Abstract
BACKGROUND: Energy associated with proximal aortic stretch during systole is recovered as diastolic elastic recoil of the aorta that facilitates left ventricular filling. Impairment of this aortic spring mechanism may contribute to left ventricular diastolic dysfunction. However, cross-sectional and longitudinal inter-relations of cardiovascular disease risk factors, aortic stretch, and left ventricular diastolic function have not been examined. The goal of this study was to assess the cross-sectional and longitudinal associations of cardiovascular disease risk factors and systolic atrioventricular plane displacement (AVPD), a surrogate measure of stretch of the mechanically coupled ascending aorta, with measures of left ventricular diastolic function. METHODS: At two examinations (14±1 years apart) in Framingham Heart Study participants (N=7117; mean age 50 years, 55% women), we assessed AVPD and left ventricular diastolic function using echocardiography. We measured systolic AVPD using the integral of the tissue Doppler s' wave. Additionally, we assessed e' (the peak early diastolic tissue velocity of the lateral mitral annulus) and E/e' (the ratio of peak early mitral inflow velocity and e'). RESULTS: In cross-sectional analyses, higher AVPD was associated with higher e' (β per SD±standard error=0.43±0.01; P<0.001) and lower E/e' (β=-0.35±0.01; P<0.001). In longitudinal models (between two examinations), greater change in (Δ) AVPD between visits was associated with higher Δe' (β=0.40±0.01; P<0.001) and lower ΔE/e' (β=-0.23±0.01; P<0.001). We observed significant effect modification (interaction P-values: <0.001 to 0.045) for cross-sectional and longitudinal associations by median age, sex, obesity status, hypertension treatment, and the extent of aortic stiffness (assessed via carotid-femoral pulse wave velocity). CONCLUSION: The aortic spring function, as assessed via AVPD, may play an important role in maintaining left ventricular diastolic function, with putative effects modified by aortic stiffness, obesity, age, and sex.