Science / Medicine : Warfarin Eases Risk of Strokes

Low doses of blood-thinning drugs are highly effective in reducing the risk of strokes caused by abnormal heartbeats, a study confirms. Such strokes afflict 75,000 Americans annually.

In March, a major study found that a single daily aspirin tablet dramatically reduced strokes triggered by atrial fibrillation, abnormally rapid beating of the heart’s upper chambers.

A new report, published last week in the New England Journal of Medicine, found that the drug warfarin also worked well in people with this condition.

Both aspirin and warfarin interfere with the body’s tendency to form blood clots. The heart’s rapidly beating chambers can produce these clots, which may travel to the brain and clog up blood vessels, causing strokes.

Warfarin, the active ingredient found in some brands of rat poison, is routinely used to prevent strokes in people with severe atrial fibrillation caused by damaged heart valves. However, doctors have been reluctant to use this medicine in people with milder cases because of the chance it could cause serious bleeding.

The new study found that the bleeding risk is slight when the drug is carefully controlled by physicians.