P6.15 ATTENUATION OF ARTERIAL STIFFNESS GRADIENT WITH AGE AND ITS IMPACT ON CENTRAL PULSE WAVE PROFILE IN DIALYSIS PATIENTS

Abstract

Background: Arterial stiffness has been considered as an index of vascular ageing. However, the relationship between age and stiffness of various segments of the arterial tree is heterogeneous. Moreover, the hemodynamic impact of vascular stiffness is thought to be related to the attenuation or even reversal of the physiological arterial stiffness gradient. The objectives of the present study were to evaluate the impact of age on aortic (central elastic artery) and brachial (muscular conduit artery) stiffness and to assess hemodynamic correlates of the arterial stiffness gradient. Method/results: In 310 dialysis patients (67 years [25th-75thpercentiles: 56–76], 185(60%) men, 134(43%) diabetes and 162(52%) cardiovascular disease), we measured aortic and brachial stiffness by pulse wave velocity of carotid-femoral (cf-PWV) and carotid-radial (cr-PWV) using direct distances (Complior). Arterial stiffness gradient was determined by cf-PWV/cr-PWV (PWV ratio). Central pulse wave parameters were obtained through generalized transfer function applied to the radial artery pulse profile (Sphygmocor). Mean cf-PWV, cr-PWV and PWV ratio were respectively of 13.52 ±4.07m/s, 8.76 ±1.68m/s and 1.59 ±0.52m/s. Cr-PWV decreased with age (β=−0.031, R=−0.274, P0.001), while cf-PWV (β=0.144, R=0.529, P0.001) and PWV ratio (β=0.021, R=0.613, P0.001) increased. In contrast to cf-PWV and cr-PWV, PWV ratio was not associated with MBP (P=0.997). Conclusion: The use of PWV ratio may be a more logical choice for risk determination than aortic stiffness as it provides a better estimation of the loss of arterial stiffness gradient and is not influenced by MBP in this population.