Echo-tracking derived measures of arterial stiffness, implemented in a echo-machine, allow the assessment of local arterial stiffness [Beta stiffness (B), pressure-strain elasticity modulus (EP) and arterial compliance (AC)] deriving the pressure–diameter curve of the artery and calculating the local pulse wave velocity (PWV) from the time delay between the two adjacent distension. Clinical studies have demonstrated that parameters of local arterial stiffness can predict cardiovascular mortality. The aim of the present study was to evaluate carotid arterial stiffness obtained by echo-tracking system in a healthy population and to investigate clinical correlates as there are no reference values available yet.Design and method:
1092 healthy subjects aged 2–92 years (586 male, 506 female) were enrolled from 3 European centers. Local arterial stiffness was evaluated at the level of the left CCA 1 to 2 cm before its bifurcation using a high-definition echo-tracking ultrasound (Hitachi Aloka Inc). Stiffness indices were derived from measurement of arterial diameters and brachial artery pressure.Design and method:
Statistical models were developed to describe relationships with age, and nomograms plotted to obtain median values.Results:
A significant correlation was found between stiffness parameters and age in both genders demonstrating an increase in EP, B and PWV and a downward trend in AC with ageing (males: B stiffness r = 0.655; EP r = 0.69; AC r = −0.59; PWV r = 0.74 p < 0.0001. Females: B stiffness r = 0.66; EP r = 0.71; AC r = −0.58; PWV r = 0.74, p < 0.0001). Nevertheless we found significantly higher stiffness values (and lower AC) in females. The subjects were then divided into 9 age groups (ages: 2–11, 12–19, 20–29, 30–39, 40–49, 50–59, 60–69, 70–79 and over 80) and stratified by gender. Within the single groups, stiffness was not different between gender except AC which was lower in females. In a multivariate model, carotid stiffness were constantly and independently associated with age, gender, mean blood pressure, pulse pressure, heart rate and body surface area.Conclusions:
The results of the present study have been used to produce reference values of carotid stiffness parameters obtained by echo-tracking system in a large healthy population.