Initial Antiplatelet Strategy and 1-Year Outcomes in East Asian Patients With Acute Myocardial Infarction and Renal Dysfunction.

BACKGROUND AND OBJECTIVES: The optimal P2Y12 inhibitor for patients with acute myocardial infarction and renal impairment (AMI-RI) remains unclear, particularly in East Asian populations. This study compared the real-world effectiveness and safety of initial ticagrelor versus clopidogrel therapy in Korean patients with AMI-RI. METHODS: We analyzed 7,590 patients with AMI-RI (estimated glomerular filtration rate [eGFR] <90 mL/min/1.73 m²) from a nationwide multicenter registry. Of these, 3,793 received ticagrelor and 3,797 received clopidogrel as initial P2Y12 therapy. The primary efficacy endpoint was major adverse cardiac and cerebrovascular events (MACCEs), and the primary safety endpoint was clinically significant bleeding. Propensity score matching (PSM) was performed to adjust for baseline differences. RESULTS: At 1 year, after PSM (n=1,869 per group), no significant differences were observed between ticagrelor and clopidogrel in the primary efficacy endpoint (MACCE; hazard ratio [HR], 0.810; p=0.212) or clinically significant bleeding (HR, 1.056; p=0.795). Renal function-stratified analyses showed consistent outcomes across eGFR categories, with no significant differences in MACCE after adjustment. During follow-up, a substantial proportion of patients initially treated with ticagrelor switched to clopidogrel, whereas most patients in the clopidogrel group maintained their initial therapy. CONCLUSIONS: Among Korean patients with AMI-RI, most clopidogrel users continued therapy, whereas many ticagrelor users switched during the 1-year follow-up. After propensity score adjustment, no statistically significant differences in ischemic or clinically significant bleeding outcomes were observed between the initial ticagrelor and clopidogrel strategies. These findings should be interpreted as inconclusive rather than indicative of equivalence.