One-Year Outcomes of Early Therapy With Ticagrelor vs Clopidogrel in CYP2C19 Loss-of-Function Carriers With Stroke or TIA Trial.

Background and Objectives: The Ticagrelor or Clopidogrel with Aspirin in High-Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE-2) trial showed that among Chinese patients with minor ischemic stroke or transient ischemic attack (TIA) who were carriers of CYP2C19 loss-of-function alleles, dual-antiplatelet therapy with ticagrelor-aspirin reduced the 90-day risk of stroke without increased severe or moderate bleeding compared with clopidogrel-aspirin. However, whether dual-antiplatelet therapy with ticagrelor was superior to clopidogrel beyond the 90 days of follow-up remained unclear. In this study, we reported 1-year follow-up outcomes of the CHANCE-2 trial.
Methods: The CHANCE-2 trial is a randomized, double-blind, placebo-controlled trial at 202 centers in China. Patients with a minor stroke or TIA who carried CYP2C19 loss-of-function alleles were randomized within 24 hours after symptom onset, in a 1:1 ratio, to receive ticagrelor and placebo clopidogrel or to receive clopidogrel and placebo ticagrelor for 90 days; both groups received aspirin for the first 21 days. After day 90, treatment was as per the choice of the clinician and the patient.
Results: Among 6,412 patients, the proportion of patients on ticagrelor plus aspirin, clopidogrel plus aspirin, ticagrelor alone, clopidogrel alone, aspirin alone, other antiplatelet, and no antiplatelet beyond month 3 to 1 year was 0.09%, 1.56%, 0.13%, 2.66%, 73.65%, 0.78%, and 21.13% in the ticagrelor-aspirin group and 0.03%, 1.63%, 0.19%, 2.60%, 72.83%, 0.66%, and 22.06% in the clopidogrel-aspirin group, respectively. The primary outcome of new stroke occurred in 252 patients (7.91%) in the ticagrelor-aspirin group and 310 patients (9.73%) in the clopidogrel-aspirin group by 1 year of follow-up (hazard ratio 0.80; 95% CI 0.68-0.95; p = 0.007); new stroke beyond 3 months to 1 year occurred in 61 patients (2.07%) and 67 patients (2.32%) ( p = 0.48), respectively. Primary safety outcome of severe or moderate bleeding occurred in 17 patients (0.53%) in the ticagrelor-aspirin group and 20 patients (0.63%) in the clopidogrel-aspirin group ( p = 0.61).
Discussion: For CYP2C19 loss-of-function allele carriers, early dual-antiplatelet therapy with ticagrelor is superior to clopidogrel at 1 year in reducing recurrent stroke.
Trial Registration Information: URL: clinicaltrials.gov. Unique identifier: NCT04078737.
Classification of Evidence: This study provides Class II evidence that for patients with minor stroke or TIA with TIACYP2C19 loss-of-function, ticagrelor plus aspirin for 21 days is superior to clopidogrel plus aspirin in reducing the 1-year risk of recurrent stroke.