AbstractThe aim of this study was to investigate the association among the PlA1/A2 gene polymorphism, laboratory aspirin resistance and adverse clinical outcomes in coronary artery disease (CAD) patients who were on aspirin maintainance therapy. A comprehensive literature search was performed and 35 eligible clinical trials including 19025 CAD patients were recruited. Adverse clinical outcomes involving all-cause death, non-fatal myocardial infarction (MI), ischemic stroke and target vessel revascularization (TVR) were analyzed. The definition of aspirin resistance in each study was accepted. Meta-analysis was performed using the Review Manager 5.3.5 System. In CAD patients, the PlA2 gene carriers had similar incidence of laboratory aspirin resistance compared to those with PlA1/A1 genotype [29.7% vs 28.3%, OR = 0.94 (95% CI 0.63 to 1.40, P = 0.74)], and there were no significant differences in the adverse clinical outcomes between the PlA2 carriers and the PlA1/A1 genotype patients. However, the laboratory aspirin non-responders had higher risks of death [7.9% vs. 2.5%, OR = 2.42 (95% CI 1.86 to 3.15, P < 0.00001)] and TVR [4.5% vs. 1.7%, OR = 2.20 (95% CI 1.19 to 4.08, P = 0.01)] compared to the responders. In aspirin-treated CAD patients, the laboratory aspirin resistance predicts all-cause death and TVR. However, the PlA1/A2 gene polymorphism predicts neither the laboratory aspirin response nor the clinical outcomes.