Editorial comment on ‘A novel approach indirectly comparing benefit: risk across oral antithrombotic therapies in patients with atrial fibrillation’. Are the evidences of current dose-adjusted anticoagulation with warfarin stroke prevention for patients with atrial fibrillation sufficient enough to compare with newly developed non-vitamin K oral anticoagulants?

In this issue of the Journal, Dogliotti et al . evaluated the risk and benefit of non-vitamin K antagonistic oral anticoagulants [new oral anticoagulants (NOACs)] using a meta-analysis of published trials and have concluded that NOACs should be preferred. New oral anticoagulants are used in atrial fibrillation (AF) patients to prevent strokes in the primary and secondary prevention settings.1,2 Since AF are reported to be an independent risk factor for strokes, antithrombotic therapies are recommended by practice guideline in various regions.1,2 Previously published meta-analysis of randomized clinical trials revealed that anticoagulation therapies reduce the risk of stroke in AF patients by 64% compared with placebo.3 Despite these evidences proving such high efficacy, anticoagulation therapies are not used widely. This is mostly due to the fear of increased risk of bleeding, shown in clinical trials and real-world patients, who have more complexities, compared with clinical trial patients with strict inclusion and exclusion criteria (Figure 1). Before NOACs were developed, vitamin K antagonists such as warfarin were the only clinically available oral anticoagulants for many countries. Thus the efficacy of anticoagulation compared with placebo in previous decade meant the preventive effects of … [↵][1]*Corresponding author. Tel: +81 463 931 121, Fax: +81 463 936 679, Email: sgoto3{at}mac.com, shinichi{at}is.icc.u-tokai.ac.jp [1]: #xref-corresp-1-1