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Mayo Clinic study: Don't stop taking aspirin before heart surgery

Aspirin use associated with lower mortality, but doesn't raise bleeding risk

Mayo Clinic

"Aspirin reduces clotting of the blood, so it can help prevent a heart attack or stroke by making it less likely a clot will form and block an already narrowed artery," explains R. Scott Wright, M.D., the Mayo Clinic cardiologist who led the study. "However, many surgeons who are concerned about excessive bleeding due to inadequate clotting have advised their patients to stop taking aspirin in the days before their operation. We designed this study to provide guidance on whether continuing aspirin therapy in the days before surgery is beneficial or risky."

The researchers collected data from 1,636 patients who had first-time coronary artery bypass surgery at Mayo Clinic in 2000, 2001 and 2002. Patients were divided into two groups: those who had taken aspirin within the five days before surgery (1,316 patients), and those who had not (320). Characteristics of the two groups were similar, except patients in the aspirin group were more likely to have had a previous heart attack, while those not taking aspirin were more likely to be on dialysis. All members of both groups received aspirin therapy following surgery, starting six hours after their operation.


The in-hospital mortality for the aspirin group (1.7 percent) was significantly less than that for those not receiving aspirin (4.4 percent), and there was no increased risk of reoperation for excessive internal bleeding.

The study results suggest a reduction in strokes and related events, but the trend was not strong enough to be statistically significant.

"This is a very strong association of survival with taking aspirin in the days leading up to surgery," says Dr. Wright. "The study further confirms aspirin's benefits for patients with known cardiovascular disease. It also shows there is no increased risk of bleeding, which eliminates the main reason why physicians and surgeons would ask patients to discontinue aspirin therapy. Patients with heart disease who are not taking aspirin should ask themselves -- and their doctors -- 'Why not?'"


The findings are published this week in Circulation: Journal of the American Heart Association. Other co-authors include Kevin Bybee, M.D., Brian Powell, M.D., Uma Valeti, M.D., A. Gabriela Rosales, M.S., Stephen Kopecky, M.D., and Charles Mullany, M.B. M.S.

The study was funded by Mayo Clinic's Division of Cardiovascular Diseases. Dr. Wright has previously received research grant support from Bayer Pharmaceuticals.

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