Efficacy of anticoagulation therapy in elderly patients with clinically diagnosed Alzheimer’s disease and atrial fibrillation: a clinical outcomes study

Introduction Clinically diagnosed Alzheimer’s disease (AD) and atrial fibrillation (AF) are prevalent in the elderly, and their co-occurrence presents a complex management dilemma, balancing stroke prevention against bleeding risks, particularly in the context of cognitive impairment. This real-world cohort study aimed to evaluate the clinical outcomes of anticoagulant therapy in elderly patients with AD and AF. Methods We analyzed data from 342 patients (mean age 78.5 years; 58.3% female) with non-valvular AF and AD. Patients were categorized into anticoagulant ( n = 247; 72.2%) and non-anticoagulant ( n = 95; 27.8%) groups, with direct oral anticoagulants (DOACs) used in 57.9% of treated patients. Over a mean follow-up of 2.1 years, outcomes were compared between groups. Results Anticoagulation was associated with a significantly lower incidence of ischemic stroke/systemic embolism (annualized rate 2.9% vs. 7.1%; hazard ratio [HR] = 0.35, 95% CI 0.17–0.73, p = 0.005) and all-cause mortality (6.3% vs. 15.1%; HR = 0.32, 95% CI 0.19–0.54, p < 0.001) compared to no anticoagulation. DOACs were superior to warfarin in preventing stroke/embolism (HR = 0.36, 95% CI 0.15–0.87, p = 0.022). While major bleeding was higher with anticoagulation (6.1% vs. 0.9%; HR = 4.31, 95% CI 1.02–18.19, p = 0.047), the critical risk of intracranial hemorrhage was not significantly increased (1.6% vs. 1.0%; HR = 0.46, 95% CI 0.11–1.98, p = 0.30), and DOACs demonstrated a safer profile versus warfarin for major bleeding (HR = 0.24, 95% CI 0.06–0.89, p = 0.034). Key predictors for bleeding and thromboembolism, for example, advanced age, previous stroke history, and high HAS-BLED scores, were identified. Discussion In conclusion, anticoagulation, particularly with DOACs, provides a favorable net clinical benefit by significantly reducing stroke and mortality without a marked increase in intracranial hemorrhage in elderly AD patients with AF, supporting its judicious use. Further prospective studies are warranted to refine personalized decision-making. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251271276 , Identifier: CRD420251271276.