Real-world outcomes following dual antiplatelet therapy in mild-to-moderate ischemic stroke with anterior versus posterior circulation infarct: a READAPT study propensity matched analysis

Background: Dual antiplatelet therapy (DAPT) is a cornerstone of secondary prevention in patients with minor ischemic stroke or high-risk transient ischemic attack. The effectiveness and safety of DAPT may differ between patients with posterior (PCI) and anterior circulation infarct (ACI).Objectives: We aimed to compare short-term outcomes following DAPT between mild-to-moderate stroke patients with PCI versus ACI.Design: Propensity-matched analysis from a prospective real-world multicentric cohort study (READAPT).Methods: We included patients with noncardioembolic mild-to-moderate stroke (National Institute of Health Stroke Scale of 0-10) who initiated DAPT within 48 h of symptom onset. Patients were categorized into ACI or PCI based on the infarct(s) location on brain neuroimaging. The primary effectiveness outcome was the 90-day risk of ischemic stroke or other vascular events. The secondary effectiveness outcomes were the 90-day modified Rankin Scale (mRS) score distribution, 24-h early neurological improvement or deterioration, and all-cause mortality. The safety outcomes included the 90-day risk of any bleedings and 24-h hemorrhagic transformation.Results: We matched 281 PCI patients with 651 ACI patients. The 90-day risk of ischemic stroke or other vascular events was low and similar between PCI and ACI groups (3.1% vs 2.9%, respectively; hazard ratio 0.98, (95% confidence interval (CI) 0.45-2.14); p = 0.845). Patients with PCI had worse 90-day mRS ordinal distribution compared to those with ACI (odds ratio 1.18 (95% CI 1.01-1.39); p = 0.046). There were no differences in other secondary outcomes. Safety outcomes had low incidence and did not differ between groups (any bleedings: 3.2% vs 2.6%; 24-h hemorrhagic transformation: 1.8% vs 1.2%). We found no differences in the risk of ischemic stroke or other vascular events between patients with PCI and ACI across subgroups defined by sex, age, presumed stroke etiology, stroke severity, prestroke mRS, hypertension, diabetes, acute reperfusion therapies, DAPT loading dose, or presence of symptomatic intracranial stenosis.Conclusion: Our findings suggest that effectiveness and safety outcomes after DAPT in patients with mild-to-moderate noncardioembolic ischemic stroke are consistent regardless of infarct location in the anterior or posterior circulation territory. However, patients with PCI may experience worse short-term functional outcome.Trial registration: URL: www.clinicaltrials.gov; Unique identifier: NCT05476081.