摘要Objective To investigate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity and its association with long-term clinical outcome in patients with coronary heart disease(CHD)undergoing percutaneous coronary intervention(PCI).Methods In total,675 patients were enrolled.Based on the platelet inhibition rate,patients were categorized into two groups:clopidogrel low responsiveness(CLR)and normal clopidogrel responsiveness(NCR).The CLR group was divided into ticagrelor and clopidogrel group based on the antiplatelet drugs used in the follow-up treatment.Patients were classified into three groups(normal metabolizer,intermediate metabolizer,and poor metabolizer)based on the CYP2C19 genotype.We aimed to evaluate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity.The cumulative rates of 12-month all-cause deaths,major ad-verse cardiovascular events(MACCEs),and bleeding events were calculated.Results CLR was observed in 44.4％of the overall population.Significant differences were observed in the platelet inhibition rate of clopidogrel among the three metabolic genotypes(P<0.05).At the 12-month follow-up,13 patients(1.9％)died and 96 pa-tients(14.2％)experienced MACCEs.Patients with CLR(9.6％vs.11.7％vs.22.1％,P<0.05)or poor metabolizer(10.7％vs.16.4％vs.22.6％,P = 0.026)experienced a higher rate of MACCEs.A MACCEs risk score between zero and two was calculated.The highest incidence of MACCEs significantly increased with the 2-positive results,and the area under the curve(AUC)was 0.712(95％CI:0.650-0.774,P<0.05).There was no significant difference between the group with a score of one and the occurrence of MACCEs(P>0.05).Conclusions Low response to clopidogrel in CHD patients is correlated with CYP2C19 gene polymorphism.CYP2C19 geno-typing combined with platelet reactivity is an independent predictor of 12-months MACCEs in patients with clopidogrel treat-ment after PCI,which is better than either test alone.