Hernandez I, et al. – This study assessed the safety as well as efficacy of warfarin and the new oral anticoagulants (NOACs) apixaban, dabigatran and rivaroxaban in atrial fibrillation (AF). Researchers reported that NOACs showed greater efficacy than warfarin in preventing stroke, systemic embolism (SE) and death, but offered different bleeding risk, with rivaroxaban having higher risk and apixaban lower risk than warfarin. Overall, apixaban demonstrated the most favorable effectiveness, safety and persistence profile.

Methods

• Researchers identified patients newly diagnosed with AF who initiated apixaban, dabigatran, rivaroxaban, warfarin or no oral anticoagulation therapy in 2013-2014, using 2013-2014 claims from a 5% random sample of Medicare beneficiaries.
• Outcomes included the composite of ischemic stroke, systemic embolism (SE) and death, any bleeding event, gastrointestinal bleeding, intracranial bleeding, and treatment persistence.
• They also constructed Cox Proportional Hazard models that controlled for patient characteristics to compare outcomes between each pair of treatment groups.

Results

• Findings reported that the composite risk of ischemic stroke, SE and death was lower for NOACs than warfarin: hazard ratio (HR) 0.86; 95%CI 0.76-0.98 for apixaban, 0.73; 95%CI 0.63-0.86 for dabigatran and 0.82; 95%CI 0.75-0.89 for rivaroxaban, all compared to warfarin.
• Researchers noted that there were no differences in effectiveness across NOACs.
• They also observed that the risk of any bleeding was lower with apixaban than warfarin (HR 0.79; 95%CI 0.70-0.90), but higher with rivaroxaban than warfarin (HR 1.15; 95%CI 1.07-1.24).
• In addition, data revealed that apixaban (HR 0.69; 95%CI 0.60-0.79) and dabigatran (HR 0.79; 95%CI 0.69-0.92) were associated with lower bleeding risk than rivaroxaban.
• According to results, treatment persistence was highest for apixaban (82%), and lowest for dabigatran and warfarin (64%) (p-value<0.001).