Feb. 10, 2011 (Los Angeles) -- The experimental anti-clotting drug apixaban beat aspirin at preventing dangerous blood clots or strokes in people with the abnormal heart rhythm atrial fibrillation, according to final results of the so-called AVERROES trial.
Today, the final results were presented at the American Stroke Association International Stroke Conference 2011 and simultaneously published online in The New England Journal of Medicine.
If approved, apixaban will offer an alternative to the old standby, warfarin, which many people can't or won't take.
In the study of about 5,600 patients with atrial fibrillation in which warfarin therapy was considered unsuitable, apixaban cut the risk of stroke by more than half compared with aspirin.
For every 1,000 patients treated with apixaban instead of aspirin for one year, 21 strokes, nine deaths, and 33 hospitalizations will be avoided, says Hans-Christoph Diener, MD, chair of the department of neurology at the University of Essen, Germany.
However, two of 1,000 patients will suffer a major bleed, he says. Diener, who presented the results here on behalf of the AVERROES investigators, consults for Bristol-Myers Squibb and Pfizer, which funded the study.
"The results of this trial will change medical practice," Diener tells WebMD.
The study followed patients with atrial fibrillation (AF), a condition characterized by irregular heart rhythms. The majority of patients with atrial fibrillation are more likely to suffer a stroke than people without atrial fibrillation because their irregular heartbeats may allow blood to pool in an upper chamber of the heart. Pooled blood is more likely to form clots, which can travel to the brain and block blood flow, causing a stroke.
Warfarin is the usual treatment, but up to half of patients can't take it because of increased bleeding risk or drug interactions, or refuse to take it. If too much is given, you can suffer a dangerous bleed; take too little, and you're at risk for a deadly blood clot related to the atrial fibrillation.