Abstract
BACKGROUND: Echocardiographic (2-dimensional echocardiography) thresholds indicating disease or impaired functional status compared with normal physiological aging in individuals aged ≥65 years are not clearly defined. In the present study, we sought to establish standard values for 2-dimensional echocardiography parameters related to chamber size and function in older adults without cardiopulmonary or cardiometabolic conditions.
METHODS: In this cross-sectional study of 3032 individuals who underwent 2-dimensional echocardiography at exam 6 in the MESA (Multi-Ethnic Study of Atherosclerosis), 608 participants fulfilled our inclusion criteria of healthy aging, with normative values defined as the mean ± 1.96 standard deviation and compared across sex and race and ethnicity. Functional status measures included NT-proBNP (N-terminal pro-B-type natriuretic peptide), 6-minute walk distance, and Kansas City Cardiomyopathy Questionnaire. Prognostic performance using MESA cutoffs was compared with established guideline cutoffs using time-to-event analysis.
RESULTS: The normative aging cohort (69.5±7.0 years, 46.2% male, 47.5% White) had lower NT-proBNP, higher 6-minute walk distance, and higher (better) Kansas City Cardiomyopathy Questionnaire summary values. Women had significantly smaller chamber sizes and better biventricular systolic function. White participants had the largest chamber dimensions, whereas Chinese participants had the smallest, even after adjustment for body size. Current guidelines identified 81.6% of healthy older adults in MESA as having cardiac abnormalities.
CONCLUSIONS: Among a large, diverse group of healthy older adults, we found significant differences in cardiac structure and function by sex and race/ethnicity, which may signal sex-specific cardiac remodeling with advancing age. It is crucial for existing guidelines to consider the observed and clinically significant differences in cardiac structure and function associated with healthy aging. Our study highlights that existing guidelines, which grade abnormalities in echocardiographic cardiac chamber size and function based on younger individuals, may not adequately address the anticipated changes associated with normal aging.