Emergency department triage of acute myocardial infarction patients and the effect on outcomes

Study Objective — More than half of all acute myocardial infarction patients still do not meet benchmark reperfusion times, and the triage assessment that all patients receive when they arrive at an emergency department (ED) is a hospital-level process that has not been studied as a potential contributor to delays. Our objective was to examine the triage of acute myocardial infarction patients (ST-elevation and non-ST elevation myocardial infarction) and determine whether it is associated with subsequent delays in acute myocardial infarction processes of care.

Methods — We conducted a retrospective cohort analysis of a population-based cohort of acute myocardial infarction patients admitted to 102 acute care hospitals in Ontario, Canada, from July 2000 to March 2001. Main outcome measures were the rate of low-acuity triage (defined as a Canadian Triage and Acuity Scale score of III, IV, or V) among acute myocardial infarction patients and its association with delays in time from ED arrival to initial ECG (door-to-ECG time) and to administration of fibrinolysis (door-to-needle time).

Results — Among 3,088 acute myocardial infarction patients, the rate of low acuity triage was 50.3%. Median door-to-ECG and door-to-needle time was 12.0 and 40.0 minutes, respectively. In adjusted quantile regression analyses, low-acuity triage was independently associated with a 4.4-minute delay in median door-to-ECG time and a 15.1-minute delay in median door-to-needle time. The adjusted odds of achieving benchmark door-to-ECG and door-to-needle times were 0.54 (95% confidence interval 0.46 to 0.65) and 0.44 (95% confidence interval 0.30 to 0.65), respectively, for acute myocardial infarction patients assigned a low-acuity ED triage score.

Conclusion — Half of acute myocardial infarction patients were given a low acuity triage score when they presented to an ED in Ontario, which was independently associated with substantial delays in ECG acquisition and to reperfusion therapy. The quality of ED triage may be an important factor limiting performance on key measures of quality of acute myocardial infarction care.