Abstract P020: Atrial Fibrillation and White Matter Microstructural Integrity: The Atherosclerosis Risk in Communities Neurocognitive Study

Abstract

Background: Evidence suggests atrial fibrillation (AF) is associated with increased risk of cognitive decline and dementia, even in the absence of stroke. Pathways such as AF-induced brain hypoperfusion and small vessel disease resulting in white matter abnormalities may also compromise cerebrovasculature and brain tissue, which would lead to cognitive impairment and dementia. However, mechanisms responsible for the association between AF and cognitive impairment independent of stroke and cerebral infarcts remain relatively unexplored. The study aims to assess the cross-sectional association between prevalent AF and white matter microstructural integrity (WMMI) as a marker for cerebrovascular disease. Methods: We performed a cross-sectional analysis of 1937 participants attending the ARIC-Neurocognitive Study (ARIC-NCS) in 2011-2013 that were either black or white and with brain magnetic resonance imaging (MRI). Prevalent AF was defined by a history of AF based on study ECG and hospitalization record. WMMI was defined using regional average fractional anisotropy and mean diffusivity from Diffusion Tensor Imaging measurements in the MRI. We excluded participants with a prior history of stroke or cerebral infarct. A multivariable regression model was used to assess the association between AF and WMMI measures. Results: Among 1943 participants (mean age = 76 years, 28% black, 60% female), 7% (N= 133) had prevalent AF. After multivariable adjustment, prevalence of AF was not associated with WMMI measurements (Table). Conclusion: In a community-based study, prevalent AF was not independently associated with WMMI in the absence of stroke or cerebral infarct. However, the reduced sample size of the AF population as well as the cross-sectional study design are important limitations. Further longitudinal studies are needed to investigate prospectively the association of AF with early markers of white matter disease.