CYP2C19 and intermediate coronary syndrome: Using CYP2C19 genotype combined with platelet function test to guide individualized antiplatelet therapy after complex coronary artery PCI is beneficial to reducing ischemic events in a short period (1 year), mainly due to reducing the risk of readmission for recurrent unstable angina pectoris, and improving the quality of daily life of patients without increasing the risk of massive hemorrhage, which can improve clinical prognosis.