Patient Characteristics and Real-World Treatment of Very Elderly Patients with Nonvalvular Atrial Fibrillation in Japan: An Administrative Claims Database Study.

Introduction: Very elderly patients with nonvalvular atrial fibrillation (NVAF) are at high risk for both ischemic and hemorrhagic events. This study aimed to understand the characteristics and real-world treatment of very elderly patients with NVAF in Japan.

Methods: We conducted a retrospective analysis of electronic health records and claims data from acute care hospitals for very elderly patients with NVAF with medical records available on or after their 80th birthday. The outcomes of interest were (1) characteristics of very elderly patients and (2) patterns of anticoagulation and impact of clinical condition on anticoagulation.

Results: Of 1,278,404 patients with newly diagnosed atrial fibrillation (AF), 443,820 were eligible for the analysis. Mean ± standard deviation age was 84.5 ± 5.5 years, CHADS score was 2.4 ± 1.0, and CHADS-VASc score was 4.3 ± 1.3. Among patients diagnosed with NVAF before age 80 years, 39.1% were not receiving anticoagulation therapy, while among those diagnosed with NVAF at age ≥ 90 years, 46.1% were not prescribed any anticoagulant. Patients diagnosed with NVAF before 80 years of age tended to stop anticoagulation therapy, especially those receiving warfarin, upon reaching 80 years of age. Among those who were newly diagnosed with NVAF after 80 years, most received reduced doses of direct oral anticoagulants (DOACs).

Conclusions: A significant proportion of very elderly patients with NVAF in Japan were diagnosed with NVAF after the age of 80 years and were not receiving anticoagulation therapy, particularly with increasing age. Furthermore, warfarin use declined with age, and patients on DOACs frequently received reduced doses.