BACKGROUND - Among patients identified prehospital with ST-segment-elevation myocardial infarction, emergency medical service transport from the field directly to the catheterization laboratory, thereby bypassing the emergency department (ED), may shorten time to reperfusion.
METHODS AND RESULTS - We studied 1687 patients identified prehospital with ST-segment-elevation myocardial infarction from the Reperfusion in Acute Myocardial Infarction in Carolina Emergency Departments (RACE) project, transported via emergency medical service directly to 21 North Carolina hospitals for primary percutaneous coronary intervention between July 2008 and December 2009. Treatment time intervals were compared between patients evaluated in the ED (ED evaluation) and those transported directly to the catheterization laboratory (ED bypass). Emergency medical service transported 1401 (83.0%) patients to the ED, whereas the ED was bypassed for 286 (17.0%) patients. Overall, first medical contact to device activation within 90 minutes was achieved in 913 (54.1%) patients. Among patients evaluated in the ED, median time (25th-75th percentiles) from ED arrival to catheterization laboratory arrival was 30 (20-41) minutes. First medical contact to device activation occurred faster (75 [59-93] versus 90 [76-109] minutes; P<0.001) and was more frequently achieved within 90 minutes (74.1% versus 50.1%; P<0.001) among ED bypass patients.
CONCLUSIONS - Among patients identified prehospital with ST-segment-elevation myocardial infarction and transported directly to a percutaneous coronary intervention hospital, only 1 in 2 achieve device activation within 90 minutes. A median of 30 minutes is spent in the ED, contributing significantly to the failure to achieve timely reperfusion. The strategy to bypass the ED is used infrequently and represents a potential opportunity to improve reperfusion times.