Culture-negative bivalvular endocarditis with myocardial destruction in a patient with systemic lupus erythematosus: a case report

Culture-negative endocarditis (CNE) is known by many names including marantic endocarditis (ME), non-bacterial thrombotic endocarditis, verrucous endocarditis, and Libman-Sacks vegetations in collagen vascular diseases, specifically, systemic lupus erythematosus (SLE). First described by Zeigler [1] in 1888 and derived from the Greek marantikos, meaning "wasting away", ME typically involves a single valve with rare involvement of two or more valves [2]. Structural valve disease is common in the SLE population and the valve abnormality usually consists of leaflet thickening with small vegetations often discovered at autopsy [2,3]. The pathophysiology of vegetation formation is not entirely understood, but involves platelet deposition on a damaged endothelial surface, possibly from up-regulated cytokines and immune complex damage, with an absence of inflammatory cells [3,4]. Though typically asymptomatic, there is an excess incidence of stroke, embolism, and heart failure. Valvular lesions appear to be unrelated to duration or activity of illness and may occur at any time [2]. There are few cases of multi-valvular involvement with ME and even fewer cases that involve direct myocardial damage. We present the case of a woman with SLE admitted for an elective mitral valve repair who was found to have mitral and aortic valve culture-negative vegetations with atrial destruction. A thorough workup for a possible microbial etiology utilizing current advanced techniques was negative.A 42 year old woman with SLE for the past 12 years and end stage renal disease requiring peritoneal dialysis was admitted to the hospital for congestive heart failure. Her SLE was controlled on hydroxychloroquine and prednisone 10 mg daily for the past 5 years. Prior to admission, she had a long-standing IV/VI systolic murmur, and a transthoracic echocardiogram revealed severe mitral regurgitation with a left ventricular ejection fraction of 35%. A subsequent transesophageal echocardiogram showed