University of MI studies: The numbers don’t lie

Two recent studies conducted at the University of Michigan in Ann Arbor bring into stark relief the differences between men and women when it comes to the triage and diagnosis of acute myocardial infarction. In a study by Moscucci et al.,1 here are some of the key findings:

  • In addition to waiting 13 minutes longer than men to have emergency angioplasty or percutaneous coronary intervention, it took women on average an extra 20 minutes to reach the ED after their symptoms began, resulting in half an hour more of wasted time and damaged heart muscle.
  • In all, patients of both sexes whose angioplasty began within 90 minutes of arrival at the hospital had a 50% lower risk of dying in the hospital than those who waited longer.
  • In all, the researchers found only 25% of the female patients underwent emergency angioplasty within the recommended 90 minutes, as compared with 34% of men.
  • Even after receiving this treatment, one in every 13 women in the study died, compared with one in every 32 men.

All of the patients had the same kind of heart attack: acute ST-segment elevation myocardial infarction.

Educate public on symptoms

Since the gender difference in the time it took to get to the ED was even greater than it was in door-to-balloon time, EDs should place a greater emphasis on public education, says Ron Dobson, MD, director of emergency services at Swedish Medical Center in Seattle. "Most reasonably educated people today know that if you have chest pain, you should be concerned about your heart," he says, "But I don’t think they are aware of these other symptoms [i.e., fatigue, sleep disturbance, indigestion, and vague anxiety] that can be associated with it, so they are less likely to come in or to call 911."

Jennifer Gegenheimer-Holmes, RN, BSN, MHSA, director of operations of the ED at University of Michigan Hospitals and Health Centers in Ann Arbor, agrees, while noting that it is something that has been talked about in nursing circles.

In the University of Michigan School of Nursing study, the researchers found that out of 108 nurse triage inferences, 47 patients were admitted to the hospital. Of those 47, nurses made an initial inference of acute coronary syndrome (ACS) in 22 (47%). Of those 22, 15 received an admission diagnosis of ACS, but 11 of the 25 patients who the nurses did not think had ACS were diagnosed as having ACS on admission to the hospital.

The author refers to a "mental template" that may prevent triage nurses from diagnosing ACS correctly when patients present with atypical symptoms. Despite the fact that 80% to 90% of people with coronary heart disease have diabetes, hypertension, hyperlipidemia, or smoke, the nurses interviewed omitted the first three of these factors as significant predictors of ACS.


1. Moscucci M, Smith DE, Jani S, et al. Gender differences in time to treatment for patients undergoing primary percutaneous coronary intervention for acute ST segment elevation MI: An important target for quality improvement. Presented at the American Heart Association Scientific Sessions. Dallas; November 2004.