In patients with atrial fibrillation, anticoagulant therapy is recommended to prevent stroke. In the past, warfarin was recommended as an anticoagulant, but recently, novel anticoagulants called direct oral anticoagulants (DOAC; or non-vitamin-K oral anticoagulants (NOAC)) have been developed. Through a number of studies, particularly those conducted by the National Cerebral and Cardiovascular Center including the BAT (Bleeding with Antithrombotic Therapy) and SAMURAI-NVAF (Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-NonValvular Atrial Fibrillation) studies, various new findings have come to light concerning the relationship between antithrombotic agents, atrial fibrillation and stroke. However, as yet few details are known regarding the relationship between atrial fibrillation and dementia. Recently, reports have come out suggesting a risk of dementia with atrial fibrillation, but currently, much is unknown regarding the relationship between this mechanism and anticoagulants.

In FY2015, the National Center for Geriatrics and Gerontology, with support from the Japan Agency for Medical Research and Development, initiated the “Organized Registration for the Assessment of Dementia on Nation-wide General Consortium toward Effective Treatment in Japan,” otherwise known as the “ORANGE Registry.” In ORANGE Registry research, dementia is divided into stages: (1) the pre-clinical stage, (2) the mild cognitive impairment stage, and (3) the dementia care stage, with the goal of promoting social awareness of dementia, clinical trials and clinical research, and to prepare an infrastructure for implementing measures for dealing with dementia as reflected in the new ORANGE Plan. (Click here for details ).

In this study (Strategy to obtain warfarin or direct oral anticoagulant’s benefit by evaluating registry: Strawberry study), we investigate the relationship between oral anticoagulants, cognitive dysfunction and stroke in patients with atrial fibrillation using the ORANGE Registry research infrastructure as a foundation. Measures for dealing with dementia and stroke are a pressing issue for Japan and its ageing society. We have launched a website to allow people to learn about our research. We hope our study contributes to the treatment of dementia and stroke. We are most grateful for your continued guidance and encouragement.
Principal Investigator Naoki Saji, MD, PhD
(Vice Director, Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology)