Stroke prevention in atrial fibrillation: do we still need warfarin?

Oral anticoagulation with vitamin K antagonists (warfarin, phenprocoumon) is successful in both primary and secondary stroke prevention in patients with atrial fibrillation, yielding a 60-70% relative reduction in stroke risk compared with placebo, as well as a mortality reduction of 26%. However, these agents have a number of well documented shortcomings. Acetylsalicylic acid (ASA) reduces the relative risk of stroke by a nonsignificant 19% compared with placebo, and increased bleeding risk offsets any therapeutic gain from the combination of ASA with clopidogrel. This review describes the current landscape and developments in stroke prevention in patients with atrial fibrillation, with special reference to secondary prevention.

A number of new drugs for oral anticoagulation that do not exhibit the limitations of vitamin K antagonists are under investigation. These include direct factor Xa inhibitors and direct thrombin inhibitors. Recent studies (RE-LY, ROCKET-AF, AVERROES, ARISTOTLE) provide promising results for new agents, including higher efficacy and significantly lower incidences of intracranial bleeds compared with warfarin. The new substances show similar results in secondary as in primary stroke prevention in patients with atrial fibrillation.

New anticoagulants add to the therapeutic options for patients with atrial fibrillation, and offer a number of advantages over warfarin, for both the clinician and patient, including a favourable bleeding profile and convenience of use. Consideration of these new anticoagulants will improve clinical decision making.