When warfarin can hurt
Two drugs are not always better than one when it comes to using blood thinners to treat clogged arteries in the legs, U.S. researchers have reported.
They found that adding a blood thinner such as warfarin to daily clot-preventing drugs such as aspirin is no better -- and sometimes more dangerous -- for preventing heart attacks, strokes and other circulatory problems in people with peripheral artery disease.
About 1 in 16 people over 40 -- 8.5 million people in the United States -- have some degree of clogging in the arteries outside their hearts. They face a higher risk of death from heart disease.
Doctors have known for years that anti-platelet drugs such as aspirin reduce that risk.
Because blood thinners are used to treat clots that develop from peripheral artery disease, researchers thought adding them to the mix might cut the risk further.
The new study, in the July 19 issue of the New England Journal of Medicine, shows that such hopes are unfounded.
Results from 2,161 volunteers treated at 80 medical centers in seven countries demonstrate that adding the second drug had virtually no effect on the risk of heart attack, stroke, a severe clot outside the heart, or death from any type of heart disease.
The rates were 15.9% in the combination group and 17.4% in the anti-platelet-only group, an insignificant difference.
However, 4% of the people getting combination therapy suffered life-threatening bleeding, compared with just 1.2% getting an anti-platelet drug.
