2021-01-09
To investigate the association between protease-activated receptor-1 (PAR-1) gene F2R polymorphisms and efficacy of clopidogrel for minor stroke or TIA.
Three single nucleotide polymorphisms (CYP2C19*2 [681G>A, rs4244285], CYP2C19*3 [636G>A, rs4986893], and F2R [IVSn-14 A/T, rs168753]) were genotyped among 2,924 patients randomized to clopidogrel plus aspirin (n = 1,461) or aspirin alone (n = 1,463). The primary efficacy outcome was new stroke (ischemic or hemorrhagic) and the safety outcome was any bleeding.
Among patients with minor ischemic stroke or TIA who were receiving clopidogrel and aspirin, those carrying the F2R IVSn-14 T allele had a lower rate of recurrent stroke than those who were not.
Overall, 859 (29.4%) were AA homozygotes, 1,479 (50.6%) were AT heterozygotes, and 586 (20.0%) were TT homozygotes for F2R IVSn-14 polymorphisms; 1,716 (58.7%) were carriers of at least 1 CYP2C19 loss-of-function allele (*2 or *3). Compared with aspirin alone, patients with clopidogrel-aspirin treatment had a low risk of new stroke in patients with AT genotype (7.6% vs 11.3%; hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.44-0.89) and TT genotype (5.8% vs 11.6%; HR, 0.46; 95% CI, 0.25-0.82) but not in carriers of the AA genotype (10.8% vs 11.6%; HR, 0.95; 95% CI, 0.63-1.44) (p = 0.03 for interaction).