Neuropathologic changes associated with atrial fibrillation in a population-based autopsy cohort.
BACKGROUND
Atrial fibrillation (AF) is associated with higher risk of dementia and Alzheimer's disease. To better understand the mechanism, we examined neuropathologic changes seen with AF.


METHODS
We analyzed data from an autopsy series arising from a population-based, prospective cohort study set within Group Health, an integrated health care delivery system. Participants were people aged 65 and older, community-dwelling, and nondemented at study enrollment, who died during follow-up and underwent autopsy. AF was defined from medical records. Permanent AF was defined as having two or more electrocardiograms showing AF between 6 and 36 months apart with no evidence of sinus rhythm in between. The primary study outcomes were gross infarcts, neuritic plaques, and neurofibrillary tangles, ascertained using consensus guidelines. Adjusted relative risks and 95% CIs were calculated using modified Poisson regression, weighted to account for selection into the autopsy cohort.


RESULTS
Three hundred and twenty-eight participants underwent autopsy; 134 (41%) had AF. People with AF were more likely to have gross infarcts than those without AF (45% vs 31%; relative risk 1.82, 95% CI 1.23-2.71); in 30%, these infarcts were not clinically recognized before death. Alzheimer's disease neuropathologic changes were not associated with ever having AF but were more common in people with permanent AF. Adjusted relative risks for frequent neuritic plaques and neurofibrillary tangles were 1.47 (0.96-2.28) and 1.40 (0.79-2.49), respectively, for people with permanent AF versus no AF.


CONCLUSIONS
AF is associated with gross infarcts. Permanent AF may contribute to Alzheimer's disease neuropathologic changes, but more study is needed.
Group Health Research Institute, 1730 Minor Avenue, Suite 1600, Seattle, WA 98101-1448. dublin.s@ghc.org.
Sascha
S
Dublin
Melissa L
ML
Anderson
Susan R
SR
Heckbert
Rebecca A
RA
Hubbard
Joshua A
JA
Sonnen
Paul K
PK
Crane
Thomas J
TJ
Montine
Eric B
EB
Larson
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology / Q000473:pathology; D001281:Atrial Fibrillation / Q000150:complications* / Q000473:pathology* / Q000523:psychology; D001344:Autopsy; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000453:epidemiology / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male
Alzheimer's; Brain aging; Cardiac arrhythmias; Cardiovascular.; Stroke