Atrial fibrillation: a spectrum of risk with a uniform treatment effect of novel anticoagulants?

Abstract

This editorial refers to ‘Outcomes of apixaban vs. warfarin by type and duration of atrial fibrillation: results from the ARISTOTLE trial,’ by S. Al-Khatib et al. , doi:10.1093/eurheartj/eht135 The last several years have seen the completion of five pivotal outcomes trials evaluating three novel oral anticoagulants (NOACs) in > 55 000 patients with atrial fibrillation (AF) from around the world.1–5 Each of these studies has shown that the respective new agent is at least as efficacious as, if not superior to, warfarin in reducing stroke or non-central nervous system embolism; all three NOACs were shown to be superior to warfarin in reducing intracranial haemorrhage. The large, diverse populations enrolled across broad geographic regions and practice settings provide an opportunity to explore questions about the specific cohorts of patients with AF of clinical interest, the natural history of the disease, and the pragmatic challenges physicians confront each day in clinical practice. The analyses from the ARISTOTLE study database by Al-Khatib and colleagues6 provide important information about outcomes in groups with different subtypes of AF and about treatment effects with apixaban compared with placebo in the same subtypes. We agree with the authors' two primary conclusions: (i) patients with persistent or permanent AF have higher event rates (including rates of systemic embolus and bleeding complications) compared with patients with paroxysmal AF events after adjusting for baseline differences; and (ii) the effects of apixaban compared with warfarin in patients defined by AF subtype are consistent …