The new oral anticoagulants.

In patients with nonvalvular atrial fibrillation oral anticoagulation with the vitamin K antagonists acenocoumarol, phenprocoumon and warfarin reduces the risk of stroke by more than 60%, whereas single or double antiplatelet therapy is much less effective and sometimes associated with a similar bleeding risk as vitamin K antagonists. Besides bleeding, INR monitoring and high interindividual variability remain the largest drawbacks of vitamin K antagonists. In the last decade oral agents have been developed that directly block the activity of thrombin (factor IIa), as well as drugs that directly inhibit activated factor X (Xa), which is the first protein in the final common pathway to the activation of thrombin. These agents have huge advantages in that they do not need monitoring and have a fast onset and offset of action. This survey addresses the role of classical and modern anticoagulation in stroke prevention in atrial fibrillation. (Neth Heart J 2010;18:314-8.).