Stroke in non-bacterial thrombotic endocarditis: a patient-level systematic review of clinical characteristics, management, and outcomes.

BACKGROUND AND PURPOSE: Stroke is a frequent manifestation of non-bacterial thrombotic endocarditis (NBTE), yet current knowledge largely stems from case reports and small case series. This systematic review summarizes stroke presentation, imaging features, management, and outcomes in patients with NBTE-related stroke. METHODS: We conducted a patient-level systematic review of published case reports and case series. PubMed, MEDLINE, Embase, Web of Science, and PsycINFO were searched from inception through August 2025 for studies reporting individual patients with NBTE-related stroke. Extracted data included demographics, vascular risk factors, stroke presentation, imaging features, NBTE etiology, treatment (unfractionated heparin/low-molecular-weight heparin [UFH/LMWH], vitamin K antagonists [VKA], direct oral anticoagulants [DOACs], and/or valvular surgery), and outcomes. Multivariable regression was used to explore factors associated with recurrent stroke and mortality. RESULTS: We included 236 patients with NBTE and stroke from 218 studies (median age 56 years [IQR: 43-63], 63% female). Left hemispheric stroke syndromes predominated among clinical presentations (27%), and multi-vessel territory ischemic infarcts (>2 territories) were observed in 65%. Conventional vascular risk factors were infrequent (0%-21%), whereas deep vein thrombosis (43%) and systemic embolism (41%) frequently preceded or coincided with stroke onset. Malignancy (70%) and autoimmune disease (25%) were the main NBTE etiologies. Anticoagulation was initiated in 70%, and 21% underwent valvular surgery. Over a median follow-up of 2.0 months, stroke recurred in 43% and death occurred in 49% of patients. Malignant etiology (aOR 10.3, P < 0.001) and metastases (aOR 3.9, P < 0.001) were associated with increased mortality, while VKA use (aOR 0.08, P < 0.001) and autoimmune etiology (aOR 0.1, P < 0.001) were associated with lower mortality. Malignancy (aOR 2.8, P < 0.001) and DOAC use (aOR 5.2, P = 0.012) were associated with increased risk of recurrent stroke. CONCLUSION: NBTE should be considered in stroke patients lacking conventional vascular risk factors, particularly those with malignancy or autoimmune disease. Malignancy and DOAC use were associated with higher recurrent stroke risk, while VKA use was associated with lower mortality; however, these anticoagulant-class findings should be considered hypothesis-generating and interpreted cautiously given the case-report evidence base, small treatment subgroups, potential confounding, and limited follow-up. WHAT THIS STUDY ADDS: By synthesizing patient-level data from published case reports and case series, this review provides a stroke-focused characterization of NBTE, including clinical presentation, infarct topography, underlying etiologies, management strategies, recurrent cerebrovascular events, and mortality. The findings highlight multifocal infarction, malignancy-associated NBTE, and recurrent stroke despite anticoagulation as key clinical concerns, while emphasizing that observed associations with anticoagulant class should be viewed as hypothesis-generating rather than definitive treatment guidance.