Please login or register to print this page.

Clinical Articles, News & Views

Apixaban versus warfarin and aspirin: results from AVERROES and ARISTOTLE

The efficacy and safety of apixaban compared with aspirin are consistent in subgroups of patients who have previously attempted but failed Vitamin K antagonist (VKA) therapy, irrespective of the reason for discontinuation, according to a study published recently in the European Heart Journal.1

Of 5,599 patients, 2,216 (40%) had previously failed VKA treatment [main reasons: poor international normalised ratio (INR) control 42%, refusal 37%, bleeding on VKA 8%]. Compared with those expected to be unsuitable for VKA therapy, those who had previously failed were older, more often male, had higher body mass index, more likely to have moderate renal impairment and a history of stroke and less likely to have heart failure or to be medically undertreated.

The effects of apixaban compared with aspirin were found to be consistent in those who previously failed and those who were expected to be unsuitable, for both SSE (P interaction 0.13) and major bleeding (P interaction 0.74) and were also consistent among different subgroups of patients who had previously failed VKA therapy defined by reasons for unsuitability, age, sex, renal function, CHADS2 score, aspirin dose, duration, indication, and quality of INR control of prior VKA use.

Efficacy and safety of apixaban versus warfarin: the ARISTOTLE trial

The benefits of apixaban versus warfarin were found to be consistent in patients with atrial fibrillation (AF) regardless of age, according to another recent European Hear Journal study.2 Owing to the higher risk at older age, the absolute benefits of apixaban were greater in the elderly, say the authors.

A total of 18,201 patients with AF and a raised risk of stroke were randomised to warfarin or apixaban 5 mg b.d. with dose reduction to 2.5 mg b.d. or placebo in 831 patients with ≥2 of the following criteria: age ≥80 years, body weight ≤60 kg, or creatinine ≥133 μmol/L. The authors used Cox models to compare outcomes in relation to patient age during 1.8 years median follow-up. Of the trial population, 30% were <65 years, 39% were 65 to <75, and 31% were ≥75 years.

The rates of stroke, all-cause death, and major bleeding were higher in the older age groups (P < 0.001 for all). Apixaban was more effective than warfarin in preventing stroke and reducing mortality across all age groups, and associated with less major bleeding, less total bleeding, and less intracranial haemorrhage regardless of age (P interaction >0.11 for all). Results were also consistent for the 13% of patients ≥80 years. No significant interaction with apixaban dose was found with respect to treatment effect on major outcomes.


1. Coppens M, Synhorst D, Eikelboom JW, Yusuf S, Shestakovska O, Connolly SJ. Efficacy and safety of apixaban compared with aspirin in patients who previously tried but failed treatment with vitamin K antagonists: results from the AVERROES trial. Eur Heart J 2014;35:1856–63.

2. Halvorsen S, Atar D, Yang H, et al. Efficacy and safety of apixaban compared with warfarin according to age for stroke prevention in atrial fibrillation: observations from the ARISTOTLE trial. Eur Heart J 2014;35:1864–72.

Published on: August 5, 2014

Members Area

Log in or Register now.



Subscribe to our RSS feed


Sign up for our regular email newsletters & be the first to know about fresh articles and site updates.


    None Found


  • ArrhythmiaAlliance
  • Stars
  • Anticoagulation Europe
  • Atrial Fibrillation Association

You are not logged in

You need to be a member to print this page.
Sign up for free membership, or log in.

You are not logged in

You need to be a member to download PDF's.
Sign up for free membership, or log in.