Prehospital electrocardiographic manifestations of acute myocardial ischemia independently predict adverse hospital outcomes.
BACKGROUND
Prehospital electrocardiography (PH ECG) is becoming the standard of care for patients activating Emergency Medical Services for symptoms of acute coronary syndrome (ACS). Little is known about the prognostic value of ischemia found on PH ECG.


OBJECTIVE
The purpose of this study was to determine whether manifestations of acute myocardial ischemia on PH ECG are predictive of adverse hospital outcomes.


METHODS
This study was a retrospective analysis of all PH ECGs recorded in 630 patients who called 911 for symptoms of ACS and were enrolled in a prospective clinical trial. ST-segment monitoring software was added to the PH ECG device with automatic storage and transmission of ECGs to the destination Emergency Department. Patient medical records were reviewed for adverse hospital outcomes.


RESULTS
In 630 patients who called 911 for ACS symptoms, 270 (42.9%) had PH ECG evidence of ischemia. Overall, 37% of patients with PH ECG ischemia had adverse hospital outcomes compared with 27% of patients without PH ECG ischemia (p < 0.05). Those with PH ECG ischemia were 1.55 times more likely to have adverse hospital outcomes than those without PH ECG ischemia (95% CI 1.09-2.21; p < 0.05), after controlling for other predictors of adverse hospital outcomes (i.e., age, sex, and medical history).


CONCLUSIONS
Evidence of ischemia on PH ECG is an independent predictor of adverse hospital outcomes. ST-segment monitoring in the prehospital setting can identify high-risk patients with symptoms of ACS and provide important prognostic information at presentation to the Emergency Department.
Department of Physiological Nursing, University of California, San Francisco, School of Nursing, San Francisco, California, USA.
Jessica K
JK
Zègre Hemsey
Kathleen
K
Dracup
Kirsten E
KE
Fleischmann
Claire E
CE
Sommargren
Steven M
SM
Paul
Barbara J
BJ
Drew
D054058:Acute Coronary Syndrome / Q000453:epidemiology; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology; D004562:Electrocardiography; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D017202:Myocardial Ischemia / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012770:Shock, Cardiogenic / Q000453:epidemiology; D012907:Smoking / Q000009:adverse effects; D014693:Ventricular Fibrillation / Q000453:epidemiology