In a subanalysis, apixaban (Eliquis) reduced the risk of stroke or systemic embolism and demonstrated fewer major bleeding events versus warfarin consistently across age groups, including older patients with nonvalvular atrial fibrillation.
Results were from a pre-specified subanalysis of the Phase 3 ARISTOTLE trial in relation to patient age. ARISTOTLE was designed to evaluate the efficacy and safety of apixaban compared to warfarin for reducing the risk of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (NVAF) and at least one additional risk factor for stroke. This subanalysis found consistent results across age groups for reducing the risk of stroke or systemic embolism, fewer major bleeding events and reducing the risk of all-cause mortality. These data were published recently in the European Heart Journal.
Apixaban was more effective than warfarin in reducing the risk of stroke or systemic embolism, was associated with less major bleeding, less total bleeding and less intracranial haemorrhage, regardless of age and in reducing all-cause mortality across age groups. The p-value for interaction across age groups was non-significant (p>0.11 for all) for the major outcomes of stroke or systemic embolism, major bleeding, and all-cause mortality, meaning that the results of this subanalysis were consistent with the overall results of the ARISTOTLE trial.
Although the ARISTOTLE trial was neither designed nor powered to investigate the differences for safety and efficacy of apixaban compared to warfarin for individual age groups, a pre-specified subanalysis of the ARISTOTLE trial was performed according to age. The efficacy and safety of apixaban compared with warfarin were assessed according to age during the 1.8 years median follow-up. Of the trial population, 30 percent were under age 65, 39% were 65 to 74 years old and 31% were 75 years or older. In the overall ARISTOTLE trial population, the rates of stroke, major bleeding and all-cause mortality were higher in the older age groups (p<0.001 for all) across treatment groups.