Non-bacterial thrombotic endocarditis and pancreatic cancer: A literature review.
Authors: Lee Amanda , Hussain Fahad , Huba Mahalia , Paracha Awais , Kwait Brittany , Siddiqui Zohair , Patel Humail , Papale Anthony , King Daniel 
Published: June 2024

e24002

Background: Non-bacterial thrombotic endocarditis (NBTE) is a condition in which sterile vegetations are deposited on the cardiac valves, disrupting their function, and posing a risk for embolic stroke. It is a rare condition with rates in autopsy studies ranging from 0.9-1.6%1, and with some of the highest rates observed in patients with pancreatic cancer (PC).2 A review of PC-associated NBTE was conducted to improve our understanding and recognition of this rare but serious clinical entity. Methods: We performed a literature search in PubMed from database inception to November 2023 pairing keywords “Non-Bacterial Thrombotic Endocarditis”, “NBTE”, “Marantic Endocarditis”, “Sterile Endocarditis”, and “Libman-Sacks Endocarditis” with “Pancreatic Cancer”, “Adenocarcinoma of the Pancreas”, and “Neuroendocrine Pancreatic Cancer”. We also used the search term “Marantic Endocarditis associated with Pancreatic Cancer: A case series”. The database was filtered only for full text, English language, and human species. Results: We reviewed 17 studies and included 19 patients in this review. Diagnostic presentation included cerebral vascular accident (CVA) (n = 8), endocarditis (n = 3), or a thrombotic pathology such as deep venous thrombosis (DVT) or pulmonary embolism (PE) (n =4). NBTE (n = 12) was predominantly diagnosed before pancreatic cancer (n = 5). Echocardiography was positive for vegetations in most specified cases (14/15), blood cultures were negative in all specified cases (12/12), and abdominal imaging was consistent with pancreatic cancer in all specified cases (15/15). Metastatic disease was found in 13 out of 19 cases, with spread to liver (n = 13), lung (n = 2), and the adrenal glands (n = 1). Valvular localization identified mitral valve (n = 13), aortic valve (n = 7), and the tricuspid valve (n = 2). Treatment primarily focused on anticoagulation (n = 17), with low molecular weight heparin (n = 8) being the most common agent followed by unfractionated heparin (n = 6). 14 patients had expired by study publication, with 7 deaths occurring due to complications from pancreatic cancer and 2 occurring due to complications from NBTE. Conclusions: NBTE is a rare condition with non-specific presentation, with some of the highest rates seen in PC. Diagnosis of NBTE should prompt immediate treatment as per guidelines and investigation for an underlying malignancy. In PC, especially with metastatic disease, clinicians should maintain a low threshold to initiate an endocarditis work-up in the presence of neurologic symptoms or evidence of cardiac dysfunction. However, it is also important to note that 31% of NBTE cases occurred in the absence of metastatic PC, suggesting that even patients without advanced disease are at risk. Although NBTE associated with PC remains rare, given the severity of both conditions, clinicians should consider work-up for one disease process in the presence of the other.