Clopidogrel With Aspirin in Acute Minor Stroke or Transient Ischemic Attack (CHANCE) Trial

BACKGROUND: The Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial showed that the combined treatment of clopidogrel and aspirin decreases the 90-day risk of stroke without increasing hemorrhage in comparison with aspirin alone, but provided insufficient data to establish whether the benefit persisted over a longer period of time beyond the trial termination. We report the 1-year follow-up outcomes of this trial. METHODS AND RESULTS: The trial was a randomized, double-blind, placebo-controlled trial conducted at 114 centers in China. We randomly assigned 5170 patients within 24 hours after onset of minor stroke or high-risk transient ischemic attack to clopidogrel-aspirin therapy (loading dose of 300 mg of clopidogrel on day 1, followed by 75 mg of clopidogrel per day for 90 days, plus 75 mg of aspirin per day for the first 21 days) or to the aspirin-alone group (75 mg/d for 90 days). The primary outcome was stroke event (ischemic or hemorrhagic) during 1-year follow-up. Differences in outcomes between groups were assessed by using the Cox proportional hazards model. Stroke occurred in 275 (10.6%) patients in the clopidogrel-aspirin group, in comparison with 362 (14.0%) patients in the aspirin group (hazard ratio, 0.78; 95% confidence interval, 0.65-0.93; P=0.006). Moderate or severe hemorrhage occurred in 7 (0.3%) patients in the clopidogrel-aspirin group and in 9 (0.4%) patients in the aspirin group (P=0.44). CONCLUSIONS: The early benefit of clopidogrel-aspirin treatment in reducing the risk of subsequent stroke persisted for the duration of 1-year of follow-up. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00979589.