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Women more likely than men to be readmitted to hospital after bypass surgery


Women are more likely to have a worse outcome than men after bypass surgery in Ontario, a new study from the Institute for Clinical Evaluative Sciences (ICES) shows.

“Our study provides new data regarding the disparity between women and men in long-term, non-fatal cardiac outcomes up to 11 years following bypass surgery,” said lead author and ICES Research Fellow Dr. Veena Guru.

To conduct the study, investigators analyzed data from 66,193 patients (14,393 women) discharged from Ontario hospitals following bypass surgery between 1991 and 2002 to compare death, cardiac hospital readmission (for angina, heart failure, or heart attack), repeat revascularization (with angioplasty or bypass surgery), and stroke readmission between men and women.

Women tended to be older than men and were more likely to be admitted to hospital with urgent and severe heart conditions just before surgery. As well, women were more likely to suffer from other diseases, including diabetes, lung disease, and vascular disease at the time it was determined that they required surgery.

The results also showed that women were 1.5 times more likely to be readmitted for unstable angina and heart failure compared to men in the first year after bypass surgery, and their readmission rates remained higher than men’s after that. Despite that, women had similar rates of death, heart attack, stroke, and repeat revascularization as men.

“One of the reasons for these differences could be related to the fact that women were less likely to receive arterial grafts, which use arteries from other parts of the body, than vein grafts during bypass surgery,” said Dr. Guru. “Arterial grafts tend to stay open longer than vein grafts and provide a better long-term outcome. “

As well, women may be more likely than men to have delayed presentation to hospital due to atypical symptoms and delayed recognition by medical personnel. This could be because women may be less likely than men to approach physicians with their heart problems and seek medical help.”

Dr. Guru also points to other research that indicates certain women may have genetic predispositions to developing heart disease. She highlights the “need to understand the best revascularization strategy for women and to create an optimal management plan that helps to close this gender gap in non-fatal outcomes.”

The study, “Gender differences in outcomes after hospital discharge from coronary artery bypass grafting”, is in the January 31, 2006 issue of the journal Circulation.

Author affiliations: ICES (Drs. Guru, Austin, and Tu); Sunnybrook and Women’s College Health Sciences Centre, University of Toronto (Drs. Guru, Fremes, Austin, and Tu); Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation (Dr. Blackstone).

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.


  • Julie Dowdie
  • Media Relations Officer, ICES
  • (416) 480-4780 or cell (416) 432-8143

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