Clinical significance of non-vitamin K antagonist oral anticoagulants in the management of atrial fibrillation

Abstract

Atrial fibrillation (AF) is the most commonly observed rhythm disorder in clinical practice. It is associated with a high risk of thromboembolic stroke and increased cardiovascular mortality. Vitamin K antagonists (VKAs), the only oral anticoagulants used for thromboembolic prophylaxis in AF patients over the past 60 years, have been effective in reducing thromboembolic stroke, compared with placebo and aspirin, in this group of patients. However, VKAs have a very narrow therapeutic window, so regular monitoring of the therapeutic effect is obligatory for their use. The need for regular assessment of blood anticoagulation often causes dissatisfaction and reduces patients' quality of life. Non-VKA oral anticoagulants (NOACs), such as dabigatran, a direct thrombin inhibitor, and 3 factor Xa inhibitors, namely rivaroxaban, apixaban, and edoxaban, have been developed in recent years and have increased the armamentarium available to the physician for thromboprophylaxis in non-valvular AF (NVAF) patients. This review describes the characteristics of NOACs, analyzing aspects related to their use in the thromboprophylaxis of NVAF patients. It also discusses how to optimize NOAC therapy in specific clinical conditions, such as renal or liver impairment, and concomitant assumption of drugs potentially interfering with NOACs action. Finally, it focuses on NOAC-related bleeding management in the setting of non-cardiac surgery or radiofrequency catheter ablation of NVAF.