A multicenter prospective cohort study to investigate the effectiveness and safety of apixaban in Japanese elderly atrial fibrillation patients (J‐ELD AF Registry)

BACKGROUND: A global, randomized clinical trial indicated the efficacy and safety of apixaban in stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). However, data in the elderly NVAF patients ≥75 years, especially those on reduced dose, are limited. HYPOTHESIS: To confirm the current dose reduction criteria of apixaban in elderly NVAF patients. METHOD: With a large-scale, multicenter prospective observational study, one-year outcomes after administration of on-label doses of apixaban were analyzed in Japanese NVAF patients aged ≥75 years. Endpoints were stroke or systemic embolism, bleeding requiring hospitalization, total death, and cardiovascular death. RESULTS: A total of 3031 patients (average age, 81.7 years; female, 48.2%) taking standard (5 mg bid) or reduced dose (2.5 mg bid) of apixaban were enrolled from 110 facilities. Standard and reduced apixaban doses were administered in 1284 (42.4%) and 1747 (57.6%) patients, respectively. Event rates (/100 person-years) in standard and reduced dose groups were 1.67 and 1.56, respectively, for stroke or systemic embolism, 1.42 and 2.25 for bleeding requiring hospitalization, 1.41 and 4.46 for total death, and 0.41 and 1.36 for cardiovascular death. Reduced apixaban dose was not significantly associated with stroke or systemic embolism and bleeding requiring hospitalization, but was independently associated with total and cardiovascular death. CONCLUSIONS: Incidences of stroke or systemic embolism and bleeding requiring hospitalization were similar between standard and reduced apixaban doses in the elderly NVAF patients. The incidences of total and cardiovascular death were significantly higher in the reduced dose group due to the coexisting higher risks in this group.