RESUMO
The strategy of prehospital activation by the emergency medical system (EMS) in patients with ST-elevation myocardial infarction (STEMI) has been poorly adopted among the US hospitals that currently offer 24/7 primary percutaneous coronary intervention. In this study, we report a single center experience after the implementation of this strategy. From 2008 to 2011, we identified a total 188 STEMI patients (age 65 ± 15 years) presenting via EMS for primary percutaneous coronary intervention. Of these, 112 (59.6%) underwent prehospital activation (EMS group), whereas the remaining 76 (40.4%) underwent emergency department activation [emergency department (ED) group]. Baseline demographic characteristics were similar between both groups. The overall median door-to-balloon (DTB) time was 49 ± 14 minutes. Patients undergoing prehospital activation had on average significantly lower overall DTB times (EMS 44 ± 11 minutes vs. ED 57 ± 15 minutes; P < 0.001). Concordantly, DTB times <60 minutes were much more commonly achieved with this strategy (EMS 95.5% vs. ED 64.5%; P < 0.001). Fallouts beyond the recommended 90-minute DTB time were seen among ED patients only. No difference in in-hospital death (EMS 5.4% vs. ED 6.6%; P = 0.75) or cumulative 30-day mortality (EMS 6.3% vs. ED 7.9%; P = 0.68) was observed between both groups. However, on average, EMS patients had higher postinfarct left ventricular ejection fraction (EMS 48 ± 9.5% vs. ED 39 ± 14.6%; P = 0.004). Differences in DTB time and left ventricular ejection fraction remained significant after adjusting for differences in baseline characteristics. In conclusion, the prehospital activation strategy is largely effective and should be systematically adopted in the treatment scheme of STEMI patients to lower mechanical reperfusion times and reduce the potential for untoward clinical outcomes.
