Abstract WP528: Safety and Effectiveness of Rivaroxaban Among Japanese Elderly Patients With Nonvalvular Atrial Fibrillation in Everyday Clinical Practice

Abstract

Introduction: Nonvalvular atrial fibrillation (AF) is common in elderly patients, who face increased risk of thromboembolism and bleeding during antithrombotic therapy. Xarelto post-authorization safety & effectiveness study in Japanese patients with atrial fibrillation (XAPASS) is a prospective observational post-marketing surveillance study mandated by the Japanese authority. It aims to examine safety and effectiveness of rivaroxaban in everyday clinical practice. This analysis evaluated one-year outcomes and patient characteristics associated with major bleeding or thromboembolic events among elderly patients enrolled in XAPASS. Methods: A total of 11,308 patients with AF newly starting rivaroxaban were enrolled between April 2012 and June 2014. As of September 2017, one year follow-up data were collected from 9578 patients, and 4685 patients (48.9%) were aged ≥75 years. Results: Patients aged ≥75 years had higher rates of major bleeding (2.22 versus 1.35 events per 100 patient-years; p=0.004), and the composite endpoint of stroke, systemic embolism or myocardial infarction (2.41 versus 1.21 events per 100 patient-years; p<0.0001) compared with those aged <75 years. Rates of intracranial hemorrhage were less than 1% in both patient groups aged ≥75 years and <75 years (0.85 versus 0.59 events per 100 patient-years). There was no significant difference in major bleeding or thromboembolism among patients in age groups of 75-79, 80-84, and ≥85 years. Multivariate analysis identified hepatic impairment and concomitant use of acetylsalicylic acid as risk factors of major bleeding events in patients aged ≥75 years (p=0.041 and p<0.0001, respectively). History of stroke was identified as a risk factor of thromboembolic events in the same patient group (p<0.0001). Conclusions: Although elderly patients had higher rates of bleeding and thromboembolic events than younger patients, no significant difference was found in the outcomes between age groups of 75-79, 80-84, and ≥85 years. Benefit and risk of antithrombotic therapy should be thoroughly assessed in elderly patients. Additionally, elderly patients with risk factors of bleeding or thromboembolic events should be carefully monitored while taking anticoagulants.