Oral anticoagulant (OAC) therapy is associated with decreased risk for dementia among patients with nonvalvular atrial fibrillation (NVAF), according to results of a study published in Neurology.
Data for this study were sourced from the Clinical Practice Research Datalink (CPRD) database that has been collecting patient information from over 700 general practices in the United Kingdom since 1987. For this study, patients (N=142,227) aged older than 50 years with incident atrial fibrillation (AF) diagnosed between 1988 and 2017 were evaluated for dementia risk through 2019.
The study population comprised individuals with a mean age of 74.9 (SD, 10.0) years, 47.5% were women, 24.1% were obese, 67.0% had hypertension, and 20.4% were taking 12 or more classes of medications.
Within the first 3 months after AF diagnosis, 59,226 individuals used OACs and 83,001 did not.
Among the OAC users, there were 4354 dementia events during a 380,947 person-year follow-up and for the non-users, 3669 dementia events during a 281,719 person-year follow-up. Overall, after adjusting for 54 covariates, risk for dementia was decreased among OAC users compared with non-users (adjusted hazard ratio [aHR], 0.88; 95% CI, 0.84-0.92). Dementia risk tended to decrease with duration of use from 2 or fewer (aHR, 0.90; 95% CI, 0.84-0.95) to more than 5 (aHR, 0.88; 95% CI, 0.81-0.95) years of OAC use.
In subgroup analyses, risk for dementia was decreased for OAC users who had ischemic stroke or transient ischemic attack (aHR, 0.82), were aged 75 years or older (aHR, 0.84), did not have chronic kidney disease (aHR, 0.87), had a CHA2DS2-VASc score of 2 to 9 (aHR, 0.87), had a CHADS2 score of 0 to 1 (aHR, 0.88), and were men (aHR, 0.90) compared with their non-OAC user counterparts.
Stratified by type of dementia, OAC use was associated with lower risk for Alzheimer disease (HR, 0.90; 95% CI, 0.82-0.99) and unspecified dementia (HR, 0.77; 95% CI, 0.71-0.83) but not for other dementia subtypes.
Similar findings that OAC therapy decreased risk for dementia were observed in a sensitivity analysis with antiplatelet use as an active comparator (aHR, 0.87; 95% CI, 0.83-0.92) and in a propensity-matched analysis (aHR, 0.85; 95% CI, 0.81-0.89).
The results of this study may be limited as no data about treatment compliance are available.
“…when balancing the risks and benefits of OAC use in these patients, the potential benefit of OACs in preventing dementia is an important consideration for the management of NVAF,” the study authors wrote.
Rahman A, Michaud J, Dell’Aniello S, et al. Oral anticoagulants and the risk of dementia in patients with nonvalvular atrial fibrillation: a population-based cohort study. Neurology. Published online December 29, 2022. doi:10.1212/WNL.0000000000206748