Extending Dual Antiplatelet Therapy Beyond 3 Months in Acute Ischemic Stroke Due to Large-Artery Atherosclerosis

Abstract

Background: The optimal duration of dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel following acute ischemic stroke due to large-artery atherosclerosis remains uncertain. Methods: We retrospectively analyzed data from a prospective, multicenter stroke registry (2011-2018) linked to a national health insurance claims database. Patients included had acute ischemic stroke attributable to large-artery atherosclerosis, initiated DAPT within 48 hours of admission and remained free of primary outcome events during the first 30 days. Temporal trends in DAPT usage were evaluated, and landmark analyses assessed the impact of DAPT continuation for up to 6 months after stroke on clinical outcomes. The primary outcome was a composite of recurrent stroke, myocardial infarction, major bleeding, and all-cause death within 1.5 years post-stroke. Results: A total of 4814 patients (mean age, 68.1 +/- 11.8 years; 64.1% men) 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 ratios, 0.78 [95% CI, 0.64-0.94] at 3 months; and 0.78 [95% CI, 0.61-0.98] at 6 months). In the analysis of secondary outcomes, DAPT continuation did not significantly affect stroke recurrence or major bleeding, but was associated with a significant reduction in all-cause death. Conclusions: In patients with acute ischemic stroke due to large-artery atherosclerosis, DAPT duration has lengthened over time and continuation beyond 3 months appears to confer net clinical benefits, without increasing the risk of major bleeding.