Study design of J-ELD AF: A multicenter prospective cohort study to investigate the efficacy and safety of apixaban in Japanese elderly patients

Background: Apixaban, one of the non-vitamin K antagonist oral anticoagulants, was reported to be effective and safe in stroke prevention in patients with atrial fibrillation (AF) based on the global randomized clinical trial, but data are limited on the efficacy and safety of apixaban in Japanese elderly patients. Methods and results: The J-ELD AF Registry is a large-scale, contemporary observational study, continuously and prospectively registering elderly Japanese patients with AF aged 75 years or older who are currently taking apixaban or the elderly who are to receive apixaban in daily clinical practice, and accumulating the outcomes during one-year follow-up period. In addition to standard baseline characteristics, prothrombin time and anti-Xa activity will be measured to investigate the biomarker characteristics. The primary efficacy endpoints will be stroke and systemic embolism, and the primary safety endpoint will be major bleeding requiring hospitalization. The secondary endpoints in this study will be all-cause death, cardiovascular death, acute myocardial infarction, and the composite of stroke/ systemic embolism, cardiovascular death, and acute myocardial infarction. As a primary analysis, the primary/secondary endpoints in the enrolled patients will be totalized for the entire group, and the incidence of events will be described by age, CHADS2 score, HAS-BLED score, and apixaban dose (5 or 2.5 mg bid). The factors that independently predict the incidence of the primary/secondary endpoints will be searched for by Cox regression. The relationship between the biomarkers and the primary/ secondary endpoints will also be examined in an explorative manner. Conclusion: This study will provide important information on the efficacy and safety of apixaban in elderly Japanese patients aged 75 years or older, and those of low-dose administration of apixaban (2.5 mg bid) for which many of the Japanese elderly are indicated. (C) 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.