Objective:To investigate the relationship between CYP2C19 gene polymorphism and clinical efficacy of clopidogrel in patients with coronary artery disease(CAD).Method:A total of 260 patients with CAD was enrolled,including 160 patients with PCI and 100 patients without PCI or CABG.According to CYP2C19 gene detection,the patients were divided into 3groups.The patients who were fast metabolism received clopidogrel 75mg/day(n=122).Patients with medium or slow metabolism were received normal dosage clopidogrel 7...