A Contemporary 20-Year Cleveland Clinic Experience of Nonbacterial Thrombotic Endocarditis: Etiology, Echocardiographic Imaging, Management, and Outcomes.

Background: Nonbacterial thrombotic endocarditis, or marantic endocarditis, is rare. Contemporary data on the etiology, echocardiographic evaluation, and management of nonbacterial thrombotic endocarditis are limited.

Methods: A single-center retrospective cohort study was performed. Electronic medical records and echocardiographic records were searched for patients ages ≥18 years with a confirmed diagnosis of nonbacterial thrombotic endocarditis between January 1999 and November 2019. Demographic, echocardiographic, and management data were collected.

Results: Of 600,577 transthoracic echocardiograms (TTEs) and 89,264 transesophageal echocardiograms (TEEs), 42 patients had nonbacterial thrombotic endocarditis (mean age: 54 ± 14.5 years; 66.7% were female). The median duration of follow-up was 8.2 (interquartile range 3.3-24.4) months. Seventeen patients (40.5%) had malignancy, 33.3% had systemic lupus erythematosus, and 35.7% had antiphospholipid antibody syndrome. Stroke was the most common presentation (59.5%). TTE enabled the diagnosis in 19 cases (45.2%), compared with TEE, which identified the condition in 33 of 34 (97.1%) cases in which it was utilized. Three-dimensional echocardiography was performed in 17 TEEs. The most common valves involved were mitral (61.9%), and aortic (23.8%) valves. Thirty-two patients were managed with anticoagulation. Ten patients underwent surgery. Sixteen (38.1%) patients died, most of whom had a diagnosis of advanced malignancy.

Conclusion: In a contemporary 20-year cohort, TTE and TEE played important roles in diagnosis, with superior diagnostic performance of TEE for nonbacterial thrombotic endocarditis. Mortality was high, and advanced malignancy portended a worse prognosis. Management in most cases was therapeutic anticoagulation. In select cases, surgery provided favorable outcomes.