Study Design and Baseline Characteristics of the EXPAND Study: Evaluation of Effectiveness and Safety of Xa Inhibitor, Rivaroxaban for the Prevention of Stroke and Systemic Embolism in a Nationwide Cohort of Japanese Patients Diagnosed as Non-Valvular Atrial Fibrillation

The use of rivaroxaban, a factor Xa inhibitor, has been increasing for prevention of ischemic stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF) in Japan. We conducted the nationwide multicenter study, termed as the EXPAND Study, to address its effectiveness and safety in the real-world practice of patients with non-valvular AF in Japan. The EXPAND Study is a prospective, non-interventional, observational cohort study to evaluate the effectiveness and safety of rivaroxaban in non-valvular AF patients in a real-world clinical practice. A total of 7,178 patients with non-valvular AF were enrolled in 684 medical institutes between November 20, 2012 and June 30, 2014. As for the baseline demographic and clinical characteristics of 7,164 patients, the proportion of female patients was 32.2%, and those of patients with creatinine clearance < 50 mL/min and non-paroxysmal (persistent or permanent) AF were 21.8% and 55.1%, respectively. The proportions of patients complicated with hypertension, congestive heart failure, diabetes mellitus, and a history of ischemic stroke were 70.9%, 25.9%, 24.3%, and 20.2%, respectively. The proportions of patients with a CHADS(2) score <= 1 and a CHA(2)DS(2)-VASc score <= 1 were 37.3% and 13.6%, respectively. They were followed up until March 31, 2016 for a mean follow-up period of approximately 2.5 years. The findings of the EXPAND Study will help to establish an appropriate treatment with rivaroxaban for Japanese patients with non-valvular AF.