DOACs associated with lower mortality in comparison to Warfarin, Finds study

"Misaligned DOAC dosing was common in nursing homes and was associated with clinical and mortality outcomes", exclaims Matthew Alcusky, the lead author from the Department of Population and Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA, USA.

Research comparing direct-acting oral anticoagulants (DOACs) to warfarin has excluded nursing home residents, a vulnerable and high-risk population. Therefore, the researchers carried out this study to compare the safety and effectiveness of DOACs versuswarfarin.

This new-user cohort study went on from 2011-2016 where US nursing home residents aged > 65 years with non-valvular atrial fibrillation were enrolled in fee-for-service Medicare for > 6 months. The initiators of DOACs (2881 apixaban, 1289 dabigatran, 3735 rivaroxaban) were 1:1 propensity-matched to warfarin initiators.

The main measures included ischemic stroke or transient ischemic attack (i.e., ischemic cerebrovascular event), bleeding (extracranial or intracranial), other vascular events, death, and a composite of all outcomes. Also, absolute rate differences (RD) and cause-specific hazard ratios (HR) with 95% confidence intervals (CI) were estimated. Subgroup analyses were performed by the alignment of DOAC dosing with labeling.

Based on the methodology, the main outcome observed by Alcusky and his colleagues was that the clinical outcome rates for dabigatran and rivaroxaban users were similar versus warfarin users.

On the other hand, the ischemic cerebrovascular event rates were higher among dabigatran and rivaroxaban users that received reduced dosages without an indication. And the overall apixaban users had higher ischemic cerebrovascular event rates and lower bleeding rates but outcome rates varied by dosing alignment.

To highlight the mortality risk, it was noted that the "Mortality rates (per 100 person-years) were lower for apixaban (RDs - 9.30; 95% CI - 13.18 to - 5.42), dabigatran (RDs - 10.79; 95% CI - 14.98 to - 6.60), and rivaroxaban (RDs - 8.92; 95% CI - 12.01 to - 5.83) versus warfarin; however composite outcome findings were similar."

Hence the authors drew the following conclusion-

"Among US nursing home residents, the DOACs were each associated with lower mortality versus warfarin. Misaligned DOAC dosing was common in nursing homes and was associated with clinical and mortality outcomes. Overall, DOAC users had lower rates of adverse outcomes including mortality compared with warfarin users."