ABSTRACT NUMBER: ESOC2026A620 IMPACT OF CLINICAL AND NEUROIMAGING MARKERS ON ISCHEMIC EVENTS IN ANTICOAGULATED AF: BAT2

Abstract Background and aims Despite oral anticoagulation (OAC), residual risk factors for ischemic stroke in atrial fibrillation (AF) patients remain unclear. We aimed to identify clinical and neuroimaging risk factors for ischemic events in AF patients receiving OAC. Methods We analyzed AF patients receiving OAC from the BAT2 prospective multicenter cohort across 52 hospitals. Baseline brain MRI assessed white matter hyperintensities, cerebral microbleeds (CMBs), lacunes, enlarged perivascular spaces, non-lacunar infarcts, and intracranial arterial stenosis. Cox proportional hazards regression with stepwise selection identified factors associated with ischemic events. Results Of 5,378 patients enrolled, 1,019 AF patients on OAC (80% on DOACs) were included. Among these AF patients, 55 ischemic events occurred during median 2-year follow-up, including 43 ischemic strokes. Compared with non-AF patients (n=4,209), AF patients were older (median: 76 vs. 71 years), had a lower proportion of women (30.5% vs 33.7%), worse renal function, more frequent history of congestive heart failure, and poorer medication adherence. Non-lacunar infarcts were more common in AF patients, whereas lacunes and intracranial stenosis were less common. Independent risk factors for ischemic events were ≥5 deep CMBs (adjusted hazard ratio [aHR] 2.87, 95%CI 1.03–8.05), non-lacunar infarcts (aHR 2.67, 1.40–5.10), and severe intracranial stenosis (aHR 3.12, 1.23–7.91). For ischemic stroke specifically, ≥5 deep CMBs (aHR 3.94, 1.39–11.23) and non-lacunar infarcts (aHR 2.94, 1.37–6.30) showed similar associations. Conclusions In AF patients receiving OAC, ≥5 deep CMBs, non-lacunar infarcts, and severe intracranial arterial stenosis were associated with increased risk of ischemic events and ischemic stroke. Conflict of interest Soya Iwamoto