Abstract:ObjectiveTo investigate the antiplatelet effect of CYP2C19 gene combined with platelet function test(PFT) after complex percutaneous coronary intervention(PCI). Methods A total of 136 patients with complex coronary artery lesions underwent PCI in Cangzhou Central Hospital from January 2019 to January 2021 were selected for prospective research, and were randomly divided into observation group and control group(n=68, each). Before PCI, aspirin combined with clopidogrel was given in both groups, and the dosage reached 300 mg each. After PCI, in observation group, different metabolic types were distinguished according to the detection of CYP2C19 gene； the patients with low response after PFT of the intermediate metabolic type and the patients with gene slow metabolic type were considered to be clopidogrel resistance, and the clopidogrel in the dual antiplatelet was adjusted to ticagrelor. In control group, aspirin and clopidogrel were still used. At 4 weeks after PCI, the serum levels of cardiac tmponin I(cTnI), creatine kinase MB isoenzyme(CK-MB) and high-sensitivity C-reactive protein(hs-CRP) were detected, and the major adverse cardiovascular events(MACE) and the bleeding events were observed at 1 month and 12 months after PCI. Results The serum levels of cTnI, hs-CRP and CK-MB in observation group were significantly lower than those in control group(P＜0.05,P<0.01). At 1 month after surgery, there was no significant difference in the total incidence of MACE between observation group and control group(2.94% vs 5.88%, P＞0.05), however, at 12 months after surgery that in observation group was significantly lower compared with control group (8.82% vs 23.53%, P＜0.05). There was no statistical difference in the total incidence of bleeding between observation group and control group(10.29% vs 8.82%, P＞0.05). Conclusion CYP2C19 gene combined with PFT can improve myocardial injury and inflammatory indexes within 1 month through guiding antiplatelet therapy after complex PCI, and reduce MACE within 12 months after operation without increasing the bleeding risk.