(Medical Xpress)—An aspirin a day may not always keep heart disease away, say two University of Florida cardiologists. But a new algorithm they have developed outlines factors physicians should weigh as they assess whether a patient would benefit from a daily dose of the drug.
Approximately 50 million people in the United States pop a daily aspirin pill to treat or prevent heart disease. Of these, at least half take more than 100 milligrams of the drug—more than one baby aspirin—a day. Although aspirin has been widely used in cardiovascular medicine over the past 20 to 30 years, a review of research papers suggests that the widely used over-the-counter medicine does not benefit everyone to the same degree, report Dr. Ki Park and Dr. Anthony A. Bavry in the May issue of Cleveland Clinic Journal of Medicine.
"Not all patients with coronary disease are the same," said Park, a physician in the department of medicine's division of cardiovascular medicine.
Park and Bavry's algorithm leads physicians through a series of questions that consider the patient's age, sex and current health status. The answers help them determine whether the course of care should include aspirin.
"It's an evolving assessment that should be repeated every few years as conditions change," Park said.
Most studies on the effects of aspirin therapy in patients who had previous heart attacks have focused on men. While examining the literature, Park and Bavry found that less is known about the effects of aspirin on women, people with diabetes, the elderly and even patients who are at risk of a heart attack but have never had one.
"In this paper we highlight gaps in knowledge where we don't fully know if aspirin should be used or not," said Bavry, an assistant professor of cardiovascular medicine. "There's still room to study its optimal use."
While people may see aspirin as a harmless drug, taking a daily aspirin does carry some risk of side effects such as gastrointestinal bleeding. Park and Bavry's review contains an analysis to help physicians determine whether the risks outweigh the benefits.
Their review showed that while aspirin therapy remains a good way to prevent further heart attacks, more is not better. A low-dose aspirin, such as an 81-milligram pill, gives the same amount of protection as a standard dose of 325 milligrams and lowers the risk of bleeding.
But even at a lower dose, the current literature suggests certain patients may not benefit from aspirin therapy. In women, for instance, evidence shows aspirin can help prevent certain types of stroke, but does not appear to prevent heart attacks as effectively as it does in men. On the other hand, women appear to have a lower risk of gastrointestinal bleeding than men do.
Risk factors also change with age and the estimated 10-year risk for heart disease. The rise in use of cholesterol-lowering drugs called statins also can affect whether a patient should take aspirin. And aspirin therapy for patients with diabetes, who are automatically considered to be at high risk for cardiovascular disease, remains controversial.
"A lot goes in to estimating a patient's risk," Bavry said.