A 45-year-old woman complaining of consciousness disturbance demonstrated multiple brain infarctions. Echocardiogram showed vegetation on the posterior mitral leaflet. Infectious endocarditis was initially suspected and we started empirical antibiotics. However, mitral vegetation grew rapidly and caused severe mitral regurgitation. Acute heart failure was so poorly controlled by conservative treatment that we concluded cardiac surgery was indicated. Mitral valve replacement was safely performed, and there was no sign of heart failure or recurrent thromboembolism during the postoperative course. Thereafter, multiple hepatic masses and a solid lesion in the pancreatic head were detected by computed tomography. The patient finally died of multiple organ failure that presumably resulted from malignancy in the terminal stage. The clinical course of this case can be explained by the pathology of nonbacterial thrombotic endocarditis (NBTE). The standard treatment for NBTE consists of systemic anticoagulation as well as controlling the underlying malignancy. However, we could not diagnose this case as NBTE before surgery. Although mitral valve replacement was finally effective to control acute heart failure in this case, NBTE should be exactly diagnosed as quickly as possible and the treatment policy should be deliberated.
Keywords: Heart failure; Mitral valve; Nonbacterial thrombotic endocarditis; Surgery; Vegetation.