Risks of Using Aspirin to Prevent Heart Attack Or Stroke Differ by Gender and Age

Patients and clinicians should consider risk factors- including age, gender, diabetes, blood pressure, cholesterol levels, smoking and risk of gastrointestinal bleeding- before deciding whether to use aspirin to prevent heart attacks or strokes, according to new recommendations from the U.S. Preventive Services Task Force. These recommendations do not apply to people who have already had a heart attack or stroke.

The recommendations are published in the March 17 issue of the Annals of Internal Medicine. The Task Force reviewed new evidence from the National Institutes of Health’s Women’s Health Study published since the last Task Force review of this topic in 2002, including a recent meta-analysis of the risks and benefits of aspirin and found aspirin may have different benefits and harms in men and women. The Task Force found good evidence that aspirin decreases first heart attacks in men and first strokes in women.

The more risk factors people have, the more likely they are to benefit from aspirin. The Task Force recommends that men between the ages of 45 and 79 should use aspirin to reduce their risk for heart attacks when the benefits outweigh the harms for potential gastrointestinal bleeding.

Women between the ages of 55 and 79 should use aspirin to reduce their risk for ischemic stroke when the benefits outweigh the harms for potential gastrointestinal bleeding. Ischemic strokes occur as a result of an obstruction within a blood vessel supplying blood to the brain and are potentially prevented by aspirin use. The risk of gastrointestinal bleeding with and without aspirin use increases with age and is twice as high in men as in women. Other risk factors for gastrointestinal bleeding include upper gastrointestinal tract pain, gastrointestinal ulcers, and using non-steroidal anti-inflammatory drugs.

The Task Force recommended against using aspirin to prevent either strokes or heart disease in men under 45 or women under age 55 because heart attacks are less likely to occur in men younger than 45 and ischemic strokes are less likely to occur in women younger than 55, and because limited evidence exists in these age groups.

People age 80 and older could benefit more than younger people from aspirin because of their higher risk of cardiovascular disease, but the harms are also greater because the risk of gastrointestinal bleeding increases with age. The Task Force could not find clear evidence that the benefits of using aspirin outweigh the risks in people 80 years or older.

“The decision about whether the benefits of taking aspirin outweigh the harms is an individual one. Patients should work with their clinicians to look at their risk factors and decide if taking aspirin to lower their risk for heart attacks or strokes outweighs the potential risk of gastrointestinal bleeding,” said Task Force Chair Ned Calonge, M.D., who is also chief medical officer and state epidemiologist for the Colorado Department of Public Health and Information.