Temporal changes in emergency department triage of patients with acute myocardial infarction and the effect on outcomes

Background — All patients who present to an emergency department (ED) are triaged. The ED triage score may determine when patients are seen by a physician. Half of patients with acute myocardial infarction (AMI) were given a low priority score in Ontario in 2000/2001. The researchers assessed the appropriateness of ED triage and its association with quality indicators and outcomes in a more recent AMI cohort and compared this with previous findings.

Methods — The researchers conducted a retrospective cohort study of a population-based cohort of patients with AMI admitted to 96 hospitals in Ontario, Canada, in 2004/2005. Outcome measures included rate of low-priority ED triage (score of 3, 4, or 5), compared with an earlier cohort (fiscal year 2000) at the same sites, and the adjusted effect of low-priority ED triage on door-to-electrocardiogram, door-to-needle, and door-to-balloon time; hospital length of stay (LOS); and mortality.

Results — Among 6,605 patients with AMI, low-priority triage was less frequent than in the earlier cohort, at 33.3% versus 50.3%. In patients with ST-segment elevation myocardial infarction (STEMI), it was 25.9%, versus 43.8% previously. Between cohorts, the greatest improvement in triage occurred in patients with chest pain, in those seen at higher AMI volume EDs, and in ambulatory patients; patients seen at low AMI volume EDs, those with diabetes, and the elderly showed the least improvement. Being assigned a low-priority triage score was associated with an adjusted increase in median door-to-electrocardiogram and door-to-needle time of 12.2 (P < .001) and 20.7 minutes (P < .001), respectively, longer than in the earlier cohort (4.4 and 15.1 minutes). It was associated with hospital LOS >75th percentile (odds ratio [OR] 1.25, P < .001), and higher 90-day (OR 1.50, P = .02) and 1-year mortality (OR 1.37, P = .05) in patients with STEMI.

Conclusion — Emergency department triage of patients with AMI improved substantially over 5 years. For the third of patients with AMI who continue to receive a low priority score, including 25% of patients with STEMI, the associated delays in diagnosis and therapy were greater than previously and were associated with increased hospital LOS and mortality. Given the impact of this initial, cursory assessment, hospital systems should consider monitoring the quality of their ED triage.