Berman JP, et al. - Researchers assessed the longitudinal relationship of incident atrial fibrillation (AF) and the cross-sectional relationship of prevalent AF with brain magnetic resonance imaging (MRI) abnormalities in a community-based cohort, the ARIC study (Atherosclerosis Risk in Communities). They included 963 non-prevalent stroke or AF participants who experienced brain MRI from 1993 to 1995 and a second MRI from 2004 to 2006 in the longitudinal analysis. Subclinical cerebral infarctions, sulcal size, ventricular size. White matter hyperintensity volume and total brain volume were included outcomes for the cross-sectional analysis. Greater probabilities of increased subclinical cerebral infarctions, worsening sulcal grade, and worsening ventricular grade were seen in those who developed AF. Following multivariable adjustment, greater chances of higher sulcal and ventricular grade and no difference in white matter hyperintensity or total brain volume were seen in those with AF. These morphological changes are linked with aging and dementia and more studies are needed to define these mechanisms.