Poor agreement between carotid-femoral pulse wave velocity (c-f pwv) and 24 hour pwv determined with two different methods

Objective: The gold standard of arterial stiffness determination is measurement of the carotide-femoral pulse wave velocity (cf-PWV). It was suggested that 24 hour measurement might give addition or more insights in the estimation of the global cardiovascular (CV) risk Our aim was to analyze association/concordance between cf-PWV values (SphygmoCor) with the values obtained with 24h measurments (Mobil-o-Graph and Arteriograph). Design and method: This study included 154 patients with the primary hypertension (women 69.5%, mean age 38.5). In all of them we collected various clinical and laboratory data and antroplogical paramaters. Parameters of arterial stiffness were measured with the SphygmoCor and 24h using Mobil-o-Graph and Arteriograph devices during the regular working day. Concordance correlation coefficient (CCC) was calculated. the Bland Altman method was used to estimate the deviation of methods Limits of agreement (LoA) are defined as the mean difference ± 1.96 SD difference. Results: Statistically significant correlation was observed between cf-PWV and data obtained with Arteriograph: 24h, day, night; and Mobilograph: 24h, day and night (r = 0.500, p < 0.001; r = 0.485, p < 0.001; r = 0.519, p < 0.001); r = 0.697, p < 0.001, r = 0.691, p < 0.001) r = 0.665, p < 0.001, respectively). cf-PWV shared 25% and 49% of the variance (R2) with the Arteriograph and Mobilograph, respectively. CCC was weak for both methods, Arteriograph and Mobilograph (CCC 0.49 95%CI 0.36-0.60; 0.50 95% CI 0.41-0.58, respectively). Large difference was observed for both methods, being larher for Arteriograph than with Mobilograph (-0.31 m/s (LoA -4.8 to 4.8) ; 1.6 m/s (LoA -1.69 to 4.89, respectively). Conclusions: In the group of young treated hypertensive patients with mild CV risk we found week agreement between cf-PWV and 24h PWV data. Better concordance was found between cf-PWV and Mobilograph than with Arteriograph. It could be concluded that cf-PWV and 24h PWV could not be used intercheangable. More results are needed to answer whether 24 h PWV has the same clinical value as cf-PWV