eMedicine Specialties > Cardiology > Valvular Heart Disease

Libman-Sacks Endocarditis

Author: Xiushui (Mike) Ren, MD, Clinical Cardiology Fellow, Division of Cardiology, Kanbar Cardiac Center, California Pacific Medical Center
Coauthor(s): Elyse Foster, MD, Director of Adult Echocardiography Laboratory, Assistant Professor, Department of Internal Medicine, Division of Cardiology, Moffitt Hospital, University of California at San Francisco; Elizabeth W Ryan, MBBS, Consulting Staff, Department of Medicine, Division of Cardiology, Austin and Repatriation General Centre, Australia
Contributor Information and Disclosures

Updated: Sep 16, 2008

Introduction

Background

Libman-Sacks (verrucous) endocarditis is the most characteristic cardiac manifestation of the autoimmune disease systemic lupus erythematosus (see Systemic Lupus Erythematosus for more information). Libman and Sacks first published a description of these atypical, sterile, verrucous vegetations in 1924.¹

Postmortem studies describe mulberrylike clusters of verrucae on the ventricular surface of the posterior mitral leaflet, often with adherence of the mitral leaflet and chordae to the mural endocardium. The lesions typically consist of accumulations of immune complexes and mononuclear cells. The condition is not always recognized on echocardiographic images. With the introduction of steroid therapy for systemic lupus erythematosus, improved longevity of patients appears to have changed the spectrum of valvular disease.

Valvular abnormalities occur as masses (classic Libman-Sacks vegetations; see Media file 1), diffuse leaflet thickening, valvular regurgitation, and, infrequently, stenosis. Valvular regurgitation is noted most commonly in patients with leaflet thickening, which is thought to represent the chronic healed phase of disease. The left-sided valves are involved most often.

Lesions similar to those described by Libman and Sacks also occur in association with primary or secondary antiphospholipid syndrome. The role of these autoantibodies in the pathogenesis of Libman-Sacks endocarditis is disputed.

Lesions are usually clinically silent. Heart failure, valvular dysfunction, valve replacement, embolic phenomena, and secondary infective endocarditis can complicate valvular abnormalities.

Pathophysiology

Libman-Sacks endocarditis most commonly involves mitral and aortic valves. However, all 4 cardiac valves and the endocardial surfaces can be involved.

Valvular abnormalities are often clinically silent, without significant valvular dysfunction. Valvular regurgitation is more common than stenosis, which is rare. Valvular dysfunction can result in cardiac failure. Embolic phenomena and secondary infective endocarditis are uncommon but can result in neurological and systemic complications.

Frequency

International

Valvular abnormalities are commonly detected in patients with lupus. The characteristic Libman-Sacks vegetations are reported postmortem in approximately 50% of fatal lupus cases. Current echocardiographic studies reveal valvular abnormalities in 28-74% of patients, with valve masses in 4-43% of patients with systemic lupus erythematosus. Higher rates are generally detected with transesophageal imaging and in subjects with antiphospholipid antibodies (41% with masses), although this observation is not universal.

One cohort study found that Libman-Sacks endocarditis was found in 11% of patients with lupus.² Pure mitral regurgitation was the most common valvular abnormality, followed by aortic regurgitation, combined mitral stenosis and regurgitation, and combined aortic stenosis and regurgitation. At baseline, Libman-Sacks endocarditis was significantly associated with underlying lupus disease activity. During the follow-up echocardiograph, patients with previous valvular lesions had worsened valve function, and more patients developed new valve lesions.

Patients with valve masses often have coexistent leaflet thickening, which is noted in 71% of patients with valve masses. Echocardiography detects valvular thickening in 19-52% of patients with systemic lupus erythematosus.

In older patients with a longer mean duration of systemic lupus erythematosus and a larger cumulative dose of steroids, valves that appear to be thickened and rigid occur more commonly than verrucous vegetations. The prevalence of regurgitation in patients with thickened valve leaflets has been reported to be as high as 73%.

The prevalence of valvular abnormalities detected during echocardiography in patients with primary antiphospholipid syndrome has been reported at 30-32%. Abnormal echocardiographic findings are most common in those with peripheral arterial thromboses, noted in up to 64% of patients. Leaflet thickening is the most frequent abnormality, noted in 10-24% of patients. Vegetationlike masses occur in 6-10% of patients.

Mortality/Morbidity

• Mortality is undefined. Patients with systemic lupus erythematosus have an increased mortality rate compared with the general population. Cardiovascular mortality is ranked third in these patients but includes a wide spectrum of pathology.
• The combined rate of heart failure, valvular replacement, thromboembolism, and secondary infective endocarditis has been reported to be as high as 22% in lupus patients with valvular disease, compared with 8% of patients without valvular disease. Most patients do not have clinically significant valvular dysfunction. Regurgitation is noted on echocardiography images in 25-61% of lupus patients and in 10-24% of patients with primary antiphospholipid syndrome. The prevalence of moderate or severe regurgitation has been reported in 0-12% (severe in 3%, moderate in 9%) of patients with antiphospholipid syndrome and 4-26% of lupus patients. The reported need for valve replacement varies from 1-8% of cases.
  
  The occurrence of clinically significant embolic phenomena is thought to be low. Although stroke rates are higher in patients with lupus and antiphospholipid syndrome, multifactorial etiologies for neurological events are often present, making the specific contribution of valvular abnormalities difficult to determine. The likely prevalence of secondary infective endocarditis is low, but it has not been widely reported. Potential contributing factors to infective endocarditis are systemic lupus erythematosus, medications prescribed for lupus, and underlying valvular abnormalities.

Race

US statistics show systemic lupus erythematosus to be more prevalent in black and Hispanic women.

Sex

Systemic lupus erythematosus and primary antiphospholipid syndrome occur 5-9 times more often in women; therefore, patients with cardiac valvular lesions are generally young women.

Clinical

History

• Persons with Libman-Sacks endocarditis are usually asymptomatic.
• Cardiac failure might develop secondary to valvular dysfunction (most commonly mitral regurgitation), leading to dyspnea, orthopnea, paroxysmal nocturnal dyspnea, peripheral edema, and lethargy.
• Cerebrovascular embolism might occur, leading to symptoms of cerebral ischemia, including focal weakness and/or numbness, visual loss, dysphasia, dysarthria, dysphagia, and memory loss.
• Rarely, systemic thromboembolism can result in a wide spectrum of symptoms, including pain, coldness and numbness of the peripheries, or acute abdominal syndromes with pain and vomiting.
• Secondary infective endocarditis might manifest as fever, weight loss, night sweats, lethargy, and chest pain. These symptoms can be difficult to distinguish from underlying systemic lupus erythematosus disease activity.
• Symptoms of systemic lupus erythematosus might be noted, including a history of rash, arthritis (joint pain and swelling), and sweating.
• Features of antiphospholipid syndrome might be noted in the history, including recurrent miscarriage, arterial thromboses, venous thromboses, and/or thrombocytopenia.
  • Patients may report pain, numbness and discoloration of the extremities, focal neurological symptoms (eg, focal weakness and/or numbness, visual loss, dysphasia, dysarthria, dysphagia, memory loss), and ischemic chest pain with arterial thromboses.
  • Venous thromboembolism might result in peripheral swelling, pleuritic chest pain, dyspnea, and hemoptysis. Neurological symptoms due to cerebral ischemia can also occur in the event of a paradoxical embolus.

Physical

• Physical examination findings can be normal.
• The following cardiac murmurs might be heard:
  • Ejection systolic murmur (crescendo decrescendo): This is most commonly the result of a hyperdynamic state due to associated conditions and can indicate aortic valve thickening with or without stenosis.
  • Holosystolic murmur of mitral regurgitation or tricuspid regurgitation
  • Early diastolic murmur of aortic regurgitation, with or without an Austin-Flint murmur
  • Middiastolic, rumbling murmur of mitral stenosis
• Other valvular dysfunction (eg, pulmonary stenosis or regurgitation, tricuspid stenosis) might occur, but only rarely is this due to Libman-Sacks endocarditis.
• The following signs of ventricular enlargement and cardiac failure might be noted:
  • Tachypnea and cyanosis
  • Pulse (plateau pulse, low-volume pulse, pulsus alternans)
  • Jugular venous distension
  • Displaced apex beat
  • Third and/or fourth heart sounds
  • Pulmonary rales
  • Congestive hepatomegaly
  • Sacral and peripheral edema
• A focal neurological deficit secondary to embolic phenomena or thrombosis with or without the antiphospholipid syndrome might be noted.
• Signs due to underlying systemic lupus erythematosus might be present, including rash and joint swelling.

Causes

• The pathogenesis is unknown.
• Antiphospholipid antibodies are frequently associated with valvular abnormalities.
  • These autoimmune antibodies are directed against negatively charged phospholipids present in endothelial cell membranes.
  • Immunohistological studies suggest a pathogenetic role of these autoimmune antibodies. However, a similar prevalence and severity of valvular disease has been described in lupus patients without these antibodies; their presence does not seem to be required.
• Impaired antithrombotic mechanisms present in patients with antiphospholipid syndrome also might be implicated in the pathogenesis of thrombosis and valvular lesions. Areas of endothelial damage caused by turbulence and the jet effect on the left side of the heart are potential sites of platelet and fibrin deposition.
• Steroid therapy is implicated in the modification of the nature of valvular abnormalities and in the dysfunction observed in patients with systemic lupus erythematosus.
  • With the introduction of steroid therapy, valvular thickening and regurgitation appear to occur more commonly, with histologically active lesions identified less frequently.
  • Data are circumstantial and might reflect improved longevity of patients. Firm conclusions cannot be made.

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