News Release

Researchers Declare War(Farin) On Stroke

Peer-Reviewed Publication

American Heart Association

DALLAS, Dec. 9 -- Although the drug warfarin prevents up to 80 percent of strokes suffered by those who have atrial fibrillation, which is irregular heart beat, it is woefully underused in the patients who have this common heart condition, according to a study in this month's Stroke, a journal of the American Heart Association.

The researchers examined 272 patients who had atrial fibrillation, which results in an increased risk for clot formation in the heart. They found only 38 percent received warfarin, a blood thinner used to decrease the tendency for blood to form clots. Of those not given warfarin, 63 percent were also not taking aspirin, another drug proven to fight stroke. In those studied who had at least one additional risk factor for stroke and had no mitigating condition to prevent use of warfarin, only 40 percent received the drug.

"We have a medication that has been shown to be highly effective, but we have found that the medical community is not getting this therapy to all of the patients who need it," says Lawrence M. Brass, M.D., professor of neurology at Yale University. "Physicians know that atrial fibrillation is a risk factor for stroke and most report they use warfarin to treat it on a regular basis. However, less than half of patients with atrial fibrillation are actually getting warfarin."

When the upper portion of the heart (the atria) is pumping irregularly, some blood does not get circulated through the heart, which can result in the formation of blood clots. Warfarin is prescribed for patients with atrial fibrillation to prevent potential clots.

Atrial fibrillation, which affects approximately 2.5 million Americans, is a major risk factor for stroke. Complications of atrial fibrillation are a contributing factor in about 15 percent of the 500,000 strokes that occur each year in the United States. According to Brass, warfarin can prevent many of the strokes that occur in people with atrial fibrillation. He adds that full implementation of these preventive therapies could save thousands of lives and prevent tens of thousands of strokes. In addition, health care costs attributable to stroke treatment could be drastically lowered.

Aspirin has been shown to reduce the incidence of stroke by 20 percent in people with atrial fibrillation. Studies have shown that warfarin reduces the risk of stroke up to 80 percent in those with atrial fibrillation. "For patients who have this irregular heart beat, they should know they are at increased risk for stroke and work with their doctors to ensure that they are on the best stroke prevention therapy," says Brass, chief of the neurology service at the Veterans Administration Hospital of Connecticut.

Warfarin is more expensive than aspirin, one reason it is used less frequently. On average, a month's prescription of warfarin costs $10 compared to a few dollars for a similar amount of aspirin. Patients on warfarin usually take one tablet per day and then have the dosage adjusted as per a doctor's recommendation in the months following initial treatment.

The variables associated with the use of warfarin were younger age groups, prior stroke or transient ischemic attack (TIA) and the use of beta-blockers, ACE inhibitors or diuretics. Those with limited activities of daily living or using aspirin were found to have a lower rate of warfarin use. For those with coronary disease, there was a trend toward a higher rate of warfarin use.

In response to their findings, Martha Radford, M.D. and her fellow researchers in Connecticut have initiated performance improvement programs that include a reminder system for physicians who treat patients with atrial fibrillation. This initiative has increased the rate of warfarin use by up to 50 percent over a 24-month period, says Brass.

The study is part of the Connecticut Peer Review Organization (CPRO), an effort launched to improve quality of care for Medicare patients in Connecticut hospitals. The cohort consisted of 635 Medicare patients aged 65 and older discharged from Connecticut hospitals between Jan 1, 1994 and June 30, 1994. Co-authors of the study are Harlan M. Krumholz, M.D.; Jeanne M. Scinto, Ph.D., M.P.H.; and Martha Radford, M.D.

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Media advisory: Dr. Brass can be reached at (203) 785-3351. Reporters may call (214) 706-1173 for copies of the report. (Please do not publish telephone number.)


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