Takeaway
- Atrial fibrillation roughly triples the risk for dementia among older adults, even in the absence of stroke.
Why this matters
- Isolated neurocognitive effect of atrial fibrillation is unclear.
Key results
- With mean 10.4-year follow-up, atrial fibrillation conferred similarly elevated dementia risk:
- In the cohort overall (adjusted HR, 2.8; P=.004).
- In a subset stroke free at baseline and during follow-up (adjusted HR, 2.9; P=.013).
- In stratified analyses, risk was significantly elevated by atrial fibrillation only among:
- Men (adjusted HR, 4.6; P<.001; interaction sex by atrial fibrillation, P=.047).
- Noncarriers of APOE ε4 allele (adjusted HR, 4.2; P<.001; interaction APOE by atrial fibrillation, P=.128).
- Population attributable risk for dementia resulting from atrial fibrillation:
- 12.9% in cohort overall.
- 12.1% in stroke-free subset.
Study design
- Swedish population-based cohort study of 561 adults aged 70 years having comprehensive physical and neuropsychiatric examinations in 2000-2001 and followed-up at ages 75 and 79 years.
- Main outcome: dementia (DSM, Third Edition revised, criteria based on neuropsychiatric examinations, proxy reports, National Patient Register).
- Funding: Swedish state.
Limitations
- Atrial fibrillation history ascertained from proxies.
- Milder strokes not captured.
- Limited ability to perform subgroup analyses.
- Possible attrition bias.
References
References