Atrial fibrillation as an independent predictor of cognitive decline: a national inpatient sample analysis

Background Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with increased risk of stroke, heart failure, and mortality. Emerging evidence suggests that AF may also contribute to cognitive decline and dementia, even in the absence of overt cerebrovascular events, but this relationship remains incompletely characterized. Purpose To evaluate the association between atrial fibrillation and cognitive impairment in older adults, and to assess the impact of oral anticoagulation on dementia risk. Methods A retrospective analysis was conducted using the National Inpatient Sample (NIS) database from 2018 to 2023. Patients aged ≥65 years with a diagnosis of atrial fibrillation were included. Individuals with prior ischemic stroke or mechanical valves were excluded. Patients were stratified into three groups: AF without cognitive impairment, AF with cognitive impairment/dementia, and cognitive impairment without AF (control). Multivariable analyses were performed adjusting for age, sex, comorbidities, and anticoagulation use. Results A total of 187,452 hospitalised patients with AF were identified, of whom 36,215 (19.3%) had cognitive impairment or dementia. Compared with patients without AF, AF was independently associated with cognitive decline (adjusted OR 1.48; 95% CI 1.36–1.61). This association remained significant after excluding patients with prior stroke (OR 1.41; 95% CI 1.28–1.56). Patients receiving direct oral anticoagulants (DOACs) had a lower prevalence of cognitive impairment compared with those on vitamin K antagonists (14.9% vs 18.5%; p=0.008), suggesting a potential protective effect. Conclusion Atrial fibrillation is independently associated with cognitive impairment and may represent a preclinical marker of neurocognitive decline. The observed association persists even in the absence of overt stroke, supporting alternative mechanisms such as microembolism, hypoperfusion, and systemic inflammation. Anticoagulation, particularly with DOACs, may confer a protective effect. These findings highlight AF as a systemic condition with important neurocognitive implications and support early, comprehensive management strategies aimed at both cardiovascular and neurological outcomes.