Paroxysmal atrial fibrillation and administration of antiplatelet therapy are still negative determinants of warfarin use in non-valvular atrial fibrillation patients treated by Japanese cardiologists.

nce patients with non-valvular atrial fibrillation (NVAF) develop cardioembolic stroke, the neurological symptoms are often severe and outcome is poor. Prevention of cardioembolic stroke is, therefore, important in those with NVAF, and warfarin for those with a CHADS2 score ≥2 is recommended and for those with a CHADS2 score of 1 it may be considered, according to the 2008 guideline of the Japanese Circulation Society for the management of AF.1 However, underuse of warfarin has become a big issue worldwide. Although the efficacy of warfarin for the prevention of stroke in NVAF patients is well established, many patients with NVAF who would benefit from warfarin treatment do not receive it. A systemic review indicated increasing age, increasing bleeding risk, previous bleeds, falls risk, comorbidities and ability to comply with warfarin therapy as factors influencing attitudes of physicians regarding warfarin therapy.2 In Japan, detailed analysis of the non-use of warfarin has not been performed.