Non-bacterial thrombotic endocarditis: a clinical and pathophysiological reappraisal

Abstract

Non-bacterial thrombotic endocarditis (NBTE), formerly recognized as marantic endocarditis, represents a rare cardiovascular pathology intricately linked with hypercoagulable states, notably malignancy and autoimmune disorders. Characterized by the development of sterile vegetations comprised of fibrin and platelets on cardiac valves, NBTE poses a diagnostic challenge due to its resemblance to infective endocarditis. Therapeutic endeavours primarily revolve around addressing the underlying aetiology and instituting anticoagulant regimens to forestall embolic events, with surgical intervention seldom warranted. Non-bacterial thrombotic endocarditis frequently coexists with malignancies and autoimmune conditions, such as lupus and antiphospholipid antibody syndrome, and, more recently, has been associated with COVID-19. Its pathogenesis is underpinned by a complex interplay of endothelial dysfunction, hypercoagulability, hypoxia, and immune complex deposition. Clinical manifestations typically manifest as embolic phenomena, particularly cerebrovascular accidents, bearing substantial mortality rates. Diagnosis necessitates a high index of suspicion and meticulous exclusion of infective endocarditis, often facilitated by advanced cardiac imaging modalities. Anticoagulation, typically employing low molecular weight heparin or warfarin, constitutes the cornerstone of pharmacological intervention. Surgical recourse may be warranted in instances of refractory heart failure or recurrent embolic events. Given its multifaceted nature, the management of NBTE mandates a multidisciplinary approach, with prognosis contingent upon individual clinical intricacies. Future endeavours should prioritize further research to refine therapeutic strategies and enhance patient outcomes.

Keywords: Cardio-embolism; Endocarditis; Marantic endocarditis; Non-bacterial thrombotic endocarditis.