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Americans twice as likely to be hospitalized for irregular heartbeat as Ontarians: ICES study


Patients with atrial fibrillation (irregular heart beat) who present at the emergency department (ED) were hospitalized nearly twice as often in the US when compared to Ontario, according to new research conducted in collaboration with the Institute for Clinical Evaluative Sciences (ICES).

Atrial fibrillation (AF) is an irregular and often rapid heart rate. During AF, the heart's two upper chambers beat chaotically and irregularly — out of coordination with the two lower chambers of the heart. AF symptoms often include heart palpitations, shortness of breath and weakness. AF is a major risk factor for stroke.

“The United States hospitalizes nearly twice as many patients who present in the emergency department with atrial fibrillation per capita as Ontario, with the greatest discrepancy occurring in younger patients,” says Dr. Clare Atzema, author and scientist at ICES.

Nearly 70 per cent of ED visits for AF between 2007 and 2009 ended in hospitalization in the United States, a percentage that has remained constant since 2000. In comparison, in Ontario, only 37 per cent of visits resulted in a hospital admission during the same time period, which has dropped by 10 per cent since 2002.

The researchers say it is not clear from this study what the optimal admission rate is, but such substantial variation suggests the need for better clinical decision tools to identify those patients who will benefit from hospitalization.

The study, published today in the Journal of the American College of Cardiology (JACC), found a substantially higher number of younger patients with AF are being admitted to hospital in the US when compared to Ontario.

“The greatest inter-country differences were in ED visits made by patients under the age of 65: in Ontario only 25 per cent of these visits result in hospitalization, versus 65 per cent in the US. Older patients are at increased risk of death following the ED visit for AF compared to younger patients, which may justify the need for hospitalization. But the rationale behind admitting the majority of younger patients with AF is less evident,” notes Atzema.

The cross-sectional study was conducted using data from the United States and Ontario on ED visits with a primary diagnosis of AF between January 1, 2007 and December 31, 2009. Findings include:

  • There were an estimated 1,320,123 ED visits for AF in the US, and 56,413 visits in Ontario.
  • ED visits for AF resulted in hospitalization nearly twice as often in the US compared to the Ontario cohort.
  • ED deaths were rare in both settings.
  • ED cardioversions – a procedure that can restore a fast or irregular heartbeat to a normal rhythm – were nearly half as frequent in the US.

“In addition to exposing patients to the risk of hospital-associated complications, the financial cost of hospitalization – which is by far the most expensive component of AF care – is tremendous and not obviously justified. Differences in the financial incentives (and disincentives) for hospitals to admit low risk patients in the US and Ontario may contribute to the variation in hospitalization,” added Atzema.

The researchers add that inter-country comparisons represent a first step toward reducing unnecessary hospitalizations, and in turn promoting responsible healthcare resource utilization.

The study “Emergency department management of atrial fibrillation in the United States versus Ontario, Canada,” was published today in the Journal of the American College of Cardiology (JACC).

Authors: Barrett TW, Vermeulen MJ, Self WH, Jenkins CA, Ferreira AJ, Atzema CL.

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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  • Deborah Creatura
  • Communications, ICES
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