Incident Atrial Fibrillation: Direct Oral Anticoagulants vs Warfarin
Individual anticoagulant agents were not assessed for their effect on stroke or mortality risk.
Direct oral anticoagulants (DOACs) are associated with a lower risk for stroke and death compared with warfarin in patients with incident atrial fibrillation (AF), according to a study published in the Journal of the American Heart Association.
In this population-based cohort study, investigators evaluated a total of 34,965 patients with incident AF to determine outcomes related to DOACs and warfarin anticoagulant. Participants were taking either warfarin (n=9292), apixaban (n=1786), dabigatran (n=3156), or rivaroxaban (n=4654) at the time of an event or study termination.
In the entire cohort, patients taking DOACs had a lower risk for both hemorrhagic stroke (hazard ratio [HR], 0.60; 95% CI, 0.40-0.91) and all stroke and death (HR, 0.90; 95% CI, 0.83-0.97) compared with patients taking warfarin.
Although there were reductions in the risk for ischemic stroke in the DOAC arm vs patients not taking anticoagulation therapy, similar risks for ischemic stroke were observed between those taking DOACs and those taking warfarin (HR, 1.12; 95% CI, 0.94-1.34). During the trial period, the use of DOACs increased and surpassed the use of warfarin.
The investigators did not assess the effect of individual DOACs on stroke or mortality risk, which may limit the findings. Additionally, the researchers suggested the potential existence of residual confounding as a result of unmeasured clinician, patient, and health system data.
Findings from this trial also indicated that anticoagulation is currently underused in patients with high-risk AF, and “the increasing use of DOACs is not yet closing the gap between scientific evidence and clinical practice in the general population.”
Yu AYX, Malo S, Svenson LW, Wilton SB, Hill MD. Temporal trends in the use and comparative effectiveness of direct oral anticoagulant agents versus warfarin for nonvalvular atrial fibrillation: a Canadian population-based study [published online October 28, 2017]. J Am Heart Assoc. doi:10.1161/JAHA.117.007129