Cancer-Associated Marantic Endocarditis and Direct Oral Anticoagulants: Case Report and Systematic Review

Nonbacterial thrombotic endocarditis (NBTE) involves sterile vegetations on heart valves due to systemic hypercoagulability, often linked to malignancies. It is frequently underdiagnosed and presents significant clinical management challenges, often manifesting as thromboembolic events like ischemic stroke. We aim to report the first case of cancerassociated NBTE that showed a positive response to rivaroxaban as a maintenance anticoagulant, with 3D echocardiographic evidence of vegetation reduction, and to evaluate the performance of direct oral anticoagulants (DOACs) in treating cancer-associated NBTE through a systematic review of case reports. A case study and a systematic review of case reports on the use of DOACs in the setting of cancer-associated non-valvular atrial fibrillation (NVAF) were presented. Electronic databases were searched, and relevant studies were selected based on predefined eligibility criteria. Data were extracted and analyzed qualitatively, focusing on demographics, clinical presentation, anticoagulation and anticancer therapies, and outcomes (surgery, NBTE resolution, thromboembolic events, and mortality). In addition to our case, thirty-three studies were included in the systematic review. Most patients were already on DOAC therapy before the NBTE diagnosis. Lung and pancreatic cancers were the most common primary neoplasms. The aortic and mitral valves were most frequently affected. Anticoagulation therapy often shifted from DOACs to heparin upon NBTE diagnosis, with low-molecular-weight heparin showing better outcomes in vegetation resolution and thromboembolic event prevention. This study reinforces the suggestion that heparins are more appropriate for treating cancer-associated NBTE. However, satisfactory DOAC outcomes warrant further research. Effective NBTE management with DOACs appears to be strongly associated with the successful control of the underlying neoplasm.