS] and sympathetic nervous system) using ACEIs/ARBs, angiotensin receptor-neprilysin inhibitors (ARNIs), beta-blockers, and aldosterone antagonists resulting in long-term survival benefit

Preload reduction results in decreased pulmonary capillary hydrostatic pressure and reduction of fluid transudation into the pulmonary interstitium and alveoli. Preload and afterload reduction provide symptomatic relief. Inhibition of the RAAS and sympathetic nervous system produces vasodilation, thereby increasing cardiac output and decreasing myocardial oxygen demand. While reducing symptoms, inhibition of the RAAS and neurohumoral factors also results in significant reductions in morbidity and mortality.[157, 158, 159] Diuretics are effective in preload reduction by increasing urinary sodium excretion and decreasing fluid retention, with improvement in cardiac function, symptoms, and exercise tolerance.[3, 8]

Once congestion is minimized, a combination of three types of drugs (a diuretic, an ACEI or an ARB, and a beta-blocker) is recommended in the routine management of most patients with heart failure.[3, 8] This combination can accomplish all of the above goals. ACEIs/ARBs and beta-blockers are generally used together. Beta-blockers are started in the hospital once euvolemic status has been achieved.

If there is evidence of organ hypoperfusion, use of inotropic therapies and/or mechanical circulatory support (eg, intra-aortic balloon pump, extracorporeal membrane oxygenator [ECMO], left ventricular assist device [LVAD]) and continuous hemodynamic monitoring are indicated.[3, 8, 160] If arrhythmia is present and if uncontrolled ventricular response is thought to contribute to the clinical scenario of acute heart failure, either pharmacologic rate control or emergent cardioversion with restoration of sinus rhythm is recommended.

A study of 85 patients with confirmed hypertensive acute heart failure found that the intravenous (IV) calcium channel blocker clevidipine (Cleviprex) was safe and more effective than standard IV drugs for rapidly reducing blood pressure and improving dyspnea.[161, 162] In the 32 study patients who received clevidipine, dyspnea resolved completely in 3 hours, compared with 12 hours in the 53 patients who received usual care (mainly IV nitroglycerin or nicardipine). Target blood pressure range was achieved more often (71% vs 37% for standard care; P =.002) and reached sooner (P =.0006) in patients receiving clevidipine .[161, 162]

Prior to hospital discharge, ARNIs are recommended as de novo treatment in patients with acute HF for improvement in health status, lower N-terminal pro-brain natriuretic peptide (NT-proBNP), and improved LV remodeling parameters relative to ACEIs/ARBs.[4, 5]

Diuretics

Diuretics remain the cornerstone of standard therapy for acute heart failure. In such patients, IV administration of a loop diuretic (ie, furosemide, bumetanide, torsemide) is preferred initially because of potentially poor absorption of the oral form in the presence of bowel edema. In patients with hypertensive heart failure who have mild fluid retention, thiazide diuretics may be preferred because of their more persistent antihypertensive effects.[3, 8]

Diuretics can be given by bolus or continuous infusion and in high or low doses. In a study of patients with acute decompensated heart failure, however, Felker et al found that there were no significant differences in effect on symptoms or renal function changes with furosemide given either by bolus or by continuous infusion; additionally, no differences were found with high versus low doses.[163] The dose and frequency of administration depend on the diuretic response 2-4 hours after the first dose is given. If the response is inadequate, then increasing the dose and/or increasing the frequency can help enhance diuresis.

Diuretic resistance is diagnosed if there is persistent pulmonary edema despite the following[164] :

• Repeated doses of 80 mg of furosemide or
• Greater than 240 mg of furosemide per day (including continuous furosemide infusion) or
• Combined diuretic therapy (including loop diuretics with thiazide or an aldosterone antagonist)

Volume status, sodium levels, water intake, and hemodynamic status (for signs of poor perfusion) need to be reevaluated in case of diuretic resistance. Diuretic resistance is a known effect of long-term use of these agents. Some approaches to managing resistance to diuretics include increasing the dose and/or frequency of the drug, restricting sodium or water intake, administering the drug as an IV bolus or IV infusion, and combining diuretics.[3, 165] In addition, diuretic resistance is an independent predictor of mortality in patients with chronic heart failure.[166] Eventually, alternative strategies, such as hemodialysis or ultrafiltration,[167] may be used to overcome it. Other agents, such as vasopressin antagonists and adenosine receptor blockers, can be used to assist diuretics.

Transition to oral diuretic therapy is made when the patient reaches a near-euvolemic state. The oral diuretic dose is usually equal to the IV dose. In most cases, 40 mg/day of furosemide is equivalent to 20 mg of torsemide and 1 mg of bumetanide. Weight, signs and symptoms, fluid balance, electrolyte levels, and renal function must be monitored carefully on a daily basis.

Vasodilators

Vasodilators (eg, nitroprusside, nitroglycerin, or nesiritide) may be considered as an addition to diuretics for patients with acute heart failure for relief of symptoms. Vasodilators decrease preload and/or afterload.

Nitrates are potent venodilators. These agents decrease preload and therefore decrease LV filling pressure and relieve dyspnea. They also selectively produce epicardial coronary artery vasodilatation and help with myocardial ischemia. Although nitrates can be used in different forms (sublingual, oral, transdermal, IV), the most common route of administration in acute heart failure is IV. However, their use is limited by tachyphylaxis and headache.

Sodium nitroprusside is a potent, primarily arterial, vasodilator that causes a very efficient afterload reduction and decrease of intracardiac filling pressures. This agent is particularly helpful for patients who present with severe pulmonary congestion in the presence of hypertension and severe mitral regurgitation. Sodium nitroprusside requires not only careful hemodynamic monitoring, often necessitating indwelling catheters, but also monitoring for cyanide toxicity, especially in the presence of renal dysfunction. Sodium nitroprusside should be titrated to off rather than abruptly stopped because of the potential for rebound hypertension.

Nesiritide (human brain natriuretic peptide [BNP] analogue) is a vasodilator that was initially thought to alleviate dyspnea faster than nitroglycerin when used in combination with diuretics.[168, 169] This agent reduces pulmonary capillary wedge pressure (PCWP), right atrial pressure, and systemic vascular resistance but has no effect on heart contractility.

Ultrafiltration and refractory heart failure

In ultrafiltration, blood is removed from the body and run through a device that applies hydrostatic pressure across a semipermeable membrane to separate isotonic plasma water. Solutes cross the semipermeable membrane freely, so fluid can be removed without causing significant changes in the concentration of electrolytes and other solutes in serum.[170]

Ultrafiltration was shown to be an effective alternative to IV diuretics in the Ultrafiltration Versus Intravenous Diuretics for Patients Hospitalized for Acute Decompensated Heart Failure (UNLOAD) trial.[171]

Indications for hospitalization

A patient whose condition is refractory to standard therapy will often require hospitalization to receive IV diuretics, vasodilators, and inotropic agents. Hospitalization is indicated for acute heart failure in the presence of the following[9] :

• Severe acute decompensated heart failure (low blood pressure, worsening renal dysfunction, altered mentation)
• Dyspnea at rest
• Hemodynamically significant arrhythmia
• Acute coronary syndrome

Hospitalization should also be considered in the presence of the following[9] :

• Worsening congestion with or without dyspnea
• Worsening signs and symptoms of systemic or pulmonary congestion, even in the absence of weight gain
• Major electrolyte abnormalities
• Associated comorbid conditions (eg, pneumonia, pulmonary embolism, diabetic ketoacidosis, stroke/strokelike symptoms)
• Repeated implantable cardioverter-defibrillator (ICD) firings
• New diagnosis of heart failure with signs of active systemic/pulmonary congestion

Most patients requiring hospitalization should be admitted to a telemetry bed or intensive care unit; a small percentage can be admitted to the floor or observation unit. The goal is to continue the diagnostic and therapeutic processes started in the office or emergency department. Treatment includes the following:

• Optimization of volume and hemodynamic status using careful clinical monitoring, and optimization of the heart failure medical regimen
• Consideration of surgical intervention with a ventricular device
• Provision of heart failure education, behavior modification, and exercise and diet recommendations
• Enrollment in heart failure disease management programs for patients with advanced and difficult-to-control heart failure

Invasive hemodynamic monitoring

Invasive hemodynamic monitoring is not indicated for stable patients with heart failure who respond appropriately to medical therapy.[3, 9, 115] The Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness [ESCAPE] trial showed no mortality or hospitalization benefit in such cases.[115] In patients with acute decompensated heart failure, the following are indications for invasive hemodynamic monitoring[3, 9, 172] :

• Respiratory distress
• Signs of impaired perfusion
• Inability to determine intracardiac pressures on the basis of clinical examination
• No improvement in clinical status despite maximal heart failure therapy

Clinical situations in which invasive hemodynamic monitoring is recommended to guide therapy include the following[3, 9] :

• Persistent symptomatic hypotension despite initial therapy
• Worsening renal function despite initial therapy or despite adjustment of recommended therapies
• Need for parenteral vasoactive agents after initial clinical improvement
• Presumed cardiogenic shock requiring escalating inotrope and/or pressor therapy and consideration of mechanical support
• When advanced device therapy or cardiac transplantation is under consideration

Physicians have implemented different monitoring methods in an attempt to reduce hospitalization for heart failure. The results have been equivocal, regardless of the severity of heart failure. No differences in death or hospitalization for heart failure have been found with either standard outpatient monitoring or intense telemonitoring for heart failure.[173, 174] ​

The FDA approved the first permanently implantable wireless hemodynamic monitoring system (CardioMEMS HF System) in 2014 for patients with New York Heart Association (NYHA) class III heart failure with a history of hospitalization for heart failure within the past year.[175, 176] The device measures pulmonary artery (PA) pressures (eg, systolic, diastolic, and mean) as well as heart rate, and consists of a sensor/monitor implanted permanently in the PA, a transvenous catheter to deploy the sensor within the distal PA, and an electronics system that acquires and processes the signal from the sensor/monitor and transfers PA measurements to a secure database.[175, 176] This device also permits ambulatory monitoring and is designed to detect early-stage elevations in PA pressure, so that appropriate medical intervention can be provided before worsening elevation leads to congestion.[177]

Approval for the device was based on results from 550 patients from the open-label CHAMPION study (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients), in which the device reduced hospitalizations by 30% compared with standard care.[176, 177]

Discharge

The patient must be on a stable oral regimen for at least 24 hours before discharge. Patients are ready for discharge when they meet the following criteria:

• Exacerbating factors have been addressed
• Volume status has been optimized
• Diuretic therapy has been successfully transitioned to oral medication, with discontinuation of IV vasodilator and inotropic therapy for at least 24 hours
• Oral chronic heart failure therapy has been achieved with stable clinical status

Before discharge, patient and family education should be completed, and extensive postdischarge instructions and follow-up in 3-7 days should be arranged. Refractory end-stage heart failure (American College of Cardiology/American Heart Association [ACC/AHA] stage D, NYHA class IV) is often difficult to manage on an outpatient basis. Therefore, these patients may be referred to a heart failure program with expertise in management of refractory heart failure.[3]

To ensure compliance and understanding of a complex medical regimen, a follow-up phone call can be made 3 days after discharge by a nurse with training in heart failure. Ideally, the patient should be seen in clinic 7-10 days after discharge.

It is safe to initiate, and to consider, ARNI in recently hospitalized stable patients with HFrEF, including those who have not received ACEI/ARB.[68]

Treatment of heart failure with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) is directed toward alleviating symptoms and addressing the underlying condition triggering HFpEF.[4, 5]  Evaluation of cardiac ischemia or sleep apnea as potential precipitating factors should also be considered.

The 2022 American College of Cardiology/American Heart Association/Heart Failure Society of American (ACC/AHA/HFSA) guideline's new treatment recommendations for HFpEF (LVEF ≥50%) include diuretics (class 1) and sodium-glucose cotransporter-2 (SGLT2) inhibitors (class 2a). Class 2b recommendations are included for mineralocorticoid receptor antagonists (MRAs), angiotensin receptor-neprilysin inhibitors (ARNIs), and angiotensin receptor blockers (ARBs).[4, 5]  

The guideline indicates no benefit for the routine use of nitrates or phosphodiesterase-5 inhibitors to increase activity or quality of life, as well as for the routine use of nutritional supplements in HFpEF.[4, 5]  

There is a paucity of randomized, controlled studies addressing HFpEF. Control of blood pressure, volume, or other risk factors is the mainstay of therapy.[4, 5, 9] Lifestyle modification is important and may include the following: 

• Low-sodium diet
• Restricted fluid intake
• Daily measurement of weight
• Exercise
• Weight loss

Diuretic therapy is recommended to reduce fluid retention. However, patients must be monitored carefully to avoid hypotension.

Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) are used as indicated for patients with atherosclerotic disease, prior myocardial infarction (MI), diabetes mellitus, or hypertension. Use of candesartan, irbesartan, or perindopril has not been shown to decrease mortality but has produced a trend toward improved morbidity and decreased hospitalizations.[178] Some evidence shows that losartan and valsartan may promote left ventricular (LV) reverse remodeling, with improvement in diastolic function and regression of LV hypertrophy (LVH).

Sacubitril/valsartan was approved in 2015 to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with New York Heart Association (NYHA) class II-IV heart failure and reduced ejection fraction.[135] In 2021, this indication was expanded to include heart failure in adults with preserved ejection fraction based on the PARAGON-HF study.[136]

Beta-blockers are indicated for patients with prior MI or hypertension and for control of ventricular rate in those with AF. In the Acute Decompensated Heart Failure National Registry (ADHERE), the subset of patients with HFpEF not treated with a beta-blocker had a higher mortality, potentially because of the higher incidence of coronary artery disease (CAD) in this population.[179]

Aldosterone receptor blockers are indicated for hypertension and to reduce myocardial fibrosis, although no randomized, controlled studies have been performed to evaluate their role in HFpEF. Calcium channel blockers may improve exercise tolerance via their vasodilatory properties, and nondihydropyridine calcium channel blockers are also used for ventricular rate control in patients with AF. Amlodipine has antianginal properties and is also indicated in hypertension.

Restoration of sinus rhythm should be considered if the patient remains symptomatic despite the above efforts. Use of digitalis or inotropes in patients with HFpEF is not indicated.

Management of right ventricular (RV) failure includes treatment of the underlying cause; optimization of preload, afterload, and RV contractility; maintenance of sinus rhythm; and atrioventricular synchrony. Hypotension should be avoided, as it can potentially lead to further RV ischemia.

General measures should be applied, as follows:

• Sodium and fluid restriction
• Moderate physical activity, with avoidance of isometric exercises
• Avoidance of pregnancy
• Compliance with medications
• Avoidance, or rapid treatment of, precipitating factors

Precipitating factors include the following:

• Sleep apnea
• Pulmonary embolism
• Sepsis
• Arrhythmia
• Ischemia
• High altitude
• Anemia
• Hypoxemia

Use of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) is beneficial if RV failure is secondary to left ventricular (LV) failure; the efficacy of these agents in isolated RV failure is not known. The same recommendation applies for use of beta-blockers. The role of nesiritide in RV failure is not well defined. Use of digoxin in RV failure associated with chronic obstructive pulmonary disease (COPD) not associated with LV dysfunction does not appear to improve exercise tolerance or RV ejection fraction (EF). Treatment of pulmonary-induced RV failure is to address the correction of a primary pulmonary etiology and a decrease in RV afterload via specific pulmonary artery vasodilatory therapies (see Primary Pulmonary Hypertension for treatment).

In patients with severe, hemodynamically compromising RV failure, inotropic therapy is administered, using dobutamine (2-5 mcg/kg/min), dobutamine and inhaled nitric oxide, or dopamine alone. Milrinone is preferred if the patient is tachycardic or on beta-blockers.

Anticoagulation indications are standard for evidence of an intracardiac thrombus, thromboembolic events, pulmonary arterial hypertension, paroxysmal or persistent atrial fibrillation/flutter, and mechanical right-sided valves. Hypoxemia should be corrected, and positive pressure should be avoided when mechanical ventilation is needed.

Atrial septostomy can be considered as a palliative measure in patients with severe symptoms in whom standard therapy has failed. RV mechanical assist device is indicated only for RV failure secondary to LV failure or post–cardiac transplantation.

The prognosis in patients with RV failure depends on the etiology. Volume overload, pulmonary stenosis, and Eisenmenger syndrome are associated with a better prognosis. Decreased exercise tolerance predicts poor survival.

Devices for electrophysiologic intervention in heart failure include pacemakers, cardiac resynchronization therapy (CRT) devices, and implantable cardioverter-defibrillators (ICDs). CRT should be considered in patients with NYHA class II-IV, an LVEF of 35% or less, normal sinus rhythm and a QRS duration of 150 ms or longer, with a left bundle branch pattern.[3, 61]

In April 2014, the FDA approved 10 Medtronic biventricular pacemakers, some with defibrillators and some without, for use in patients with less severe systolic heart failure and atrioventricular (AV) block.[180, 181] Approval was based on a study of 691 patients with first-, second-, or third-degree AV block, New York Heart Association (NYHA) class I-III heart failure, and left ventricular ejection fraction (LVEF) below 50%, in which biventricular pacing over 3 years reduced all-cause mortality by 26%, reduced heart failure-related urgent care, and increased LV end-systolic volume index by more than 15%.[180, 181]

Pacemakers

Maintaining a normal chronotropic response and AV synchrony may be particularly significant for patients with heart failure.[8] Because right ventricular (RV) pacing may worsen heart failure due to an increase in ventricular dysynchrony, placement of a dual-chamber pacemaker in heart failure patients in the absence of symptomatic bradycardia or high-degree AV block is not recommended.

Implantable cardioverter-defibrillators

The role of implantable cardioverter-defibrillators (ICDs) has rapidly expanded. Sudden death is 5-10 times more common in patients with heart failure than in the general population. ICD placement results in remarkable reductions in sudden death from ischemic and nonischemic sustained ventricular tachyarrhythmias in heart failure patients. (See also the Medscape Drugs & Diseases articles Cardioverter-Defibrillator Implantation and Pacemakers and Implantable Cardioverter Defibrillators.)

In moderately symptomatic heart failure patients with an LVEF of 35% or less, primary prevention with an ICD provides no benefit in some cases but substantial benefit in others. A model based on routinely collected clinical variables can be used to predict the benefit of ICD treatment, according to a study by Levy et al.[182] Using data from the placebo arm of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) with their risk prediction model, Levy et al showed that patients could be classified into five groups on the basis of predicted 4-year mortality. In the treatment arm, ICD implantation decreased the relative risk of sudden cardiac death by 88% in patients with the lowest baseline mortality risk but only by 24% in the highest-risk group. ICD treatment decreased relative risk of total mortality by 54% in the lowest-risk group but only by 2% in the highest-risk group.[182]

It is important to note that use of the SCD-HeFT model has not been prospectively validated for risk stratification in the decision for ICD implantation. More trials are needed.

In a 2021 study that evaluated predictors (overall and according to HF cause) of sustained ventricular arrhythmic (SVA) events in 193 patients with HF and reduced EF (≤35%), Santangelo et al found ICD implantation was beneficial in primary prevention of sudden cardiac death and that it was independent of the cause of HF.[183] Of the 193 patients, 51 had nonischemic and 142 had ischemic causes of HF; a total of 32 patients had SVAs, with a similar incidence between the patient groups (15.6% nonischemic HF vs 16.9% ischemic HF). A univariate analysis showed SVA predictors were comorbidities: hypertension, diabetes, chronic renal failure, atrial fibrillation, chronic obstructive pulmonary disease, and NYHA class III or higher.[183]

Cardiac resynchronization therapy/biventricular pacing

Patients with heart failure and interventricular conduction abnormalities (roughly defined as those with a QRS interval >120 ms) are potential candidates for cardiac resynchronization therapy (CRT) by means of an inserted biventricular pacemaker. CRT aims to improve cardiac performance by restoring the heart’s interventricular septal electrical and mechanical synchrony.[9, 184] Thus, it reduces presystolic mitral regurgitation and optimizes diastolic function by reducing the mismatch between cardiac contractility and energy expenditure.[185]

The combination of biventricular pacing with ICD implantation (CRT-ICD) may be beneficial for patients with NYHA class II heart failure, an LVEF of 30% or less, and a QRS duration longer than 150 ms. The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) and Resynchronization/Defibrillation for Ambulatory Heart Failure Trial (RAFT) investigators reported significant improvement in mortality and morbidity with CRT-ICD treatment versus ICD alone in this group of patients.[186]

Patients with unfavorable coronary sinus anatomy often cannot have a CRT properly placed adjacent to the posterolateral wall of the LV. A study by Giraldi et al suggests that in such patients, a mini-thoracotomy allows for proper lead placement.[187] These patients, when compared to those who had typical transvenous placement (thus not allowing for the preferred posterolateral wall lead placement), had improved outcomes in terms of improved EF and decreased end-systolic volume.[187]

Regarding technique, three cardiac leads are placed transvenously: an atrial lead, an RV lead, and an LV lead (which is threaded through the coronary sinus and out one of its lateral wall tributaries). Surgeons have assisted difficult transvenous LV placements by epicardially inserting LV leads using a number of techniques (eg, mini-thoracotomy, thoracoscopy, robotically assisted methods).

Clinical trials of cardiac resynchronization therapy

Several prospective, randomized trials have been performed to evaluate the effectiveness of CRT. The Multicenter InSync Randomized Clinical Evaluation (MIRACLE) study group demonstrated an improvement in NYHA functional class, quality of life, and LVEF.[188]

As noted above, the MADIT-CRT demonstrated reduction in the risk of heart failure events in patients treated with CRT plus an ICD over that of individuals treated with ICD alone. This randomized trial included 1820 patients with an EF of 30% or less, a QRS duration of 130 ms or more, and NYHA class I or II symptoms.[189] ​During an average follow-up of 2.4 years, death from any cause or a nonfatal heart failure event occurred in 17.2% of patients in the CRT-ICD group versus 25.3% of patients in the ICD-only group. In particular, there was a 41% reduction in the risk of heart failure events in patients in the CRT group, which was evident primarily in patients with a QRS duration of 150 ms or more. CRT was associated with a significant reduction in LV volume and improvement in the EF. No significant difference occurred between the two groups in the overall risk of death.[189]

In a follow-up to MADIT-CRT, women seemed to achieve a better response result from resynchronization therapy than men, with a significant 69% reduction in death or heart failure and a 70% reduction in heart failure alone. Those benefits were associated with consistently greater echocardiographic evidence of reverse cardiac remodeling.[190]

Additional findings from MADIT-CRT concerned the relative effects of metoprolol and carvedilol in heart failure patients with devices in place.[191] The key variables were (a) rate of hospitalization for heart failure or death and (b) incidence of ventricular arrhythmia.

Treatment with carvedilol yielded a significantly lower rate of hospitalization for heart failure or death than treatment with metoprolol (23% vs 30%), a reduction that was especially pronounced in patients undergoing CRT with implantable cardioverter-defibrillator (CRT-D), including those with left bundle-branch block (LBBB).[191] The incidence of ventricular arrhythmia was 26% with metoprolol and 22% with carvedilol. There was a clear dose-dependent relation for carvedilol, which was not seen for metoprolol.

In addition to augmenting functional capacity, CRT also appears to favorably affect mortality. The Cardiac Resynchronization-Heart Failure (CARE-HF) trial, which studied CRT placement in patients with NYHA class III or IV heart failure due to LV systolic dysfunction and cardiac dyssynchrony, showed a 36% reduction in death with biventricular pacing.[192]

In the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) trial, biventricular pacing reduced the rate of death from any cause or hospitalization for any cause by approximately 20%. The COMPANION trial was conducted in patients with NYHA class III or IV heart failure due to ischemic or nonischemic cardiomyopathies and a QRS interval of at least 120 ms. The addition of a defibrillator to biventricular pacing incrementally increased the survival benefit, resulting in a substantial 36% reduction in the risk of death compared with optimal pharmacologic therapy.[193]

In both the CARE-HF and the COMPANION studies, mortality was largely due to sudden death.[192, 193]

Noting that high percentages of RV apical pacing could promote LV systolic dysfunction, the investigators from Biventricular versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block (BLOCK-HF) trial found that biventricular pacing improved outcomes in patients with AV block and NYHA class I-III heart failure over that of RV pacing.[194] A total of 691 volunteers received a pacemaker or ICD with leads in both ventricles (the LV lead was kept inactive in about half of participants). At follow-up (average, 37 months), 55.6% of the patients in the RV pacing group had died or had worsening heart failure, compared with 45.8% in the biventricular pacing group. The rate of adverse events was comparable in the two groups, and most problems occurred during the first month.[194]

In selected patients with heart failure, a reduced ejection fraction (EF ≤ 35%), and acceptable coronary anatomy, surgical revascularization in addition to guideline-directed medical therapy (GDMT) aids in improvement of symptoms, cardiovascular hospitalizations, and long-term all-cause mortality.[4, 5]

Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are revascularization procedures that should be considered in selected patients with heart failure and coronary artery disease (CAD). The choice between CABG and PCI depends on the following factors:

• Patient comorbidities
• Procedural risk
• Coronary anatomy
• Likely extent of viable myocardium in the area to be revascularized
• Ischemic symptoms
• Left ventricular (LV) function
• Presence of hemodynamically significant valvular disease

In patients who are at low risk for CAD, findings from noninvasive tests such as exercise electrocardiography (ECG), stress echocardiography, and stress nuclear perfusion imaging should determine whether subsequent angiography is indicated.[3, 8, 9]

Studies of medical versus surgical therapy for CAD have historically focused on patients with normal LV function. However, a significantly increased survival rate after CABG in a subset of patients with an LV ejection fraction (EF) below 50%, in comparison with the survival rate in patients who were randomly selected to receive medical therapy, was demonstrated in the Veterans Affairs Cooperative Study of Surgery. This survival benefit was particularly evident at the 11-year follow-up point (50% CABG vs 38% medical therapy).[195] However, at 18-year follow-up, overall survival rates were 30% for the CABG group and 33% for the medical therapy group; the investigators noted that CABG appeared to be effective for reducing mortality solely in those with a poor natural history and did not reduce the myocardial infarction incidence or combined incidence infarction or death.[196] Patients with low risk and a good prognosis with medical therapy received no survival benefit with CABG at any point during the follow-up period.

Surgical revascularization prolonged survival to a greater degree than did medical therapy in most clinical and angiographic subgroups in the Coronary Artery Surgery Study (CASS) of patients with left main equivalent disease.[197] Of importance, this study demonstrated that surgical therapy markedly improved the 5-year cumulative survival rate in patients with an EF of less than 50% (80% vs 47%).[195]

These early randomized trials were limited by their inclusion of patients who had what is currently considered a good EF. That is, many patients referred for coronary revascularization live with EFs below 35%.

According to a number of studies, surgical revascularization can benefit patients who have ischemic heart failure and substantial areas of viable myocardium in the following ways:

• Reduced mortality rates
• Improved New York Heart Association (NYHA) classification
• Favorable alteration of LV geometry
• Increased LVEFs

For example, surgical revascularization confers a dramatic survival benefit in patients with a substantial amount of hibernating myocardium (ie, regions of the heart that are dysfunctional under ischemic conditions but that can regain normal function after blood flow is restored).[198, 199] For patients with at least 5 of 12 segments showing myocardial viability, revascularization has been found to result in a cardiac mortality of 3%, versus 31% for medically treated patients with viable myocardium.

Coronary artery bypass grafting

The role of CABG in patients with CAD and heart failure has been unclear. Clinical trials from the 1970s that established the benefit of CABG for patients with CAD excluded patients with an EF below 35%. In addition, major advances in medical therapy and cardiac surgery have taken place since these trials.[200]

Investigators from Yale University and the University of Virginia, among many others, published their results of CABG in patients with extremely poor LV function who were on the transplant waiting list. Elefteriades et al reported that in patients with EFs below 30% who underwent CABG, the survival rate was 80% at 4.5 years.[201] This figure approaches that of cardiac transplantation. Kron et al reported a similar 3-year survival rate (83%) in patients who underwent coronary artery bypass with an EF below 20%.[202]

STICH trial

The Surgical Treatment for Congestive Heart Failure (STICH) study found no significant difference between medical therapy alone and medical therapy plus CABG with respect to death from any cause (the primary study outcome).[200, 203, 204] STICH included 1212 patients with an EF of 35% or less and CAD amenable to CABG. Patients were randomized to either CABG with intensive medical therapy or medical therapy alone and followed up for a median of 56 months.

There was no difference between the treatment groups for all-cause mortality.[200] Owing to the lack of significant difference in the primary endpoint, the secondary endpoints should be viewed cautiously. Except for 30-day mortality, secondary study results favored CABG; compared with study patients assigned to medical therapy alone, patients assigned to CABG had lower rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes.[200] Surprisingly, the presence of viable, hibernating myocardium was not predictive of improved outcomes from CABG.[114]

Taken together, these findings suggest that in the absence of severe angina or left main disease, medical therapy alone remains a reasonable option for patients with an EF of 35% or less and CAD. Furthermore, current methods of assessing myocardial viability/hibernating myocardium may not accurately predict benefit from revascularization, although cardiac magnetic resonance imaging offers a promise of accuracy in identifying viable myocardium and predicting the success of revascularization in patients with low EFs.[111]

Results from the STICH Extension Study (STICHES), which evaluated the long-term, 10-year outcomes of CABG in 1212 patients with ischemic cardiomyopathy and an ejection fraction of 35% or less, concluded that the rates of death from any cause, death from cardiovascular causes, and death from any cause or hospitalization for cardiovascular causes were significantly lower in patients who underwent CABG and received medical therapy than among those who received medical therapy alone.[161]

The adoption of techniques on and off cardiopulmonary bypass, as well as beating-heart techniques for revascularization, highlight the aim of treating high-risk patients.[205] The surgery in the STICH trial was performed with these modern surgical advantages. Preventive strategies include the increased use of bilateral mammary and arterial grafting.[206]

Valvular heart disease may be the underlying etiology or an important aggravating factor in heart failure.[3, 8, 9]

Aortic valve replacement

Diseases of the aortic valve can frequently lead to the onset and progression of heart failure. Although the natural histories of aortic stenosis and aortic regurgitation are well known, patients are often followed up conservatively after they present with clinically significant heart failure.

Heart failure is a common indication for aortic valve replacement (AVR), but one must be cautious in patients with a low left ventricular ejection fraction (LVEF) and possible aortic stenosis. Assessment of contractile reserve with dobutamine has been demonstrated as a reliable method to determine which patients with low EF and aortic stenosis may benefit from AVR.[207]

If no contractile reserve is present (a finding that suggests some ventricular reserve), the outcome with standard AVR is poor. In this situation, transplantation might be the only option, although the use of percutaneous valves, an apical aortic conduit, or a left ventricular assist device (LVAD) may offer an intermediate solution.

Indications

Decision making regarding valve surgery should not be delayed by medical treatment. Be cautious in using vasodilators (angiotensin-converting enzyme inhibitors [ACEIs], angiotensin-receptor blockers [ARBs], and nitrates) in patients with severe aortic stenosis, as these agents may cause significant hypotension.[3, 8, 9, 61]

Surgery is recommended in selected patients with symptomatic heart failure and severe aortic stenosis or severe aortic regurgitation, as well as in asymptomatic patients with severe aortic stenosis or severe aortic regurgitation and impaired LVEF (< 50%). This intervention may be considered in patients with a severely reduced valve area and LV dysfunction.

Patient survival

Of the three classic symptoms of aortic stenosis—syncope, angina, and dyspnea—dyspnea is the most robust risk factor for death. Only 50% of patients with dyspnea in this setting are still alive within 2 years.[208] Angina is associated with a mortality risk of 50% within 5 years, whereas syncope confers a 50% mortality risk in 3 years.

In contrast, the age-corrected survival rate for patients undergoing AVR for aortic stenosis is similar to that for the normal population.[209] Once patients develop severe LV dysfunction, however, the results of AVR are somewhat guarded.[210] Because of poor LV function, these patients are unable to develop significant transvalvular gradients (ie, low-output, low-gradient aortic stenosis).

A critical aspect of the decision for or against AVR is whether the ventricular dysfunction is truly valvular or reflects other forms of cardiomyopathy, such as ischemia or restrictive processes. Valvular dysfunction improves with AVR; other forms do not.

Precise measurement of the area of the aortic valve is difficult, because the calculated area is directly proportional to cardiac output. Also, the Gorlin constant varies at lower outputs. Therefore, in this situation, valvular areas might be considered critically small when at surgery the valve is found to be only moderately diseased.

Preoperative evaluation with dobutamine testing to increase contractile reserve or with vasodilator-induced stress echocardiography by using the continuity equation rather than the Gorlin formula can be helpful in making this distinction. The results can guide the physician or surgeon in determining whether the patient is a candidate for the relatively high-risk procedure.[211] Nevertheless, because of the possibility of ventricular recovery and lengthened patient survival, most patients with heart failure and aortic stenosis are offered valve replacement.[212]

Surgical timing

Timing of surgical intervention for aortic insufficiency is more challenging in patients just described than in patients with aortic stenosis. However, as before, once symptoms occur and once evidence of LV structural changes become apparent, morbidity and mortality due to aortic insufficiency increase.[213]

As with aortic stenosis, early intervention before the onset of severe LV dysfunction is crucial to improving the survival of patients with aortic insufficiency, as was shown in a retrospective review from the Mayo Clinic.[214, 215] In this study, in which 450 patients who underwent AVR for aortic insufficiency were compared according to ranges of EF (< 35%, 35-50%, >50%), although the group with severe dysfunction had an operative mortality of 14%, the EF improved, and the group's 10-year survival rate was 41%.[214, 215]

Mitral valve repair

Mitral valve regurgitation can either cause or result from chronic heart failure. Its presence is an independent risk factor for cardiovascular morbidity and mortality.[216] In addition to frank rupture of the papillary muscle in association with acute myocardial infarction (MI), chronic ischemic cardiomyopathies result in migration of the papillary muscle as the ventricle dilates. This dilation causes tenting of the mitral leaflets, restricting their coaptation.

Dilated cardiomyopathies can have similar issues, as well as annular dilatation. In addition to mitral regurgitation, the alteration in LV geometry contributes to volume overload, increases LV wall tension, and leaves patients susceptible to exacerbations of heart failure.[217]

Mitral valve surgery in patients with heart failure has gained favor because it abolishes the regurgitant lesion and decreases symptoms. The pathophysiologic rationales for repair or replacement are to reverse the cycle of excessive ventricular volume, to allow for ventricular unloading, and to promote myocardial remodeling.

Among other researchers, a group from Michigan advocated mitral repair in the population with heart failure. Bolling and colleagues demonstrated that mitral valve repair increased the EF, improved NYHA classes from 3.9 to 2.0, and decreased the number of hospitalizations, although the results were reproducible by other centers.[218] Additional effects with repair in these patients were an increase in coronary blood flow reserve afforded by the reduction in LV volume.[219]

Despite the potential benefits of mitral reconstruction surgery, a retrospective review showed no reduction in long-term mortality among patients with severe mitral regurgitation and significant LV dysfunction who underwent mitral valve repair.[220] Mitral valve annuloplasty was not predictive of clinical outcomes and did not improve mortality. Factors associated with lower mortality were ACEI use, beta blockade, normal mean arterial pressures, and normal serum sodium concentrations.[220] The results of this analysis were not overly surprising. For example, in most patients in this situation, heart failure is not due to flail leaflets but is secondary to ventricular dysfunction.

In evaluating studies of heart failure with mitral regurgitation, it is important to separate the etiology (eg, ischemic vs dilated) as well as the surgical approaches. Future trials must be designed to distinguish differences between various surgical strategies, such as annuloplasty, resuspension of the papillary muscle, secondary chordal transection, ventricular reconstruction, passive restraints, and chordal-sparing valve replacement. A paramount goal with these procedures is for the patient to have little or no residual mitral regurgitation.[221]

Indications

Consider mitral valve surgery in patients with heart failure and severe mitral valve regurgitation whenever coronary revascularization is an option.[8] Candidates would include the following[8] :

• Patients with severe mitral regurgitation due to an organic structural abnormality or damage to the mitral valve in whom symptoms of heart failure develop
• Patients with an LVEF greater than 30%
• Patients with severe ischemic mitral regurgitation and an LVEF greater than 30% when coronary artery bypass grafting (CABG) is planned

Cardiac resynchronization therapy (CRT) should be considered in eligible patients with functional mitral regurgitation, as it may improve LV geometry and papillary muscle dyssynchrony as well as potentially reduce mitral regurgitation.[8]

Annuloplasty

Treatment of cardiomyopathy-associated mitral regurgitation most commonly involves the insertion of either a complete or a partial band attached to the annulus of the mitral valve. Thus, mitral repair deals with only one aspect of the patient's overall pathophysiologic condition. That is, annuloplasty rings may assist with tenting of the leaflet, but they do not address displacement of the papillary muscle with ventricular scarring.[222] In many patients, the underlying problem (ie, primary myopathy) continues unabated.

In general, ischemic mitral regurgitation is a ventricular problem. Many operations allow for coaptation and no mitral regurgitation when the patient leaves the operating room. However, as the LV continues to dilate, mitral regurgitation often recurs. Therefore, it is overambitious to say that annuloplasty cures this condition. As a result, many other approaches have been attempted (eg, chordal cutting, use of restraint devices, papillary relocation). However, results have been mixed.

Mitral valve replacement

If repair is deemed improbable, mitral replacement should be performed. Traditional mitral valve replacement includes complete resection of the leaflets and the chordal attachments. This destruction of the subvalvular apparatus results in ventricular dysfunction. In patients with mitral regurgitation and heart failure, preservation of the chordal attachments to the ventricle with valve replacement might provide results similar to, or even better than, those of annuloplasty.[223, 224]

Although the benefits in terms of quality of life (decreased heart failure) might not portend increased survival in these high-risk patients,[225, 226] they likely keep low-EF mitral valve interventions in the armamentarium of surgeons who manage heart failure.

A relatively recent approach to functional and degenerative mitral valve regurgitation is percutaneous mitral valve repair,[227, 228] using devices such as the MitraClip system. The EVEREST (Endovascular Valve Edge-to-Edge Repair Study II) randomized trial reported low rates of morbidity and mortality and reduction of acute mitral regurgitation to less than 2+ in the majority of patients, with sustained freedom from death, surgery, or recurrent mitral regurgitation in a substantial proportion of patients.[229]

A systematic review and meta-analysis of data from 2615 patients over nine studies found that percutaneous edge-to-edge mitral valve repair with the MitraClip is likely to be a safe and effective option in patients with both functional and degenerative mitral regurgitation.[230] Similarly, data from the German Transcatheter Mitral Valve Interventions (TRAMI) Registry found comparable MitraClip results for procedural safety of percutaneous mitral valve repair, efficacy, and clinical improvement after 1 year between patients with severely impaired LVEF (EF < 30%) and those with preserved LV function (EF >50%).[231] Over two thirds (69.5%) of those with an EF below 30% improved by one or more NYHA functional class, a significantly higher proportion than the 56.8% of patients with preserved LV function whose NYHA class improved (P< 0.05).

After a transmural myocardial infarction (MI) occurs, the ventricle pathologically remodels from its normal elliptical shape to a spherical shape. This change in geometry is in part responsible for the constellation of symptoms associated with heart failure and decreased survival.[232, 233]

Several ventricular restoration techniques exist. All aim to correct the above-described pathologic alteration in geometry. Most approaches involve incising and excluding nonviable myocardium with either patch or primary reconstruction to decrease ventricular volume.

The Batista procedure (reduction left ventriculoplasty) was designed with the intent of providing ventricular restoration, but it was associated with high failure rates. Although the initial enthusiasm for ventricular resection to treat nonischemic dilated cardiomyopathies has faded, a long-established finding is that resection of dyskinetic segments associated with left ventricle (LV) aneurysms can increase patients' functional status and prolong life.[234, 235]

The success of early lytic and percutaneous therapy for acute MI has decreased the incidence of true LV aneurysms. As such, ventricular restoration now focuses on excluding relatively subtle regions of akinetic myocardium.

Benefits from ventricular restoration using the technique described by Dor were reported in by the International Reconstructive Endoventricular Surgery Returning Torsion Original Radius Elliptical Shape to the Left Ventricle (RESTORE) group.[236] The investigators reported that among the patients studied, ejection fractions (EFs) increased from 29.6% to 39.5%, the end-systolic volume index decreased, and New York Heart Association (NYHA) functional classes improved from 67% class III/IV patients before surgery to 85% class I/II patients after surgery.[236]

The major study of ventricular reconstruction has been the STICH trial.[237] Investigators randomly assigned 1000 patients with an EF below 35%, coronary artery disease that was amenable to coronary artery bypass grafting (CABG), and dominant anterior LV dysfunction that was amenable to surgical ventricular reconstruction to undergo either CABG alone or CABG with surgical ventricular reconstruction (SVR) and found that SVR reduced the end-systolic volume index by 19%, as compared with a reduction of 6% with CABG alone. The median follow-up was 48 months. Cardiac symptoms and exercise tolerance improved to a similar degree in both groups. However, no significant difference was observed in death from any cause and hospitalization for cardiac causes.[237] On the basis of these results, SVR cannot be recommended for routine use in patients with ischemic cardiomyopathy and dominant anterior left ventricular dysfunction.

In some cases of extreme cardiopulmonary failure (ie, American College of Cardiology/American Heart Association [ACC/AHA] stage D), the only recourse is complete support with extracorporeal membrane oxygenation (ECMO). ECMO provides both oxygenation and circulation of blood, allowing the lungs and heart time to recover.[160] Unlike cardiopulmonary bypass, whose duration of use is measured in hours, ECMO can be used for 3-10 days.

For ECMO, one cannula is placed percutaneously via the right jugular vein or femoral vein into the right atrium, or it is placed surgically into the right atrial appendage, and another cannula is placed arterially either in the femoral artery or in the aortic arch. The drained venous blood is pumped through the ECMO device, where it is oxygenated, warmed, and anticoagulated. It is then returned to the arterial circulation.

ECMO devices can be used for short-term circulatory support in patients who are expected to recover from a major cardiac insult. Despite encouraging results with ECMO for the management of cardiogenic shock, most patients requiring circulatory assistance can be helped with ventricular support alone.

Ventricular assist devices (VADs) are invaluable tools in the treatment of heart failure, particularly in those with advanced heart failure.[238] A number of these devices are available to support the acutely or chronically decompensated heart (ie, American College of Cardiology/American Heart Association [ACC/AHA] stage D). Depending on the particular device used, the right ventricle (RV) and left ventricle (LV) can be assisted with a LV assist device (LVAD), a RVAD, or a biventricular assist device (BiVAD). An alternative term for a VAD is a ventricular assist system (VAS).[239, 240]

In concept, LVADs, RVADs, and BiVADs are similar. Blood is removed from the failing ventricle and diverted into a pump that delivers blood to either the aorta (in the case of an LVAD) or the pulmonary artery (in the case of an RVAD). An exception is the Impella device, which is inserted percutaneously into the LV; it draws blood from the LV and expels it into the ascending aorta.

LVADs can often be placed temporarily. In patients with acute, severe myocarditis or those who have undergone cardiotomy, this approach can serve as a bridge to recovery, unloading the dysfunctional heart and perhaps allowing reverse remodeling; in patients with end-stage heart failure, it can serve as a bridge to heart transplantation,[3, 8, 9, 116] allowing them to undergo rehabilitation and possibly go home before transplantation.

Long-term use (ie, destination therapy rather than bridge therapy) may be a consideration when no definitive procedure is planned.[8] Patients with severe heart failure who are not transplant candidates and who otherwise would die without treatment are candidates for lifetime use of VADs. Destination therapy with LVADs is superior to medical therapy in terms of quantity and quality of life, according to the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial and several later studies.[241, 242]

In the United States, several Food and Drug Administration (FDA)–approved options are available for bridging the patient to recovery and transplantation. These options continue to change and evolve. Some examples include the following:

• Abiomed AB5000 Ventricle
• AB Portable Driver
• Thoratec CentriMag Blood Pump
• Thoratec PVAD (Paracorporeal Ventricular Assist Device)
• Thoratec IVAD (Implantable Ventricular Assist Device)
• HeartMate XVE LVAD (also known as HeartMate I)
• HeartMate II LVAS
• TandemHeart Percutaneous LVAD
• HeartAssist 5 Pediatric VAD

The HeartMate LV and HeartWare HVAD[243] assist systems are the only LVADs that are approved by the US Food and Drug Administration (FDA) for destination therapy. Other devices are also under study in the United States for use as destination therapy (eg, Jarvik 2000 VAS[244] ).

The HeartMate XVE LVAD does not require warfarin anticoagulation, unlike another well-known first-generation pulsatile pump, the Novacor LVAD. The newer axial-flow pumps (eg, HeartMate II LVAS, Jarvik 2000, HeartAssist 5 Pediatric VAD) are relatively small and easy to insert, and they reduce morbidity; however, these devices do require anticoagulation.

Potential complications of VADs include mechanical breakdown, infection, bleeding, and thromboembolic events. Despite these potential drawbacks, however, the survival rate for patients receiving VADs is roughly 70%. This rate is impressive given the severity of illness in this cohort of patients. Furthermore, the evolving technology raises a host of clinical and physiologic questions that, when studied and answered, continue to advance the field.

Selected trials

In the REMATCH study, survival rates of medically treated and LVAD-treated patients were, respectively, 25% and 52% at 1 year and 8% and 23% at 2 years.[245] This study offered the first prospective, randomized data of very ill, non–transplant-eligible patients with heart failure receiving optimal medical therapy versus an early-generation HeartMate LVAD. In addition to survival advantage, LVAD recipients had improvements in several measures of quality of life.

Modifications in technique and perioperative care have reduced the rates of LVAD-related morbidity and mortality observed in the REMATCH trial.[246] Although REMATCH was a single study in very high risk patients, the data serve as proof of concept for the future development of VAD technologies.

Despite the need for an external energy source, most patients can use mechanical circulatory devices in the outpatient setting. Many patients have lived productive lives for longer than 4-6 years with their original device (depending on the device).

Starling et al used INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) data to determine that following postmarket approval by the FDA, the HeartMate II LVAS, a continuous-flow LVAD, continues to have excellent results as a bridge to heart transplantation relative to other types of LVADs in the following measures[247] :

• The 30-day operative mortality was 4% for the group receiving the HeartMate II compared with 11% for other LVADs
• Ninety-one percent of the group receiving the HeartMate II reached transplantation, cardiac recovery, or ongoing LVAD support by 6 months, compared with 80% for the group receiving other LVADs
• Renal function test measurements such as creatinine and blood urea nitrogen levels were lower in the HeartMate II group
• For all adverse events, the rates were similar or lower for the group that received the HeartMate II, with bleeding being the most frequent adverse event for both groups
• Survival for patients remaining on support at 1 year was 85% for the HeartMate II group, versus 70% for the group with other LVADs
• Relative to baseline, both groups had significant improvement of quality of life at 3 months of support, which was sustained through 12 months

In another study, Ventura et al used a large national data registry to compare posttransplant outcomes between pulsatile-flow (HeartMate XVE [HeartMate I]) and continuous-flow (HeartMate II) LVADs as bridges to transplantation and found similar 1- and 3-year survival rates but less risk of early allograft rejection and sepsis with the HeartMate II device.[248]

Patients with class IV stage D heart failure who are symptomatic despite optimal medical heart failure therapy for 45 of 60 days or who require inotropic support for 14 days or intra-aortic balloon pump (IABP) support for 7 days and have no contraindication for anticoagulation are eligible for implantation on LVAD HM II as destination therapy if they are not eligible for or do not desire cardiac transplantation. The INTERMACS registry has established a patient profile (1-7) that determines urgency to implantation and assesses risk and survival at 90 days.

Recommendations for clinical management of continuous-flow LVAD assist providers with standardized care for this patient population.[249] Bleeding, infection, and stroke are postimplantation complications, and death may occur due to right heart failure, sepsis, or stroke. A multidisciplinary approach to LVAD implantation is needed, as destination therapy identifies patients at high risk for complications and the need to optimize these patients medically before surgery. In a report from INTERMACS, 1-year survival for destination-therapy patients was 61% for pulsatile devices and 74% for continuous-flow devices.[250]

Selected patients with severe heart failure, debilitating refractory angina, ventricular arrhythmia, or congenital heart disease that cannot be controlled despite pharmacologic, medical device, or alternative surgical therapy should be evaluated for heart transplantation.[4, 9] The patient must be well informed, motivated, and emotionally stable; have a good social support network; and be capable of complying with intensive medical treatment.[8]

Since Christiaan Barnard performed the first orthotopic heart transplantation in 1967, the world has seen tremendous advancement in the field of cardiac transplantation. For patients with progressive end-stage heart failure despite maximal medical therapy who have a poor prognosis and no viable alternative form of treatment,[8] heart transplantation has become the criterion standard for therapy.[3]

Compared to patients who receive only medical therapy, transplant recipients have fewer rehospitalizations; marked functional improvements; enhanced quality of life; more gainful employment; and longer survival, with 50% surviving 10 years postoperatively.[251] Heart transplantation is associated with a 1-year survival rate of 83%; subsequently, survival decreases in a linear manner by approximately 3.4% per year.

Careful selection of donors and recipients is critical for ensuring good outcomes. In addition, transplant teams must strive to minimize potential perioperative dangers, including ischemic times, pulmonary hypertension, mechanical support, and cardiogenic shock.

For more information, see the Medscape Drugs and Diseases article Heart Transplantation.

Indications

Absolute indications for heart transplantation include hemodynamic compromise following heart failure, such as in the following scenarios[3] :

• Refractory cardiogenic shock
• Dependence on intravenous (IV) inotropic support for adequacy of organ perfusion
• Peak oxygen consumption per unit time (VO ₂) below 10 mL/kg/min
• Severe ischemic symptoms with consistent limitations of routine activity that are not amenable to revascularization procedures (coronary artery bypass grafting [CABG], percutaneous coronary intervention [PCI])
• Recurrent symptomatic ventricular arrhythmias despite all therapeutic interventions

Relative indications for heart transplantation include the following[3] :

• Peak VO ₂ between 11 and 14 mL/kg/min (or 55% of predicted) with major limitation of routine activities
• Recurrent unstable ischemia that is not amenable to other treatment
• Recurrent instability of fluid balance/renal function despite patient compliance with medical therapy

In the absence of other indications, however, the following are not sufficient indications for heart transplantation[3] :

• Low left ventricular ejection fraction (LVEF)
• History of New York Heart Association (NYHA) class III/IV heart failure symptoms
• Peak VO ₂ above 15 mL/kg/min (and >55% predicted)

Contraindications

Heart transplantation is contraindicated in patients with the following conditions[8] :

• Active infection
• Severe peripheral arterial or cerebrovascular disease
• Irreversible pulmonary hypertension
• Active malignancy
• Significant renal failure (creatinine clearance < 30 mL/min)
• Systematic disease with multiorgan involvement
• Other serious comorbidity with a poor prognosis
• Body mass index (BMI) avove 35 kg/m ²
• Current alcohol or drug use
• Insufficient social supports to achieve compliant care

Note that the Heart Failure Society of America (HFSA) indicates that cardiomyoplasty and partial left ventriculectomy (Batista operation) is not recommended to treat heart failure, nor should it be used as an alternative to heart transplantation.[9]

Coronary graft atherosclerosis

The Achilles heel of the long-term success of heart transplantation is the development of coronary graft atherosclerosis, the cardiac version of chronic rejection. Coronary graft atherosclerosis is uniquely different from typical coronary artery disease in that it is diffuse and is usually not amenable to revascularization.

Shortage of donor hearts

In the United States, fewer than 2500 heart transplantation procedures are performed annually[252, 253] ; between January 1988 and September 2017, an average of 2350 people received heart transplants per year.[253] Each year, an estimated 10-20% of patients die while awaiting a heart transplant. Of the 5 million people with heart failure, approximately 30,000 to 100,000 have such advanced disease that they would benefit from transplantation or mechanical circulatory support.[254] This disparity between the number of patients needing transplants and the availability of heart donors has refocused efforts to find other ways to support severely failing hearts.

The creation of a suitable total artificial heart (TAH) for orthotopic implantation has been the subject of intense investigation for decades.[255] In 1969, Dr Denton Cooley implanted the Liotta TAH (which is no longer made) into a high-risk patient after failing to wean the patient off cardiopulmonary bypass after left ventricular (LV) aneurysm repair. The patient was sustained until a donor heart became available after 3 days, but the patient subsequently died of pneumonia and multiple organ failure.[256]

Compared with LV assist devices (LVADs), the TAH has several potential advantages, including the ability to assist patients with severe biventricular failure; a lack of device pocket and thus a lessened risk of infection; and the opportunity to treat patients with systemic diseases (eg, amyloidosis, malignancy) who are not otherwise candidates for transplantation.[257, 258, 259, 260, 261]

Two TAHs have received the most attention:

• SynCardia (formerly CardioWest) TAH
• AbioCor TAH

The SynCardia TAH is a structural cousin of the original Jarvik-7 TAH that was implanted into patient Barney Clark with great publicity in 1982. In 2004, investigators reported data that allowed this device to receive FDA approval for use as a bridge to transplantation.

The AbioCor TAH involves a novel method of transcutaneous transmission of energy, freeing the patient from external drivelines. The patient exchanges the external battery packs, which can last as long as 4 hours. This TAH is unique in that it is the first TAH to use coils to transmit power across the skin; therefore, no transcutaneous conduits are needed. This feature allows for the advantages of a closed system, which potentially reduces sources of infection, a known complication of earlier devices.

The first clinical implantation of the AbioCor TAH was performed in July 2001. Before the end of 2004, 14 patients had received this device as part of a trial in patients whose expected survival was less than 30 days. Although all subsequently died, 4 patients were ambulatory after surgery, and 2 were discharged from the hospital to a transitional-care setting. One of the discharged patients was discharged on postoperative day 209. A limitation of the AbioCor TAH is its large size, which permits its implantation in only 50% of men and 20% of women. In 2006, the FDA approved the Abiocor TAH as a permanent TAH for humanitarian uses.

The SynCardia and AbioCor TAHs require recipient cardiectomy before implantation. The devices are similar in that they are sewn to atrial cuffs and to the great vessels after the native heart is explanted.

A European study involving the CARMAT TAH is evaluating survival on this device of patients with advance heart failure at 180 days postimplant or survival to cardiac transplantion if occurring before 180 days postimplant.[262]

Despite several decades of effort, the clinical application of artificial-heart technology remains immature. However, with the approval of the SynCardia and AbioCor devices as well as with new efforts to create small pumps, TAHs will ultimately be routine components of heart failure surgery for very sick patients with heart failure and biventricular failure.

Please note that the entire Guidelines section outlines select guidelines and recommendations. The reader is invited to consult the original guidelines for more detailed information.

Heart Failure Criteria, Classification, and Staging

Guideline contributor: Henry H Ooi, MD, MRCPI, Director, Advanced Heart Failure and Cardiac Transplant Program, Nashville Veterans Affairs Medical Center; Assistant Professor of Medicine, Vanderbilt University School of Medicine.

Heart failure criteria, classification, and staging

Framingham classification

In the Framingham classification, the diagnosis of heart failure is based on the concurrent presence of either two major criteria or one major and two minor criteria.[1]

Major criteria comprise the following:

• Paroxysmal nocturnal dyspnea
• Weight loss of 4.5 kg or more in 5 days in response to treatment
• Neck vein distention
• Rales
• Acute pulmonary edema
• Hepatojugular reflux
• S ₃ gallop
• Central venous pressure greater than 16 cm water
• Circulation time of 25 seconds or longer
• Radiographic cardiomegaly
• Pulmonary edema, visceral congestion, or cardiomegaly at autopsy

Minor criteria (accepted only if they cannot be attributed to another medical condition) are as follows:

• Nocturnal cough
• Dyspnea on ordinary exertion
• A decrease in vital capacity by one third the maximal value recorded
• Pleural effusion
• Tachycardia (rate of ≥120 bpm)
• Hepatomegaly
• Bilateral ankle edema

New York Heart Association (NYHA) classification

The NYHA functional classification of heart failure is widely used in practice and in clinical studies. It is based on symptom severity and the amount of exertion needed to provoke symptoms. NYHA heart failure classes are as follows[2] :

• Class I: No limitation of physical activity
• Class II: Slight limitation of physical activity, in which ordinary physical activity leads to fatigue, palpitation, or dyspnea; the person is comfortable at rest
• Class III: Marked limitation of physical activity, in which less-than-ordinary activity results in fatigue, palpitation, or dyspnea; the person is comfortable at rest
• Class IV: Inability to carry on any physical activity without discomfort but also symptoms of heart failure at rest, with increased discomfort if any physical activity is undertaken

American College of Cardiology Foundation/American Heart Association (ACCF/AHA) staging systems

The 2013 ACCF/AHA staging system complements the NYHA classification to reflect the progression of disease and comprises four stages, as shown in Table 3. below.[3]

Table 3. 2013 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) Heart Failure Staging System (Open Table in a new window)

2022 ACC/AHA/Heart Failure Society of America classification

The updated ACC/AHA/HFSA disease-staging terminology characterizes the syndrome as a continuum.[4, 5, 6, 7]

Table 4. 2022 ACC/AHA/Heart Failure Society of America (HFSA) Heart Failure Staging System (Open Table in a new window)

Table 5. 2022 ACC/AHA/HFSA Classification of Heart Failure (HF) by Left Ventricular Ejection Fraction (LVEF) (Open Table in a new window)

2022 American College of Cardiology/American Heart Association/Heart Failure Society of America (ACC/AHA/HFSA) recommendations for genetic evaluation and testing

Genetic screening and counseling are recommended for first-degree relatives of selected individuals with genetic or inherited cardiomyopathies to detect cardiac disease and to encourage review of therapies for lowering HF progression and sudden death.[4]

It is reasonable to refer select patients with nonischemic cardiomyopathy for genetic counseling and testing to identify conditions that could guide treatments for patients and family member.[4]

2021 European Society of Cardiology guidelines for genetic counseling and testing

Arrhythmogenic cardiomyopathy (ACM)

Offer genetic counseling and testing all patients with suspected ACM and all first-degree adult relatives of patients with ACM and a disease-causing mutation, regardless of their phenotype to preclinically identify genetically affected individuals.[68]

Genetic family screening may also be used for arrhythmic risk stratification.[68]  

First-degree relatives with the same definite disease-causing mutation as the patient should undergo clinical evaluation, electrocardiography (ECG), echocardiography, and possibly cardiac magnetic resonance imaging (CMRI).[68]  In the setting of no definite identified genetic mutation in the patient or no genetic testing is undertaken, consider clinical evaluation in first-degree adult relatives with ECG and echocardiography, and repeat every 2-5 years or less if nondiagnostic abnormalities are present.

Dilated cardiomyopathy (DCM) or hypokinetic nondilated cardiomyopathy (HNDC)

All patients with suspected DCM or HNDC and all first-degree adult relatives of such patients and a definite disease-causing mutation, regardless of their phenotype, should undergo genetic counseling and testing to preclinically identify genetically affected individuals.[68]  Repeat the evaluation every 5 years or less in first-degree adult relatives when aged younger than 50 years or in the presence of nondiagnostic abnormalities.

All first-degree relatives of patients should undergo clinical evaluation, ECG, echocardiography, and possibly CMRI.[68]

Findings from clinical evaluation, genetic testing, and imaging studies noted above can identify patients with DCM or HNDC who have the greatest risk of arrhythmia and/or deserve other specific treatments.[68] Early identification of asymptomatic relatives may allow early treatment and prevent progression to HF,  as well as appropriate genetic counseling.

Hypertrophic cardiomyopathy (HCM)

Offer genetic counseling and testing all patients with suspected HCM and all first-degree adult relatives of patients with HCM and a disease-causing mutation, regardless of their phenotype to preclinically identify genetically affected individuals.[68]

First-degree relatives with the same definite disease-causing mutation as the patient should undergo clinical evaluation with ECG and echocardiography.[68]  In the setting of no definite identified genetic mutation in the patient or no genetic testing is undertaken, consider clinical evaluation in first-degree adult relatives with ECG and echocardiography, and repeat every 2-5 years or less if nondiagnostic abnormalities are present.

2013 ACC Foundation/AHA guidelines for screening and genetic testing for DCM

Familial DCM (DCM with two close relatives who meet the criteria for idiopathic DCM)[3]

• First-degree relatives not known to be affected should undergo periodic, serial echocardiographic screening with assessment of LV function and size.
• Although the screening frequency is uncertain, every 3-5 years is reasonable.
• Consider genetic testing in conjunction with genetic counseling.

Idiopathic DCM [3]

• Inform first-degree relatives of index diagnosis.
• Relatives should discuss with their clinicians whether they should undergo echocardiographic screening.
• Although the value of genetic testing is unclear in this setting, it is potentially valuable in patients with significant cardiac conduction disease and/or a family history of premature sudden cardiac death.

2011 Heart Rhythm Society (HRS) and the European Heart Rhythm Association (EHRA) select recommendations for genetic testing for channelopathies and cardiomyopathies

Long QT syndrome (LQTS)[263]

Comprehensive or LQT1-3 (KCNQ1, KCNH2, and SCN5A)–targeted LQTS genetic testing is recommended for the following:

• Individuals with a strong clinical index of suspicion for LQTS based on the patient's clinical history, family history, and expressed electrocardiographic (ECG) (resting 12-lead ECGs and/or provocative stress testing with exercise or catecholamine infusion) phenotype
• Asymptomatic individuals with idiopathic QT prolongation on serial 12-lead ECGs defined as QTc over 480 ms (prepuberty) or longer than 500 ms (adults); may also be considered in asymptomatic individuals with idiopathic QT prolongation on serial 12-lead ECGs for QTc values over 460 ms (prepuberty) or longer than 480 ms (adults)

Mutation-specific genetic testing is recommended for family members following identification of the LQTS mutation in an index case.

Catecholaminergic polymorphic ventricular tachycardia (CPVT)[263]

• Comprehensive or CPVT1 and CVPT2 ( RYR2 and CASQ2)–targeted CPVT genetic testing is recommended for any individual with a clinical index of suspicion for CPVT based on the patient's clinical history, family history, and expressed ECG phenotype during provocative stress testing with cycle, treadmill, or catecholamine infusion.
• Mutation-specific genetic testing is recommended for family members following identification of the CPVT mutation in an index case.

Brugada syndrome (BrS)[263]

• Consider comprehensive or BrS1 ( SCN5A)–targeted BrS genetic testing for individuals with a clinical index of suspicion for BrS based on the patient's clinical history, family history, and expressed ECG (resting 12-lead ECGs and/or provocative drug challenge testing) phenotype.
• Mutation-specific genetic testing is recommended for family members following identification of the BrS mutation in an index case.
• Genetic testing is not indicated in individuals with an isolated type 2 or type 3 Brugada ECG pattern.

Cardiac conduction disease (CCD)[263]

• Consider genetic testing as part of the diagnostic evaluation for individuals with either isolated CCD or CCD with concomitant congenital heart disease, particularly in cases of a documented positive family history of CCD.
• Mutation-specific genetic testing is recommended for family members following identification of the CCD mutation in an index case. 

Short QT syndrome (SQTS)[263]

• Consider comprehensive or SQT1-3 ( KCNH2, KCNQ1, and KCNJ2)–targeted SQTS genetic testing for individuals with a clinical index of suspicion for SQTS based on the patient's clinical history, family history, and ECG phenotype.
• Mutation-specific genetic testing is recommended for family members following identification of the SQTS mutation in an index case.

HCM [263]

• Comprehensive or targeted ( MYBPC3, MYH7, TNNI3, TNNT2, TPM1) HCM genetic testing is recommended for individuals with a clinical diagnosis of HCM based on the patient's clinical history, family history, and ECG/echocardiographic phenotype.
• Mutation-specific genetic testing is recommended for family members following identification of the HCM mutation in an index case.

​ACM / arrhythmogenic right ventricular cardiomyopathy (ARVC)[263]

• Comprehensive or targeted ( DSC2, DSG2, DSP, JUP, PKP2, and  TMEM43) ACM/ARVC genetic testing can be useful for individuals who fulfill the task force diagnostic criteria for ACM/ARVC.
• Consider genetic testing for patients with possible ACM/ARVC (1 major or 2 minor criteria) based on the 2010 task force criteria. ^[264]
• Mutation-specific genetic testing is recommended for family members following identification of the ACM/ARVC mutation in an index case.
• Genetic testing is not recommended for patients with only a single minor criterion according to the 2010 task force criteria. ^[264]  

DCM [263]

• Comprehensive or targeted ( LMNA and  SCN5A) DCM genetic testing is recommended for individuals with DCM and significant cardiac conduction disease (ie, first-, second-, or third-degree heart block) and/or a family history of premature unexpected sudden death.
• Mutation-specific genetic testing is recommended for family members following identification of the DCM mutation in an index case.
• Genetic testing can be useful for individuals with familial DCM to confirm the diagnosis, identify those at highest risk of arrhythmia/syndromic features, facilitate cascade screening among family members, and aid in family planning.

Left ventricular noncompaction (LVNC)[263]

• Genetic testing may be useful for individuals with a clinical diagnosis of LVNC based on the patient's clinical history, family history, and ECG/echocardiographic phenotype
• Mutation-specific genetic testing is recommended for family members following identification of the LVNC mutation in an index case.

Restrictive cardiomyopathy (RCM)[263]

• Consider genetic testing for individuals with a suspected clinical diagnosis of RCM based on the patient's clinical history, family history, and ECG/echocardiographic phenotype.
• Mutation-specific genetic testing is recommended for family members following identification of the RCM mutation in an index case.

2010 Heart Failure Society of America (HFSA) recommendations for genetic evaluation of cardiomyopathy

Note the following[9] :

• For all patients with cardiomyopathy, obtain a detailed family history for at least 3 generations (HCM, DCM, arrhythmic right ventricular dysplasia [ARVD], LVNC, RCM, and cardiomyopathies associated with extracardiac manifestations)
• Carefully assess the patient's medical history as well as that of asymptomatic first-degree relatives, with special focus on heart failure symptoms, arrhythmias, presyncope, and syncope.
• Screen asymptomatic first-degree relatives for cardiomyopathy (HCM, DCM, ARVD, LVNC, RCM, and cardiomyopathies associated with extracardiac manifestations)
• Screen for cardiomyopathy at intervals in asymptomatic at-risk relatives who are known to carry the disease-causing mutation(s) (For details, see Recommendations 17.2e and 17.2f in  HFSA Guideline Approach to Medical Evidence for Genetic Evaluation of Cardiomyopathy ^[9] )
• Screen for cardiomyopathy in asymptomatic at-risk first-degree relatives who have not undergone genetic testing or in whom a disease-causing mutation has not been identified.

Note: Due to the complexity of genetic evaluation, testing, and counseling of patients with cardiomyopathy, it is recommended that patients be referred to centers with expertise in these matters and in family-based management.[9]

Guidelines for the diagnosis and management of heart failure have been issued by the following organizations:

• American College of Cardiology Foundation/American Heart Association (ACCF/AHA) ^[3]
• American College of Cardiology (ACC)/AHA/Heart Failure Society of America (HFSA) ^{[4, 5]}
• HFSA ^[9]
• European Society of Caridiology (ESC) ^{[8, 68]}

The ACC/AHA/HFSA guidelines,[3, 4, 5, 61]  HFSA guidelines,[9] ​ and ESC guidelines[8, 68]  all recommend the following basic laboratory tests and studies in the initial evaluation of patients with suspected heart failure:

• Complete blood count (CBC), which may indicate anemia or infection as potential causes of heart failure
• Urinalysis (UA), which may reveal proteinuria, which is associated with cardiovascular disease
• Serum electrolyte levels, which may be abnormal owing to causes such as fluid retention or renal dysfunction
• Blood urea nitrogen (BUN) and serum creatinine levels, which may indicate decreased renal blood flow
• Fasting blood glucose levels, because elevated levels indicate a significantly increased risk for heart failure (diabetic and nondiabetic patients
• Liver function tests (LFTs), which may show elevated liver enzyme levels and indicate liver dysfunction due to heart failure
• Electrocardiography (ECG) (12-lead), which may reveal arrhythmias, ischemia/infarction, and coronary artery disease (CAD) as possible causes of heart failure

In addition, these guidelines recommend measuring B-type natriuretic peptide (BNP) and N-terminal pro-B-type (NT-proBNP) natriuretic peptide levels, which are increased in heart failure and useful for risk stratification.[3, 4, 5, 8, 9, 61]  Baseline measurements correlate closely with the New York Heart Association (NYHA) heart failure functional classification and can be useful for prognosis in acutely decompensated patients.[61] The ACCF/AHA, HFSA, and ESC also indicate obtaining BNP or NT-proBNP levels in the workup of heart failure particularly when the diagnosis is unclear.[3, 8, 9] The HFSA recommends this test in all cases of suspected heart failure, particularly in ambiguous cases.[9]

The ACC/AHA recommendations also include obtaining a lipid profile and thyroid stimulating hormone (TSH) level.[3, 4, 5]  These tests reveal potential cardiovascular or thyroid disease as causes of heart failure. If the clinical presentation also suggests an acute coronary syndrome, the ESC recommends obtaining levels of troponin I or T[8, 68] ; increased troponin levels indicate injury to the myocytes and the severity of heart failure.

The ACCF/AHA, ACC/AHA, HFSA, and ESC also recommend the following imaging studies and procedures[3, 4, 5, 8, 9, 68] :

• Chest radiography (posterior-anterior, lateral), which may show pulmonary congestion, an enlarged cardiac silhouette, or other potential causes of the patient's symptoms
• Two-dimesional echocardiographic and Doppler flow ultrasonographic studies, which may reveal ventricular dysfunction and/or valvular abnormalities
• In the setting of inadequate echocardiography, alternative imaging (cardiac magnetic resonance imaing [CMRI], cardiac computed tomography [CCT], radionuclide imaging), to assess left ventricular (LV) ejection fraction (EF) ^{[4, 5]}
• Coronary arteriography in patients with a history of exertional angina or suspected ischemic LV dysfunction, which may reveal CAD
• Maximal exercise testing with/without respiratory gas exchange and/or blood oxygen saturation, which assesses cardiac and pulmonary function with activity, the inability to walk more than short distances, and a decreased peak oxygen consumption reflect more severe disease
• Noninvasive stress imaging (stress echocardiography, single-photon emission CT [SPECT], CMRI, or positron emission tomography [PET]), for detecting myocardial ischemia in those with HF and CAD who are candidates for coronary revascularization

Other studies may be indicated in selected patients,[3]  such as the following:

• Screening for hemochromatosis, in which iron overload affects cardiac function
• Screening for sleep-disturbed breathing, which affects neurohormonal activation
• Screening for human immunodeficiency virus (HIV), which may result in heart failure from possible direct infectious effects, from disease treatment effects causing CAD, or from other causes
• Testing for rheumatologic diseases, amyloidosis, or pheochromocytoma, all of which may cause cardiomyopathy
• Serum and urine electrophoresis for light-chain disease
• Genetic screening, testing, and/or counseling for at-risk patients with a first-degree relative who has been diagnosed with a cardiomyopathy leading to heart failure, which may aid in detecting early disease onset and guide treatment ^{[4, 5, 34]}
• Holter monitoring, which may reveal arrhythmias or abnormal electrical activity (eg, in patients with heart failure and a history of myocardial infarction (MI) who are being considered for electrophysiologic study to document ventricular tachycardia [VT] inducibility) ^{[8, 9]}

Routine use of invasive hemodynamic monitoring is not recommended in HF.[4, 5] However, invasive hemodynamic monitoring may help to guide management in selected patients with HF who have persisitent or worsening symptoms, signs, diagnostic parameters, and in whom hemodynamics are uncertain.[4, 5]

The 2022 ACC/AHA/HFSA and the 2020 Canadian Cardiovascular Society (CCS) and Canadian Heart Failure Society (CHFS) recommend that when cardiac amyloidosis (CA) is suspected, rule out light-chain amyloidosis (AL amyloidosis) using serum free light chains (kappa and lambda), and serum and urine protein electrophoresis with immunofixation.[4, 5, 265] Accurate identification of the amyloid subtype is essential to initiate specific treatment and avoid inappropriate application of therapy.

When the suspicion is high for cardiac amyloidosis but without evidence of serum/urine monoclonal light chains, perform bone scintigraphy to confirm the presence of transthyretin cardiac amyloidosis (ATTR-CA).[4, 5] For a positive diagnosis of ATTR-CA, perform genetic testing with TTR gene sequencing to differentiate the hereditary variant from wild-type ATTR-CA.

The following are practical tips regarding CA by the CCS/CHFS[265] :

• In the setting of undifferentiated CA, the presence of light chains does not confirm the diagnosis of light chain cardiac amyloidosis (AL-CA) because monoclonal gammopathy of unknown significance and ATTR-CA can coexist. In such settings, tissue biopsy is often necessary to exclude AL-CA.
• Perform technetium-labeled scintigraphy, where available, to diagnose ATTR-CA when plasma cell dyscrasias have been ruled out.
• Patient selection for tafamidis, a transthyretin tetramer stabilizer, should reflect the inclusion criteria for the Transthyretin Amyloidosis Cardiomyopathy Trial (ATTR-ACT) that showed clinical benefits of tafamidis over placebo with respect to mortality and cardiovascular hospitalization, including established ATTR-CA and objective evidence of HF (with elevated natriuretic peptides, where available).
• Do not routinely consider treatment with tafamidis for patients with New York Heart Association (NYHA) class IV symptoms or severe functional disability, measured using a 6-minute walk test < 100 m. (These patient were excluded from ATTR-ACT.) Subgroup analysis from the ATTR-ACT trial suggested that the reduction in cardiovascular hospitalizations seen with tafamidis might be limited to patients with less severe symptoms (NYHA class I or II).
• Because of the complexity in diagnosing CA and the potential for offering advanced or experimental treatment options, consider referring patients with CA to experienced centers. Other agents are currently under investigation, which might modify current treatment recommendations.

Catheterization and angiography

According to the ACCF/AHA, HFSA, and ESC cardiac catheterization and coronary angiography should be considered for patients with heart failure in the following situations[3, 8, 9] :

• When symptoms worsen without a clear cause in patients with heart failure, no angina, and known CAD
• In heart failure caused by systolic dysfunction in association with angina or regional wall-motion abnormalities and/or scintigraphic evidence of reversible myocardial ischemia when revascularization is being considered
• When the pretest probability of the underlying ischemic cardiomyopathy is high and surgical coronary procedures are being considered
• Before cardiac transplantation or LV assist device placement
• In cases of heart failure secondary to postinfarction ventricular aneurysm or other mechanical complications of MI

Endomyocardial biopsy

According to the 2013 ACCF/AHA and 2022 ACC/AHA/HFSA guidelines, routine endomyocardial biopsy (EMB) is not recommended in all cases of HF given the risk of complications. However, it may be considered in the following situations[3, 4, 5] :

• In rapidly progressive heart failure or worsening ventricular dysfunction that persists despite appropriate medical therapy
• In suspected cases of acute cardiac rejection status after heart transplantation or myocardial infiltrative processes
• In rapidly progressive and unexplained cardiomyopathy for which active myocarditis, especially giant cell myocarditis, is being considered
• When a specific diagnosis is suspected and EMB would influence therapy

The ESC guidelines recommend considering EMB in rapidly progressive HF despite appropriate medical therapy when there is a probability of a specific diagnosis that can be confirmed only in mycardial samples and there is an effective specfic therapy available.[8]  EMB is also indicated in patients with suspected phenotypes that require specific treatments, such as giant cell myocarditis, eosinophilic myocarditis, sarcoidosis, vasculitis, systemic lupus erythematosus, other systemic autoimmune inflammatory conditions, or storage diseases.[68]

The HFSA suggests that EMB be considered in patients with rapidly progressive clinical heart failure or ventricular dysfunction, despite appropriate medical therapy, as well as in patients suspected of having myocardial infiltrative processes (eg, sarcoidosis, amyloidosis) or in patients with malignant arrhythmias out of proportion to their LV dysfunction (eg, sarcoidosis, giant cell myocarditis).[9]

Assessment of functional capacity

The ACCF/AHA indicates the 6-minute walk test may be indicated in patients with heart failure whose adequacy of rate control is in question[3] ; the HFSA indicates it is a good indicator of functional status and prognosis in patients with heart failure.[9]

The ACCF/AHA and HFSA do not recommend routine maximal exercise stress testing.[3, 9]  HFSA guidelines indicate it may be useful in situations such as the following with measurement of gas exchange[9] :

• To assess the disparity between symptomatic limitation and objective indicators of disease severity
• To distinguish non HF-related causes of functional limitation, specifically cardiac versus pulmonary
• To consider whether patients are candidates for cardiac transplantation or mechanical circulatory support
• To determine the prescription for cardiac rehabilitation

ACCF/AHA and ESC guidelines note that values of peak oxygen consumption of less than 50% of predicted or less than 14 mL/kg/min reflect poor cardiac performance and a likelihood of 1-year survival less than 50%, facilitating referral for cardiac transplantation or mechanical circulatory device placement.[3, 8]

By definition, stage A patients are at high risk for heart failure but do not have structural heart disease or symptoms of heart failure. For these individuals, guidelines from the American College of Cardiology Foundation/American Heart Association (ACCF/AHA), Heart Failure Society of America (HFSA), ACC/AHA/HFSA, and the European Society of Cardiology recommend nonpharmacologic management focused on prevention through reduction of risk factors. Measures include the following[3, 4, 8, 9, 68] :

• Treat hypertension and lipid disorders
• Encourage smoking cessation
• Discourage heavy alcohol intake and illicit drug use
• Control and/or prevent diabetes mellitus
• Encourage physical activity
• Encourage weight reduction if obese or overweight

For patients with chronic heart failure, the ACCF/AHA, HFSA, and ESC recommend regular aerobic exercise to improve functional capacity and symptoms.[3, 8, 9]  However, ACCF/AHA cautions that limitation of activity is appropriate during acute heart failure exacerbations and in patients with suspected myocarditis. Most patients should not participate in heavy labor or exhaustive sports.[3]

The ACCF/AHA and ESC recommend specific patient education to facilitate self-care and close observation and follow-up are important aspects of care. Close supervision, including surveillance by the patient and family, home-based visits, telephone support, or remote monitoring should be provided to improve adherence.[3, 9]

Dietary sodium should be restricted to 2-3 g/day according the ACCF/AHA and HFSA,[3, 9]  although the ACCF/AHA notes that evidence to support this recommendation is inconclusive.[3]

Fluid restriction to 2 L/day is recommended for patients with evidence of hyponatremia (Na <  130 mEq/dL) and for those whose fluid status is difficult to control despite sodium restriction and the use of high-dose diuretics.[3, 8, 9]

The ACCF/AHA, HFSA, and ESC guidelines recommend caloric supplementation for patients with evidence of cardiac cachexia.[3, 8, 9]  The HFSA recommends against the use of anabolic steroids for these patients.[9]

The HFSA recommends against naturoceutical use for relief of symptomatic heart failure or for the secondary prevention of cardiovascular events.[9] Avoid natural or synthetic products containing ephedra (ma huang), ephedrine, or its metabolites, as well as products that have significant drug interactions with digoxin, vasodilators, beta blockers, antiarrhythmic drugs, and anticoagulants.[9]

The 2022 ACCF/AHA/HFSA recommendations for nonpharmacologic management of HF focuses on self-care support[4] :

• Multidisciplinary teams should provide care to those with HF, to facilitate guideline-directed medical therapy, address potential barriers to self-care, lower the risk of rehospitalization for HF, and improve survival.
• Provide specific education and support to those with HF to facilitate multidisciplinary HF self-care.
• To reduce mortality, it is reasonable to vaccinate patients with HF against respiratory illnesses.
• It is reasonable to screen adults with HF for risk factors for poor self-care (eg, depression, social isolation, frailty, low health literacy) to improve management.

2022 ACC/AHA/HFSA Recommendations

The American College of Cardiology, American Heart Association, and Heart Failure Society of America (ACC/AHA/HFSA) replaced their 2013 and 2017 guidelines on the management of heart failure (HF) with significant and paradigm-shifting additional treatment options that include new/repurposed drug therapies that benefit almost without regard to ejection fraction (EF).[4, 5]

• Four core foundational medication classes (sodium-glucose cotransporter-2 inhibitors [SGLT2Is], beta blockers, mineralocorticoid receptor antagonists [MRAs], and renin-angiotensin system [RAF] inhibitors) are now included in guideline-directed medical therapy (GDMT) for HF with reduced EF (HFrEF). Angiotensin receptor-neprilysin inhibitors (ARNIs), angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin receptor blockers (ARBs) are recommended as first-line agents in HFrEF.
• SGLT2Is are a class 2a (moderate) recommendation in HF with mildly reduced ejection fraction (HFmrEF), whereas ARNIs, ACEIs, ARBs, MRAs, and beta blockers are class 2b (weak) recommendations for this patient population.
• There are new recommendations for HF with preserved EF (HFpEF) for SGLT2Is (class 2a), MRAs (class 2b), and ARNIs (class 2b). Renewed recommendations include those for treatment of hypertension (class 1 [strong]) and of atrial fibrillation (AF) (class 2a); use of ARBs (class 2b); as well as avoidance of the routine use of nitrates or phosphodiesterase-5 (PDE5) inhibitors (class 3 [no benefit]).

At risk for HF (stage A) (class I recommendations)

In hypertensive patients at risk for HF, control blood pressure with GDMT for hypertension to prevent symptomatic HF.

Use SGLT2i's in those with type 2 diabetes and either established cardiovascular (CV) disease or at high CV disease risk to prevent hospitalizations for HF.

Pre-HF (stage B) (class I recommendations)

• Patients with an LVEF of 40% or less: Use an ACEI to prevent symptomatic HF and lower mortality; or use beta blockers to prevent symptomatic HF.
• Those with a recent or remote history of myocardial infarction (MI) or acute coronary syndrome (ACS): Use statins to prevent symptomatic HF and adverse CV events.
• Those with a recent or remote history of MI or ACS and an LVEF of 40% or less: Use evidence-based beta blockers to lower mortality
• Those with a recent MI and an LVEF of 40% or less who are not able to tolerate ACEIs: Use angiotensin receptor blockers (ARBs) to prevent symptomatic HF and lower mortality.
• Patients who are a minimum of 40 days post-MI with an LVEF of 30% or less and New York Heart Association (NYHA) class I symptoms while on GDMT and with a reasonable expectation of meaningful survival for longer than 1 year: The ACC/AHA/HFSA recommend an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death to lower total mortality.

HFrEF

Pharmacotherapy for (NYHA class II-IV HFrEF (LVEF ≤40%) to reduce the risk of HF hospitalization and death:

• Use an ACEI, an MRA, or dapagliflozin or empagliflozin for those with HFrEF
• Use a beta-blocker for those with stable HFrEF
• Use sacubitril/valsartan as a replacement for ACEI
• Use an ARB in symptomatic patients unable to tolerate and ACEI or ARNI (they should also receive a beta blocker and an MRA)

Use loop diuretics in those with HFrEF who have signs/symptoms of congestion to alleviate HF symptoms, improve exercise capacity, and reduce HF hospitalizations.

HFmrEF

Pharmacotherapy for (NYHA class II-IV HFmrEF includes the following:

• Use diuretics in patients with congestion and HFmrEF to alleviate signs/symptoms.
• An ACEI, ARB, beta blocker, MRA, or sacubitril/valsartan may be considered to reduce the risk of HF hospitalization and death.

HFpEF

Use diuretics in patients with congestion and HFpEF to alleviate signs/symptoms.

2016 ACC/AHA/HFSA Recommendations

In 2016, the ACC/AHA/HFSA  published a focused update on new pharmacologicaly therapy for heart failure[63]  which were developed in collaboration with the International Society for Heart and Lung Transplantation (ISHLT). The recommendations are aligned with those of the 2016 ESC guidelines[8]  and the 2017 ACC/AHA focused updates to the 2013 guidelines,[61] and are summarized below.

Class I

Reduction of morbidity and mortality

In patients with chronic heart failure with reduced ejection fraction (HFrEF),  one of the following agents should be administered in conjunction with evidence-based beta blockers: 

• Angiotensin-converting enzyme  inhibitors (ACEIs) (Level of evidence: A)
• Angiotensin receptor blockers (ARBs) (Level of evidence: A) 
• Angiotensin receptor–neprilysin inhibitor (ARNI) (Level of evidence: B-R) 

In patients with prior or current symptoms of chronic HFrEF, ACEIs are beneficial. (Level of evidence: A) 

In patients with prior or current symptoms of chronic HFrEF who are intolerant to ACEIs because of cough or angioedema, ARBs are recommended. (Level of evidence: A) 

In patients with chronic symptomatic HFrEF New York Heart Association (NYHA) class II or III, replace an ACEI or ARB with an ARNI. (Level of evidence: B-R) 

Class IIa

Ivabradine can reduce heart failure hospitalization for patients receiving guideline-directed evaluation and management who have symptomatic (NYHA class II-III) stable chronic HFrEF (left ventricular ejection fraction of ≤35%) and who are in sinus rhythm with a heart rate of at least 70 bpm at rest.(Level of evidence: B-R) 

Class III

ARNI should not be given in the following situations:

• Concomitantly with or within 36 hours of the last dose of an ACEI
• Patients with a history of angioedema

2020 CCS/CHFS Guidelines

The 2020 Canadian Cardiovascular Society (CCS) and Canadian Heart Failure Society (CHFS) presented new evidence for angiotensin receptor neprilysin inhibitors (ARNIs) in HFpEF as well as for SGLT2 inhibitors and HF.[265]

New evidence for ARNIs in HFpEF

The Prospective Comparison of ARNI (angiotensin receptor-neprilysin inhibitors) with ARB (angiotensin-receptor blockers) Global Outcomes in Heart Failure With Preserved Ejection Fraction (PARAGON-HF) trial, which compared sacubitril/valsartan with valsartan in HFpEF patients, showed a modest but nonsignificant 13% reduction in the primary outcome of first and recurrent HF hospitalizations and cardiovascular death. A secondary end point analysis revealed improvement in quality of life and renal function, which suggested potential benefits with sacubitril/valsartan compared with valsartan. The data further suggest heterogeneity in the treatment response with greater benefit in women and in individuals with a lower LVEF.

The CCS/CHFS indicate that the statistically negative results of the primary end point analysis preclude any recommendation for the general use of sacubitril/valsartan in patients with HFpEF.

New evidence for SGLT2 inhibitors and HF

The CCS/CHFS recommend use of SGLT2 inhibitors (eg, empagliflozin, canagliflozin, dapagliflozin) for treatment of patients with type 2 diabetes and atherosclerotic cardiovascular disease to reduce the risk of HF hospitalization and death (strong recommendation).

SGLT2 inhibitors, such as dapagliflozin, are recommended for use in patients with the following features:

• Type 2 diabetes, aged >50 years, with additional risk factors for atherosclerotic cardiovascular disease, to reduce the risk of HF hospitalization (strong recommendation)

• Mild to moderate HF due to reduced LVEF (≤ 40%) and concomitant type 2 diabetes, to improve symptoms and quality of life and to reduce the risk of hospitalization and cardiovascular mortality (strong recommendation)

• Mild to moderate HF due to reduced LVEF (≤ 40%) and without concomitant diabetes, to improve symptoms and quality of life and to reduce the risk of hospitalization and cardiovascular mortality (conditional recommendation)

The CCS/CHFS recommend SGLT2 inhibitors, such as canagliflozin, be used in patients aged >30 years with type 2 diabetes, and macroalbumineric renal disease, to reduce the risk of HF hospitalization and progression of renal disease (strong recommendation).

Practical tips

Note that SGLT2 inhibitors are currently contraindicated for patients with type 1 diabetes.

The most common adverse effects of SGLT2 inhibitors are genital mycotic infections (GMIs), with the highest risk in women (10%-15% risk), those with previous GMIs, and uncircumcised men. GMIs can generally be managed with antifungal drugs and do not require discontinuation of therapy.

SGLT2 inhibitors might result in an up to 15% temporary reduction of estimated glomerular filtration rate (eGFR) (usually resolves within 1-3 months). These drugs have also been associated with acute kidney injury, and increased monitoring is warranted in those at risk.

SGLT2 inhibitors do not cause hypoglycemia in the absence of concomitant insulin and/or secretagogue therapy. Background therapies might need adjustment to prevent hypoglycemia.

SGLT2 inhibitors should be held in the setting of concomitant dehydrating illness as part of “sick day” management. Patients should be educated on “sick day” management.

These agents have been associated with diabetic ketoacidosis (incidence 0.1%). Patients might present with normal or only modestly elevated blood glucose level (< 14 mmol/L). Rarely, SGLT2 inhibitors might be associated with normal anion gap acidosis (best detected with measurement of serum ketones). Nonspecific symptoms associated with diabetic ketoacidosis include dyspnea, nausea/vomiting, abdominal pain, confusion, anorexia, excessive thirst, and lethargy.

Exercise caution when combining SGLT2 inhibitors, ARNIs, and diuretics because of their concomitant effects to promote diuresis.

The 2010 Heart Failure Society of America (HFSA) guidelines indicate that device therapy is an integral part of the treatment of heart failure and that considerations such as the nature and severity of the condition and any patient comorbidities are essential in optimizing the use of this therapy.[9] The Committee for Practice Guidelines (CPG) of the European Society of Cardiology (ESC) as well as the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) emphasized the importance of medical devices in heart failure in their respective 2010 and 2012 focused updates on these interventions.[116, 266]

More recently, the 2022 ACC/AHA/HFSA guidelines also provided the following level recommendations for implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden cardiac death to lower total mortality:[4]

• Individuals with nonischemic dilated cardiomyopathy (DCM) or ischemic heart disease that is a minimum of 40 days post myocardial infarction (MI), who have a left ventricular (LV) ejection fraction (EF) of 35% or less and aNew York Heart Association (NYHA) class II or III symptoms while on chronic guideline-directed medical therapy (GDMT), as well as having a reasonable expectation of meaningful survival for longer than 1 year
• Patients with a minimum of 40 days post-MI who have an LVEF of 30% or less and NYHA class I symptoms while on GDMT, with a reasonable expectation of meaningful survival for longer than 1 year

Cardiac resynchronization therapy (CRT) is recommended for individuals with an LVEF of 35% or less, sinus rhythm, left bundle branch block (LBBB) with a QRS duration of at least 150 ms, and a NYHA class II, III, or ambulatory IV symptoms on GDMT to lower total mortality and hospitalizations as well as improve symptoms and quality of life.

Pacemakers

Because right ventricular (RV) pacing may worsen heart failure due to an increase in ventricular dysynchrony, the 2010 HFSA Practice Guidelines recommend against placement of a dual-chamber pacemaker in heart failure patients in the absence of symptomatic bradycardia or high-degree atrioventricular (AV) block.[9]

The ACC/AHA heart failure guidelines recommend consideration of CRT for patients with heart failure who have indications for permanent pacing (eg, first implant, upgrading of a conventional pacemaker) and NYHA class III-IV symptoms or those who have an LVEF below 35% despite being on optimal heart failure therapy and who may have a dependence on RV pacing.[3, 266]  These recommendations also include patients with NYHA class II symptoms and the presence of LBBB with a QRS duration that is at least 150 ms. The ESC guidelines have similar recommendations.[8]  

Implantable cardioverter-defibrillators

ACC Foundation (ACCF)/AHA guidelines recommend placing an ICD in virtually all patients with an LVEF below 35%. The ACCF/AHA and ESC recommend ICD placement for the following categories of heart failure patients[3, 8, 267] :

• Patients with LV dysfunction (LVEF ≤35%) from a previous MI who are at least 40 days post-Ml
• Patients with nonischemic cardiomyopathy; with an LVEF of 35% or less; in NYHA class II or III; receiving optimal medical therapy; and expected to survive longer than 1 year with good functional status
• Patients with ischemic cardiomyopathy who are at least 40 days post-MI; have an LVEF of 30% or less; are in NYHA functional class I; are on chronic optimal medical therapy; and are expected to survive longer than 1 year with good functional status
• Patients who have had ventricular fibrillation (VF)
• Patients with documented hemodynamically unstable ventricular tachycardia (VT) and/or VT with syncope; with an LVEF below 40%; on optimal medical therapy; and expected to survive longer than 1 year with good functional status

Cardiac resynchronization therapy/biventricular pacing

The 2013 ACCF/AHA guidelines recommend CRT for patients in sinus rhythm or atrial fibrillation with a QRS duration of 120 ms or longer (the greatest benefit is in patients with a QRS >150 ms) and an LVEF of 35% or less with persistent, moderate-to-severe heart failure (NYHA class III and functional NYHA class IV) despite optimal medical therapy.[3]  A 2012 update of ACC/AHA/HRS guidelines on CRT expanded class I indications to patients with NYHA class II symptoms and LBBB duration of 150 ms or longer.[266]  Additional CRT recommendations include[3, 266] :

• Patients with a reduced LVEF and a QRS of 150 ms or longer who have NYHA I or II symptoms
• Patients with a reduced LVEF who require chronic pacing and in whom frequent ventricular pacing is expected
• CRT is not recommended for patients with NYHA class I or II symptoms and non-LBBB pattern with a QRS duration shorter than 150 ms
• CRT is not indicated in patients who are not expected to survive for more than 1 year due to their comorbidities or frailty

The 2022 ACC/AHA/HFSA guidelines indicate an "upgrade" to CRT should be considered for patients with an LVEF of 35% or less who have received a conventional pacemaker or an ICD and who then develop worsening HF despite optimal medical therapy and who have a signficant proportion of RV pacing.

The ESC guidelines gives class I recommendations for the use of CRT in the following groups[8] :

• Symptomatic patients in sinus rhythm with a QRS duration of 150 ms or longer, LBBB QRS morphology and an LVEF of 35% or less despite optimal medical therapy. (Level of evidence: A)
• Symptomatic patients in sinus rhythm with a QRS duration of 130-149 ms or longer, LBBB QRS morphology and an LVEF of 35% or less despite optimal medical therapy. (Level of evidence: B)
• CRT rather than RV pacing for patients with heart failure with reduced ejection fraction (HFrEF) regardless of NYHA class, including patients with atrial fibrillation who have an indication for ventricular pacing and a high degree AV block. (Level of evidence: A)

CRT should be considered for the following groups[8] :

• Symptomatic patients in sinus rhythm with a QRS duration of 150 ms or longer, non-LBBB QRS morphology and an LVEF of 35% or less despite optimal medical therapy. (Class IIa; level of evidence: B)
• Patients with LVEF of 35% or less in NYHA Class III-IV despite optimal medical therapy, if they are in atrial fibrillation and have a QRS duration of 130 ms or longer provided a strategy to ensure biventricular capture is in place or the patient is expected to return to sinus rhythm. (Class IIa; level of evidence: B)

CRT may be considered for the following groups[8] :

• Symptomatic patients in sinus rhythm with a QRS duration of 130-149 ms, non-LBBB QRS morphology and with an LVEF of 35% or less despite optimal medical therapy. (Class IIb; level of evidence: B)
• Patients with HFrEF who have received a conventional pacemaker or an ICD and subsequently develop worsening heart failure despite optimal medical therapy and who have a high proportion of RV pacing. (Class IIb; level of evidence: B)

CRT is contraindicated in patients with a QRS duration below 130 ms. (Class III; level of evidence: A)

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA), Heart Failure Society of America (HFSA), and European Society of Cardiology (ESC) guidelines recommend coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) revascularization procedures in selected patients with heart failure and coronary artery disease (CAD) to improve symptoms and survival.[3, 8, 9] In patients who are at low risk for CAD, findings from noninvasive tests such as exercise electrocardiography (ECG), stress echocardiography, and stress nuclear perfusion imaging should determine whether subsequent angiography is indicated.

In selected patients with heart failure, reduced ejection fraction (EF) (ef ≤35%), and a suitable coronary anatomy, surgical revascularization and guideline-directed medical therapy helps improve symptoms, cardiovascular hospitalizations, and long-term all-cause mortality.[4, 5]

The ACCF/AHA guidelines recommend revascularization procedures for the following heart failure patients[3] :

• CABG or PCI for those on medical therapy with angina and suitable coronary anatomy, especially significant left main stenosis (>50%) or left main equivalent
• CABG to improve survival in patients with mild to moderate left ventricular (LV) systolic dysfunction (EF OF 35%-50%) and significant (≥70% stenosis) multivessel CAD or proximal left anterior descending (LAD) artery stenosis in the presence of viable myocardium
• CABG to improve morbidity and survival for patients with an LVEF of 35% or less, heart failure, and significant multivessel CAD
• CABG may also be considered in patients with ischemic heart disease, severe LV systolic dysfunction (EF < 35%), and operable coronary anatomy, regardless of whether or not viable myocardium is present

The ESC guidelines are in general agreement with those of ACCF/AHA, with the choice between CABG and PCI individualized for each patient.[8] In addition, the ESC points out that the benefit-risk balance of revascularization in patients without angina and without viable myocardium remains uncertain.

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) recommends aortic valve replacement for patients with critical aortic stenosis and predicted surgical mortality of 10% or less, as well as transcatheter aortic valve replacement for selected patients who are considered to be inoperable.[3] The benefit of transcatheter mitral valve repair or mitral valve surgery for functional mitral insufficiency is unclear and should only be considered after careful candidate selection.

The 2022 ACC/AHA/Heart Failure Society of America (HFSA) has the following level I recommendations for valvular heart disease in those with heart failure (HF)[4] :

• A multidisciplinary management strategy according to clinical practice guidelines for valvular heart disease to prevent worsening HF and adverse clinical outcomes
• Optimization of guideline-directed medical therapy (GDMT) for those with chronic severe secondary mitral regurgitation (MR) and HF with reduced ejection fraction (EF) (HFrEF) before any intervention for secondary MR related to left ventricular (LV) dysfunction

The HFSA indicates that isolated mitral valve repair or replacement for severe mitral regurgitation secondary to ventricular dilatation in the presence of severe LV systolic dysfunction is not generally recommended.[9]

Although the European Society of Cardiology (ESC) recommends optimized medical treatment for aortic stenosis, it also cautions that vasodilators may cause hypotension and should be used with caution. Surgical decision making should not be delayed. For patients unfit for surgery, transcatheter aortic valve replacement should be considered. Additional valvular surgery recommendations include[8] :

• Aortic valve repair or replacement in all symptomatic patients with severe aortic regurgitation as well as asymptomatic patients with an LV EF of 50% or less who are fit for surgery.
• Consider a combination valve and coronary surgery for secondary mitral regurgitation in symptomatic patients with an LVEF below 30% with suitable arteries for revascularization. Surgery is also recommended for those with severe mitral regurgitation with an LVEF over 30% undergoing coronary artery bypass grafting.
• Isolated mitral valve surgery in patients with severe functional mitral regurgitation and severe LV systolic dysfunction (LVEF < 30%) who cannot be revascularized or have non-ischemic cardiomyopathy is questionable; conventional medical and device therapy are preferred. In selected cases, consider repair to avoid or postpone transplantation.

The 2020 Canadian Cardiovascular Society (CCS) and Canadian Heart Failure Society (CHFS) recommendations for percutaneous mitral valve repair for HF and reduced EF and severe functional mitral regurgitation include the following[265] :

• The CCS/CHFS recommends maximally tolerated guideline-directed medical therapy (GDMT), including cardiac resynchronization therapy and revascularization where appropriate, be implemented before consideration of percutaneous mitral valve repair (PMVR) for patients with HF and reduced ejection fraction (HFrEF) and severe functional mitral regurgitation (FMR) (strong recommendation).
• It is suggested that patients with symptomatic HF (HFrEF) despite maximal GDMT and severe mitral regurgitation be evaluated for PMVR (weak recommendation).
• The CCS/CHFS recommends that a multidisciplinary dedicated heart team (including interventionalists, cardiac surgeons, imaging specialists, and HF specialists) evaluate and manage the care of potential candidates for PMVR (strong recommendation).

Practical tips by the CCS/CHFS include the following[265] :

• Use caution when treating FMR in patients with HFrEF.
• Patients with HFrEF and FMR who have severe left ventricular (LV) dilatation (typically LV end diastolic dimension >70 mm) and less than severe mitral regurgitation may be poor candidates for PMVR with MitraClip.
• Patients with FMR should first receive maximally tolerated GDMT, including pharmacologic and nonpharmacologic HF therapies (eg, cardiac resynchronization therapy where applicable) for a reasonable minimum period (eg, 3 months), before PMVR is considered.
• Refer patients considered for PMVR to centers experienced in evaluating patients with advanced HF, have high volumes of patients with valve disease managed medically and surgically, and have a high likelihood of achieving the volume of PMVR (eg, 2-4 per month) required for developing and maintaining competence in well-selected patients.

The following organizations have released guidelines for the utilization of mechanical circulatory support (MCS):

• Society for Cardiovascular Angiography and Interventions, American College of Cardiology, Heart Failure Society of America, and Society for Thoracic Surgeons (SCAI/ACC/HFSA/STS)
• International Society of Heart and Lung Transplantation (ISHLT)
• American Heart Association (AHA)

Historically, the intra-aortic balloon bump (IABP) and extracorporeal membrane oxygenation (ECMO) devices had been the only MCS devices available to clinicians, but axial flow pumps (eg, Impella) and left atrial to femoral artery bypass pumps (eg, TandemHeart) have more recently entered clinical practice.[268]

The 2015 SCAI/ACC/HFSA/STS clinical expert consensus-based recommendations include the following[268] :

• Percutaneous circulatory assist devices provide superior hemodynamic support (reduce left ventricular [LV] pressures, LV volumes, LV stroke volume) compared with pharmacologic therapy; this is particularly apparent for the Impella and TandemHeart devices.
• In those with cardiogenic shock who fail to stabilize or show signs of improvement after initial interventions, consider early placement of an appropriate MCS.
• For profound cardiogenic shock, IABP is less likely to provide benefit than continuous flow pumps (including the Impella CP and TandemHeart). ECMO may also be beneficial, particularly for patients with impaired respiratory gas exchange.
• Consider MCS for isolated acute right ventricular (RV) failure complicated by cardiogenic shock.
• MCS can be beneficial in high-risk percutaneous coronary intervention (PCI) (eg, multivessel, left main, or last patent conduit interventions), particularly if the patient is inoperable or has severely reduced ejection fraction or elevated cardiac filling pressures
• MCS can be utilized when patients fail to wean off of cardiopulmonary bypass.
• Early MCS may benefit patients with acute decompensated heart failure when they continue to deteriorate despite initial interventions.
• MCS can be used in severe biventricular failure via both right- and left-sided percutaneous devices or venoarterial ECMO.

However, there was insufficient evidence to support or refute routine use of MCS as an adjunct to primary revascularization in the setting of large acute MI (myocardial infarction) to reduce reperfusion injury or infarct size.[268]

In its 2013 guidelines for mechanical circulatory support, the ISHLT recommended long-term MCS for the following patients in acute cardiogenic shock (class IIa)[269] :

• Those whose ventricular function is considered unrecoverable or unlikely to recover without long-term device support (level of evidence: C)
• Those considered too ill to maintain normal hemodynamics and vital organ function with temporary MCS, or who cannot be weaned from temporary MCS or inotropic support (level of evidence: C)
• Those with the capacity for meaningful recovery of end-organ function and quality of life (level of evidence: C)
• Those without irreversible end-organ damage (level of evidence: C)
• Those who are dependent on inotropic agents (level of evidence: B)
• Those with end-stage systolic heart failure who do not fall into one of the recommendations: Routine risk stratification at regular intervals to determine the need for and optimal timing of MCS (level of evidence: C)

Additional recommendations for heart failure therapy include[269] :

• Diuretic agents for the management of volume overload during MCS (class I; level of evidence: C)
• An angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB) for managing hypertension or for risk reduction in patients with vascular disease and diabetes (class I; level of evidence: C.)
• Beta-blockers for hypertension or for rate control in patients with tachyarrhythmias (class I; level of evidence: C.)
• Mineralocorticoid receptor antagonists to limit the need for potassium repletion in patients with adequate renal function and for potential beneficial antifibrotic effects on the myocardium (class I; level of evidence: C.)
• Digoxin, potentially, for treating atrial fibrillation with rapid ventricular response (class II; level of evidence: C.)

The 2012 AHA guidelines on heart device strategies, patient selection, and postoperative care focuses on risk stratification and early referral of high-risk patients with heart failure to centers that can implant MCS.[270] The specific recommendations for MCS include[270] :

• Consider MCS as a bridge to transplantation (BTT) for eligible patients with end-stage heart failure who are failing optimal medical, surgical, and or device therapies and are at high risk for dying before receiving heart transplantation.
• Early referral for MCS before development of advanced heart failure is preferred.
• Durable, implantable MCS devices is beneficial as permanent or destination therapy for patients with advanced heart failure, high 1-year mortality resulting from HF, and the absence of other life-limiting organ dysfunction; who are failing medical, surgical, and/or device therapies; and who are not heart transplant candidates.
• Consider patients who are ineligible for heart transplantation because of pulmonary hypertension related to heart failure alone for bridge to potential transplant eligibility with durable, long-term MCS.
• Consider urgent nondurable MCS in hemodynamically compromised patients with heart failure and end-organ dysfunction and/or relative contraindications to heart transplantation/durable MCS that are expected to improve with restoration of an improved hemodynamic profile.
• Long-term MCS is not recommended in patients with advanced kidney disease in whom renal function is unlikely to recover despite improved hemodynamics.
• Consider long-term MCS as a bridge to heart-kidney transplantation on the basis of the availability of outpatient hemodialysis.

According to the American College of Cardiology Foundation/American Heart Association (ACCF/AHA) and Heart Failure Society of America (HFSA) guidelines, selected patients with refractory end-stage heart failure, debilitating refractory angina, ventricular arrhythmia, or congenital heart disease that cannot be controlled despite pharmacologic, medical device, or alternative surgical therapy should be evaluated for heart transplantation.[3, 9]

The European Society of Cardiology (ESC) guidelines recommend heart transplantation be considered for patients with progressive end-stage heart failure despite maximal medical therapy who have a poor prognosis and no viable alternative form of treatment; these patients must be well informed, motivated, and emotionally stable, and they must be capable of complying with intensive medical treatment.[8]

The ESC considers the following conditions as contraindications for heart transplantation[8] :

• Active infection
• Severe peripheral arterial or cerebrovascular disease
• Current alcohol and/or drug abuse
• Malignancy (collaborate with oncologists for risk stratification of tumor recurrence)
• Irreversible renal dysfunction (creatinine clearance < 30 mL/min)
• Pharmacologically irreversible pulmonary hypertension (consider placing a left ventricular assist device and then reevaluating eligibility)
• Multiorgan systemic disease
• Other serious comorbidity with a poor prognosis
• Pretransplant body mass index above 35 kg/m ²
• insufficient social support in the outpatient setting to achieve compliant care

Note that the HFSA does not recommend partial left ventriculectomy (Batista operation) to treat nonischemic cardiomyopathy.[9]

The Heart Failure Society of America (HFSA) guidelines recommend the following treatment goals for patients with acute decompensated heart failure (ADHF)[9] :

• Symptomatic improvement (ie, congestion, low output)
• Restoration of normal oxygenation
• Optimization of volume status
• Identification of the etiology and addressing precipitating factors
• Optimization of long-term oral therapy
• Minimization of side effects
• Identification of patients in whom revascularization or device therapy may be beneficial
• Risk stratification for venous thromboembolism and potential need for anticoagulation
• Patient education regarding medications and self-management of heart failure
• Initiation of a disease management program, where possible

HFSA indications for hospital admission in patients with ADHF are as follows[9] :

• Evidence of severely decompensated heart failure, including hypotension, worsening renal function, and altered mentation
• Dyspnea at rest
• Hemodynamically significant arrhythmia, including new onset of rapid atrial fibrillation
• Acute coronary syndromes

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) comments regarding adjustment of maintenance heart failure medications in patients admitted with ADHF are as follows:

• Oral therapy should be continued, or even uptitrated, in most patients with reduced ejection fraction heart failure.
• Most patients tolerate well the continuation of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) and beta-blockers; this also results in better outcomes.
• Only consider withholding or reducing beta-blockers in patients hospitalized after a recent beta-blocker initiation or increase in beta-blocer therapy, or in those with marked volume overload or marginal/low cardiac output.
• In patients with significant worsening of renal function, consider a reduction in, or temporary discontinuation of, ACEIs, ARBs, and/or aldosterone antagonists until renal function improves.

Pharmacologic therapy

The ACCF/AHA, HFSA, and European Society of Cardiology (ESC) agree that diuretics remain the cornerstone of standard therapy.[3, 8, 9] The aim of diuretic therapy is to achieve and maintain euvolaemia with the lowest achievable dose.[8] Intravenous (IV) administration of a loop diuretic (eg, furosemide, bumetanide, torsemide) is preferred initially.[3, 8, 9]  In patients with hypertensive heart failure who have mild fluid retention, thiazide diuretics (eg, bendroflumethiazide, hydrochlorothiazide, metolazone) may be preferred because of their more persistent antihypertensive effects.[8]

When diuresis is inadequate, the ACCF/AHA, HFSA and ESC guidelines recommend higher doses or the addition of a second diuretic (eg, a thiazide).[3, 8, 9]  Careful monitoring to avoid hypokalemia, renal dysfunction, and hypovolemia is required. The ACC/AHA and ESC suggest the use of ultrafiltration for fluid reduction when diuretic therapies are unsuccessful.[3, 8]

Vasodilators (eg, nitroprusside, nitroglycerin, or nesiritide) are recommended as an adjuvant to diuretics for relief of symptoms.[3, 8, 9] However, the ESC cautions against their use in patients with a systolic blood pressure below 90 mm Hg or those with significant mitral or aortic stenosis.[8]

The ACCF/AHA, HFSA, ESC recommend that in hospitalized patients, beta-blocker therapy should be initiated after optimization of volume status and successful discontinuation of IV diuretics, vasodilators, and inotropic agents.[3, 8, 9] Beta-blockers should be started at a low dose and only in stable patients, and should be used cautiously in patients who have required inotropes during their hospital course.[3, 8, 9]

Additional recommendations from the 2013 ACC/AHA and 2010 HSFA guidelines include the following[3, 9] :

• If symptomatic hypotension is absent, consider IV nitroglycerin, nitroprusside, or nesiritide an adjuvant to diuretic therapy for relief of dyspnea in hospitalized patients.
• Administer venous thromboembolism prophylaxis with an anticoagulant medication for patients admitted to the hospital, if the risk-benefit ratio is favorable.

Invasive hemodynamic monitoring

The 2013 ACCF/AHA and 2010 HSFA guidelines found no benefit found for the routine use of invasive hemodynamic monitoring in normotensive patients with acute decompensated heart failure and congestion with symptomatic response to diuretics and vasodilators.[3, 9]  The HSFA guidelines include a recommendation for consideration of invasive hemodynamic monitoring for patients with any of the following[9] :

• Heart failure refractory to initial therapy
• Unclear volume status and cardiac filling pressures
• Clinically significant hypotension (systolic blood pressure < 80 mm Hg) or worsening renal function during therapy
• Need for assessment of degree and reversibility of pulmonary hypertension, as part of the evaluation for possible cardiac transplantation
• Need for documentation of an adequate hemodynamic response to inotropic therapy, when considering long-term outpatient infusion

Ventilation

The HFSA recommends routine administration of supplemental oxygen only in the presence of hypoxia; noninvasive positive pressure ventilation (NIPPV) should be considered for severe dyspnea and clinical evidence of pulmonary edema.[9]  The ESC recommends noninvasive ventilation as an adjunctive therapy to improve outcomes in patients with acute respiratory failure due to hypercapnic exacerbation of chronic obstructive pulmonary disease or heart failure in the setting of acute pulmonary edema.[8]

The goals of pharmacotherapy for heart failure are to reduce morbidity and to prevent complications. Along with oxygen, medications assisting with symptom relief include: (1) diuretics, which reduce edema by reduction of blood volume and venous pressures; (2) vasodilators, for preload and afterload reduction; (3) digoxin, which can cause a small increase in cardiac output; (4) inotropic agents, which help to restore organ perfusion and reduce congestion; (5) anticoagulants, to decrease the risk of thromboembolism; (6) beta-blockers, for neurohormonal modification, left ventricular ejection fraction (LVEF) improvement, arrhythmia prevention, and ventricular rate control; (7) angiotensin-converting enzyme inhibitors (ACEIs), for neurohormonal modification, vasodilatation, and LVEF improvement; (8) angiotensin II receptor blockers (ARBs), also for neurohormonal modification, vasodilatation, and LVEF improvement; and (9) analgesics, for pain management.

The FDA approved vericiguat (Verquvo), a sGC stimulator, in 2021. Vericiguat stimulates sGC, the intracellular receptor for endogenous NO, which catalyzes cyclic guanosine monophosphate (cGMP) production. 

Ivabradine, an I(f) inhibitor is available in the United States. It blocks the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel responsible for the cardiac pacemaker I(f) "funny" current, which regulates heart rate without any effect on ventricular repolarization or myocardial contractility.

Sacubitril/valsartan (Entresto), an angiotensin receptor-neprilysin inhibitor (ARNI), was approved by the FDA in July 2015 to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with congestive heart failure (New York Heart Association [NYHA] class II-IV) and reduced ejection fraction.[135]  In 2021, this indication was expanded to include heart failure in adults with preserved ejection fraction based on the PARAGON-HF (Prospective Comparison of ARNI with ARB [angiotensin-receptor blockers] Global Outcomes in HF with Preserved Ejection Fraction) study.[136]  

The selective sodium-glucose cotransporter-2 (SGLT2) inhibitors empagliflozin and dapagliflozin are indicated to reduce the risk of cardiovascular death and hospitalization in patients with heart failure. These agents are also indicated to reduce the risk of hospitalization for heart failure in patients with type 2 diabetes mellitus who with either established cardiovascular disease or multiple cardiovascular risk factors.[139, 140, 141, 142]   

Sotagliflozin, a dual SGLT1/SGLT2 inhibitor, was approved in 2023 and is indicated to reduce the risk of cardiovascular death, hospitalization, and urgent clinic visits for heart failure in adults with heart failure, type 2 diabetes mellitus, chronic kidney disease, or other cardiovascular risk factors.[143, 144]  

Drugs that can exacerbate heart failure should be avoided, such as nonsteroidal anti-inflammatory drugs (NSAIDs), calcium channel blockers (CCBs), and most antiarrhythmic drugs (except class III). NSAIDs can cause sodium retention and peripheral vasoconstriction, and they can attenuate the efficacy and enhance the toxicity of diuretics and ACEIs. Calcium channel blockers (CCBs) can worsen heart failure and may increase the risk of cardiovascular events; only the vasoselective CCBs have been shown not to adversely affect survival. Antiarrhythmic agents can have cardiodepressant effects and may promote arrhythmia; only amiodarone and dofetilide have been shown not to adversely affect survival. 

Class Summary

Beta-blockers inhibit the sympathomimetic nervous system and block alpha1-adrenergic vasoconstrictor activity. These agents have moderate afterload reduction properties and cause slight preload reduction. In addition to decreasing mortality rates, beta-blockers also reduce hospitalizations and the risk of sudden death; improve LV function and exercise tolerance; and reduce heart failure functional class. Although other beta-blockers with similar pharmacologic properties might hypothetically be beneficial in heart failure, the target doses have not been identified in clinical trials.

Carvedilol (Coreg, Coreg CR)

Carvedilol is a nonselective beta- and alpha1-adrenergic blocker. It does not appear to have intrinsic sympathomimetic activity. Carvedilol at the target dose of 25 mg twice daily has been shown to reduce mortality in clinical trials of heart failure patients with reduced ejection fraction.

Class Summary

Certain beta-1 blockers are selective in blocking beta-1 adrenoreceptors. These agents are used in heart failure to reduce heart rate and blood pressure.

Metoprolol (Lopressor, Toprol XL)

Metoprolol is a selective beta1-adrenergic blocker at lower doses. It inhibits beta2-receptors at higher doses. It does not have intrinsic sympathomimetic activity. The long-acting formulation (metoprolol succinate) at a target dose of 200 mg daily has been shown to reduce mortality in a clinical trial of patients with heart failure and low ejection fraction.

Bisoprolol (Zebeta)

Bisoprolol is a highly selective beta1-adrenergic receptor blocker that decreases the automaticity of contractions. Bisoprolol at the target dose of 10 mg daily has been shown to reduce mortality in a clinical trial of patients with heart failure and reduced ejection fraction, but is not approved for heart failure use in the US.

Class Summary

Angiotensin-converting enzyme inhibitors (ACEIs) prevent conversion of angiotensin I to angiotensin II, which results in lower aldosterone secretion. Use of ACEIs increases survival, improves symptoms, and decreases repeat hospitalizations.

Captopril

Captopril prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in lower aldosterone secretion. Captopril at a target dose of 25 mg three times daily has been shown to improve survival in patients with low ejection fraction after myocardial infarction.

Enalapril (Vasotec)

Enalapril prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in increased levels of plasma renin and a reduction in aldosterone secretion. It helps control blood pressure and proteinuria. Enalapril decreases the pulmonary-to-systemic flow ratio in the catheterization laboratory and increases systemic blood flow in patients with relatively low pulmonary vascular resistance. It has a favorable clinical effect when administered over a long period. It helps prevent potassium loss in distal tubules. The body conserves potassium; thus, less oral potassium supplementation is needed. Enalapril at a target dose of 10 mg twice daily has been shown to improve survival in patients with heart failure and reduced ejection fraction.

Lisinopril (Prinivil, Zestril)

Lisinopril prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in increased levels of plasma renin and a reduction in aldosterone secretion. Lisinopril at a target dose of 10 mg daily has been shown to reduce mortality after myocardial infarction.

Ramipril (Altace)

Ramipril prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in increased levels of plasma renin and a reduction in aldosterone secretion. Ramipril at a target dose of 5 mg twice daily has been shown to reduce mortality in patients with heart failure after myocardial infarction.

Quinapril (Accupril)

Quinapril prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in increased levels of plasma renin and a reduction in aldosterone secretion.

Class Summary

Angiotensin receptor blockers (ARBs) are reasonable first-line therapy for patients with mild to moderate heart failure symptoms and left ventricular (LV) dysfunction when patients are already taking these agents for other indications. ARBs block the renin-angiotensin-aldosterone system (RAAS) by competitive inhibition of the AT1 receptor, thereby decreasing afterload and preventing LV remodeling. The use of ARBs increases survival and decreases hospitalization rates, but these agents are not superior to angiotensin-converting enzyme inhibitors (ACEIs). ARBs can also be used as add-on therapy for patients who have refractory heart failure symptoms despite optimal heart failure therapy.

Losartan (Cozaar)

Losartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II at tissue receptor sites. It may induce more complete inhibition of the renin-angiotensin system than ACE inhibitors, and it does not affect the response to bradykinin (less likely to be associated with cough and angioedema). These agents are used in patients unable to tolerate ACE inhibitors. Losartan has not been demonstrated to improve survival in heart failure.

Valsartan (Diovan)

Valsartan is a prodrug that produces direct antagonism of angiotensin II receptors. It displaces angiotensin II from the AT1 receptor and may lower blood pressure by antagonizing AT1-induced vasoconstriction, aldosterone release, catecholamine release, arginine vasopressin release, water intake, and hypertrophic responses. It may induce more complete inhibition of the renin-angiotensin system than ACE inhibitors, does not affect the response to bradykinin, and is less likely to be associated with cough and angioedema. It is used in patients unable to tolerate ACE inhibitors. Valsartan at a target dose of 160 mg twice daily has been shown to improve survival in patients with heart failure and reduced ejection fraction.

Candesartan (Atacand)

Candesartan blocks the vasoconstriction and aldosterone-secreting effects of angiotensin II. It may induce more complete inhibition of the renin-angiotensin system than ACE inhibitors, does not affect the response to bradykinin, and is less likely to be associated with cough and angioedema. Use candesartan in patients unable to tolerate ACE inhibitors. Candesartan at a target dose of 32 mg daily has been shown to improve survival in patients with heart failure and reduced ejection fraction.

Irbesartan (Avapro)

Irbesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II at tissue receptor sites. It may induce more complete inhibition of the renin-angiotensin system than ACE inhibitors, and it does not affect the response to bradykinin (less likely to be associated with cough and angioedema). Irbesartan has not been shown to improve survival in heart failure.

Azilsartan (Edarbi)

Azilsartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II at tissue receptor sites. It may induce more complete inhibition of the renin-angiotensin system than ACE inhibitors, and it does not affect the response to bradykinin (less likely to be associated with cough and angioedema).

Class Summary

Inotropic agents such as milrinone, digoxin, dopamine, and dobutamine are used to increase the force of cardiac contractions. Intravenous positive inotropic agents should only be used in inpatient settings — and then only in patients who manifest signs and symptoms of low cardiac output syndrome (volume overload with evidence of organ hypoperfusion).

Milrinone

Milrinone is a type 3 phosphodiesterase inhibitor that increases inotropy, chronotropy, and lusitropy, acting via cyclic guanosine monophosphate (cGMP) to increase the intramyocardial adenosine triphosphate (ATP). It is a potent vasodilator agent, being a venous and arterial vasodilator, and it is used in patients with pulmonary hypertension. Milrinone can be used in the presence of a beta-blocker. Milrinone is thought to create less tachycardia, because it does not directly stimulate beta-receptors.

Digoxin (Lanoxin)

Digoxin is a cardiac glycoside with direct inotropic effects, in addition to indirect effects, on the cardiovascular system. It acts directly on cardiac muscle, increasing myocardial systolic contractions. Indirect actions result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure. It is used to improve symptoms associated with HF by enhancing cardiac contractility. Although digoxin does not confer a survival benefit, it has reduced the number of hospitalizations that occur as a result of worsening heart failure.

Dopamine

Dopamine is a naturally occurring catecholamine that acts as a precursor to norepinephrine. It stimulates both adrenergic and dopaminergic receptors. The hemodynamic effect is dose dependent. Low-dose use is associated with dilation within renal and splanchnic vasculature, resulting in enhanced diuresis. Moderate doses enhance cardiac contractility and the heart rate. Higher doses cause increased afterload through peripheral vasoconstriction. Administer by continuous intravenous infusion. It is usually used in severe heart failure and is reserved for patients with moderate hypotension (eg, systolic blood pressure 70-90 mm Hg). Typically, moderate or higher doses are used.

Dobutamine

Dobutamine, a beta-receptor agonist, increases inotropy and chronotropy and decreases afterload, thereby improving end-organ perfusion. It produces vasodilation and increases the inotropic state. At higher dosages, it may cause increased heart rate, exacerbating myocardial ischemia. Careful hemodynamic and patient monitoring is required.

Class Summary

In addition to diuretic therapy, vasodilators are recommended as first-line therapy for patients with acute heart failure in the absence of hypotension, for relief of symptoms. Vasodilators decrease preload and/or afterload as well as reduce systemic vascular resistance (SVR).

Nitroprusside sodium (Nitropress)

Nitroprusside sodium is a potent balanced arterial and venous vasodilator, resulting in a very efficient decrease of intracardiac filling pressures. It requires careful hemodynamic monitoring using indwelling catheters and monitoring for cyanide toxicity, especially in the presence of renal dysfunction. It is particularly helpful for patients who present with severe pulmonary congestion in the presence of hypertension and severe mitral regurgitation. The drug should be titrated down to cessation rather than abruptly stopped, owing to the rebound potential.

Hydralazine

Hydralazine decreases systemic resistance through direct vasodilation of arterioles. A hydralazine and nitrate combination reduces preload and afterload. Combinations of hydralazine and nitrates are recommended to improve outcomes for African Americans with moderate-to-severe symptoms of heart failure on optimal medical therapy with ACEIs/ARBs, beta-blockers, and diuretics.

Class Summary

Nitrates improve hemodynamic effects in heart failure by decreasing left ventricular filling pressure and systemic vascular resistance. These agents also result in a slight improvement on cardiac output.

Nitroglycerin (Nitrostat, Nitro-Dur, Nitrolingual, Nitro-Time, NitroMist, Minitran)

Nitroglycerin is first-line therapy for patients who are not hypotensive. It provides excellent and reliable preload reduction. Higher doses provide mild afterload reduction. It has rapid onset and offset (both within minutes), allowing rapid clinical effects and rapid discontinuation of effects in adverse clinical situations. It produces vasodilation and increases inotropic activity of the heart. At higher dosages, it may exacerbate myocardial ischemia by increasing the heart rate.

Isosorbide dinitrate (Dilatrate-SR, Isordil Titradose)

Isosorbide dinitrate relaxes vascular smooth muscle by stimulating intracellular cyclic GMP. It decreases left ventricular pressure (preload) and arterial resistance (afterload). By decreasing left ventricular pressure and dilating arteries, it reduces cardiac oxygen demand. Chronic use of isosorbide dinitrate as a sole vasodilating agent is not recommended.

Isosorbide dinitrate and Hydralazine (BiDil)

This is a fixed-dose combination of isosorbide dinitrate (20 mg/tab), a vasodilator with effects on both arteries and veins, and hydralazine (37.5 mg/tab), a predominantly arterial vasodilator. It is indicated for heart failure in black patients, based in part on results from the African American Heart Failure Trial. Two previous trials in the general population of patients with severe heart failure found no benefit but suggested a benefit in black patients. Black patients showed a 43% reduction in mortality rate, a 39% decrease in hospitalization rate, and a decrease in symptoms from heart failure.

Isosorbide mononitrate (Monoket)

Isosorbide mononitrate causes relaxation of vascular smooth muscle and consequent dilatation of peripheral arteries and veins. Dilation of the veins promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Arteriolar relaxation reduces systemic vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload).

Class Summary

Human B-type natriuretic peptides (hBNPs) such as nesiritide are used in patients with acutely decompensated heart failure. These agents reduce pulmonary capillary wedge pressure and improve dyspnea.

Nesiritide (Natrecor)

Nesiritide is a recombinant DNA form of hBNP that dilates veins and arteries. hBNP binds to the particulate guanylate cyclase receptor of vascular smooth muscle and endothelial cells. Binding to the receptor causes an increase in cGMP, which serves as a second messenger to dilate veins and arteries. It reduces PCWP and improves dyspnea in patients with acutely decompensated HF.

Class Summary

The I(f) inhibitor ivabradine is used to lower heart rate and has been shown to reduce the risk for hospitalization.

Ivabradine (Corlanor)

Ivabradine blocks the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel responsible for the cardiac pacemaker I(f) ‘funny' current, which regulates heart rate without any effect on ventricular repolarization or myocardial contractility. It is indicated to reduce the risk of hospitalization for worsening heart failure in patients with stable, symptomatic chronic heart failure with LVEF ≤35%, who are in sinus rhythm with resting heart rate ≥70 bpm and either are on maximally tolerated doses of beta-blockers or have a contraindication to beta-blocker use.

Class Summary

Angiotensin receptor-neprilysin inhibitor (ARNI) combinations have been shown to significantly reduce cardiovascular death and hospitalization in patients with chronic heart failure.

Sacubitril/valsartan (Entresto)

An angiotensin receptor-neprilysin inhibitor (ARNI). The cardiovascular and renal effects of sacubitril’s active metabolite (LBQ657) in heart failure are attributed to the increased levels of peptides that are degraded by neprilysin (eg, natriuretic peptide). Administration results in increased natriuresis, increased urine cGMP, and decreased plasma MR-proANP (mid-regional proatrial natriuretic peptide) and NT-proBNP (N-terminal pro B-type natriuretic peptide). It is indicated to reduce the risk of cardiovascular death and hospitalization in chronic heart failure. Benefits for this indication are most clearly evident in patients with LVEF below normal. The combination drug is also indicated for symptomatic HF with systemic left ventricular systolic dysfunction in children aged 1 year and older.

Class Summary

Diuretics remain the mainstay of therapy and the current standard of care for acute heart failure. First-line diuretic therapy is a loop diuretic (furosemide, bumetanide, torsemide) in the lowest effective dose, either once or twice a day — although it can be used up to 3-4 times a day — depending on the individual response and renal function. Response to diuretic therapy often depends on bioavailability of the drug (better on an empty stomach) and nutritional level (loop diuretics are bound to proteins for renal delivery).

Furosemide (Lasix)

Furosemide increases the excretion of water by interfering with the chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in the ascending loop of Henle and distal renal tubule. The dose must be individualized to the patient. Depending on the response, administer furosemide at small dose increments (20-200 mg) until desired diuresis occurs.

Torsemide (Demadex)

Torsemide acts from within the lumen of the thick ascending portion of the loop of Henle, where it inhibits the sodium, potassium, and chloride carrier system. It increases urinary excretion of sodium, chloride, and water, but does not significantly alter the glomerular filtration rate, renal plasma flow, or acid-base balance. Torsemide is roughly twice as potent as furosemide on a milligram basis. Depending on the response, administer furosemide at small dose increments (10-100 mg) until desired diuresis occurs.

Bumetanide

Bumetanide increases the excretion of water by interfering with the chloride-binding cotransport system, which, in turn, inhibits sodium, potassium, and chloride reabsorption in the ascending loop of Henle. These effects increase urinary excretion of sodium, chloride, and water, resulting in profound diuresis. Renal vasodilation occurs following administration, renal vascular resistance decreases, and renal blood flow is enhanced. Bumetanide is roughly four times as potent as furosemide on a milligram basis. Depending on the response, administer bumetanide at small dose increments (0.5-5 mg) until desired diuresis occurs.

Class Summary

If patients with heart failure do not have a response to treatment with loop diuretics, a thiazide diuretic such as hydrochlorothiazide or metolazone can be added 30 minutes before adminstration of the loop diuretic to enhance the response. Thiazide diuretics inhibit reabsorption of sodium and chloride in the cortical thick ascending limb of the loop of Henle and the distal tubules. They also increase potassium and bicarbonate excretion as well as decrease calcium excretion and uric acid retention. Combination diuretic therapy should be monitored closely for development of hypovolemia, hypokalemia, hypomagnesemia, and hyponatremia.

Hydrochlorothiazide (Microzide)

Hydrochlorothiazide inhibits reabsorption of sodium in the distal tubules, causing increased excretion of sodium, water, potassium, and hydrogen ions.

Indapamide

Indapamide has a diuretic effect that is localized at the proximal segment of the distal tubule of the nephron. Similar to other diuretics it may enhance sodium, chloride and water excretion.

Chlorthalidone (Thalitone)

Chlorthalidone inhibits the reabsorption of sodium in distal tubules, causing increased excretion of sodium and water, as well as potassium and hydrogen ions.

Chlorothiazide (Diuril)

Chlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. It increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate

Class Summary

Metolazone is a diuretic of the quinazoline class and has thiazidelike properties. This agent interferes with the renal tubular mechanism of electrolyte reabsorption.

Metolazone (Zaroxolyn)

Metolazone increases excretion of sodium, water, potassium, and hydrogen ions by inhibiting reabsorption of sodium in the distal tubules. Metolazone may be more effective in patients with impaired renal function.

Class Summary

The potassium-sparing diuretics interfere with sodium reabsorption at the distal tubules, resulting in decreased potassium secretion. These agents have a weak diuretic and antihypertensive effect when used alone. The potassium-sparing diuretics spironolactone or triamterene are usually used in addition to the loop diuretics. Note that careful monitoring of renal function and potassium is necessary for all diuretics.

Spironolactone (Aldactone)

Spironolactone is used for the management of edema resulting from excessive aldosterone excretion. It competes with aldosterone for receptor sites in the distal renal tubules, increasing water excretion while retaining potassium and hydrogen ions. Spironolactone at a target dose of 25 mg has been shown to improve survival in patients with heart failure and reduced ejection fraction.

Amiloride (Midamor)

Amiloride is unrelated chemically to other known antikaliuretic or diuretic agents. It is a potassium-conserving (antikaliuretic) drug that, compared with thiazide diuretics, possesses weak natriuretic, diuretic, and antihypertensive activity.

Triamterene (Dyrenium)

Triamterene is a potassium-sparing diuretic with relatively weak natriuretic properties. It exerts its diuretic effect on the distal renal tubules by inhibiting the reabsorption of sodium in exchange for potassium and hydrogen. It increases sodium excretion and reduces excessive loss of potassium and hydrogen associated with hydrochlorothiazide.

Class Summary

Aldosterone antagonists are weak diuretics that reduce mortality and the risk of sudden death by blocking the effects of aldosterone, thereby decreasing myocardial and vascular inflammation and collagen production. This, in turn, prevents apoptosis, decreases stimulation of the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system (SNS), and acts as a membrane stabilizer, thus preventing arrhythmia. Aldosterone antagonists are recommended for patients who have moderately severe and severe heart failure and reduced left ventricular (LV) systolic function (Randomized Aldactone Evaluation Study [RALES]) who can be carefully monitored for preserved renal function and normal potassium concentration.

Eplerenone (Inspra)

Eplerenone selectively blocks aldosterone at the mineralocorticoid receptors in epithelial (eg, kidney) and nonepithelial (eg, heart, blood vessels, and brain) tissues; thus, it decreases blood pressure and sodium reabsorption. It is indicated to improve survival for heart failure or left LV dysfunction following acute MI. Compared with placebo, a significant risk reduction (15%) has been observed. The EMPHASIS-HF trial has shown that patients with systolic heart failure with mild symptoms treated with eplerenone have a significant reduction in cardiovascular death or heart failure hospitalization when compared with placebo.

Class Summary

Empagliflozin and dapagliflozin are inhibitors of the sodium-glucose cotransporter 2 (SGLT2), the predominant transporter responsible for reabsorption of glucose from the glomerular filtrate back into the circulation. This action increases urinary glucose excretion. 

SGLT2 inhibitors also reduce sodium reabsorption and increase the delivery of sodium to the distal tubule. This may influence several physiologic functions, such as lowering both preload and afterload of the heart and downregulating sympathetic activity. 

Empagliflozin (Jardiance)

In addition to improving glycemic control in adults with type 2 diabetes mellitus (T2DM), empagliflozin is indicated to reduce the risk of cardiovascular (CV) death and hospitalization for heart failure (HF) in adults with HF (either HF with reduced ejection fraction [HFrEF] or HF with preserved EF [HFpEF]).

It is also indicated to reduce the risk of CV death in adults with T2DM and CV disease.

Dapagliflozin (Farxiga)

Dapagliflozin is indicated to reduce hospitalization risk for heart failure in adults with T2DM and established cardiovascular disease (CVD) or multiple CV risk factors. It is also indicated to reduce the risk of CV death and hospitalization for heart failure in adults with heart failure (NYHA class II-IV) with reduced ejection fraction (HFrEF) or heart failure with preserved EF (HFpEF). 

Additionally, dapagliflozin is indicated to reduce the risk of sustained eGFR decline, ESRD, CV death, and hospitalization for heart failure in adults with chronic kidney disease at risk of progression. 

Class Summary

Inhibiting SGLT1 reduces intestinal absorption of glucose and sodium.

Inhibiting SGLT2 reduces renal reabsorption of glucose and sodium, which may influence several physiologic functions, such as lowering both pre- and afterload of the heart and downregulating sympathetic activity. 

Sotagliflozin (Inpefa)

Sotagliflozin is ndicated to reduce the risk of cardiovascular (CV) death, hospitalization for heart failure (HF), and urgent visits for HF in adults with HF or type 2 diabetes, chronic kidney disease, or other CV risk factors. 

Class Summary

Heart failure is associated with impaired nitric oxide (NO) synthesis and decreased soluble guanylate cyclase (sGC) activity, which may contribute to myocardial and vascular dysfunction. 

By directly stimulating sGC, independently of and synergistically with NO, vericiguat augments levels of intracellular cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation and vasodilation. 

Vericiguat (Verquvo)

Vericiguat stimulates sGC, the intracellular receptor for endogenous NO, which catalyzes cGMP production. It is indicated to reduce the risk of cardiovascular death and heart failure (HF) hospitalization in adults following a hospitalization for HF or a need for outpatient IV diuretics, who have symptomatic chronic HF and an ejection fraction < 45%.

Class Summary

In the presence of significant hypotension, adrenergic agonists are used to improve cardiac output and organ perfusion.

Epinephrine (Adrenaclick, Adrenalin, EpiPen, EpiPen Jr.)

Epinephrine is an alpha-agonist and its effects include increased peripheral vascular resistance, reversed peripheral vasodilatation, systemic hypotension, and vascular permeability. Beta2-agonist effects include bronchodilatation, chronotropic cardiac activity, and positive inotropic effects.

Norepinephrine (Levophed)

Norepinephrine is a naturally occurring catecholamine with potent alpha-receptor and mild beta-receptor activity. It stimulates beta1- and alpha-adrenergic receptors, resulting in increased cardiac muscle contractility, heart rate, and vasoconstriction. It increases blood pressure and afterload. Increased afterload may result in decreased cardiac output, increased myocardial oxygen demand, and cardiac ischemia. It is generally reserved for use in patients with severe hypotension (eg, systolic blood pressure < 70 mm Hg) or hypotension that is unresponsive to other medications.

Class Summary

Generally, calcium channel blockers (CCBs) should be avoided. CCBs do not play a direct role in the management of heart failure; however, these agents may be used to treat other conditions, such as hypertension or angina in heart failure patients.

CCBs may be used in heart failure with normal left ventricular ejection fraction. These drugs may also improve exercise tolerance via their vasodilatory properties.

Amlodipine (Norvasc)

Amlodipine has antianginal and antihypertensive effects. It blocks the post-excitation release of calcium ions into cardiac and vascular smooth muscle, thereby inhibiting the activation of ATPase on myofibril contraction. The overall effect is reduced intracellular calcium levels in cardiac and smooth muscle cells of the coronary and peripheral vasculature, resulting in dilatation of the coronary and peripheral arteries. It also increases myocardial oxygen delivery in patients with vasospastic angina.

Nifedipine (Adalat CC, Afeditab CR, Nifediac CC, Nifedical XL, Procardia, Procardia XL)

Nifedipine relaxes coronary smooth muscle and produces coronary vasodilation, which in turn, improves myocardial oxygen delivery. Sublingual administration is generally safe, despite theoretical concerns.

Felodipine (Cabren, Cardioplen XL, Felendil XL)

Felodipine is a dihydropyridine calcium channel blocker. It inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes. The resultant decrease in intracellular calcium inhibits the contractile processes of the smooth muscle cells, resulting in dilation of coronary and systemic arteries.

Class Summary

Patients with heart failure and depressed left ventricular (LV) ejection fraction are thought to have an increased risk of thrombus formation due to low cardiac output. Hospitalized patients with heart failure are at a high risk for venous thromboembolism and should receive prophylaxis. Anticoagulation with an international normalized ratio (INR) goal of 2-3 is indicated in the presence of: (1) an LV thrombus, (2) a thromboembolic event with or without evidence of an LV thrombus, and (3) paroxysmal or chronic atrial arrhythmias.

Warfarin (Coumadin, Jantoven)

Warfarin interferes with hepatic vitamin K–dependent carboxylation. It is used for the prophylaxis and treatment of thromboembolic disorders.

Dabigatran (Pradaxa)

Competitive, direct thrombin inhibitor. Thrombin enables fibrinogen conversion to fibrin during the coagulation cascade, thereby preventing thrombus development. Inhibits both free and clot-bound thrombin and thrombin-induced platelet aggregation.

Class Summary

Opioid analgesics such as morphine sulfate may help to relieve patients’ anxiety, distress, and dyspnea.

Morphine sulfate (Astramorph, Avinza, DepoDur, Duramorph, Infumorph 200, Infumorph 500, Kadian, MS Contin, Oramorph SR, Roxanol)

Morphine is the drug of choice for narcotic analgesia because of its reliable and predictable effects, safety profile, and ease of reversibility with naloxone. Morphine sulfate administered intravenously may be dosed in a number of ways and commonly is titrated until the desired effect is obtained. Morphine sulfate also decreases preload in heart failure and relieves dyspnea.