Numerous Small Vegetations Revealing Libman-Sacks Endocarditis in Catastrophic Antiphospholipid Syndrome
A 48-year-old man was referred to our cardiology department for the treatment of acute myocardial infarction. He had no risk factors for arteriosclerosis. Two months before this admission, he had been admitted to another hospital because of stroke with right hemiparesis; 1 month before this admission, he developed acute renal failure and hemodialysis was started. Chest radiograph demonstrated cardiomegaly and pulmonary congestion (Figure 1A). The ECG demonstrated a QS pattern in the V1 through V3 leads with ST elevation and coronary T waves in the V4 through V6 leads and left atrial overload in the V1 lead (Figure 1B). Transthoracic echocardiography (TTE) showed diffuse left ventricular hypokinesis with severe hypokinesis of the septum and anterior wall (Figure 2). Emergency coronary angiogram revealed normal epicardial coronary arteries (Figure 3). The increase in creatine kinase, diffuse left ventricular hypokinesis by TTE, and normal coronary angiogram indicated acute myocardial infarction at the level of small coronary arteries.
TTE showed severe mitral regurgitation and numerous small vegetations on the atrial surface of the mitral valve (Figure 4). TTE also showed moderate aortic regurgitation and clusters of small vegetations on the ventricular surface of the aortic valve (Figure 5). Vegetations were apposing on both the anterior and posterior leaflets of the mitral valve and on all 3 leaflets of the aortic valve at the valve closure contact line away from the leaflet tips. The day after coronary angiography, severe thrombocytopenia occurred. The titer of anticardiolipin antibody was highly increased. Catastrophic antiphospholipid syndrome was diagnosed. The anticoagulation, pulse therapy of methylpredonisolone, and cyclophosphamide were done, and therapeutic plasma exchanges were repeatedly performed. The patient, however, died of multiorgan failure that included encephalopathy.
Autopsy confirmed the TTE findings of the mitral and aortic valves (Figure 6). Numerous thrombi were present in the intramyocardial small vessels associated with multiple small foci of necrosis (Figure 7). Similar lesions were seen in the small vessels of the kidneys and brain (Figure 8). No evidence was found of vasculitis. These findings suggested that multiorgan failure was caused by systemic thrombosis in the small vessels but not by vasculitis.
Only 6% of reported cases with catastrophic antiphospholipid syndrome had vegetations revealing Libman-Sacks endocarditis. However, these suggest possible microthrombotic occlusive disease in the setting of catastrophic antiphospholipid syndrome.1,2