Impact of Non-Vitamin K Antagonist Oral Anticoagulants on Intracranial Bleeding in Asian Patients With Non-Valvular Atrial Fibrillation

The incidence of intracranial bleeding is known to be markedly higher in Japan and other East Asian countries than in countries outside of East Asia. Non-vitamin K antagonist oral anticoagulants (NOACs) have much lower risk of intracranial bleeding than warfarin, so we reviewed the effect of this class of drugs on intracranial bleeding in Asian patients with non-valvular atrial fibrillation (NVAF). Warfarin therapy in Asian or East Asian populations appears to be associated with lower efficacy, poorer safety and a much greater risk of intracranial bleeding when compared with non-Asian or non-East Asian groups. Reflecting the higher incidence of intracranial bleeding in Asia and East Asia, Asian physicians in charge usually keep the prothrombin time-international normalized ratio (PT-INR) lower than is the case in Western countries. Irrespective of the lower PT-INR of warfarin, the incidence of intracranial bleeding is still high in Asia and East Asia. Because each NOAC strongly reduces the incidence of intracranial bleeding when compared with warfarin, use of dabigatran, rivaroxaban, apixaban or edoxaban would seem the best option for stroke prevention when treating Asian patients, including Japanese with NVAF.