Comparison of Prognosis According to the Use of Emergency Medical Services in Patients with ST-Segment Elevation Myocardial Infarction.
Yonsei Medical Journal · 2022-01-27 · Observational study
Abstract
PURPOSE: This study aimed to compare long-term clinical outcomes according to the use of emergency medical services (EMS) in patients with ST-segment elevation myocardial infarction (STEMI) who arrived at the hospital within 12 hr of symptom onset. MATERIALS AND METHODS: A total of 13104 patients with acute myocardial infarction were enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health from October 2011 to December 2015. Of them, 2416 patients with STEMI who arrived at the hospital within 12 hr were divided into two groups: 987 patients in the EMS group and 1429 in the non-EMS group. Propensity score matching (PSM) was performed to reduce bias from confounding variables. After PSM, 796 patients in the EMS group and 796 patients in the non-EMS group were analyzed. The clinical outcomes during 3 years of clinical follow-up were compared between the two groups according to the use of EMS. RESULTS: The symptom-to-door time was significantly shorter in the EMS group than in the non-EMS group. The EMS group had more patients with high Killip class compared to the non-EMS group. The rates of all-cause death and major adverse cardiac events (MACE) were not significantly different between the two groups. After PSM, the rate of all-cause death and MACE were still not significantly different between the EMS and non-EMS groups. The predictors of mortality were high Killip class, renal dysfunction, old age, long door-to-balloon time, long symptom-to-door time, and heart failure. CONCLUSION: EMS utilization was more frequent in high-risk patients. The use of EMS shortened the symptom-to-door time, but did not improve the prognosis in this cohort.