Clinical Outcomes of Direct Oral Anticoagulants and Warfarin in Japanese Patients with Atrial Fibrillation Aged ≥ 85 Years: A Single-Center Observational Study.

Background: Increasing age is associated with an increase in stroke in patients with nonvalvular atrial fibrillation (NVAF). Elderly patients have several comorbidities and increased bleeding risk.

Objective: The aim of this study was to evaluate the clinical outcomes of Japanese patients with NVAF aged ≥ 85 years who were treated with direct oral anticoagulants (DOACs) or warfarin.

Methods: We retrospectively studied the records of 358 patients with NVAF aged ≥ 85 years who had taken DOACs or warfarin between 2014 and 2018. The primary endpoints were the first occurrences of thromboembolic and bleeding events and death. The secondary endpoint was the discontinuation of oral anticoagulation (OAC) therapy.

Results: During a median follow-up period of 17 months, 24 patients died. The incidence (per 100 patient-years [PY]) of thromboembolic events was 1.8 in patients treated with DOACs and 2.2 in those treated with warfarin (adjusted subdistribution hazard ratio [SHR] 0.69; 95% confidence interval [CI] 0.23-2.12 in a competing model), and the incidence of major bleeding events was 3.1 and 4.2 in patients treated with DOACs and warfarin, respectively (adjusted SHR 0.95; 95% CI 0.32-2.86). The most common cause of bleeding events was gastrointestinal bleeding. A total of 33 patients permanently discontinued OAC therapy, at a median age of 89 years and with no differences between DOACs and warfarin. The most common reason for discontinuing OAC therapy was bleeding events.

Conclusion: Our results revealed that the incidences of thromboembolism and major bleeding among patients with NVAF aged ≥ 85 years were similar for those treated with DOACs and those treated with warfarin. Approximately 10% of patients permanently discontinued OAC therapy.