Treatment of nonvalvular atrial fibrillation with oral anticoagulants decreased dementia risk in a population-based cohort.

Nonvalvular atrial fibrillation may be a risk factor for dementia. In this population-based study, researchers assessed whether oral anticoagulant (OAC) use affected dementia risk in 142,227 patients (mean age, 75 years; 47% female) with a diagnosis of nonvalvular atrial fibrillation after entry into the United Kingdom Clinical Practice Research Database. Patients did not have a diagnosis of dementia or cognitive impairment at baseline. OACs included apixaban, dabigatran, rivaroxaban and warfarin. The primary outcome was a diagnosis of dementia at follow up. Covariates included age, sex, smoking, body mass index, calendar year of cohort entry, and other risk factors and comorbidities.

Dementia incidence was 12.1 per 1000 person-years. OAC use was associated with a 12% reduction in dementia risk overall – and reductions specifically in Alzheimer’s disease and unspecified dementia – compared with nonuse after adjustment for covariates. Cumulative OAC use also decreased dementia risk at 1.5 years, with stabilisation of risk afterwards. Decreased dementia risk was seen in OAC users aged 75 years or older, but not younger patients. Similar dementia risk rates were seen with direct OACs and vitamin K antagonists. OAC use was still associated with a decreased dementia risk after considering other factors such as antiplatelet use and stroke.

Comment: The results of this study support treatment of nonvalvular atrial fibrillation to decrease dementia risk, especially in older patients. Since outcomes were identified by diagnosis of dementia made in general clinical practice, prospective studies that include neuropsychological data, neuroimaging and biomarkers will provide useful insight into the strength of these associations.

Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Jennifer Rose V. Molano, MD
Associate Professor, Department of Neurology and Rehabilitation Medicine, The University of Cincinnati, Ohio, USA.

Rahman A, et al. Oral anticoagulants and the risk of dementia in patients with non­valvular atrial fibrillation: a population-based cohort study. Neurology 2022 Dec 29; e-pub (https://doi.org/10.1212/WNL.0000000000206748).

This summary is taken from the following Journal Watch titles: Neurology, Cardiology