Left atrial diameter and vascular brain injury on MRI: The Cardiovascular Health Study

To determine the association left atrial diameter (LAD) and vascular brain injury on brain MRI.

We analyzed data from the Cardiovascular Health Study (CHS), a prospective cohort of community-dwelling adults ≥65 years old. LAD was measured from 2-dimensional transthoracic echocardiograms. Among CHS participants who underwent brain MRI, we examined associations of LAD with brain infarcts and leukoaraiosis. Primary outcomes (number for analysis) were prevalent infarcts (2,327) and degree of leukoaraiosis on initial MRI (2,315). Secondary outcomes were prevalent nonlacunar infarcts (2,327), incident infarcts (939), incident nonlacunar infarcts (1,185), and degree of leukoaraiosis on follow-up MRI adjusted for initial MRI (1,158). Relative risk (RR) and linear regression models were adjusted for demographics, vascular risk factors, and potential confounders.

Mean age of the 2,335 participants with initial brain MRI was 72.0 ± 4.8 years; 38.7% were men; and 29.0% participants had prevalent infarcts. In multivariable, fully adjusted models, LAD was associated with prevalent infarcts (RR 1.20, 95% confidence interval [CI] 1.08-1.34) and prevalent nonlacunar infarcts (RR 1.28, 95% CI 1.06-1.54) but not with leukoaraiosis (-0.08, 95% CI -0.17 to 0.07), incident infarcts (RR 1.00, 95% CI 0.78-1.29), nonlacunar infarcts (RR 0.98, 95% CI 0.67-1.42), or worsening leukoaraiosis (-0.04, 95% CI -0.10 to 0.02).

LAD is independently associated with prevalent brain infarcts, particularly nonlacunar infarcts, but not leukoaraiosis. Larger studies are needed to determine associations with incident infarct risk and whether this risk in patients with left atrial enlargement can be reduced with anticoagulant agents.