EARLY DAPT after minor stroke or high-risk TIA lowered 90-day recurrent stroke, MI, or death when started within 24 hours of onset.
Dual Antiplatelet Therapy Timing Matters
Dual antiplatelet therapy is commonly recommended soon after minor ischemic stroke or high-risk transient ischemic attack, but practice can extend beyond the first day. Investigators analyzed a large prospective multicenter cohort to clarify how timing influences the effectiveness of dual antiplatelet therapy compared with antiplatelet monotherapy.
Earlier Start, Clearer Benefit
The cohort included 41,530 patients with minor noncardioembolic ischemic stroke (NIHSS score 5 or lower) or high-risk transient ischemic attack who presented within 7 days of symptom onset across 20 stroke centers from January 2011 to April 2023. Dual antiplatelet therapy was initiated during the index hospitalization for 25,112 patients (60.5%), while the remainder received monotherapy with aspirin or clopidogrel. The primary endpoint was a 90-day composite of recurrent stroke, myocardial infarction, and death.
Overall, dual antiplatelet therapy was associated with fewer primary outcome events than monotherapy (10.7% versus 11.6%), corresponding to an adjusted hazard ratio of 0.82 (95% CI: 0.77 to 0.87). The advantage was concentrated in patients arriving within 24 hours, where in-hospital dual antiplatelet therapy initiation produced the strongest signal for benefit (hazard ratio 0.74; 95% CI: 0.69 to 0.79).
When the Window Closes
When dual antiplatelet therapy was started 24 to 72 hours after symptom onset, the analysis did not show a meaningful difference versus monotherapy (hazard ratio 1.00; 95% CI: 0.88 to 1.15). For initiation beyond 72 hours, the models suggested potential harm (hazard ratio 1.25; 95% CI: 1.01 to 1.55). In a time dependent assessment, the estimated treatment effect crossed the null at approximately 42 hours, indicating a rapidly diminishing margin as time from onset increased.
The authors adjusted for demographics, vascular risk factors, stroke subtype, relevant arterial status, and prior antiplatelet use using propensity score based inverse probability weighting within Cox models. For clinicians, the findings support prioritizing early dual antiplatelet therapy initiation, while reinforcing caution when considering delayed starts.
Reference: Shin J et al. Timing of initiation and efficacy of dual antiplatelet therapy in minor stroke or high-risk TIA. Stroke. 2026;DOI: 10.1161/STROKEAHA.125.053343.
