Prolonged emergency department stays of non-ST-segment-elevation myocardial infarction patients are associated with worse adherence to the American College of Cardiology/American Heart Association guidelines for management and increased adverse events

Ann Emerg Med. 2007 Nov;50(5):489-96. doi: 10.1016/j.annemergmed.2007.03.033. Epub 2007 Jun 20.


Study objective: We evaluate the association of emergency department (ED) length of stay with use of guideline-recommended therapies for acute treatments and clinical outcomes. Prolonged ED stays often reflect ED crowding or limited hospital capacity. We hypothesized that patients with non-ST-segment-elevation myocardial infarction who have ED stays of greater than 8 hours may have lower quality of care and worse outcomes.

Methods: Using a secondary analysis of data from an observational registry (Can Rapid Risk Stratification of Unstable Angina Patients Suppress ADverse Outcomes with Early Implementation of the ACC/AHA Guidelines, CRUSADE), we compared rates of use of 5 individual acute (<24 hours) guideline-recommended therapies in patients with non-ST-segment-elevation myocardial infarction according to ED length of stay. Patients were grouped by length of stay (short [<4 hours], average [4 to 8 hours], or long [>8 hours]). Multivariable analyses were used to determine independent association of ED length of stay with acute medications and inhospital outcomes (death and myocardial infarction).

Results: This analysis included 42,780 patients with non-ST-segment-elevation myocardial infarction. The median ED length of stay was 4.3 hours (25th to 75th percentile 2.9, 6.3); 15% of patients stayed longer than 8 hours. Patients who had long ED stays were more likely to be women and nonwhite and less likely to have health maintenance organization or private insurance. After adjustment, patients with long ED stays less often received guideline-recommended acute myocardial infarction therapies. Although risk-adjusted inhospital mortality rates were similar among groups, the rate of recurrent myocardial infarction increased among patients with long ED stays (odds ratio 1.23; 95% confidence interval 1.01 to 1.48) compared with those with average ED length of stay.

Conclusion: For patients with non-ST-segment-elevation myocardial infarction, long ED stays were associated with decreased use of guideline-recommended therapies and a higher risk of recurrent myocardial infarction. However, there was no observed difference in mortality. Factors associated with prolonged ED length of stay should be evaluated to optimize treatments and outcomes of patients with non-ST-segment-elevation myocardial infarction.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • American Heart Association
  • Crowding
  • Electrocardiography
  • Emergency Service, Hospital / organization & administration
  • Emergency Service, Hospital / statistics & numerical data*
  • Female
  • Guideline Adherence / statistics & numerical data*
  • Humans
  • Length of Stay / statistics & numerical data*
  • Male
  • Middle Aged
  • Myocardial Infarction / physiopathology
  • Myocardial Infarction / therapy*
  • Practice Guidelines as Topic
  • Quality of Health Care*
  • Recurrence
  • United States