STS: Women Narrow CABG Gender Disparity by Going Off-Pump

January 30, 2007

SAN DIEGO -- Off-pump coronary artery bypass surgery for women nearly eliminates the gender gap for cardiac morbidity and mortality, researchers said here. However, men still did better.

SAN DIEGO, Jan. 30 -- Off-pump coronary artery bypass surgery for women nearly eliminates the gender gap for cardiac morbidity and mortality, researchers said here. However, men still do better.

So found John D. Puskas, M.D., of Emory in Atlanta, and colleagues, in an observational study of more than 42,000 consecutive non-emergent bypass surgery patients. The results were presented at the Society of Thoracic Surgeons meeting.

In the study, women had a significantly higher risk of death from on-pump bypass compared with men even after adjusting for confounding factors including intraoperative conversions from one type of surgery to the other (odds ratio 1.47, 95% confidence interval 1.16 to 1.85, P=0.001).

However, the gender disparity in off-pump bypass mortality dropped to statistical insignificance (OR 1.27, 95% CI 0.95 to 1.69, P=0.10). Major adverse cardiac events showed a similar pattern.

Historically, women have had poorer outcomes than men from CABG for reasons that are not well explained, but off-pump bypass offers a way to erase some of the differences, Dr. Puskas said.

"How do we make a woman more like a man?" he quipped. "We operate on her off-pump."

The study helps surgeons edge closer to understanding which groups of patients may benefit more from off-pump than on-pump procedures, said discussant Bruce W. Lytle, M.D., of the Cleveland Clinic.

"What we would really like is to ferret out a subgroup of patients in whom off-pump does not just have a moderate benefit but in whom off-pump should be considered standard of care," he said.

"In this trial there appears to be an overall advantage for off-pump focused in a particular group-women," he added.

The study included 11,785 women and 30,662 men whose CABG procedures were recorded in the Society of Thoracic Surgeons' National Cardiac Database. Only patients treated at 63 North American medical centers experienced in both on- and off-pump procedures were included.

Overall, off-pump bypass was associated with a significantly lower risk of mortality (adjusted OR 0.83, 95% CI 0.69 to 0.98, P=0.03) and major adverse cardiac events (adjusted OR 0.71, 95% CI 0.63 to 0.81, P

Women were older (67.0 versus 64.1, P