Anticoagulant therapy in atrial fibrillation : vitamin K antagonists or novel oral anticoagulant drugs?

Abstract

Atrial fibrillation carries a five-fold increased risk of stroke and it is estimated that more than 20% of stroke in elderly patients may be attributable to atrial fibrillation.1 The use of vitamin K antagonists (VKAs) significantly reduces the rate of stroke by 64%,2 but it is hampered by the risk of severe bleeding episodes which occur in 2–13% of the patients.3 As a consequence, only half of the atrial fibrillation patients at high thromboembolic risk receive anticoagulant treatment in clinical practice.4 Recently, novel, direct, target-specific oral anticoagulant drugs have been shown to be at least as effective and at least as safe as VKAs.