Comparison of the efficacy and safety of ticagrelor and clopidogrel in patients with acute coronary syndrome after risk stratification.

OBJECTIVE: This study aimed at comparing the effectiveness and safety of ticagrelor and clopidogrel in acute coronary artery syndrome (ACS) patients stratified by the Optimal Antiplatelet Therapy for Chinese Patients with Coronary Artery Disease (OPT-CAD) risk score. BACKGROUND: Although they provide a promising basis for treatment decisions, risk scores have not been utilized to optimize P2Y12 inhibitors for ACS patients. METHODS: In 2016-2019, 16,343 ACS patients who underwent percutaneous coronary intervention at the General Hospital of Northern Theater Command were enrolled and classified as low-risk (n = 9,841) or intermediate- to high-risk (n = 6,502) according to OPT-CAD risk score. Clinical outcomes for patients receiving clopidogrel or ticagrelor were compared within risk levels. Primary endpoint was ischemic events at 12 months. Propensity score matching (PSM) was used to balance groups. RESULTS: The risk of ischemic events (2.73% vs. 3.89%, p = .02) and all-cause mortality (1.75% vs. 2.86%, p = .01) were lower in the intermediate- to high-risk patients treated with ticagrelor than those treated with clopidogrel, without an excessive risk of major bleeding (3.71% vs. 3.95%, p = .65). Among low-risk patients, ticagrelor was associated with significantly increased bleeding risk (4.13% vs. 2.85%, p < .01) compared to clopidogrel, with no difference in ischemic risk (1.04% vs. 1.25%, p = .36). Results were consistent in PSM cohorts. CONCLUSIONS: Ticagrelor improves ischemic prognosis in intermediate- to high-risk patients but shows worse safety in low-risk patients compared to clopidogrel, supporting the effectiveness of risk score-guided decision making.