P2.10: Cuff-Based Assessment of Carotid-Femoral Pulse Wave Velocity: Comparison with a Widely-Used Tonometric Method

Objective To compare measurements of carotid-femoral pulse wave velocity (PWV) using two cuff-based devices (Vicorder and XCEL), with a widely-used tonometric method (SphygmoCor). Methods Comparative measurements of PWV were made using the SphygmoCor, XCEL and Vicorder devices in 91 individuals (mean±SD age 62±18 years; range 20–89 years). All path length and PWV measurements were made as per manufacturers’ instructions, following at least 10min supine rest. Readings were made in triplicate with each device and the average values compared. The order in which devices were used was random. Since the Vicorder includes an optional algorithm to adjust for the influence of the additional femoral segment on measured PWV, both unadjusted (Vicorder) and adjusted (Vicorder_adj) values were analysed. Results PWV ranged from 4.47m/s–14.60m/s (SphygmoCor), 3.70m/s–14.03m/s (XCEL), 4.40m/s–14.20m/s (Vicorder) and 3.60m/s–16.63m/s (Vicorder_adj). The XCEL and Vicorder PWV values were significantly correlated with SphygmoCor values ( Figure 1 ). PWV measured with the XCEL was significantly lower than SphygmoCor-derived PWV (mean±SD of difference 0.42m±1.74m/s, P = 0.03), whereas Vicorder (−0.21±1.88m/s) and Vicorder_adj (0.07±2.21m/s) were not significantly different from SphygmoCor, albeit with somewhat higher SDs. Conclusion Cuff-based devices provide reasonable estimates of PWV when directly compared with a widely used tonometric method. Use of the correction algorithm in the Vicorder device resulted in a closer estimate of the average PWV as measured with SphygmoCor, but a greater spread of values around the mean. Figure 1 Correlation between SphygmoCor-derived PWV and XCEL (A), Vicorder (B) and Vicorder-adj (C) PWV values.