[New oral anticoagulants: who really needs them?].

The new oral anticoagulants (NOAC) are alternative drugs to classical vitamin K antagonists (VKA) for stroke prevention in patients with nonvalvular atrial fibrillation. They have been shown in randomized trials to be superior to warfarin in reducing clinical endpoints, although at rather small effect sizes. However, in study centers with good anticoagulation management their superiority was barely significant. The effectiveness of anticoagulation therapy is crucially dependent on individual drug adherence. NOAC potentially decrease adherence due to several reasons, among them the twice-daily dosing requirement in some of them and the nonnecessity for anticoagulation monitoring. Anticoagulation monitoring is assumed to increase adherence per se. VKA are potentially better suitable to compensate for low adherence due to their long half-lives.