Switching from Ticagrelor to Clopidogrel in Asian Patients with ST-Elevated Myocardial Infarction – A Time Dependent Analysis Study

Abstract

Background: Ticagrelor is initially prescribed after an ST-elevated myocardial infarction (STEMI) and this may be followed by a switch to clopidogrel. However, studies involving antiplatelet switching have been conflicting and only assessed at a specific switch point. The objective of this study was to investigate switching from ticagrelor to clopidogrel in an Asian population, after accounting for various switch points as in a real-world environment. Methods: A retrospective cohort of 349 STEMI patients started on ticagrelor and aspirin were followed-up for 1 year after a percutaneous coronary intervention that was performed between June 2014 and November 2016. Patients who switched to clopidogrel were compared with those who remained on ticagrelor. Outcomes measured were major adverse cardiac and cerebrovascular events (MACCEs) and clinically significant bleeding (CSB). Cox regression analysis with switch status as a time-dependent covariate was performed. Results: The switched group was not associated with MACCEs or CSB [10.0% vs. 13.8%; hazard ratio (HR) = 0.484; 95% confidence interval (CI): 0.196-1.191; p = 0.114]. There was also no significant difference when MACCEs were analyzed alone (2.3% vs. 7.7%; HR = 0.518; 95% CI: 0.137-1.957; p = 0.332). For CSB, the switched group was less likely to have an event (7.8% vs. 8.5%; HR = 0.298; 95% CI: 0.091-0.982; p = 0.047). Conclusions: This study showed no significant difference between staying on ticagrelor and switching to clopidogrel. Switching might decrease the incidence of CSB. De-escalation from ticagrelor to clopidogrel could translate to cost savings for Asian patients without compromising safety and efficacy. © 2020, Republic of China Society of Cardiology. All rights reserved.