Longitudinal uncoupling of the heart and arteries with aging in a community-dwelling population

Although mechanical energy transfer between the heart and arterial system, referred to as arterial-ventricular (AV) coupling, is an important determinant of cardiovascular performance, how AV coupling changes over time within and among individuals as they age has not been fully explored. We studied 129 participants (baseline age 21-96) of the Baltimore Longitudinal Study of Aging, free of clinical CVD. Participants underwent repeated multigated cardiac blood pool scans to estimate left ventricular (LV) volumes (SV, EDV, and ESV). Total systemic vascular resistance (TSVR), total arterial compliance (TAC), effective arterial elastance (Ea), and end-systolic LV elastance (Elv) were calculated using LV volumes and brachial BP measurements; calculated Ea/Elv was the measure of AV coupling. Linear mixed-effects models were used to estimate person-specific rates of change (Change) for each variable. The rate at which Ea increased over time was faster than the rate at which Elv increased, resulting in AV uncoupling (increased Ea/Elv) over time that was significantly greater in women than in men. Loss of arterial compliance was the main determinant of (Ea/Elv)_Change, which was negatively associated with changes in SV and EDV but positively with changes in ESV. Progressive AV uncoupling occurred with aging and was more pronounced in women than men. While Ea change did not differ by sex, Elv increased at a slower rate in women than in men. AV uncoupling was inversely associated with EDV and SV rates of change and a directly associated with an increase in ESV rate of change. Additional studies are needed to explore the functional consequences of AV uncoupling in healthy individuals with respect to the emergence of age-associated clinical cardiovascular diseases, such as heart failure with preserved ejection fraction.