Persistence of Oral Anticoagulants in Japanese Patients with Atrial Fibrillation:Non-Vitamin K Antagonist Oral Anticoagulant versus Warfarin

Atrial fibrillation (AF) is the most common form of tachyarrhythmia and a well-known stroke risk. [1-4]. Many studies have demonstrated that vitamin K antagonists such as warfarin reduce the incidence of stroke in AF patients [4,5]. In a “real world” setting, however, a US cohort study showed that one-fourth of patients initiating warfarin for the first time for AF discontinued treatment within the first year [6]. Adherence to long-term anticoagulation therapy is a key for the prevention of stroke in at-risk AF patients. Since the approval of dabigatran by the U.S. Food and Drug Administration (FDA) in 2010, and in Japan in 2011, non-vitamin K antagonist oral anticoagulants (NOACs) have appeared in clinical practice. Large-scale randomized clinical trials (RCTs) assessing their application have shown NOACs to be as safe and effective as warfarin in patients with non-valvular AF (NVAF). Adherence to medication in RCTs is often high because selected patients are enrolled in these studies and patient adherence is attentively monitored [7].