Reduced Dose NOACs Compared with Warfarin for Afib Treatment

FEBRUARY 22, 2017
Jennifer Barrett, Assistant Editor

Reduced doses of non-vitamin K antagonist oral anticoagulants (NOACs) did not appear to show significant outcome differences in terms of stroke and bleeding rates compared with warfarin in patients with atrial fibrillation (AF), according to a results of a study led by researchers at the University of Denmark.
The researchers aimed to evaluate the clinical effectiveness and safety of apixaban 2.5 mg, dabigatran 110 mg, and rivaroxaban 15 mg compared with warfarin treatment using health care information from Danish health care databases.
Patients received either warfarin (69.9%), apixaban (7.9%), dabigatran (15.9%), and rivaroxaban (6.3%). The study focused on elderly patients and individuals with impaired renal function.
The patients were monitored through registries that followed the onset of treatment. Researchers measured the effectiveness outcome of ischemic stroke/systemic embolism and principal safety outcome of any bleeding events.
After 1 year, apixaban was linked with slightly higher, but not statistically significant, higher rates of ischemic stroke/systemic embolism (4.8%), followed by warfarin (3.7%), rivaroxaban (3.5%), and dabigatran (3.3%).
Stroke and bleeding rates were shown to be slightly higher (4.8%) with apixaban 2.5 mg than with warfarin, but not statistically significant. The lowest event rate was dabigatran (3.3%), which was only slightly lower than rivaroxaban (3.5%) and warfarin (3.7%). Thromboembolic rates were slightly lower with dabigatran 110 mg and rivaroxaban 15 mg than. Bleeding rates were not significantly different for apixaban and rivaroxaban, but were significantly lower for dabigatran compared with warfarin.
The researchers concluded that there were few outcomes differences between patients who received reduced doses of NOACs compared with patients who received warfarin treatment.
Nielson PB, Skjøth F, Søgaard M, et al. Effectiveness and safety of reduced dose non-vitamin K antagonist oral anticoagulants and warfarin in patients with atrial fibrillation: propensity weighted nationwide cohort study. BMJ. 2017;356:j510. doi: