Background: Activation of emergency medical services (EMS) is critical for the early triage and treatment of patients experiencing ST-segment-elevation myocardial infarction, yet data regarding EMS use and its association with subsequent clinical care are limited.
Methods and results: We performed an observational analysis of 37 634 ST-segment-elevation myocardial infarction patients treated at 372 US hospitals participating in the National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With the Guidelines between January 2007 and September 2009, and examined independent patient factors associated with EMS transportation versus patient self-transportation. We found that EMS transport was used in only 60% of ST-segment-elevation myocardial infarction patients. Older patients, those living farther from the hospital, and those with hemodynamic compromise were more likely to use EMS transport. In contrast, race, income, and education level did not appear to be associated with the mode of transport. Compared with self-transported patients, EMS-transported patients had significantly shorter delays in both symptom-onset-to-arrival time (median, 89 versus 120 minutes; P<0.0001) and door-to-reperfusion time (median door-to-balloon time, 63 versus 76 minutes; P<0.0001; median door-to-needle time, 23 versus 29 minutes; P<0.0001).
Conclusions: Emergency medical services transportation to the hospital is underused among contemporary ST-segment-elevation myocardial infarction patients. Nevertheless, use of EMS transportation is associated with substantial reductions in ischemic time and treatment delays. Community education efforts are needed to improve the use of emergency transport as part of system-wide strategies to improve ST-segment-elevation myocardial infarction reperfusion care.