The younger the patients, the greater the mortality difference between women and men, says lead author Viola Vaccarino, M.D., Ph.D., of Emory University in Atlanta, Ga.
Although the percentage of bypass-surgery patients who died in the hospital was relatively small, the difference in both overall mortality and the death rate for patients under age 60 was significant between the two sexes, says Vaccarino, an associate professor of medicine at Emorys School of Medicine and an associate professor of epidemiology at its Rollins School of Public Health.
Coronary artery bypass surgery uses blood vessels to reroute blood flow around arterial blockages to improve the supply of blood and oxygen to the heart. Heart surgeons perform about 571,000 of them annually, including about 182,000 in women. Vaccarino and her colleagues were unable to determine why death rates were different between men and women. She says the explanation might be some unknown factor that increases the risk for women who have bypass surgery, or something in the surgical procedure itself that might be subject to change.
Clearly, we need further investigation in order to determine the causes for these mortality differences, she says.
Women who suffer heart attacks have a higher in-hospital death rate than men, and the Emory group has shown that womens mortality compared to mens is particularly high among patients younger than 60. The researchers wondered if the same pattern held true for women undergoing bypass surgery.
The researchers reviewed records of 51,187 patients in the National Cardiovascular Network database who underwent bypass surgery at 23 medical centers between October 1993 and December 1999. Of these patients, 1
Contact: Carole Bullock
American Heart Association