How to interpret 24-h arterial stiffness markers: comparison of 24-h ambulatory Mobil-O-Graph with SphygmoCor office values.

Abstract

Although applanation tonometry is the most widely used method for evaluating arterial stiffness, oscillometric ambulatory blood pressure monitoring devices using specific algorithms for pulse wave analyses have been validated more recently. Currently, it is not clear how to interpret 24-h mean values of arterial stiffness parameters. The objective of this study was to compare 24-h mean values of arterial stiffness parameters obtained using 24-h ambulatory blood pressure monitoring device (Mobil-O-Graph) against a validated single-measure tonometric system (SphygmoCor). We measured brachial and central arterial pressure, augmentation index (AIx), and carotid-to-femoral pulse wave velocity (cfPWV) using SphygmoCor device in 82 high and very high cardiovascular risk patients. The Mobil-O-Graph device for the 24-h blood pressure and arterial stiffness parameter monitoring was used on the same day and started within 2 h after measurements using SphygmoCor were done. Mean AIx values were 26.38±9.95 for SphygmoCor office measurement and 26.69±8.45 for Mobil-O-Graph 24-h mean values. The mean difference was -0.31±9.78 (P=0.775). CfPWV values were 10.56±2.59 m/s for SphygmoCor office measurement and 8.72±1.29 m/s for Mobil-O-Graph 24-h mean values. The difference of 1.84±2.15 m/s was statistically significant (P<0.001). Correlation coefficients for AIx and cfPWV between two methods were 0.444 and 0.468, respectively (P<0.001). The agreement between SphygmoCor single measurement and Mobil-O-Graph 24-h mean values of arterial stiffness parameters is moderate. The 24-h mean values of cfPWV obtained by Mobil-O-Graph are significantly lower than SphygmoCor values obtained in the office, whereas 24-h AIx mean values do not have a significant bias.