Temporal Patterns of Antithrombotic Therapy and Clinical Outcomes After Atrial Fibrillation-Related Stroke

Abstract

Background This study aimed to describe the temporal evolution of antithrombotic treatment strategies and associated clinical outcomes after atrial fibrillation-related acute ischemic stroke.Methods This multicenter prospective cohort study enrolled patients with acute ischemic stroke and atrial fibrillation from 16 tertiary stroke centers across South Korea between February 2018 and January 2021, with follow-up completed by January 2022. The primary outcome was a composite of recurrent stroke, myocardial infarction, and all-cause death. Secondary outcomes included individual components of the primary outcome and major bleeding events.Results The median follow-up duration was 1.92 years. Among 2965 patients (mean +/- SD age, 75.3 [10.2] years; 54.1% male), antithrombotic strategies varied widely in the acute phase. Within 48 hours of admission, 50.9% received antiplatelet-only therapy (29.4% single, 21.5% dual), 23.2% received non-vitamin K antagonist oral anticoagulant monotherapy, and 10.4% received a combination of antiplatelets and anticoagulants. By discharge, non-vitamin K antagonist oral anticoagulant monotherapy had become the predominant treatment strategy (65.7%), and this pattern persisted throughout follow-up. The incidence of the primary end point was highest in the first 2 weeks (32.70 [95% CI, 29.64-36.06] per 100 person-months) and declined thereafter. Across all time periods, patients receiving non-vitamin K antagonist oral anticoagulant monotherapy consistently had lower incidence rates (3-month rate, 4.95 [95% CI, 4.37-5.61] per 100 person-months) than those receiving antiplatelet-only therapy (11.98 [95% CI, 9.57-15.01]) or no antithrombotic therapy (18.44 [95% CI, 14.26-23.86]).Conclusions In this prospective cohort of patients with atrial fibrillation-related stroke, early antithrombotic treatment strategies were heterogeneous but evolved primarily toward use of non-vitamin K antagonist oral anticoagulant monotherapy. Treatment selection was associated with marked differences in outcomes, particularly during the early high-risk period.