Libman-Sacks Endocarditis Workup

Updated: Dec 14, 2020
  • Author: Mary C Rodriguez Ziccardi, MD; Chief Editor: Richard A Lange, MD, MBA  more...
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Workup

Laboratory Studies

Laboratory testing for Libman-Sacks endocarditis should include the following:

  • Blood cultures: Infective endocarditis should be excluded
  • Complete blood cell (CBC) count: Neutrophilia may indicate infection; coexistent anemia may be present
  • Antiphospholipid antibody(ies): These include anticardiolipin antibody, lupus anticoagulant, Venereal Disease Research Laboratory (VDRL), and Russell viper venom test
  • Coagulation profile: Include the prothrombin time and activated partial thromboplastin time
  • Antinuclear antibody(ies): Test with or without antiextractable nuclear antigens or anti–beta2 glycoprotein
  • Anti-deoxyribonucleic acid (DNA) antibody assay (double-stranded): A workup for systemic lupus erythematosus may be indicated
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Echocardiography

Whether transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) should be used depends on the clinical scenario.

TTE is valuable for the initial evaluation of cardiac murmurs and for quantification of left atrial volume and left ventricular volume, mass, and contractile function; thus, TTE is used for the initial visualization and assessment of the valve morphology and function. The most important finding is valvular disease characterized by valvular thickening and valvular vegetations. If TTE is not diagnostic but the clinician has a high index of suspicion, TEE is more sensitive, has superior resolution of the cardiac valves, and is useful in the detection of valvular lesions (especially in the left-sided valves) than TTE.

One study compared TTE with TEE for the diagnosis of Libman-Sacks endocarditis. [12] Using TEE as the standard, TTE demonstrated low sensitivity (63% overall, 11% for valve vegetations), low specificity (58%), low negative predictive value (40%), and moderate positive predictive value (78%) for detection of Libman-Sacks endocarditis. Thus, TEE should be performed when the TTE is nondiagnostic or when the pretest probability is high.

The use of three-dimensional (3D) echocardiography in Libman-Sacks endocarditis has been described. [13] In a study of systemic lupus erythematosus (SLE) patients who underwent 40 paired 3D and 2D TEE studies, investigators found evidence for the added value of 3D TEE in the workup for Libman-Sacks endocarditis. [14] Specifically, they found that 3D TEE yields clinically relevant information that complements 2D TEE for the detection, characterization, and association with cerebrovascular disease of Libman-Sacks endocarditis. [14]

Results of echocardiography

Irregular borders, heterogeneous echodensity, and an absence of independent motion characterize the masses (ie, verrucous vegetations) on the cardiac valves and endocardium. The masses are usually small and sessile, but they can be as large as 10mm. The basal portion and midportion of the mitral and aortic valves are involved most commonly, but the tips of the leaflets can also be affected. [6]

Diffuse leaflet thickening of the mitral and aortic valves or focal leaflet thickening of the midbasal leaflet can be observed.

Acoustic shadowing suggesting calcification is possible but uncommon. Valvular regurgitation can be seen. Valvular stenosis may be present but is rare. Left ventricular enlargement and/or dysfunction can be observed.

Coexistent cardiac complications of systemic lupus erythematosus may include pericardial effusion or thickening, left ventricular hypertrophy (due to hypertension), left ventricular dilatation, left ventricular segmental dysfunction, left ventricular global dysfunction, or elevated pulmonary artery pressure.

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Other Imaging Studies

Chest radiography

Cardiomegaly and pulmonary congestion may be noted on chest radiography. The presence of calcified masses and valvular tissue is possible but rare.

Angiography

Coronary angiography can be performed if cardiac ischemia is suggested and if valve replacement surgery is indicated, because systemic lupus erythematosus is associated with premature atherosclerotic coronary artery disease and coronary vasculitis.

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Cardiac Catheterization

Perform coronary angiography if cardiac ischemia is suggested and if valve replacement surgery is indicated, because systemic lupus erythematosus is associated with premature atherosclerotic coronary artery disease and coronary vasculitis. However, if large aortic lesions are present, noninvasive coronary artery evaluation (such as computed tomography [CT] angiography) may be indicated because catheterization may cause embolization.

Left-sided pressure tracings, ventriculography, and aortography might yield additional information regarding valvular dysfunction and left ventricular function.

Right-sided heart catheterization is useful for determining pulmonary artery pressure and pulmonary vascular resistance because cardiac and pulmonary pathology can occur with lupus. Use caution because the severity of valvular dysfunction in the presence of pulmonary disease may be overestimated.

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Histologic Findings

The different stages of Libman-Sacks endocarditis have been described as active, active and healed, and healed lesions. These can be characterized as follows:

  • Active verrucae - Consist of clumps of fibrin on and within the valvular leaflet tissue, which is focally necrotic, with plasma cells and lymphocytes

  • Combined active and healed lesions - Contain vascularized, fibrous tissue adjacent to fibrinous and necrotic areas

  • Healed lesions - Consist of dense, vascularized, fibrous tissue

Histologic examinations of patients with lupus who undergo valve replacement often show the latter 2 stages, with the excised, dysfunctional leaflet tissue being fibrotic, retracted, and partially calcified with fibrinous deposits. Overlying thrombi have also been reported on valves examined at operation. Hematoxylin bodies can also be present.

Immunoglobulin and complement deposits have been identified subendothelially and in the core of vegetations.

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