Association of Right Heart Structure and Function with Cognition and Brain MRI Measures in the Multi-Ethnic Study of Atherosclerosis

BackgroundRecent studies in selected populations suggest that impaired venous return may affect brain health. We examined associations of right heart structure and function with cognition and MRI markers of brain health in a community-based cohort. MethodsThe Multi-Ethnic Study of Atherosclerosis (MESA) is a longitudinal cohort study of individuals 45 to 84 years of age who were free of clinically apparent cerebrovascular or cardiovascular disease at baseline in 2000-2002. From echocardiograms performed at Exam 6 during 2016-2018, we measured: right atrial pressure and end-systolic area; pulmonary artery systolic pressure; and right ventricular free wall strain, fractional area change, and end-diastolic area. Outcome variables were the Cognitive Assessment Screening Instrument, Digit Span, and Digit Symbol Coding tests and MRI-determined volumes of total white matter, total gray matter, and white matter hyperintensity -- as well as fractional anisotropy. Cognitive measures were obtained at Exam 6, and MRI measures, within a median of 18 months of echocardiograms. Covariates were demographics, APOE-{varepsilon}4 allele status, vascular risk factors, and echocardiographic markers of left heart function. We used general linear models to examine associations between each exposure and outcome variable. ResultsIn 1,913 participants with cognitive testing and echocardiography data, we found no associations between any of the echocardiographic exposure variables and worse scores on any of the cognitive tests. Similarly, in 1,035 participants with echocardiography and MRI data, we found no associations between any of the echocardiographic exposure variables and any of the MRI variables. DiscussionWe found no associations in this cohort of right heart structure and function with cognition or brain MRI measures. These findings do not support the hypothesis that right heart dysfunction impedes venous return sufficiently to adversely affect brain health among people without clinically apparent heart failure.