Costello M, et al. - This phase III randomized controlled trials were undertaken to determine if the effect of non-vitamin-K oral anticoagulants (NOACs) varied by stroke severity compared with warfarin. The authors identified candidates who were randomized to receive NOACs or warfarin for stroke prevention in the setting of non-valvular atrial fibrillation. Acute stroke was reported in 1,403 participants (787 in the NOAC group and 616 in the warfarin group) in clinical trials assessing the NOACs usually prescribed in clinical practice (four trials). Findings suggested an association of NOACs with a lower risk of both fatal/disabling and non-disabling stroke vs warfarin for the prevention of stroke in atrial fibrillation.