Standard versus high loading doses of clopidogrel in Asian ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention: insights from the Korea Acute Myocardial Infarction Registry

Background The optimal loading dose of clopidogrel in Asian patients with ST-segment elevation myocardial infarction (STEMI) has not been fully investigated. We compared bleeding, vascular complications, and midterm outcomes of a 300-mg versus a 600-mg loading dose of clopidogrel in a large series of Korean patients with STEMI undergoing primary percutaneous coronary intervention (PCI). Methods A total of 2,664 STEMI patients (age 61.96 ± 11.91 years, men 70.4%) who underwent primary PCI were enrolled in this study. The patients were divided into a standard loading dose group (300 mg; n = 1,447 patients) and a high loading dose group (600 mg; n = 1,217 patients). Bleeding and vascular complications, and in-hospital and clinical outcomes up to 12 months were compared between the 2 groups. Results In-hospital bleeding and vascular complications were similar between the 2 groups. There were no differences in bleeding and vascular complications and in 1- and 12-month clinical outcomes, including mortality, myocardial infarction, repeated PCI, and major adverse cardiac events, between the 2 groups. These findings were consistent even after the propensity score–matched analysis. Conclusions The standard loading dose of clopidogrel may be as safe and similarly effective as the high loading dose in Asian STEMI patients undergoing primary PCI.