USA: Incident atrial fibrillation (AF) is associated with a modest dementia risk that is more prominent in younger patients and those without chronic kidney disease, a large study of diverse adults in California has shown. The risk, however, did not vary across ethnicity, race, or sex.
The study's findings were published in The Journal of the American Heart Association on 8 Mar 2023.
In the study of nearly 200,000 adults, incidence rates for dementia over a median follow-up of 3.3 years were 2.79 versus 2.04 per 100 person-years in individuals with versus without atrial fibrillation, respectively. (This means that over one year, there would be an average of 2.79 dementia diagnoses among 100 people with atrial fibrillation and 2.04 diagnoses among 100 people without atrial fibrillation. This translates to 279 per 10,000 and 204 per 10,000.)

After adjustments, atrial fibrillation was associated with a 13% higher risk of dementia. Adults aged <65 years had a 65% higher risk than older adults, and those without chronic kidney disease had a 14% higher risk than those with chronic kidney disease.
Key findings include:
Incidence rates (per 100 person‐years) for dementia over a median follow‐up of 3.3 (interquartile range, 1.7–5.4) years were 2.79 and 2.04 per 100 person‐years in persons with versus without incident AF, respectively.
In adjusted models, incident AF was associated with a significantly greater risk of diagnosed dementia (subdistribution hazard ratio [sHR], 1.13).
With additional adjustment for interim stroke events, the association of incident AF with dementia remained statistically significant (sHR, 1.10).
Associations were stronger for age <65 (sHR, 1.65) versus ≥65 (sHR, 1.07) years; and those without (sHR, 1.20) versus those with chronic kidney disease (sHR, 1.06).
No meaningful differences were seen by sex, race, or ethnicity.
“These data highlight a possible link between atrial fibrillation and risk of subsequent dementia in certain populations. Further studies are needed to understand the mechanisms to explain this association, which may inform the use of treatments for atrial fibrillation,” said corresponding author Nisha Bansal, MD, MAS, of the University of Washington School of Medicine.
Reference:
Nisha Bansal, Leila R. Zelnick, Jaejin An, Teresa N. Harrison, Ming‐Sum Lee, Daniel E. Singer, Dongjie Fan and Alan S. Go, Published8 Mar 2023 Journal of the American Heart Association. 2023;0:e028290