Oral Anticoagulants in Very Elderly Nonvalvular Atrial Fibrillation Patients With High Bleeding Risks
Ken Okumura, Takeshi Yamashita, Masaharu Akao, Hirotsugu Atarashi, Takanori Ikeda, Yukihiro Koretsune, Wataru Shimizu, Shinya Suzuki, Hiroyuki Tsutsui, Ḱazunori Toyoda, Atsushi Hirayama, Masahiro Yasaka, Takenori Yamaguchi, Satoshi Teramukai, Tetsuya Kimura, Y Morishima, Atsushi Takita, Hiroshi Inoue
Abstract
Background: Data on the effectiveness and safety of oral anticoagulant (OAC) agents in very elderly nonvalvular atrial fibrillation patients with high bleeding risk are lacking. Objectives: This study examined 2-year outcomes and effects of OAC agents among these patients using the ANAFIE (All Nippon Atrial Fibrillation in the Elderly) registry (N = 32,275) data. Methods: score: ≥2; and presence of ≥1 bleeding risk factor: creatinine clearance of 15-30 mL/minute, prior bleeding at critical sites, body weight of ≤45 kg, or continuous antiplatelet use) and reference groups. Results: In the high-risk (n = 7,104) and reference (n = 25,171) group patients, 89.0% and 93.4%, respectively, used OAC agents. Of these, respectively, 30.1% and 24.2% used warfarin, and 58.9% and 69.1% used direct-acting OAC (DOAC) agents. Compared with the reference group, the high-risk group had higher incidences of stroke/systemic embolism, major bleeding, intracranial hemorrhage, gastrointestinal bleeding, cardiovascular events, and all-cause death. In the high-risk group, DOAC agent use vs nonuse of OAC agents was associated with reduced incidences of stroke/systemic embolism (HR: 0.53; 95% CI: 0.36-0.79) and all-cause death (HR: 0.65; 95% CI: 0.52-0.81) but not with major bleeding (HR: 1.09; 95% CI: 0.63-1.89). DOAC agents were superior to warfarin in effectiveness and safety. For high-risk patients, history of major bleeding, severe liver dysfunction, and falls within 1 year were independent risk factors for major bleeding. Conclusions: High-risk elderly nonvalvular atrial fibrillation patients had higher event incidences. DOAC agents were associated with reduced risk of stroke/systemic embolism and all-cause death vs nonuse of OAC agents or warfarin. (Prospective Observational Study in Late-Stage Elderly Patients With Nonvalvular Atrial Fibrillation [ANAFIE registry]; UMIN000024006).