Association of the Timing of Atrial Fibrillation Detection and Insular Involvement With the Risk of Embolic Events After Acute Ischemic Stroke.

Objective: Atrial fibrillation (AF) detected after insular stroke might arise from autonomic and inflammatory mechanisms triggered by insular damage, and be associated with a low embolic risk. We assessed the association of the timing of AF detection and insular involvement with the risk of embolic events after acute ischemic stroke. Methods: Acute ischemic stroke patients with AF who underwent brain magnetic resonance imaging at baseline were enrolled. Patients were classified according to the timing of AF detection (AF detected after stroke [AFDAS] or known AF [KAF]) and insular involvement. The primary outcome was embolic events defined as recurrent ischemic stroke, transient ischemic attack, and systemic embolism within 90 days. Results: Of 1,548 patients, 360 had AFDAS with insular cortex lesions (+I), 409 had AFDAS without insular cortex lesions (−I), 349 had KAF+I, and 430 had KAF−I. Cumulative incidence rates of embolic events at 90 days in patients with AFDAS+I, AFDAS−I, KAF+I, and KAF−I were 0.8%, 3.5%, 4.9%, and 3.3%, respectively. Patients with AFDAS−I (adjusted hazard ratio 5.04, 95% confidence interval 1.43–17.75), KAF+I (6.18, 1.78–21.46), and KAF−I (5.26, 1.48–18.69) had a significantly higher risk of embolic events than those with AFDAS+I. Interpretation: Acute ischemic stroke patients with AFDAS and insular cortex lesions had a lower risk of embolic events than those who had AFDAS without insular cortex lesions or those with KAF, regardless of insular involvement. ANN NEUROL 2024;95:338–346 [ABSTRACT FROM AUTHOR]