Have you been told to take low-dose aspirin to prevent heart attacks? You may want to reconsider, assuming you don't show any symptoms. A new study finds that aspirin doesn't prevent heart attacks or strokes in people who have a high risk of heart disease yet show no symptoms. Half of the 3,350 people in the study were given low-dose aspirin after a screening test showed they had a higher-than-average risk for heart disease. They had a similar number of heart attacks and strokes to the other half of participants taking a placebo, researchers reported Tuesday in the Journal of the American Medical Association. The study is the first to look at an apparently healthy population, screen them for their heart disease risk using a test that detects artery blockages in their legs and then try to reduce that with aspirin, lead author F. Gerald Fowkes said. Aspirin has been shown to lower heart attacks in people who have symptoms of heart disease, and more studies are needed to find a way to prevent cardiovascular problems in people who have a high risk and no symptoms, he said. "One of the problems we have with coronary heart disease and stroke is we're still not that good at preventing it in people who are supposedly healthy," said Fowkes, a professor of epidemiology at the University of Edinburgh, in a telephone interview Tuesday. "We've not cracked that. This was an opportunity to pick people who are at increased risk and try to target a new population to try to prevent getting a heart attack or stroke." Research is needed to see if Lipitor and Crestor, two cholesterol-lowering drugs called statins, work in these patients to reduce their risk of heart attack or stroke, Fowkes said. Another approach is to test whether Plavix, an anti-clotting drug, works in this group. More than 81 million people in the United States have one or more forms of cardiovascular disease, including coronary artery disease, high blood pressure and chest pain, according to the American Heart Association. It is the leading cause of death in the U.S.
Aspirin helps prevent clots from forming in the arteries and has been shown to be effective in people who have symptoms of heart disease, said Jeffrey Berger, an assistant professor of medicine and surgery at New York University, who wrote an accompanying editorial in the journal.
"I still think aspirin is a very effective drug," Berger said Tuesday. "We just have to find the right population to do it in for prevention of first heart attack or stroke."
Fowkes said he isn't sure why aspirin didn't appear to work in the study. It may be that the trial wasn't large enough to detect a difference or people didn't continue taking their aspirin, he said.
The study included 3,350 people who had a low score on a test called the Ankle Brachial Index. The test measures blood pressure at the ankle compared with pressure in the arm. It is used to determine if someone has peripheral artery disease, or blocked arteries in their legs and other parts of the body, which increases the risk of heart attack and stroke.
Those in the study were randomly assigned to receive either a low- dose, 100 milligram aspirin tablet or a placebo. They were followed for about eight years. The researchers found that 181 people, or 10.8 percent, of the aspirin group and 176 people, or 10.5 percent, of the placebo group had a heart attack or stroke.
The study was sponsored in part by the British Heart Foundation and Bayer, maker of a low-dose aspirin for cardiac health.