Mitral Stenosis Guidelines

The American College of Cardiology (ACC) and American Heart Association (AHA) released their updated recommendations on managing valvular heart disease in December 2020. ^{[24, 25]} Key messages are outlined below.

Valvular heart disease (VHD) stages (stages A-D) in patients should be classified based on symptoms, valve anatomy, severity of valve dysfunction, and response of the ventricle and pulmonary circulation.

When evaluating patients with VHD, findings from the history and physical examination (PE) should be correlated with those from noninvasive testing (ie, electrocardiography [ECG], chest x-ray, transthoracic echocardiography [TTE]). If conflict exists between results on the PE and that of initial noninvasive studies, consider obtaining further noninvasive (computed tomography [CT], cardiac magnetic resonance imaging [CMRI], stress testing) or invasive (transesophageal echocardiography [TEE], cardiac catherization) studies to decide the optimal treatment strategy.

In the setting of VHD and atrial fibrillation (AF) (except for patients with rheumatic mitral stenosis [MS] or a mechanical prosthesis), the decision to use oral anticoagulation with either a vitamin K antagonist (VKA) or a non-VKA anticoagulant to prevent thromboembolic events should be a shared decision-making process based on the CHA2DS2-VASc score (congestive heart failure [CHF], hypertension, age ≥75 years, diabetes mellitus, previous stroke/transient ischemic attack/thromboembolic event, vascular disease, age 65-74 years, sex). Oral anticoagulation with a VKA should be given to those with rheumatic MS or a mechanical prosthesis and AF.

All those with severe VHD under consideration for valve intervention should be evaluated by a multidisciplinary team, either with a referral or in consultation with a primary or comprehensive valve center.

Bioprosthetic valve dysfunction may occur because of either degeneration of the valve leaflets or valve thrombosis. Catheter-based treatment for prosthetic valve dysfunction is reasonable in selected patients for bioprosthetic leaflet degeneration or paravalvular leak in the absence of active infection.

Go to 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy: Developed by the Task Force on cardiac pacing and cardiac resynchronization therapy of the European Society of Cardiology (ESC) With the special contribution of the European Heart Rhythm Association (EHRA) for full details.

For more information, please go to Aortic Stenosis, Aortic Regurgitation, Mitral Regurgitation, and Tricuspid Regurgitation.

For more Clinical Practice Guidelines, please go to Guidelines.

Guidelines for the management of patients with valvular heart disease (VHD) were published in August 2021 by the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS), ^[26] including the following recommendation on mitral valve disease:

Intervention is recommended for symptomatic patients with severe, high-gradient aortic stenosis or with severe low-flow, low-gradient aortic stenosis with LVEF < 50% and evidence of flow reserve, as well as for asymptomatic patients with severe stenosis who have systolic LV dysfunction (LVEF < 50%) without another cause or who have symptoms on exercise testing.

In 2014, the American Heart Association/American College of Cardiology(AHA/ACC) released a revision to its 2008 guidelines for management of patients with valvular heart disease (VHD). ^[12] They published a focused update to these guidelines in 2017. ^[27] Similarly, in 2017, the European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) issued a revision of its 2012 guidelines, which were an update of their 2007 guidelines. ^{[5, 28]}

The 2014 AHA/ACC guidelines classify progression of mitral stenosis (MS) into 4 stages (A to D) as follows ^[12] :

• Stage A: At risk of MS
• Stage B: Asymptomatic with progressive MS (mild to moderate)
• Stage C: Asymptomatic with severe MS
• Stage D: Symptomatic with severe MS

The AHA/ACC and ESC/EACTS guidelines require intervention decisions for severe VHD to be based on an individual risk-benefit analysis. ^{[5, 12, 27, 28]} Improved prognosis should outweigh the risk of intervention and potential late consequences, particularly complications related to prosthetic valves. ^{[5, 27, 28]}

Recognizing the known limitations of the EuroSCORE (European System for Cardiac Operative Risk Evaluation) and the STS (Society of Thoracic Surgeons) score, the AHA/ACC guidelines suggest using STS plus three additional indicators: frailty (using accepted indices), major organ system compromise not to be improved postoperatively, and procedure-specific impediment when assessing risk. ^[12]

Diagnosis

The 2014 AHA/ACC guidelines include the following class I recommendations for diagnostic testing and the initial diagnosis of MS ^[12] :

• Transthoracic echocardiography (TTE) for the initial evaluation of patients with signs or symptoms of MS to establish the diagnosis, determine the hemodynamic severity (mean pressure gradient, mitral valve area, pulmonary artery pressure), assess concomitant valvular lesions, and demonstrate valve morphology (to determine suitability for mitral commissurotomy). (Level of evidence: B)
• TEE in patients under consideration for percutaneous mitral balloon commissurotomy (PMBC) to assess the presence or absence of left atrial (LA) thrombus and to further evaluate the severity of mitral regurgitation (MR). (Level of evidence: B)
• Exercise testing with Doppler or invasive hemodynamic assessment to evaluate the response of the mean mitral gradient and pulmonary artery pressure when there is a discrepancy between resting Doppler echocardiographic findings and clinical symptoms or signs. (Level of Evidence: C)

The ESC/EACTS guidelines recommend transesophageal echocardiography (TEE) be considered to exclude LA thrombus before percutaneous mitral commissurotomy or after an embolic episode when TTE is of suboptimal quality. ^[28] Intervention is indicated in symptomatic patients with severe valve disease and/or ventricular dysfunction unless patient is unsuitable for surgery. ^{[5, 28]} These guidelines also indicate stress testing in asymptomatic patients or symptoms that are equivocal or discordant with the severity of their MS. ^{[5, 28]}

Medical management

The 2014 AHA/ACC guidelines class I recommendations indicate anticoagulation (a vitamin K antagonist, as opposed to direct oral anticoagulants ^[27] ) in patients with MS and the following conditions (level of evidence: B) ^[12] :

• Atrial fibrillation (AF) (paroxysmal, persistent, or permanent)
• A prior embolic event
• An LA thrombus

Heart rate control may provide benefit in individuals with MS and AF and fast ventricular response (class IIa; level of evidence: C); it may also be considered in those with MS and normal sinus rhythm with exercise-associated symptoms (class IIb; level of evidence: B). ^[12]

The 2012 and 2017 ESC/EACTS guidelines recommend anticoagulation in patients with MS and permanent or paroxysmal AF, using a target international normalize ratio in the upper half of the range 2-3. ^{[5, 28]}  As with the AHA/ACC guidelines, a vitamin K antagonist is recommended rather than other anticoagulants. For those with MS and sinus rhythm, anticoagulation is indicated in those with a previous embolism or in the presence of an LA thrombus (class I; level of evidence C), as well as in those whose TEE reveal dense spontaneous echo contrast or an enlarged LA (class IIa; level of evidence C). The guidelines do not consider aspirin and other antiplatelet agents as valid alternatives. ^{[5, 28]}

Interventions

The 2014 AHA/ACC, 2012 ESC/EACTS, and 2017 ESC/EACTS guidelines recommend PMBC for all patients with Stage D disease (symptomatic with severe MS; mitral valve area ≤1.5 cm²), no contraindications, and favorable valve morphology (class I; level of evidence A). ^{[5, 12, 28]} Surgical intervention is recommended in patients with severe MS (Stage D) and New York Heart Association (NYHA) class III-IV symptoms who are not at high risk for surgery and who are not candidates for or have had failure of a previous PMBC (class I; level of evidence B). ^{[12, 28]}

Contraindications to PMBC include a mitral valve area over 1.5 cm², presence of an LA thrombus, more than mild MR, severe or bicommissural calcification, absence of commissural fusion, severe concomitant aortic valve disease or severe combined tricuspid stenosis and regurgitation, and concomitant coronary artery disease requiring bypass surgery. ^{[5, 28]}

A comparison of the additional recommendations for surgical intervention and PMBC for mitral stenosis is provided in Table 4 below.

Table 4. Recommendations for Mitral Stenosis (MS) Intervention (Open Table in a new window)

Infective Endocarditis

Both the AHA and ESC released updated guidelines for the management of infective endocarditis (IE) in 2015, ^{[29, 30]} and these were reaffirmed in their 2017 guidelines. Major recommendations for the management of IE are summarized below ^[29] :

Class I recommendations

• The Modified Duke Criteria should be used in evaluating a patient with suspected IE. ^[12] (Level of evidence: B)
• At least 3 sets of blood cultures from different venipuncture sites should be obtained, with the first and last samples drawn at least 1 hour apart. (Level of evidence: A)
• Appropriate antibiotic therapy should be initiated and continued after blood cultures are obtained with guidance from antibiotic sensitivity data and infectious disease consultants.(Level of evidence: B)
• TTE should be performed in all cases of suspected IE. (Level of evidence: B)
• TEE should be performed if the initial TTE images are negative or inadequate in patients for whom there is an ongoing suspicion for IE or when there is concern for intracardiac complications in patients with an initial positive TTE. (Level of evidence: B)
• If there is a high suspicion of IE despite an initial negative TEE, then a repeat TEE in 3 to 5 days or sooner if clinical findings change. (Level of evidence: B)
• Repeat TEE should be performed after an initially positive TEE if clinical features suggest a new development of intracardiac complications. (Level of evidence: B)
• Patients with IE should first be evaluated and stabilized in the hospital before being considered for outpatient therapy, and they should be at low risk for IE complications (eg, heart failure, systemic emboli). (Level of evidence for both: C)

Surgery should be performed before completion of a full therapeutic course of antibiotics in patients with the following (all level of evidence: B) ^[29] :

• IE and valve dehiscence, intracardiac fistula, or severe prosthetic dysfunction resulting in symptoms of heart failure
• IE caused by fungi or highly resistant organisms (eg, vancomycin-resistant Enterococcus, multidrug-resistant gram-negative bacilli)
• IE complicated by heart block, annular or aortic abscess, or destructive penetrating lesions
• Persistent bacteremia lasting longer than 5 to 7 days after administration of appropriate antimicrobial therapy and exclusion of other potential sites of infection

Months to years after completion of medical therapy for IE, patients should have ongoing observation for and education about recurrent infection and delayed onset of worsening valve dysfunction (level of evidence: C). ^[29]

Class III recommendations

Patients should not receive antibiotics before blood cultures are obtained for unexplained fever (level of evidence: C). ^[29]

Antimicrobial therapy should not be initiated for the treatment of undefined febrile illnesses unless the patient’s condition (eg, sepsis) warrants it (level of evidence: C). ^[29]

Prophylaxis against infective endocarditis (IE)

American Heart Association (AHA) guidelines do not recommend infective endocarditis prophylaxis for most patients with rheumatic heart disease. ^{[12, 29]} However, the maintenance of optimal oral health care remains an important component of an overall healthcare program. For the relatively few patients with rheumatic heart disease in whom infective endocarditis prophylaxis remains recommended (eg, those with prosthetic valves or prosthetic material used in valve repair, previous infective endocarditis, unrepaired cyanotic or repaired congenital heart disease, or cardiac transplant recipients with valve regurgitation from a structurally abnormal valve), the current AHA recommendations should be followed before dental procedures that involve manipulation of gingival tissue, manipulation of the periapical region of teeth, or perforation of the oral mucosa (class IIa; level of evidence: C-LD ^[27] ). ^{[12, 29]}

These recommendations advise the use of an agent other than a penicillin to prevent infective endocarditis in those receiving penicillin prophylaxis for rheumatic fever because oral alpha-hemolytic streptococci are likely to have developed resistance to penicillin. ^[29]

The indication for antibiotic prophylaxis for endocarditis was significantly reduced in the 2012 ESC/EACTS guidelines, although they recommended considering antibiotic prophylaxis for high-risk procedures in high-risk patients and were otherwise in agreement with the AHA guidelines. ^[28] These were reaffirmed in the 2017 updated ESC/EACTS guidelines. ^[5]