Safety and efficacy of direct oral anticoagulants in geriatric patients with non-valvular atrial fibrillation: A single-center retrospective study

Introduction Direct oral anticoagulants (DOACs) are widely employed for antithrombotic prophylaxis in patients with atrial fibrillation (AF). However, there is still uncertainty about their risk-benefit profile in older patients. Here, we evaluated the efficacy, safety, and dose appropriateness of DOACs in a real-world population of outpatients with non-valvular AF, with a specific focus on subjects aged over 80 years and/or with reduced renal function. Materials and methods Single-center retrospective study including patients who had been prescribed a DOAC between May 2014 and May 2021 for long-term anticoagulation in non-valvular AF. Patients anticoagulated for <4 weeks were excluded. The primary efficacy outcome was a composite of cardiovascular (CV) death, stroke, or systemic embolism. The primary safety outcome was major bleeding. Results A total of 1154 patients (median age 84 yrs., range 57–100 yrs.), among which 862 were 80 years and older, were included. In the subgroup of subjects ≥80 yrs., a subtherapeutic dose of DOAC was associated with an increased incidence of CV mortality, stroke, or systemic embolism (multivariable Cox regression, HR = 2.09, 95 % CI: 1.09–4.02), with no benefit in terms of prevalence of bleeding events (21.5 % vs. 18.6 %, p = 0.428), and the incidence of adverse safety and efficacy outcomes was not increased in patients with a reduced renal function (eGFR ≤30 mL/min). Plasma concentration of DOACs, assessed in a subset of 367 patients, did not increase with advanced age (≥ 80 yrs., two-way ANOVA, p = 0.656) nor with declining eGFR (≤30 mL/min, two-way ANOVA, p = 0.643) and was not associated with adverse safety and efficacy outcomes. Conclusions Data from our study support the use of DOACs in populations of older adults and remark on the risks associated with inappropriate prescriptions in terms of CV mortality and adverse events.