Comparison of clopidogrel and ticagrelor in treating acute coronary syndrome undergoing PCI: A systematic review and meta-analysis

Objective: The study aims to evaluate and compare the efficacy and safety between ticagrelor and clopidogrel in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Methods: We searched MEDLINE (via PubMed), Cochrane, Embase, and the Cochrane library databases for eligible citations (the last search was up to December 2021). Subgroup analyses were performed based on region, study design, dose, and single-center/multicenter. Meta regressions were conducted to explore the source of heterogeneity. A sensitivity analysis was conducted to assess the robustness of the results. Funnel plots and Egger's test were preformed to test publication bias of the meta-analysis. Results: A total of 29 studies were included, totaling 165,981 patients. Ticagrelor reduced the overall incidence rate of major adverse cardiovascular events (MACEs) (HR 0.74; 95% CI, 0.62, 0.89; P = 0.001; I2 = 88.3%, P < 0.001) and all-cause mortality (HR 0.85; 95% CI, 0.75, 0.97; P = 0.019; I2 = 39.7%, P = 0.052) compared with clopidogrel. However, there was a higher risk of major bleeding (HR 1.21; 95% CI, 1.02,1.44; P = 0.026, I2 = 59.3%, P = 0.012) and all bleeding (HR 1.42; 95% CI, 1.24, 1.62; P < 0.001, I2 = 76.4%, P < 0.001) with ticagrelor compared to clopidogrel. The stability of the results was demonstrated by sensitivity analysis. Furthermore, subgroup analyses and meta-regression revealed that the heterogeneity in the study may stem from factors such as whether it was conducted in a single-center or multicenter setting, as well as the geographical region. Conclusion: Ticagrelor has demonstrated superior efficacy compared to clopidogrel in ACS patients undergoing PCI, particularly in Asia and Europe. Nevertheless, it is crucial to acknowledge