Use of Direct Acting Oral Anticoagulants in Elderly Patients with Atrial Fibrillation: A Multicenter, Cross-Sectional Study in Spain.

Non-vitamin K antagonist oral anticoagulants (NOACs) have substantially improved anticoagulation. However, data on NOAC use among elderly patients are scarce. We sought to describe NOAC use among elderly AF patients in Spain. We performed a non-interventional, multicenter, multispecialty, cross-sectional study in elderly (≥75 years) AF patients treated with NOACs for stroke prevention. Patients' characteristics by NOAC treatment were compared using standardized differences (SDD). NOAC dosing was classified according to the Spanish summary of products characteristics (SmPC) into appropriate (recommended dose) and inappropriate (under and overdosed). Multivariate logistic regression analyses were used to explore factors associated with inappropriate dosing. 500 patients were included. Mean (SD) age was 81.5 (4.7) years, and 50% were women. Mean (SD) creatinine clearance was 57.4 mL/min (18.8), and 23.6% were frail. Dabigatran treatment totaled 38.4%, rivaroxaban 15.2%, apixaban 33.2%, and edoxaban 13.2%. Almost one-fourth of elderly patients treated with NOACs in Spain were inappropriately dosed (underdosing 14.4% and overdosing 9.6%). Underdosing was significantly associated with weight (OR = 1.03, 95%CI = 1.0-1.1), while higher a EHRA score decreased the risk of underdosing (OR = 0.47, 95%CI = 0.2-1.0). Overdosing was significantly associated with a history of ischemic stroke (OR = 2.95, 95%CI = 1.1-7.7). Addressing incorrect dosing among elderly AF patients is relevant to improve patient outcomes.