Association of Pre-hospital ECG Administration With Clinical Outcomes in ST-Segment Myocardial Infarction: A Systematic Review and Meta-analysis

Background Delays in reperfusion for patients with myocardial ischemia leads to increased morbidity and mortality. The objective of this review was to identify, evaluate, and critically appraise the evidence on whether pre-hospital electrocardiography (ECG) reduces patient mortality and improves post—ST-segment myocardial infarction patient-oriented outcomes. Methods We searched PubMed/MEDLINE, EMBASE, and Cochrane Library (1990-2015) for controlled clinical studies. We also searched conference proceedings, trial registries, and reference lists of narrative and systematic reviews. Two reviewers independently identified and extracted data from studies that compared pre-hospital ECG with standard of care in patients with suspected myocardial infarction who underwent primary percutaneous coronary intervention. Internal validity was assessed using the Newcastle-Ottawa scale. Results We screened 21,197 citations and included 63 unique studies (plus 22 companion publications). Most studies were of moderate quality. Pre-hospital ECG was associated with significantly fewer deaths (relative risk, 0.68; 95% confidence interval [CI], 0.63-0.74; 45 studies; 71,315 patients; I 2 , 0%), reduced time to reperfusion (mean difference, −35.32 minutes; 95% CI, −44.02 to −26.61; 26 studies; 27,524 patients; I 2 , 97%), shorter hospital stays (mean difference, −0.63 days; 95% CI, −1.05 to −0.20; 10 studies; 39,275 patients; I 2 , 39%), and more patients had first medical contact to device time I 2 , 93%). Conclusions Use of pre-hospital ECG is associated with decreased mortality and overall better patient outcomes.