Epidemiologic Determinants of Cardiac Structure and Function in Rural Residents: RURAL ECHO

ABSTRACT Rural dwelling adults in the US South suffer disproportionate cardiovascular disease (CVD) burden and mortality. The Appalachia and Mississippi Delta (AMD) regions are particularly at risk, embedded in the stroke, heart attack and heart failure (HF) mortality belts, where the determinants are multifactorial. Echocardiography

is an ideal methodology to study CVD and determine high risk imaging phenotypes for incident heart failure owing to its ability to noninvasively assess cardiac structure and function simultaneously. Due to the excess of CVD in the AMD region, we therefore expect a high prevalence of abnormal cardiac structure and function

among rural adults, but this has not been explicitly shown. The NHLBI-funded Risk Underlying Rural Areas Longitudinal (RURAL) cohort study, by assessing a broad array of phenotypic, biologic, and social determinants of health represents a unique, cost-effective opportunity to implement a study to fill the gaps

described, reduce excess CVD burden, and achieve health equity for all Americans. The long-term goal of this proposal is to understand the burden of adverse cardiac remodeling in the absence of symptoms (i.e., Stage B HF) in the AMD region and factors contributing to it so that interventions during subclinical disease states may

avert clinical HF later in life. The overall objectives of this application are to apply in-depth echocardiographic phenotyping to the entire RURAL cohort and combine these echo data with the broad array of data acquired in RURAL to identify those factors which selectively amplify or mitigate HF risk. Using the infrastructure of the

parent study’s mobile examination unit (MEU) – ‘a clinic on wheels’ – we will perform echocardiography on all participants at baseline to characterize cardiac structure and function using a novel artificial-intelligence (AI) echo approach. Our central hypothesis is that there is a significant burden of Stage B HF, which is associated

with exposures spanning multiple domains and which can be delineated by integrating the multimodality imaging on the MEU. We will achieve our objectives through these specific aims: (Aim 1) Use AI Echo and meticulous core lab analysis to extensively characterize cardiac structure and function in RURAL; (Aim 2)

Determine associations of AI Echo findings with traditional biologic risk factors and comorbidities, with an exploratory sub-Aim to determine associations between Stage B HF and social determinants of health; and (Aim 3) To interrogate mechanisms of Stage B HF by determining relationships between echo-based imaging

biomarkers, CV calcifications, adiposity and CV risk. The proposed study will provide the largest and most comprehensive echocardiographic dataset focused on rural adults that untangles the relative importance of the association between biologic and social factors on Stage B HF and incorporates advanced methodology to

discover sub-phenotypes of Stage B HF based on multimodality imaging. RURAL Echo promises to yield new knowledge on rural CV health that is highly relevant to individual and US public health.