Aspirin's Benefits Unclear in PAD Patients
Analysis Fails to Clarify Role of Aspirin Therapy in Patients With Peripheral Artery Disease
May 12, 2009 -- A new analysis raises more questions about the benefits of aspirin therapy in patients with peripheral artery disease, a condition characterized by restricted blood flow to the arms and legs that is common among people with diabetes.
Like coronary artery disease (CAD), peripheral artery disease (PAD) is associated with an increased risk for heart attack and stroke.
But unlike coronary artery disease, it is not clear whether aspirin therapy helps reduce this risk.
In the new analysis of combined data from 18 randomized trials with more than 5,000 patients, daily aspirin therapy was not associated with a significant decrease in heart attacks and death from heart attack or stroke.
The research appears in the May 13 issue of the Journal of the American Medical Association.
Millions With PAD May Not Benefit From Aspirin
Between 8 million and 12 million Americans have PAD, according to the American Heart Association.
Study co-author William R. Hiatt, MD, of the University of Colorado, Denver, tells WebMD that about half of these patients also have known coronary artery disease and should definitely be on aspirin therapy.
But he adds that it is far from clear if the benefits of aspirin outweigh the risks in the roughly 4 million to 6 million patients with PAD who don’t have documented coronary artery disease.
“My interpretation is that there is really no compelling reason to prescribe aspirin to these patients, but I suspect that is going to be a bit controversial,” he says. “Others may beg to differ.”
In PAD, fatty deposits build up in the inner linings of the arteries that send blood to all parts of the body except the heart and brain. Just as CAD restricts blood flow to the heart, PAD restricts blood flow to the arms, legs, feet, and other major organs.
Many patients with PAD experience cramping in their legs during strenuous activity, but others have no symptoms at all.
The American Heart Association and the American College of Cardiology recommend aspirin therapy for patients with PAD, and the American Diabetes Association recommends aspirin for diabetic people at high risk of having a heart attack or stroke.
But negative findings from several recent studies have raised doubts the benefits of aspirin therapy in patients with PAD and diabetes.
Aspirin for PAD: More Study Needed
In the newly published analysis, Hiatt and colleagues combined data from trials comparing outcomes among patients with PAD who took aspirin therapy to those of patients who did not.
They found that:
- Aspirin therapy was associated with a 12% reduction in cardiovascular events, which was not statistically significant.
- A statistically significant (34%) reduction in nonfatal strokes was seen in the aspirin group.
- Most of the studies did not assess the incidence of major bleeding, which is the biggest risk associated with aspirin therapy.