Impact of anticoagulation on cognitive decline and clinical outcomes in patients with atrial fibrillation and dementia: A retrospective cohort study

Background Atrial fibrillation (AF) and dementia frequently coexist in older adults, yet the impact of anticoagulation on cognitive and clinical outcomes in this population remains uncertain. Objective To evaluate the effects of anticoagulation on cognitive and clinical outcomes in patients with AF and dementia. Methods This retrospective cohort study included 291 patients aged ≥65 years with AF and dementia, treated at a tertiary center between January 2020 and December 2024. Patients were grouped by anticoagulation status. Cognitive, functional outcomes (Mini-Mental State Examination [MMSE], Activities of Daily Living [ADL], Clinical Dementia Rating–Sum of Boxes [CDR-SB]) and clinical endpoints (all-cause mortality, hospitalization, major adverse cardiovascular events, and bleeding) were assessed over a median 28-month follow-up. Results Anticoagulated patients were younger (82.8 versus 85.1 years, p = 0.01). Anticoagulation was associated with slower cognitive/functional decline, with medium effect sizes, ΔMMSE mean difference: 2.0 points (95% CI: −3.5 to −0.4; p = 0.048), ΔADL mean difference: 10.9 points (95% CI: −19.6 to −2.3; p = 0.02), ΔCDR-SB mean difference: −1.4 points (95% CI: 0.4 to 2.4; p < 0.01). In multivariable Cox models, anticoagulation reduced hospitalization risk (HR 0.60; 95% CI: 0.43–0.84; p < 0.01) and all-cause mortality (HR 0.59; 95% CI: 0.40–0.88; p = 0.01). Benefits were most pronounced in very mild dementia and Alzheimer's disease. Conclusions In this retrospective, confounder-adjusted study, anticoagulation was associated with slower cognitive/functional decline and lower hospitalization/mortality risk in AF and dementia patients. The findings warrant prospective research to investigate whether anticoagulation has disease-modifying effects in early-stage dementia.