Women Fare Better after Bypass Surgery without Heart-Lung Machine

Women are less likely to die or have a heart attack or stroke after having bypass surgery performed without a heart-lung machine, called off-pump, than if they have conventional bypass surgery with a heart-lung machine, called on-pump, says John D. Puskas, MD, MSc, of the Emory Heart and Vascular Center.

The new findings are reported in the cardiovascular surgery supplement of Circulation: Journal of the American Heart Association. “We found that there was a higher risk of death, stroke and heart attack in women who had traditional cardiopulmonary bypass (on-pump) than men who had either type of bypass,” says Dr. Puskas, lead author of the study and professor of surgery at Emory University School of Medicine. “But the differences between the genders became statistically insignificant when we compared men and women who had off-pump bypass.” In the study, Dr. Puskas and Emory colleagues analysed risk factors and outcomes of 11,413 men and women who had coronary artery bypass grafting (CABG) between January 1997 and May 2005 to determine if the off-pump procedure altered a gender-based disparity. Overall, women tend to have a higher risk for death or complications than men after either type of CABG. The differences were strikingly in favour of the off-pump option for women. Compared to men having on-pump CABG:

• Women who had on-pump bypass had a 60 percent increased risk of death, but women who had off-pump CABG had a 37 percent reduction in the risk of death
• Women had a 71 percent increased risk of stroke or other major adverse cardiac event with on-pump CABG, but had about a 26 percent reduction in those risks with off-pump CABG
• Women had more than a two-fold risk of heart attack with on-pump surgery, while women having off-pump CABG had only a 69 percent higher risk
• Many of these risks for men were not significantly different whether they had on-pump or off-pump bypass.

“This study represents seven years of operations, more than 11,000 patients and 14 surgeons,” says Dr. Puskas, who also serves as associate chief of cardiothoracic surgery at Emory University Hospital and chief of cardiac surgery at Emory Crawford Long Hospital. He says further study is needed to explain why off-pump surgery narrows the gender disparity in clinical outcomes after bypass surgery. Additional Emory researchers include: Robert Guyton, MD; Patrick D. Kilgo, MS; Michael Kutner, PhD; Sorin V. Pusca, MD; and Omar Lattouf, MD. (Source: Circulation : Jennifer Johnson : Emory University : November 2007)