OBJECTIVETo assess the association of CYP2C19 gene polymorphisms with the incidence of ischemic stroke among patients receiving clopidogrel therapy following coronary stenting for coronary artery disease.

METHODSClinical data of patients receiving clopidogrel therapy after coronary stenting were retrospectively studied. For a case-control study, 137 patients with acute cerebral infarction and 122 non-stroke patients were selected. Based on the variants of the CYP2C19 gene detected by a DNA microarray assay, the patients were further divided into the wild-type group(CYP2C19*1/*1) and mutant group(defined by the presence of at least one loss-of-function allele, including CYP2C19*1/*2, CYP2C19*1/*3, CYP2C19*2/*2, CYP2C19*2/*3 and CYP2C19*3/*3). The incidences of ischemic stroke in the two groups were compared through a chi-square analysis. The influence of CYP2C19 gene polymorphisms and clopidogrel therapy on the incidence of ischemic stroke was analyzed through multivariable logistic regression.

RESULTSA total of 259 patients were enrolled. The case and control groups showed no difference in terms of gender and age. There were 123 cases (47.5%) in the CYP2C19 wild-type group and 136 cases (52.5%) in the mutant group. The incidence of ischemic stroke of mutant group was significantly higher than that of wild-type group (59.9% vs. 44.3%, X2=6.398, P=0.042). Multivariate analysis revealed that loss-of-function polymorphisms of the CYP2C19 gene carried a 1.13 times greater risk for ischemic stroke compared to wild-type genotype (OR=2.13, 95%CI: 1.23-3.71).

CONCLUSIONThe efficacy of clopidogrel for the prevention of ischemic stroke in post-coronary stent patients may be reduced by the insufficiency of the CYP2C19 gene. The dosage of clopidogrel therapy should be adjusted based on its polymorphisms.