Comparison of Low-Dose Direct Oral Anticoagulants for Patients <80 Versus ≥80 Years of Age With Atrial Fibrillation.

Evidence on the efficacy and safety of low-dose direct oral anticoagulant (DOAC) in older patients with nonvalvular atrial fibrillation is still scarce. We conducted a single-center prospective registry of patients with nonvalvular atrial fibrillation treated with DOACs: the DIRECT registry (n = 2,216; follow-up, 407 ± 388 days, UMIN000033283). The whole population was divided into 2 groups: the older group (age ≥80 years, n = 548) versus the younger group (age <80 years, n = 1,668). Primary safety and efficacy end points were major bleeding according to the International Society on Thrombosis and Haemostasis criteria, and stroke or systemic embolism (SSE), respectively. Effects of known risk factors and low-dose DOAC on major bleeding and SSE were assessed using a multivariable Cox proportional hazards model. In the older group, low-dose DOAC was associated with lower bleeding events (hazard ratio 0.279, 95% confidence interval 0.087 to 0.892, p = 0.031) but was not associated with increased SSE (p = 0.894). In the younger group, low-dose DOAC was neither associated with risk of major bleeding nor SSE (both p >0.05). In conclusion, in older patients, low-dose DOAC was associated with reduced risk of major bleeding without compromising its efficacy.