Nonbacterial thrombotic endocarditis in multiple heart valves.

Abstract

A 64-year-old female with lung cancer stage IV presented to the emergency department with progressive dyspnea and spontaneous bruising. She has already received chemotherapy and target therapy around 1 year and suffered from pulmonary embolism 1 month ago. Chest X-ray showed persistent lung cancer with fibrosis and atelectasis. Due to progressive dyspnea with heart murmur, echocardiography was arranged and results showed aortic, mitral, tricuspid valve, and pulmonary valve with significant vegetation (Figure 1A-C, video 1-3 in online supporting information). Severe tricuspid regurgitation, aortic regurgitation, and moderate mitral regurgitation were also noted (Figure 1D,E, video 4 in online supporting information). However, several sets of blood cultures revealed negative finding. Laboratory data showed low C-reactive protein, high BNP, severe thrombocytopenia, and disseminated intravascular coagulation (DIC). Therefore, nonbacterial thrombotic endocarditis (NBTE) was diagnosed. During hospitalization, chemotherapy was performed and frequent blood transfusions were given for severe coagulopathy, but this patient finally died due to progressive heart failure. NBTE is a disease characterized by the presence of vegetations on cardiac valves, which consist of fibrin and platelet aggregates and are devoid of inflammation or bacteria. It is a rare condition most often found postmortem with rates in autopsy series ranging from 0.9% to 1.6%.1 It has been reported in patients with advanced stage malignancy, connective tissue disease, autoimmune disease, hypercoagulable states, and so on.2 The demonstration of valvular vegetations on echocardiography in the absence of systemic infection in patients who are at high risk of NBTE provides strong evidence for diagnosis. NBTE vegetations are typically small (diameter < 1 cm), broad based and irregular in shape. Left side heart valves were more commonly involved than right side. However, involvement of multiple heart valves was rarely reported.3 Currently, only five cases of NBTE have been reported in the literature.1, 3 Three of them were diagnosed by autopsy and the others were diagnosed by transesophageal echocardiography.1, 3 Our case was unique due to large vegetations and involvement of four valves. In addition, the case was the first case reported to be diagnosed by transthoracic echocardiography. Treatment of NBTE usually consists of systemic anticoagulation and treating the underlying disease. The prognosis was extremely poor in the literature especially for the cases of advanced malignancy with DIC, which condition is also similar to our case. All authors declare no conflict of interest. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.