EXTENDING DUAL ANTIPLATELET THERAPY BEYOND THREE MONTHS IN ACUTE ISCHEMIC STROKE DUE TO LARGE ARTERY ATHEROSCLEROSIS

초록

Background and Aims: The optimal duration of dual antiplatelet therapy (DAPT) following acute ischemic stroke (AIS) due to large artery atherosclerosis (LAA) remains uncertain. Methods: We retrospectively analyzed patients enrolled in a prospective multicenter stroke registry between 2011 and 2018, successfully linked to a national health insurance claims database, diagnosed with AIS attributable to LAA, and initiated DAPT within 48 hours of admission. Temporal trends in DAPT usage were evaluated, and landmark analyses assessed the impact of DAPT continuation for up to 6 months post-stroke on clinical outcomes. The primary outcome was defined as a composite of recurrent stroke, myocardial infarction, major bleeding, and mortality, within 1.5 years post-stroke. Results: A total of 4,814 patients (mean age, 68.1 ± 11.8 years; 64.1 % male) were analyzed. The median duration of DAPT significantly increased from 36 days in 2011 to 122 days in 2018 (p < 0.001). Continuing DAPT beyond 3 months reduced the risk of the primary outcome, with benefits sustained for up to 6 months (adjusted hazard ratio: 0.78, 95 % confidence interval: 0.64–0.94 at 3 months; 0.78, 0.61–0.98 at 6 months). Sensitivity analysis using stabilized inverse-probability treatment weighting confirmed a significant reduction in the primary outcome at the 3-month timepoint, but not at 6 months. Conclusions: The duration of DAPT following AIS due to LAA increased over the study period and demonstrated a net clinical benefit beyond 3 months, with no significant rise in major bleeding risk. These findings support consideration of extending DAPT beyond 3 months in selected AIS patients with LAA.