Clopidogrel plus aspirin reduces major vascular events, but may increase hemorrhage risk
TUESDAY, March 31 (HealthDay News) -- In atrial fibrillation patients for whom vitamin K-antagonist therapy such as warfarin is not indicated, adding clopidogrel to aspirin reduces the risk of major vascular events but increases the risk of major hemorrhage, according to a study published online March 31 in the New England Journal of Medicine to coincide with the American College of Cardiology's 58th Annual Scientific Sessions held March 29 to 31 in Orlando, Fla.
Stuart J. Connolly, M.D., of McMaster University in Hamilton, Ontario, Canada, and colleagues randomly assigned 7,554 patients to receive either daily clopidogrel at a dosage of 75 mg, or placebo, in addition to aspirin.
After a median follow-up of 3.6 years, the researchers found that the rate of major vascular events was lower in the combination group than in the aspirin-alone group (6.8 percent per year versus 7.6 percent per year, respectively). They found that the difference was primarily due to a decreased rate of stroke (2.4 percent per year versus 3.3 percent per year). But the investigators also found that the combination group had a higher rate of major bleeding (2 percent per year versus 1.3 percent per year).
"The purpose of the ACTIVE-A trial was to determine if the addition of clopidogrel to aspirin would reduce major vascular events and stroke in patients with atrial fibrillation, at an acceptable risk of increased hemorrhage," Connolly said in a statement. "If you treated 1,000 patients over the course of three years by adding clopidogrel to aspirin, you would prevent 28 strokes, 17 of which would be fatal or disabling, and you would prevent six heart attacks. This would occur at a cost of 20 major hemorrhages."
The study was supported by Sanofi-Aventis and Bristol-Myers Squibb; several study authors disclosed financial relationships with both companies.