Atrial fibrillation as a risk factor for cognitive decline and dementia

To assess whether AF is a risk factor for cognitive dysfunction we used prospective data on AF, repeat cognitive scores, and dementia incidence in adults followed over 45 to 85 years.

Data are drawn from the Whitehall II study, N = 10 308 at study recruitment in 1985. A battery of cognitive tests was administered four times (1997-2013) to 7428 participants (414 cases of AF), aged 45-69 years in 1997. Compared with AF-free participants, those with longer exposure to AF (5, 10, or 15 years) experienced faster cognitive decline after adjustment for sociodemographic, behavioural, and chronic diseases (P for trend = 0.01). Incident stroke or coronary heart disease individually did not explain the excess cognitive decline; however, this relationship was impacted when considering them together (P for trend 0.09). Analysis of incident dementia (N = 274/9302 without AF; N = 50/912 with AF) showed AF was associated with higher risk of dementia in Cox regression adjusted for sociodemographic factors, health behaviours and chronic diseases [hazard ratio (HR): 1.87; 95% confidence interval (CI): 1.37, 2.55]. Multistate models showed AF to increase risk of dementia in those free of stroke (HR: 1.67; 95% CI: 1.17, 2.38) but not those free of stroke and coronary heart disease (HR: 1.29; 95% CI: 0.74, 2.24) over the follow-up.

In adults aged 45-85 years AF is associated with accelerated cognitive decline and higher risk of dementia even at ages when AF incidence is low. At least in part, this was explained by incident cardiovascular disease in patients with AF.