Bahit, M. Cecilia

Easton, J. Donald

et al.

Lopes, Renato D.

Abstract: Background In the ARISTOTLE trial, the rate of stroke or systemic embolism was reduced by apixaban compared with warfarin in patients with atrial fibrillation (AF). Patients with AF and previous stroke or transient ischaemic attack (TIA) have a high risk of stroke. We therefore aimed to assess the efficacy and safety of apixaban compared with warfarin in prespecified subgroups of patients with and without previous stroke or TIA. Methods Between Dec 19, 2006, and April 2, 2010, patients were enrolled in the ARISTOTLE trial at 1034 clinical sites in 39 countries. 18\u2008201 patients with AF or atrial flutter were randomly assigned to receive apixaban 5 mg twice daily or warfarin (target international normalised ratio 2\ub703\ub70). The median duration of follow-up was 1\ub78 years (IQR 1\ub742\ub73). The primary efficacy outcome was stroke or systemic embolism, analysed by intention to treat. The primary safety outcome was major bleeding in the on-treatment population. All participants, investigators, and sponsors were masked to treatment assignments. In this subgroup analysis, we estimated event rates and used Cox models to compare outcomes in patients with and without previous stroke or TIA. The ARISTOTLE trial is registered with ClinicalTrials.gov, number NTC00412984. Findings Of the trial population, 3436 (19%) had a previous stroke or TIA. In the subgroup of patients with previous stroke or TIA, the rate of stroke or systemic embolism was 2\ub746 per 100 patient-years of follow-up in the apixaban group and 3\ub724 in the warfarin group (hazard ratio [HR] 0\ub776, 95% CI 0\ub756 to 1\ub703); in the subgroup of patients without previous stroke or TIA, the rate of stroke or systemic embolism was 1\ub701 per 100 patient-years of follow-up with apixaban and 1\ub723 with warfarin (HR 0\ub782, 95% CI 0\ub765 to 1\ub703; p for interaction=0\ub771). The absolute reduction in the rate of stroke and systemic embolism with apixaban versus warfarin was 0\ub777 per 100 patient-years of follow-up (95% CI  120\ub708 to 1\ub763) in patients with and 0\ub722 ( 120\ub703 to 0\ub747) in those without previous stroke or TIA. The difference in major bleeding with apixaban compared with warfarin was 1\ub707 per 100 patient-years (95% CI 0\ub7092\ub704) in patients with and 0\ub793 (0\ub7541\ub732) in those without previous stroke or TIA. Interpretation The effects of apixaban versus warfarin were consistent in patients with AF with and without previous stroke or TIA. Owing to the higher risk of these outcomes in patients with previous stroke or TIA, the absolute benefits of apixaban might be greater in this population

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Apixaban compared with warfarin in patients with atrial fibrillation and previous stroke or transient ischaemic attack : a subgroup analysis of the ARISTOTLE trial

Apixaban compared with warfarin in patients with atrial fibrillation and previous stroke or transient ischaemic attack : a subgroup analysis of the ARISTOTLE trial

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Institutional Repository Universiteit Antwerpen