Risk of dementia in stroke-free patients diagnosed with atrial fibrillation: data from a population-based cohort
Key result
OAC use is linked to decreased dementia incidence in incident AF, which carries stroke-independent cognitive risk.
Why the study?
Longitudinal studies assessing the association between atrial fibrillation and dementia have shown inconsistent results, necessitating further investigation in a stroke-free elderly cohort.
Does incident atrial fibrillation increase the risk of incident dementia in stroke-free elderly patients?
Key Points
- To assess whether incident atrial fibrillation increases the risk of developing dementia in a longitudinal, community-based cohort of older adults without prior stroke.
- Analyzed data from 262,611 dementia- and stroke-free participants aged ≥60 years in the Korea National Health Insurance Service-Senior cohort between 2005 and 2012 over 1,629,903 person-years of follow-up.
- Tracked incident atrial fibrillation (observed in 10,435 participants) and evaluated incident dementia using propensity score-matched comparisons and stroke-censoring models.
- Dementia incidence was 4.1 per 100 person-years in the incident atrial fibrillation group versus 2.7 per 100 person-years in propensity-matched controls, with an adjusted hazard ratio of 1.52 (95% CI 1.43–1.63), remaining elevated after censoring for stroke (HR 1.27, 95% CI 1.18–1.37).
- Incident atrial fibrillation was associated with higher risks of both Alzheimer's disease (HR 1.31, 95% CI 1.20–1.43) and vascular dementia (HR 2.11, 95% CI 1.85–2.41).
- Among individuals with incident atrial fibrillation, oral anticoagulant therapy was associated with a lower risk of dementia (HR 0.61, 95% CI 0.54–0.68), while higher CHA2DS2-VASc scores correlated with increased dementia risk.
Study Design
Type
Cohort (n=262,611)
Structured PICO
Does incident atrial fibrillation increase the risk of incident dementia in stroke-free elderly patients?
P
Population
262,611 dementia- and stroke-free adults aged ≥60 years from a Korean national cohort, assessed from 2005 to 2012.
E
Exposure
Incident atrial fibrillation
C
Comparator
Propensity score-matched atrial fibrillation-free group
O
Outcome
Incident dementiahard clinical
Main Result
Hazard Ratio: 1.52 (95% CI 1.43–1.63)
Absolute Event Rate: 4.1% vs 2.7%
Incident atrial fibrillation is associated with an increased risk of dementia independent of clinical stroke in the elderly, while oral anticoagulant use is linked to a decreased incidence of dementia.
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“We found that the people who developed atrial fibrillation had a 50% increased risk of developing dementia compared to those who did not develop the condition; this increased risk remained even after we removed those who suffered a stroke from our calculations. This means that, among the general population, an extra 1.4 people per 100 of the population would develop dementia if they were diagnosed with atrial fibrillation. The risk occurred in people aged younger and older than 70 years.”
GLGregory LipProfessor of cardiovascular medicine, University of Liverpool
“With these large figures, we can be sure of our findings. We also believe that our results can apply to other populations too, as they confirm similar findings of a link between atrial fibrillation and dementia in studies of people in Western and European countries.”
Implication
Should not change oral anticoagulant practice in elderly AF; leaves open potential dementia benefit pending randomized confirmation.
Abstract
AIMS: Atrial fibrillation (AF) is generally regarded as a risk factor for dementia, though longitudinal studies assessing the association between AF and dementia have shown inconsistent results. This study aimed to determine the effect of AF on the risk of developing dementia using a longitudinal, community-based, and stroke-free elderly cohort. METHODS AND RESULTS: The association of incident AF with the development of incident dementia was assessed from 2005 to 2012 in 262 611 dementia- and stroke-free participants aged ≥60 years in the Korea National Health Insurance Service-Senior cohort. Incident AF was observed in 10 435 participants over an observational period of 1 629 903 person-years (0.64%/year). During the observational period, the incidence of dementia was 4.1 and 2.7 per 100 person-years in the incident AF and propensity score-matched AF-free groups, respectively. After adjustment, the risk of dementia was significantly increased by incident AF with a hazard ratio (HR) of 1.52 [95% confidence interval (CI) 1.43-1.63], even after censoring for stroke (1.27, 95% CI 1.18-1.37). Incident AF increased the risk of both Alzheimer (HR 1.31, 95% CI 1.20-1.43) and vascular dementia (HR 2.11, 95% CI 1.85-2.41). Among patients with incident AF, oral anticoagulant use was associated with a preventive effect on dementia development (HR 0.61, 95% CI 0.54-0.68), and an increasing CHA2DS2-VASc score was associated with a higher risk of dementia. CONCLUSION: Incident AF was associated with an increased risk of dementia, independent of clinical stroke in an elderly population. Oral anticoagulant use was linked with a decreased incidence of dementia.
Discussion
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Cite This Study
Kim et al. (2019) conducted a cohort in Atrial fibrillation (n=262,611). Incident atrial fibrillation vs. AF-free group was evaluated on incident dementia (HR 1.52, 95% CI 1.43-1.63). Incident atrial fibrillation was associated with a significantly increased risk of dementia compared to an AF-free group (HR 1.52; 95% CI 1.43-1.63), even after censoring for stroke.