WEDNESDAY, Sept. 25, 2002 (HealthDayNews) -- The blood thinner warfarin, by itself or with aspirin, is better than aspirin alone at preventing future heart and vessel problems in heart attack patients, a new study says.
But the clot-blocking drug causes more problems with bleeding than aspirin and doesn't seem to offer any survival benefit in the people who take it, the scientists who did the study said.
"We found that warfarin was superior to aspirin alone," wrote the researchers, whose study appears in tomorrow's New England Journal of Medicine. "We also found that the combination of moderate-intensity warfarin and a low dose of aspirin was the most effective therapy for the prevention of events after" heart attacks.
An estimated 1.1 million American suffer heart attacks each year, 450,000 of which are recurrent episodes. Nearly 13 million Americans have coronary heart disease, putting them at risk of heart attacks and strokes.
The study was conducted at 20 hospitals in Norway and included 3,630 men and women whose average age was about 60. All of them had suffered a heart attack that put them in the hospital. As a result, they were being treated for "secondary prevention" to ward off additional cardiovascular ailments.
A third were given aspirin alone and a another third got high-dose warfarin -- sold as Coumadin by Bristol-Myers Squibb. The remainder received a combination of aspirin and moderate-dose warfarin.
Over the next four years, on average, 20 percent of the patients on aspirin alone had another heart attack, a clot-related stroke or died, compared with 16.5 percent of those on warfarin. The rate of these bad outcomes for patients on both drugs was about 15 percent, or nearly 30 percent lower than in the aspirin group.
Yet while warfarin was more protective than aspirin, it led to a threefold-to-fourfold increased risk of major bleeding complications. These problems can mean more treatment and higher health-care costs for patients, though they aren't always life-threatening.
Dr. Richard Becker, a researcher at the University of Massachusetts Medical School in Worcester, called the findings "compelling." Several earlier trials of warfarin had turned up conflicting results, he said, so "the timing was right for doing this study."
Still, Becker, author of an editorial accompanying the journal article, said that in America the standard of care for heart attack patients -- angioplasty to clear blocked vessels and stenting to keep them open -- doesn't call for warfarin. Rather, doctors offer these patients drugs like aspirin and clopidogrel that prevent blood cells called platelets from clumping together. Giving these people warfarin would seriously increase their risk of dangerous bleeding.
On the other hand, Becker said, in countries that don't use stents and angiography as much as the United States, front-line warfarin treatment might be more appropriate.
What To Do
To find out more about heart attacks, try the American Heart Association or the Heart Information Network. For more on blood thinners, try the Texas Heart Institute.
