Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation

Jung, Byung Chun

Abstract

In patients with nonvalvular atrial fibrillation (AF), the risk of stroke is five times that of patients with a normal sinus rhythm. Antithrombotic therapy has a pivotal role for the prevention of stroke. With the advent of new oral anticoagulants (NOAC), the strategy of antithrombotic therapy has undergone significant changes due to its better efficacy, safety, and convenience when compared with warfarin or an antiplatelet regimen. Furthermore, new aspects of antithrombotic therapy in the prevention of stroke have revealed that the efficacy of antiplatelet regimens is weak while the risk of major bleeding is not significantly different to that of oral anticoagulant therapy, especially in the elderly. To reflect these pivotal changes, the previous guidelines for use of NOACs have been updated in recent years by various societies and associations. The Korean Heart Rhythm Society (KHRS) summarized the current evidence and updated its recommendations for stroke prevention in patients with nonvalvular AF. First of all, antithrombotic therapy must carefully consider and incorporate the clinical characteristics and circumstances of each individual patient, especially with regard to balancing the benefit of stroke prevention with the risk of bleeding. They recommend using the CHA2DS2-VASc score rather than the CHADS2 score to assess the risk of stroke, and suggest the HAS-BLED score be used to validate bleeding risk. In patients with truly low risks (lone AF, CHA2DS2-VASc score of 0), no antithrombotic therapy is recommended, whereas oral anticoagulant (OAC) therapy, including warfarin (INR 2-3) or NOACs, is recommended in patients with a CHA2DS2-VASc score > or = 2 unless contraindicated. In patients with a CHA2DS2-VASc score of 1, OAC therapy should be preferentially considered. When also factoring in the bleeding risk and patient preferences, antiplatelet therapy or no therapy could be the best treatment option.