March 16 (HealthDay News) -- Amid the continuing debate over who should pop an aspirin each day to fight heart disease, and at what dose, U.S. experts have revised guidelines stating that lower doses appear to be at least as effective as higher doses and safer at preventing heart attack and stroke.
The issue of dosage has long been discussed because aspirin carries with it an increased risk for gastrointestinal bleeding, especially when taken in combination with the clot-dissolving drug clopidogrel (Plavix).
The new U.S. Preventive Services Task Force guidelines are tailored to match age and gender. Among the recommendations: Men aged 45 to 79 should take aspirin if the chances of preventing a heart attack outweigh the chances of gastrointestinal bleeding. Women aged 55 to 79 should take the drug if the chances of reducing ischemic stroke outweigh the risks of GI bleeding.
"Subsequent to the 2002 recommendations, there was more information that came out of the Women's Health Initiative, specifically, that enabled us to look at this recommendation by gender," said Dr. Michael LeFevre, a task force member and professor of family and community medicine at the University of Missouri, Columbia. "We have a recommendation for men and a recommendation for women. We did not have that before."
Aspirin seems to be more effective in men for preventing heart attack but, in women, better at preventing stroke, LeFevre added.
Dr. Carl J. Lavie, medical director of cardiac rehabilitation at the Ochsner Heart and Vascular Institute in New Orleans, added: "The benefits of aspirin use always have to be balanced against the risks. If a patient has low risk of events in the near future, aspirin should not be prescribed. If the risk is very high, clearly aspirin is needed."
The recommendations, published in the March 17 issue of the Annals of Internal Medicine, state:
- Men aged 45 to 79 with heart risk factors should take aspirin if the preventive benefits outweigh the risk of bleeding.
- At-risk women aged 55 to 79 should take aspirin if the odds of reducing a first ischemic stroke outweigh the chance of bleeding.
- Men under the age of 45 and women under 55 who have never had a heart attack or stroke should not take aspirin for prevention.
- At this time, it isn't clear whether patients aged 80 and older should take aspirin.
The task force emphasized that the recommendations only apply to people who have never had a heart attack or stroke.
The last task force recommendations came out in 2002. At the time, the panel acknowledged that the evidence for the use of aspirin in preventing heart problems was still evolving.
A second paper in the same issue of the journal reaffirms the task force guidelines, finding that lower doses of daily aspirin (75 milligrams to 81 milligrams) are equally, if not more effective, than higher doses (100 mg or more) in preventing heart attack and stroke in at-risk individuals.
The paper also found that high doses may actually do more harm, especially in people taking Plavix.
According to background information in the study, aspirin is the most used drug worldwide to prevent heart attack and stroke. More than one-third of U.S. adults are believed to take aspirin each day.
"All these trials put together really favor taking lower doses of aspirin," said Dr. Suzanne Steinbaum, director of women and heart disease at Lenox Hill Hospital in New York City.
SOURCES: Michael LeFevre, M.D., member, U.S. Preventive Services Task Force, and professor, family and community medicine, University of Missouri, Columbia; Suzanne Steinbaum, D.O., director, women and heart disease, Lenox Hill Hospital, New York City; Carl J. Lavie, M.D., medical director, cardiac rehabilitation, Ochsner Heart and Vascular Institute, New Orleans; March 17, 2009, Annals of Internal Medicine