Perspective:

In the discussion and analysis of clinical trials of so-called novel oral anticoagulants, (or more recently, target-specific oral anticoagulants), much has been made of subgroup analyses suggesting that, in some studies, warfarin management was suboptimal, which may render the studies a less than ideal comparison of warfarin with the new agents. The present study suggests that even across all quartiles of INR control, there remained a consistent trend toward superiority of apixaban over warfarin for the prevention of stroke and systemic embolism in atrial fibrillation. It is also important to note that bleeding outcomes were significantly improved with apixaban versus warfarin, and seemed to be consistently so across all quartiles of quality of warfarin care. And finally, it should be noted that the median TTR in this study was 66%, much higher than results achieved in most clinical settings. For all these reasons, this study should add to the growing clinical trial evidence suggesting that novel or target-specific oral anticoagulants result in similar or better outcomes than warfarin for the prevention of stroke in atrial fibrillation. In the case of apixaban, the current study suggests this would appear to be true regardless of the quality of warfarin therapy achieved. The European Society of Cardiology atrial fibrillation guidelines for 2012 have taken the position that this new class of drugs is preferred therapy over warfarin for the prevention of stroke and systemic embolism in atrial fibrillation. An update of the American College of Cardiology Foundation/American Heart Association atrial fibrillation guidelines is pending.