Preventing Strokes in Arrhythmia Patients

Apixaban reduces bleeding and stroke risk in atrial fibrillation patients

(RxWiki News) Atrial fibrillation, a common heart arrhythmia, is generally treated with a standard drug warfarin. However, a study suggests a new drug might provide the same treatment, but with a lower risk of stroke and embolism.

Dr. Christopher Granger, study author and professor of medicine at Duke University, said the discovery is important because it shows that apixaban as compared to warfarin is 21 percent more effective in preventing stroke and systemic embolism. The finding were recently presented at the European Society of Cardiology's 2011 Congress in Paris.

"Ask your cardiologist about new medications."

Dr. Granger said apixaban use also resulted in a 31 percent reduction in major bleeding and patients were 11 percent less likely to die. The newer anticoagulant drug also cut the risk of hemorrhagic stroke by half.

This is key for atrial fibrillation patients who are at an increased risk of strokes and blood clots because of ineffective contraction of the upper chambers of the heart.

The findings were made during a large scale randomized, double-blind clinical trial called ARISTOTLE. During the trial, 18,201 patients at 1034 clinical sites in 39 countries took either apixaban or warfarin for an average of 1.8 years. The study revealed that apixaban is safer than warfarin with a substantially lower risk of bleeding and lower rates of discontinuation.

Apixaban also was found to have practical advantages over warfarin. It does not require monitoring and has few reactions with food or other medications. It also was better tolerated and patients were less likely to stop taking it.

Dr. Granger noted that only about half of patients who should be receiving treatment for atrial fibrillation are receiving it, mostly because warfarin has limitations. Patients who take warfarin must receive regular blood tests to monitor and adjust the dosage, and they have to skip certain foods and medications that could interfere with the drug's effect. Warfarin also increases the risk of bleeding including intracranial hemorrhage.

Warfarin is a vitamin K antagonist that has been shown to prevent blood clots and reduce the risk of strokes, while apixaban is an oral direct factor Xa inhibitor.

The research was published in the New England Journal of Medicine.

Review Date: 
August 28, 2011