Introduction
Direct oral anticoagulants (DOACs) are widely used for treatment and prophylaxis of atrial fibrillation (AF), ischemic stroke, deep vein thrombosis (DVT), and pulmonary embolism (PE). The recent 2019 AHA/ACC/HRS Focused Update of the 2014 guidelines for management of patients with AF states that DOACs are recommended over warfarin in eligible patients [1]. Although warfarin has been the most widely used oral anticoagulant, due to its shortcomings including a narrow therapeutic range and wide inter-and intra-individual variability [2], DOACs are currently preferred in many clinical settings [3, 4].
Among DOACs, edoxaban is the most recently introduced drug [5] and has mainly been used as an alternative to other DOACs. However, after many studies showed that both high-dose and low-dose edoxaban were not inferior to warfarin for stroke prevention and associated with a significantly lower incidence of bleeding complications [6-9], edoxaban became a representative DOAC [1]. Hence, edoxaban is likely to be prescribed more widely in the future, depending on the clinical setting or patient profile.
Bleeding complication is one of the major concerns during edoxaban usage [10]. The generally recommended dose of edoxaban for treatment of DVT/PE and AF is 60 mg once daily. In order to reduce the incidence of bleeding complications, patients with creatinine clearance (CrCl) 15 to 50 mL/min, weights of less than or equal to 60 kg, or who are taking certain concomitant P-glycoprotein (P-gp) inhibitors are recommended to take 30 mg once daily for treatment of DVT and PE instead [5]. However, Asian patients are known to be more prone to bleeding complications than patients of other ethnicities [11], opening possibilities of other risk factors that should be given special consideration for dosage adjustment in this specific ethnic group. In this context, this study aimed to provide evidence of the association between risk factors and bleeding complications in Asian patients with an appropriate edoxaban dosage regimen.