Perspective:

This analysis is one of the largest nondirect comparisons between apixaban and rivaroxaban for stroke prevention in AF. Three important findings are reported. First, the overall rate of bleeding is modest (~1-2% per year) in the first year of therapy. These mostly represented gastrointestinal bleeds and not the more critical intracranial bleeds. However, other types of bleeding (e.g., epistaxis, retroperitoneal) were not measured. Second, the rate of bleeding appears to be lower with apixaban therapy as compared to rivaroxaban. This has been shown in other large observational studies. Third, the rate of ischemic stroke or embolism also was lower in the apixaban-treated patients. This has been shown in some (but not all) prior observational studies. However, a few important caveats must be considered. First, the follow-up period was relatively short (only ~9-10 months). Second, the outcomes relied on claims data, which are not as reliable as chart abstraction. Third, a large number of patients in each treatment group discontinued therapy. Fourth, the actual rate of aspirin use is unknown, as it is most commonly taken over-the-counter. And finally, as with all observational studies, unmeasured confounding cannot be addressed even with sophisticated propensity matching. Nonetheless, this analysis supports the findings from prior work in different populations that both apixaban and rivaroxaban have good overall safety and effectiveness profiles, with the possibility that apixaban therapy might be slightly safer and more efficacious.