LA volumes and reservoir function are associated with subclinical cerebrovascular disease: the CABL (Cardiovascular Abnormalities and Brain Lesions) study

Abstract

Objectives: The purpose of this study was to assess the relationship of left atrial (LA) phasic volumes and LA reservoir function with subclinical cerebrovascular disease in a stroke-free community-based cohort.

Background: An increase in LA size is associated with cardiovascular events including stroke. However, it is not known whether LA phasic volumes and reservoir function are associated with subclinical cerebrovascular disease.

Methods: The LA minimum (LAV(min)) and maximum (LAV(max)) volumes, and LA reservoir function, measured as total emptying volume (LAEV) and total emptying fraction (LAEF), were assessed by real-time 3-dimensional echocardiography in 455 stroke-free participants from the community-based CABL (Cardiovascular Abnormalities and Brain Lesions) study. Subclinical cerebrovascular disease was assessed as silent brain infarcts (SBI) and white matter hyperintensity volume (WMHV) by brain magnetic resonance imaging.

Results: Prevalence of SBI was 15.4%; mean WMHV was 0.66 ± 0.92%. Participants with SBI showed greater LAV(min) (17.1 ± 9.3 ml/m(2) vs. 12.5 ± 5.6 ml/m(2), p < 0.01) and LAV(max) (26.6 ± 8.8 ml/m(2) vs. 23.3 ± 7.0 ml/m(2), p < 0.01) compared to those without SBI. The LAEV (9.5 ± 3.4 ml/m(2) vs. 10.8 ± 3.9 ml/m(2), p < 0.01) and LAEF (38.7 ± 14.7% vs. 47.0 ± 11.9%, p < 0.01) were also reduced in participants with SBI. In univariate analyses, greater LA volumes and smaller reservoir function were significantly associated with greater WMHV. In multivariate analyses, LAV(min) remained significantly associated with SBI (adjusted odds ratio per SD increase: 1.37, 95% confidence interval: 1.04 to 1.80, p < 0.05) and with WMHV (β = 0.12, p < 0.01), whereas LAVmax was not independently associated with either. Smaller LAEF was independently associated with SBI (adjusted odds ratio: 0.67, 95% confidence interval: 0.50 to 0.90, p < 0.01) and WMHV (β = -0.09, p < 0.05).

Conclusions: Greater LA volumes and reduced LA reservoir function are associated with subclinical cerebrovascular disease detected by brain magnetic resonance imaging in subjects without history of stroke. In particular, LAV(min) and LAEF are more strongly associated with SBI and WMHV than the more commonly measured LAVmax, and their relationship with subclinical brain lesions is independent of other cardiovascular risk factors.

Figure 1. Left atrial volumes by real-time three-dimensional echocardiography

Measurement of LAV_max and LAV_min. LA reservoir function was calculated as LA total emptying volume (LAEV = LAV_max − LAV_min) and as LA total emptying fraction (100 × LAEV/LAV_max).

Figure 2. Subclinical brain lesions by magnetic resonance imaging

Representative axial MRI slices from study participants showing normal brain (top left panel) and subclinical ischemic changes, including white matter hyperintensities (top right panel), cortical infarction (bottom left panel), and lacunar infarction (bottom right panel).