Aspirin Can Cut Heart Attacks in People Who Have Not Yet Had Heart Problems

UNC-RTI study supports aspirin to cut heart attacks in people who have not yet had heart problemsFederal task force: recommends doctors discuss aspirin with patients at increased risk.

Contacts:Study leader Michael Pignone can be paged at (919) 216-1710. His email is [email protected].

UNC News Services Contact: David Williamson, (919) 962-8596AHRQ Contact: Farah Englert, (301) 594-6372

Chapel Hill, NC, January 14 2002A new report by North Carolina researchers has led the U.S. Preventive Services Task Force to recommend strongly that clinicians talk about the benefits and dangers of using aspirin to prevent heart attacks with healthy patients at increased risk of cardiovascular problems.

Often such patients can benefit from taking aspirin, researchers conclude. No reason exists for people not at risk, however, to take daily doses of the over-the-counter drug.

Both the study, conducted by University of North Carolina at Chapel Hill and Research Triangle Institute investigators, and the task force's recommendation appear in the Jan. 15 issue of Annals of Internal Medicine, a medical journal. The new research complements a different study reported Jan. 11 in the British Medical Journal that focused on people who already suffered heart attacks and other high-risk patients.

"It's been pretty well recognized that aspirin is helpful to people who have had heart attacks or strokes by preventing or delaying future cardiovascular events like these," said study leader Dr. Michael Pignone, assistant professor of medicine at the UNC School of Medicine. "What has been unclear, however, whether this was true for people who hadn't had heart problems, and now we think we know."

Researchers at the Evidence-Based Practice Center at UNC and RTI conducted the study for the task force, an independent body that develops preventive care recommendations. The U.S. Department of Health and Human Services' Agency for Healthcare Research and Quality (AHRQ) supports the RTI and UNC work.

Pignone, a fellow at UNC's Cecil G. Sheps Center for Health Services Research, and colleagues reviewed the five previous large trials of aspirin in adults without cardiovascular disease. They then combined and analyzed the data from the studies anew in what scientists call a meta-analysis. For the first time, the team tried to calculate how much risk patients had to face to benefit from preventive aspirin therapy. They also reviewed multiple investigations of aspirin's possible ill effects.

"We found that aspirin was beneficial for people who were at relatively high risk of heart disease, and that was no great surprise," Pignone said. "What we did differently from previous analyses, though, was that we tried to quantify exactly how much risk you need to face in order to benefit from aspirin. By doing that, we showed that aspirin is probably beneficial for people who have a 3 percent or greater risk of suffering a heart attack over the next five years."

In such cases, the chance of preventing heart attacks outweighs the negative effects of aspirin, which can include a rare kind of bleeding stroke and possible gastrointestinal tract bleeding, he said. People with less than a 1 percent heart attack risk over five years probably would not benefit from preventive aspirin and should not take it daily.

Regular use of aspirin cut the coronary heart disease risk by 28 percent in people who had never had a heart attack or stoke but were at heightened risk.

"People in the middle, who are neither high risk nor very low risk, should discuss the pros and cons of aspirin with their doctors and come to an individualized decision together," Pignone said. "If you are very interested in avoiding a heart attack and are willing to accept a small chance of a stroke then it might be good for you. On the other hand, if you especially fear having a stroke, then you might not want to take it."

No one should start taking medications on their own without discussion with a health care professional, he said. Doctors and certain other providers can calculate risks based on age, personal habits and medical histories.

Other authors of the study are Drs. Michael Hayden, former Robert Wood Johnson scholar at UNC now at Duke University; Christopher Phillips, former UNC fellow in preventive medicine now with the U.S. Air Force; and Cynthia Mulrow, professor of medicine at the University of Texas. Mulrow also is deputy editor of Annals of Internal Medicine and a member of the task force.

The new research is most applicable for middle-aged men because the studies reviewed included relatively few women and few very old people as subjects, Pignone said. Trials involving large numbers of women are under way.

More information is available at http://www.ahrq.gov/clinic/3rduspstf/aspirin/.

The RTI-UNC team is one of 12 AHRQ Evidence-Based Practice Centers in the United States and Canada. These centers review all the relevant literature on designated topics related to prevention, diagnosis, treatment, and management of common diseases and clinical conditions. Their reports provide health care practitioners and the public with important guidance for medical decisions. www.rti.org/epc

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