Efficacy and safety of ticagrelor versus clopidogrel in patients with non-ST-elevation myocardial infarction in Taiwan

The clinical efficacy of ticagrelor versus clopidogrel has not been replicated in East Asian populations. The pronounced bleeding risk with ticagrelor was of concern given the increased bleeding tendency in Asian populations. This study evaluated efficacy and safety of ticagrelor versus clopidogrel in patients with non-ST-elevation myocardial infarction (NSTEMI) in the entire Taiwan. We used the Taiwan National Health Insurance Research Database to identify 6203 patients aged ≥ 20 years with NSTEMI hospitalization and prescription of dual antiplatelets at discharge between January 2014 and December 2014. Cohorts of ticagrelor and clopidogrel were matched 1:1 based on propensity score matching to balance baseline covariates. The primary composite efficacy endpoints included death from any cause, non-fatal myocardial infarction, and non-fatal stroke. The secondary efficacy endpoints were the individual components. The primary safety endpoint was major bleeding requiring hospitalization. The incidence of primary efficacy endpoint was 20.3% in the ticagrelor users and 20.7% in the clopidogrel users (adjusted HR 0.94; 95% CI 0.73–1.22), with the median (interquartile range, IQR) follow-up period of 5.2 (2.3–8.5) months. The incidence of primary safety endpoint was 2.3% in the ticagrelor users and 3.2% in the clopidogrel users (adjusted HR 0.67; 95% CI 0.33–1.35). Regarding the secondary efficacy endpoint, patients treated with ticagrelor had significantly lower incidence of stroke (adjusted HR 0.44; 95% CI 0.21–0.94; p = 0.033). In this nationwide Taiwanese cohort of NSTEMI, treatment with ticagrelor after discharge, as compared to clopidogrel, had similar rates of ischemic composite events and major bleeding. Nevertheless, the median follow-up time was only 5.2 months, and the reduced stroke events with ticagrelor compared to clopidogrel needs further verification.