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Patients with an irregular heartbeat have a very high mortality rate when seen in the ED for other reasons


In the first study of its kind, researchers at the Institute for Clinical Evaluative Sciences (ICES) have found patients with atrial fibrillation (irregular heart beat) who present at the emergency department (ED) with another medical condition as their primary diagnosis are more likely to die than patients who receive a primary ED diagnosis of atrial fibrillation.

“We found that patients with atrial fibrillation who presented to the ED with a primary diagnosis other than their atrial fibrillation had remarkably high mortality rates. Both overall and relative to those with a primary ED diagnosis of atrial fibrillation. Almost eight per cent went on to die in-hospital, with 11 per cent dead at 30 days, 17 per cent dead at 90 days, and a full third of the patients were dead by one year after the ED visit. In comparison, patients who came to the ED primarily because of atrial fibrillation have 30-day mortality rates of 3.6 per cent at 30 days, 6.1 per cent at 90 days, and 11 per cent at one year,” says Clare Atzema, lead author and scientist at ICES. “This underscores the importance of recognizing the presence of atrial fibrillation in patients who present in the ED with another acute medical problem”

The single-site, retrospective cohort study examined all electrocardiograms (ECGs) with confirmed atrial fibrillation, performed in the ED from April 2007 to March 2008 and found:

  • Patients with atrial fibrillation and a different main ED diagnosis had a one year mortality rate of 34 per cent; which was three times higher than those with a main ED diagnosis of atrial fibrillation, at 11 per cent.
  • The most common ED diagnoses in patients who also had atrial fibrillation were heart failure, pneumonia and chest pain not-yet-diagnosed.
  • Heart failure, pneumonia, and other serious conditions that require emergency care have a higher associated mortality in patients who also have atrial fibrillation, compared to patients who do not.

“Given that the number of patients with atrial fibrillation is expected to rise rapidly in the future, future studies are needed to examine each ED diagnosis of heart failure, pneumonia and chest pain further,” says Atzema.

Authors: Clare L. Atzema, Kelvin Lam, Christine Young, Nicole Kester-Greene.

The study “Patients with atrial fibrillation and an alternative primary diagnosis in the emergency department: A description of their characteristics and outcomes,” was published in the February issue of Academic Emergency Medicine.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.



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