Background: Guidelines for reperfusion in ST-elevation myocardial infarction (STEMI) were recently adopted by the Canadian Cardiovascular Society. We have developed a blended model of prehospital thrombolytic (PHL) therapy or primary percutaneous coronary intervention (PPCI) activation, in order to achieve guideline times.
Methods: In our urban centre of 658,700 people, emergency medical services (EMS) were trained to perform and screen electrocardiograms (ECGs) for suspected STEMI. Suspected ECGs were transmitted to a physician's hand-held device. If the physician confirmed the diagnosis they coordinated initiation of either PHL or PPCI. In cases where physicians found the prehospital ECG negative for STEMI (PHENST), patients were transported to the closest emergency room.
Results: From July 21, 2008 to July 21, 2010, the Cardiac Outcomes Through Digital Evaluation (CODE) STEMI project received 380 transmitted calls. There were 226 confirmed STEMI by the on-call physician, 158 (70%) received PPCI, 48 (21%) received PHL, and 20 (9%) had angiography but no revascularization. The PPCI, median time from first medical contact to reperfusion was 76 minutes (interquartile range [IQR], 64-93). For PHL, median time from first medical contact to needle was 32 minutes (IQR, 29-39). The overall mortality rate for the STEMI patients was 8% (PHL = 4 [8.3%], PPCI = 8 [5%], medical therapy = 7 [35%]). There were 154 PHENST patients, 44% later diagnosed with acute coronary syndrome. The mortality rate for PHENST was 14%.
Conclusions: Through a model of EMS prehospital ECG interpretation, digital transmission, direct communication with a physician, and rapid coordinated service, we demonstrate that benchmark reperfusion times in STEMI can be achieved.
Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.