Ticagrelor vs Clopidogrel in CYP2C19 loss-of-function carriers with Stroke or TIA

BACKGROUNDComparisons between ticagrelor- aspirin and clopidogrel-aspirin in CYP2C19 loss-of-function carriers have not been well studied for secondary stroke prevention.METHODSWe conducted a randomized, double-blind, placebo-controlled trial of 6,412 patients with a minor ischemic stroke or TIA who carried CYP2C19 LOF alleles determined by point-of-care testing. Patients were randomly assigned within 24 hours after symptom onset, in a 1:1 ratio to receive ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2 through 90) or clopidogrel (300 mg loading dose on day 1 followed by 75 mg per day for days 2 through 90), plus aspirin (75-300 mg loading dose followed by 75 mg daily for 21 days). The primary efficacy outcome was stroke and the primary safety outcome was severe or moderate bleeding, both within 90 days. RESULTSStroke occurred within 90 days in 191 (6.0%) versus 243 (7.6%), respectively (hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.94; P=0.008). Moderate or severe bleeding occurred in 9 patients (0.3%) in the ticagrelor-aspirin group and in 11 patients (0.3%) in the clopidogrel-aspirin group; any bleeding event occurred in 170 patients (5.3%) vs 80 (2.5%), respectively. CONCLUSIONSAmong Chinese patients with minor ischemic stroke or TIA within 24 hours after symptoms onset who were carriers of CYP2C19 loss-of-function alleles, ticagrelor- aspirin was modestly better than clopidogrel-aspirin for reducing the risk of stroke but was associated with more total bleeding events at 90 days. (CHANCE-2 ClinicalTrials.gov number, NCT04078737.

Genotype‐guided dual antiplatelet use for TIA and minor stroke by imaging status: a subgroup analysis of the CHANCE‐2 trial

ObjectiveThis 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.MethodsPatients 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.ResultsOf 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 < .001) than in those negative DWI (HR, 1.22; 95% CI, 0.55–2.72; P = .63), with a significant interaction association (P for interaction = .049). The risk of moderate to severe bleeding was similar between ticagrelor/aspirin and clopidogrel/aspirin treatment in different groups.InterpretationOur study demonstrate that imaging evaluation should be emphasized before targeting the best candidates for genotype-guided dual antiplatelet therapy in future clinical research and practice