Exploring Sex Differences in Outcomes of Dual Antiplatelet Therapy for Patients With Noncardioembolic Mild-to-Moderate Ischemic Stroke or High-Risk Transient Ischemic Attack: A Propensity-Matched Analysis of the READAPT Study Cohort

Background: Sex may impact clinical outcomes in patients with stroke treated with dual antiplatelet therapy (DAPT). We aimed to investigate the sex differences in the short-term outcomes of DAPT within a real-world population of patients with noncardioembolic mild-to-moderate ischemic stroke or high-risk transient ischemic attack. Methods: We performed a propensity score-matched analysis from a prospective multicentric cohort study (READAPT [Real-Life Study on Short-Term Dual Antiplatelet Treatment in Patients With Ischemic Stroke or Transient Ischemic Attack]) by including patients with noncardioembolic mild-to-moderate stroke (National Institutes of Health Stroke Scale score of 0-10) or high-risk transient ischemic attack (age, blood pressure, clinical features, duration of transient ischemic attack, presence of diabetes [ABCD2] ≥4) who initiated DAPT within 48 hours of symptom onset. The primary effectiveness outcome was the 90-day risk of new ischemic stroke or other vascular events. The secondary effectiveness outcomes were the 90-day modified Rankin Scale score ordinal shift, vascular and all-cause mortality, and 24-hour early neurological improvement or deterioration. The safety outcomes included the 90-day risk of moderate-to-severe and any bleeding, symptomatic intracranial hemorrhage, and 24-hour hemorrhagic transformation. Outcomes were compared between sexes using Cox and generalized ordinal logistic regression analyses, along with calculating risk differences and ratios. Results: From 2278 patients in the READAPT study cohort, we included 1643 mild-to-moderate strokes or high-risk transient ischemic attacks treated with DAPT (mean age, 69.8±12.0 years; 34.3% women). We matched 531 women and men. The 90-day risk of new ischemic stroke or other vascular events was significantly lower among women than men (hazard ratio, 0.53 [95% CI, 0.28-0.99]; P=0.039). There were no significant differences in secondary effectiveness outcomes. The 90-day risk of safety outcomes was extremely low and did not differ between women and men (moderate-to-severe bleedings: 0.4% versus 0.8%; P=0.413; symptomatic intracranial hemorrhage: 0.2% versus 0.4%; P=0.563). Subgroup analysis for primary effectiveness outcome showed a lower 90-day risk of new ischemic stroke or other vascular events among women aged <50 years, baseline National Institutes of Health Stroke Scale score of 0 to 5, prestroke modified Rankin Scale score <2, large artery atherosclerosis cause, and no diabetes. Conclusions: Our findings suggest that women with noncardioembolic mild-to-moderate stroke or high-risk transient ischemic attack treated with DAPT may have lower short-term risk of recurrent ischemic events than men. Further research is needed to understand the mechanisms behind potential sex-based differences in outcomes after DAPT use. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05476081.