Impact of Emergency Medical System Transportation in ST-segment Elevation Myocardial Infarction: A Nationwide Retrospective Study

Abstract

Emergency medical system transportation has been shown to reduce treatment times in ST-segment elevation myocardialinfarction. The authors studied the Portuguese National Registry of Acute Coronary Syndromes to determine the nationwide impactof the emergency medical system transportation in the treatment of ST-segment elevation myocardial infarction. A multicentric, nationwide, retrospective study of ST-segment elevation myocardial infarction patients insertedin the National Registry from 2010 to 2017 was performed. The patients were divided into: Group I, composed of patients transportedby emergency medical system, and Group II, patients arriving to the Emergency department by other means. Of the 5702 patients studied, 25.9% were transported via emergency medical system. Rates of emergency medical systemactivation increased by 17% in the last 7 years. The emergency medical system provided a higher rate of transport to a percutaneouscoronary intervention capable centre, of Emergency department bypass, of on-site fibrinolysis, and ensured a 59-minute reduction ofthe median reperfusion time (p < 0.001). There was no difference in in-hospital mortality. In this nationwide cohort, emergency medical system transportation is associated with a reduction in reperfusion times.It provides a higher amount of salvaged myocardium and reduces the incidence of acute heart failure. However, emergency medicalsystem use did not result in lower in-hospital mortality, probably due to confounding factors of higher disease severity and comorbidity. The benefits associated with emergency medical system based transportation of patients with ST-segment elevationmyocardial infarction do not translate into lower in-hospital mortality.