Apixaban May Join Wafarin Combatting Clot For Patients With Atrial Fibrillation.

According to a post on NEJM blog and the release of the primary results of the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation trial (ARISTOTLE; ClinicalTrials.gov number, NCT00412984) indicate that Apixaban is actually superior to Wafarin.
The trial was to find if Apixaban was non inferior to Wafarin but the trail investigators found that apixaban was actually superior, reducing the risk of stroke or systemic embolism by 21% and the risk of major bleeding by 31%. In predefined hierarchical testing, apixaban, as compared with warfarin, also reduced the risk of death from any cause by 11%.

The Apixaban results follow two other, phase 3 trials that compared new anticoagulants with warfarin in patients with atrial fibrillation:
the Randomized Evaluation of Long-Term Anticoagulation Therapy trial (RE-LY, NCT00262600)(Connolly SJ, Ezekowitz MD, Yusuf S, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med 2009;361:1139-1151[Erratum, N Engl J Med 2010;363:1877.]
Full Text | Medline ) and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF, NCT00403767)- (Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med 2011;365:883-891 Full Text  | Medline ). The RE-LY trial evaluated the direct thrombin inhibitor dabigatran in two different doses, 110 mg and 150 mg, both administered twice daily. ROCKET AF evaluated the direct factor Xa inhibitor rivaroxaban at a dose of 20 mg once daily.

The trials have a number of similar conclusions. Apixaban, dabigatran, and rivaroxaban, as compared with warfarin, all significantly reduce the risk of hemorrhagic stroke. In fact, in all the studies, the reductions in the primary efficacy end point — which included hemorrhagic as well as ischemic stroke — were greatly influenced by this dramatic reduction in the risk of hemorrhagic stroke. Of the three drugs, only dabigatran at a dose of 150 mg holds the distinction of also having significantly reduced the risk of ischemic stroke as compared with warfarin; nonetheless, even in this case, there was a greater influence on hemorrhagic stroke than on ischemic cerebrovascular events. Similarly, the risk of particularly serious bleeding was reduced with each of the three drugs, as compared with warfarin, and apixaban therapy also resulted in lower rates of all major bleeding. Thus, the newer anticoagulants boast favorable bleeding profiles as compared with warfarin in patients with atrial fibrillation.

NEJM