Impact of pre-hospital electrocardiograms on time to treatment and one year outcome in a rural regional ST-segment elevation myocardial infarction network.

BACKGROUND: Pre-hospital electrocardiograms (ECGs) are believed to reduce time to reperfusion in ST Segment Elevation Myocardial Infarction (STEMI) patients. Little is known of their impact on clinical outcomes in a rural setting. Geisinger regional STEMI network provides percutaneous coronary intervention (PCI) care to over a 100-mile radius in rural central Pennsylvania.

METHODS: A retrospective analysis identified 280 consecutive STEMI patients treated with PCI between 1/1/09 and 8/31/11. Comparison between two STEMI groups was performed: 205 patients who were taken by the emergency medical system (EMS) to the nearest hospital (a non-PCI center), underwent an ECG revealing a STEMI, and were transported immediately to Geisinger Medical Center (GMC) for PCI (transfer group) versus 75 patients in whom a pre-hospital ECG was obtained and who were transported by EMS directly to Geisinger for PCI, bypassing the nearest hospital that did not perform PCI (the pre-hospital ECG group).

RESULTS: Analysis of baseline characteristics revealed that the pre-hospital ECG cohort was older (65 vs. 60 years); had a higher percentage of previous myocardial infarctions (MI) (28% vs. 15%), heart failure (11% vs. 4%), and prior PCI (23% vs. 13%; p < 0.05 all comparisons). Median time from EMS contact to pre-hospital ECG in the pre-hospital ECG group was 5 minutes; from pre-hospital ECG to the GMC ED was 34 minutes. Median time from first medical contact (EMS contact) to reperfusion (device activation) was 79 versus 157 minutes (P < 0.001), respectively in pre-hospital ECG vs. transfer groups. Mortality in the two groups at 1 year was 4.1% in the pre-hospital ECG group versus 8.3% in the transfer group (P-value = 0.34). After adjusting for the difference in age between the two groups, the 62% reduction in 1 year mortality associated with having obtained a pre-hospital ECG was still not statistically significant (P-value = 0.19).

CONCLUSION: In a rural regional STEMI network, pre-hospital ECGs decreased time from first medical contact to reperfusion by 50% and were associated with an excellent clinical outcome at 1 year. © 2016 Wiley Periodicals, Inc.