Aortic backward waves rather than stiffness account for independent associations between pulse pressure amplification...

A decreased aortic-to-brachial pulse pressure (PP) amplification, which is independently associated with cardiovascular outcomes, may index several aortic functional changes. However, that aortic functional change most likely to account for this effect is uncertain. In 706 randomly selected community participants of African ancestry with a mean age of 44.4 ± 18.2 years, we assessed aortic function using radial applanation tonometry and SphygmoCor software (including forward [Pf] and backward [Pb] wave separation analysis assuming a triangular flow waveform) and left ventricular mass index (LVMI) (echocardiography). In multivariate models with the inclusion of brachial PP, 1/PP amplification (partial r = 0.12, P < .005), reflected wave pressures (partial r = 0.09, P < .05), and aortic pulse wave velocity (PWV; partial r = 0.09, P < .05) were independently associated with LVMI. Similarly, in multivariate models with the inclusion of brachial PP, 1/PP amplification (P < .005), the reflected wave pressure (P < .01), and aortic PWV (P < .01) were independently associated with LVH. With adjustments for reflected wave pressures, the brachial PP-independent relationships between 1/PP amplification and LVMI or LVH were abolished (P > .08 for both). However, adjustments for PWV failed to modify brachial PP-independent relations between 1/PP amplification and LVMI or LVH. Similar results were noted when brachial systolic blood pressure rather than PP was included in regression models and in sensitivity analysis conducted in participants not receiving antihypertensive therapy. In conclusion, the independent relations between the reciprocal of aortic-to-brachial PP amplification and LVMI or LVH in a largely young to middle-aged sample are accounted for by variations in backward wave pressures rather than aortic stiffness.