The initial (primary) aortic functional change that accounts for pulsatile haemodynamic effects on pre-clinical left ventricular (LV) diastolic dysfunction (DD) is uncertain. We aimed to compare the relative contribution of various aortic haemodynamic parameters to preclinical DD in a young-to-middle aged community-based sample.Design and method:
In 524 randomly selected participants from a community of African ancestry (mean age = 46.8 ± 18.4 years) we assessed central aortic pulse pressure (PPc), forward wave pressure (Pf), backward wave pressure (Pb), augmented pressures (Pa), the time to wave reflection (Rt) and aortic pulse wave velocity (PWV) using applanation tonometry and SphygmoCor software. LV mass index (LVMI), early to late transmitral velocity (E/A) and E/velocity of myocardial tissue lengthening (E/e’) were determined using echocardiography.Results:
Independent of age, sex, mean arterial pressure, body mass index, diabetes mellitus or and HbA1c>6.1%, regular smoking, regular alcohol intake, treatment for hypertension, pulse rate and LVMI; PPc (p < 0.002), Pb (p = 0.0005), Pa (p < 0.002), and Pf (p < 0.02), but not Rt or aortic PWV were independently associated with E/e’ (but not with E/A). With adjustments for confounders, PPc (p < 0.005), Pb (p < 0.002) and Pa (p < 0.001), but not Pf, Rt or PWV were independently associated with an E/e’ > = 12 (moderate-to-severe DD, n = 69). The independent relations between PPc and E/e’ or moderate-to-severe DD were not affected by adjustments for PWV, Pf or Rt, but were abolished with adjustments for Pb.Conclusions:
In largely the young-to-middle aged, the impact of aortic pulse pressure on LV DD is explained by increases in aortic backward wave pressures, but not by aortic stiffness, the time to wave reflection or forward wave pressures. Hence, increases in backward wave pressures may be the primary aortic change responsible for the early development of LV DD.