Genotype‐Guided Dual Antiplatelet Use for Transient Ischemic Attack and Minor Stroke by Imaging Status: Subgroup Analysis of the CHANCE‐2 Trial

Objective This study was performed to investigate whether ticagrelor/aspirin versus clopidogrel/aspirin can further reduce the residual risk of stroke recurrence in patients with positive diffusion‐weighted imaging (DWI) in the High‐Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE‐2) trial. Methods Patients with DWI data in the CHANCE‐2 trial were included and divided into those with and without acute infarction according to their DWI findings. The primary efficacy outcome and safety outcome were stroke recurrence and moderate to severe bleeding within 3 months of follow‐up, respectively. Results Of the 6,412 patients enrolled in the CHANCE‐2 trial, 5,796 (90.4%) patients with DWI data were included in the subgroup analysis. A total of 4,369 patients (75.4%) had an acute infarction on DWI. Patients with positive DWI had higher risk of recurrent stroke (8.1%) than those without infarction (2.2%) within 3‐month follow‐up. Compared with clopidogrel/aspirin, ticagrelor/aspirin was associated with lower risk of stroke in patients with positive DWI (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.52–0.80, p < 0.001) than in those negative DWI (HR = 1.22, 95% CI = 0.55–2.72, p = 0.63), with a significant interaction association ( p for interaction = 0.049). The risk of moderate to severe bleeding was similar between ticagrelor/aspirin and clopidogrel/aspirin treatment in the different groups. Interpretation Our study demonstrates that imaging evaluation should be emphasized before targeting the best candidates for genotype‐guided dual antiplatelet therapy in future clinical research and practice. ANN NEUROL 2023;93:783–792