Impact of prehospital electrocardiogram protocol and immediate catheterization team activation for patients with ST-elevation-myocardial infarction.

Guidelines recommend implementing prehospital electrocardiograms (PH ECG) into systems of care for patients with suspected ST-elevation–myocardial infarction to reduce door-to-balloon time (DTB). We developed a PH ECG protocol with an affiliated emergency medical service, combining 4 features: (1) PH ECG acquisition; (2) emergency medical service interpretation without PH ECG transmission; (3) prehospital activation of the cardiac catheterization team; and (4) emergency department bypass. We compared data from June 1, 2006, to August 31, 2007 (preimplementation group, n 50), with data from October 1, 2007, to June 30, 2010 (postimplementation group, n 82), analyzing all patients with ST-elevation–myocardial infarction transported by an affiliated EMS and treated with primary percutaneous coronary intervention. PH ECGs were acquired in 33 (66%) and 67 (82%) patients in the preimplementation and postimplementation groups, respectively (P 0.041). Median DTB was 59 and 57 minutes for the preimplementation and postimplementation groups, respectively (P 0.28). In a prespecified subgroup analysis of postimplementation patients (n 38) who had prehospital activation of catheterization team and emergency department bypass, median DTB was 32 minutes (P 0.001 compared with preimplementation group). Our PH ECG protocol increased the frequency of PH ECG acquisition and decreased DTB for patients when all 4 features of our PH ECG protocol were carried out. Prehospital electrocardiograms (PH ECG) can decrease reperfusion times for patients with ST-elevation–myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).1–16 However, even when PH ECG are acquired, they may not be optimally utilized and integrated. A recent scientific statement by the American Heart Association (AHA) stated, “the central challenge for healthcare providers is not to simply perform PH ECG, but to use and integrate the diagnostic information from a PH ECG with systems of care.”17 The American College of Cardiology/AHA (ACC/AHA) guidelines for STEMI encourage a first medical contact-toballoon time (FMCTB) within 90 minutes for patients undergoing primary PCI.18 These recommendations encourage an “as-soon-as-possible” strategy for primary PCI, citing improved survival for every 30-minute decrement in door-toballoon time (DTB).19 Despite a class I recommendation for PH ECG acquisition, prehospital identification of STEMI, and prehospital activation of the cardiac catheterization laboratory for these patients, current studies show that PH ECG are performed on less than 30% patients with STEMI in the United States.5,8,20 We developed and implemented a comprehensive PH ECG protocol for patients in Olmsted County, Minnesota, who were transported by Gold Cross Rochester (GCR), an affiliated emergency medical service (EMS). Our PH ECG protocol consisted of the following 4 features: (1) PH ECG acquisition; (2) PH ECG interpretation by paramedics without wireless transmission; (3) prehospital activation of the cardiac catheterization laboratory; and (4) patient bypass of the emergency department (ED). To test the hypothesis that our protocol would improve timeliness of reperfusion therapy for STEMI patients, we assessed time intervals preimplementation and postimplementation of the PH ECG protocol.