Switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction undergoing successful percutaneous coronary intervention in real-world China: Occurrences, reasons, and long-term clinical outcomes

Background Although switching between ticagrelor and clopidogrel is common in clinical practice, the efficacy and safety of this de-escalation remain controversial. Hypothesis We assessed the occurrences, reasons, and outcomes of switching from ticagrelor to clopidogrel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing successful primary percutaneous coronary intervention (PCI). Methods A total of 653 patients with STEMI were randomly assigned to receive loading dose of ticagrelor or clopidogrel before PCI and then received maintenance dose, respectively, for 12 months follow-up. The primary outcome was major adverse cardiac events (MACE), including cardiovascular death, nonfatal myocardial infarction, and stroke. The secondary outcome included unexpected rehospitalization for angina, coronary revascularization, and stent thrombosis. The safety outcome was bleeding described by the Bleeding Academic Research Consortium (BARC) criteria. Results A total of 602 participants completed the study. The rate of switching from ticagrelor to clopidogrel was 48.6% and the main reason was financial burden. The rate of secondary ischemic events in the de-escalation group was higher than that in the ticagrelor group (15.1% vs 5.6%, P = 0.008), but lower than that in the clopidogrel group (15.1% vs 24.6%, P = 0.03), while there were no significant differences in MACE among the three groups (P = 0.16). De-escalation, ticagrelor, and clopidogrel did not cause significant differences in the rates of major bleeding among the three groups (BARC >= 2, P = 0.34). Conclusion Switching from ticagrelor to clopidogrel is very common in patients with STEMI in China. De-escalation might be safe but associated with high risk of ischemic events as compared to ticagrelor.