P.054 Local Arterial Wave Speed at Carotid Artery Level is Representative of Carotido-Femoral Pulse Wave Velocity and Aortic Stiffness: Evidence by a New Echo-Tracking Approach

Abstract

Carotido-femoral (CF) pulse wave velocity (PWV) is a marker of aortic stiffness. Recently a new ultrasound technique capable to provide real-time arterial waveform analysis (“E-track”, Aloka) has been developed. When calibrated for blood pressure (BP), arterial stiffness parameters and a single point local wave speed (WS) are obtained.

Aim of this study was to evaluate whether or not common carotid (CCA) local WS may be representative of CF-PWV.

Thirty-one patients free of cardiovascular disease, with or without atherosclerotic risk factors (16 males; mean age 55±12, age range 24–72; mean BP 137±17/81±21 mmHg), underwent right CCA scanning by high resolution linear US probe (7.5 to 10 MHz, Aloka SSD-5500) for E-track evaluation. Single-point WS at CCA level was computed as WS = (ΔP/2Beta). CF-PWV and carotido-radial PWV (CR-PWV) were assessed by Complior (Artech, Paris). For both methods, at least 5 consecutive beats were averaged.

Mean WS, CF-PWV and CR-PWV were 9±4m/s, 10.1±2 m/s, 10.9±1 m/s (p = n.s.). WS was directly related to CF-PWV (r = 0.60, p < 0.001) but not to CR-PWV (r = 0.22, p = n.s.). At Bland-Altman analysis, mean difference between WS and CF-PWV was –1.15±3.58, with all measurements but one within ±2sd. Both “Beta” and “Epsilon” derived by E-track also correlated directly with CF-PWV (r = 0.50 and 0.55, respectively, p < 0.005) but not with CR-PWV. Finally, the known correlations with age and pulse pressure were confirmed for both CF-PWV and WS (r between 0.40 and 0.65).

CCA stiffness and local WS appear representative of aortic stiffness as estimated by CF-PWV.