Comparison of Clinical Outcomes Between Ticagrelor and Clopidogrel in East-Asian Patients with Acute Coronary Syndrome: Large Cohort Study

Aim A high risk of bleeding is observed in East Asian patients with acute coronary syndrome (ACS). Therefore, the choice between two antiplatelet therapy drugs, ticagrelor and clopidogrel, remains controversial in this population with ACS. This study aimed to use a large cohort database to assess the clinical outcomes of ticagrelor and clopidogrel therapy, including major bleeding, recurrent ACS, and mortality, in this population. Methods Between January 2009 and December 2019, 43,696 patients were diagnosed with ACS based on the medical history (International Classification of Diseases [ICD] code) of the Chang Gung Research Database. After excluding patients without percutaneous coronary intervention, with concurrent medical problems, and on non-standard dual antiplatelet therapy (DAPT) or a single antiplatelet agent, 18,046 patients were recruited for analysis. Ticagrelor- and clopidogrel-based DAPT were administered to 3666 patients and 14,380 patients, respectively. Baseline characteristics and clinical outcomes were compared between the two groups. A total of 4225 patients were defined as a high-bleeding-risk subgroup according to Academic Research Consortium for High Bleeding Risk (ARC-HBR) score (met one major or two minor criteria), of which 466 and 3759 patients received ticagrelor- and clopidogrel-based DAPT, respectively. Results Before propensity score matching (PSM), younger age, higher prevalence of male sex, and higher body mass index were noted in the ticagrelor-based DAPT group in the whole cohort and high-bleeding-risk subgroup. After PSM, no difference in baseline characteristics and comorbidities between ticagrelor-based and clopidogrel-based DAPT groups in the whole cohort and high-bleeding-risk subgroup was noted. The Kaplan-Meier curves of recurrent ACS and major bleeding were significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of cardiovascular (CV) and all-cause mortality showed no significant differences. After PSM, in the high-bleeding-risk subgroup, the Kaplan-Meier curve of recurrent ACS was significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of major bleeding, CV, and all-cause mortality showed no significant differences. Conclusion In this large cohort study, patients receiving ticagrelor-based DAPT were at lower risk of recurrent ACS compared to those receiving clopidogrel-based DAPT, especially in the patients with myocardial infarction. Ticagrelor-based DAPT did not result in a higher risk of major bleeding in the whole ACS population and high-bleeding-risk subgroup. The rate of CV and all-cause mortality were similar between both the groups.