Abstract
BACKGROUND/AIMS: Acute myocardial infarction (AMI) is conventionally recognized as an urgent medical condition requiring timely and effective reperfusion therapy. However, the results of studies on the clinical outcomes in AMI according to hospital visit timings are inconclusive. To explore the difference in long-term outcomes between off- and on-hour percutaneous coronary interventions (PCI) in patients with AMI of Killip functional classification III-IV (Killip III-IV AMI). METHODS: Data on the characteristics and clinical outcomes of 1,751 patients with Killip III-IV AMI between November 2011 and June 2015 from the Korea Acute Myocardial Infarction Registry-National Institutes of Health registry were analyzed. All participants were allocated into two groups: off-hour (weekdays from 6:00 PM to 8:00 AM, weekends, and legal holidays) and on-hour (weekdays from 8:00 AM to 6:00 PM) groups. The incidence of major adverse cardiac and cerebrovascular events, defined as a composite of all-cause mortality, nonfatal myocardial infarction, any revascularization, cerebrovascular accident, and stent thrombosis, was the primary endpoint. RESULTS: Among the 1,751 patients, 572 (39.1%) underwent PCI during on-hours and 892 (60.9%) during off-hours. At the 3-year follow-up, no significant difference was found in the clinical outcomes between the two groups in both the unadjusted and propensity-score weighing-adjusted analyses. CONCLUSION: The outcomes of patients with Killip III-IV AMI admitted during off- and on-hours were similar.