Abstract
BACKGROUND: Echocardiographic (2DE) thresholds indicating disease or impaired functional status compared to normal physiologic aging in individuals ≥ 65 years are not clearly defined. In the present study, we sought to establish standard values for 2DE 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 2DE at Exam 6 in the Multi-Ethnic Study of Atherosclerosis (MESA), 608 participants fulfilled our inclusion criteria, with normative values defined as the mean value ± 1.96 standard deviations and compared across sex and race/ethnicity. Functional status measures included NT-proBNP, 6-minute walk distance [6MWD], and Kansas City Cardiomyopathy Questionnaire [KCCQ]. Prognostic performance using MESA cutoffs was compared to established guideline cutoffs using time-to-event analysis.
RESULTS: Participants meeting our inclusion criteria (69.5 ± 7.0 years, 46.2% male, 47.5% White) had lower NT-proBNP, higher 6MWD, and higher (better) KCCQ summary values. Women had significantly smaller chamber sizes and better biventricular systolic function. White participants had the largest chamber dimensions, while 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 across sexes and races/ethnicities, 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.