Abstract

Nonvalvular atrial fibrillation (AF) is a risk factor for stroke in elderly patients. Although warfarin has been used to prevent AF-associated stroke for more than 50 years, non-vitamin K antagonist oral anticoagulants (NOACs) including dabigatran, rivaroxaban, apixaban, and edoxaban recently have been developed to overcome the disadvantages of warfarin. Based on the results of NOAC clinical trials, Savelieva and Camm made recommendations regarding selection of NOACs in patients with nonvalvular AF. Recent accumulating evidence indicates that NOACs work differently in Asian and non-Asian individuals. In this review, we discuss the results of the large, randomized, phase 3 international clinical trials on NOACs, the subanalyses of Asians, and a Japanese phase 3 clinical trial of rivaroxaban to discriminate Japanese patient-specific characteristics with regard to their responses to NOACs and make recommendations. Our analysis revealed that rivaroxaban decreased the incidence of gastrointestinal (GI) bleeding compared with warfarin in Japanese patients. The efficacy results showed that rivaroxaban significantly decreased the incidence of ischemic stroke (hazard ratio: 0.40, 95% confidence interval: 0.17-0.96) compared with warfarin. The lower incidence of GI bleeding and ischemic stroke may be specific to Japanese patients. Based on the present and previous results, the following recommendations regarding the selection of NOACs are added in the Camm chart for Japanese patients: edoxaban for patients with a high risk of bleeding and those with a previous stroke; and rivaroxaban for patients with a high risk of ischemic stroke and a low bleeding risk, and those with previous GI bleeding.