Background This study aimed to investigate the efficacy and safety of ticagrelor-aspirin versus clopidogrel-aspirin in Chinese patients by the presence and clinical presentation of intracranial artery stenosis (ICAS) using randomized trial data from the CHANCE-2 (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events-II) trial. Methods and Results A total of 6412 patients with minor stroke or transient ischemic attack who carried CYP2C19 loss-of-function alleles were randomized to either the ticagrelor-aspirin or clopidogrel-aspirin group. Patients without imaging of the intracranial artery were excluded from the nonprespecified subgroup analysis of CHANCE-2. All patients included were classified into the following groups: without ICAS, symptomatic ICAS, or asymptomatic ICAS. The primary efficacy outcome was new strokes within 90 days. There were 5893 patients (median age, 64.8 years; 33.9% women) included, and 172 (4.9%), 171 (10.5%), and 57 (7.7%) cases of new strokes occurred within 90 days in the without ICAS, with symptomatic ICAS, and with asymptomatic ICAS groups, respectively. Ticagrelor-aspirin was associated with reduced risk of new stroke in patients without ICAS (62 [3.5%] versus 110 [6.3%]; hazard ratio [HR], 0.57 [95% CI, 0.41-0.78]) but not in those with symptomatic ICAS (HR, 0.77 [95% CI, 0.56-1.05]) or in those with asymptomatic ICAS (HR, 0.77 [95% CI, 0.43-1.38]) compared with clopidogrel-aspirin (P for interaction=0.14). There were no significant differences in the proportion of severe or moderate bleeding events among different ICAS groups. Conclusions Patients without ICAS received a significantly greater benefit from ticagrelor-aspirin than clopidogrel-aspirin after minor ischemic stroke or transient ischemic attack, and there was no statistically significant difference between treatments in patients with symptomatic ICAS or asymptomatic ICAS. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04078737.
Keywords: CYP2C19 loss‐of‐function alleles; clopidogrel; intracranial artery stenosis; ticagrelor.