Large artery stiffness is recognized as a strong, independent marker of cardiovascular risk, mainly through aortic pulse wave velocity (PWV). pOpmètre ® is a new non-invasive method, which estimates aortic PWV through finger-toe (FT) wave analysis. In a previous study, Alivon et al. (Archives of Cardiovascular Diseases 2014) have shown an acceptable correlation (r2 = 0.43 for PWV) between pOpmètre ® and the reference method. However this study led to the necessity to optimize the algorithm and the procedures because of the presence of several outliers involving mainly obese and elderly subjects, and occurrence of suboptimal toe pulses. The objective is to analyze the accordance between FT PWV measured by the pOpmètre ® with optimized algorithm and procedures, and carotid-femoral PWV (CF PWV) measured using SphygmoCor ®.Design and method:
The pOpmètre® has 2 photodiodes sensors, positioned on the finger and on the toe, next to the pulp artery. A particular attention was drawn on positioning of the toe sensor so that the pulp was in contact with the photodiode. Different signal processing chains were applied and no cut-off value was used for pulse height. Applanation tonometry was performed for CF PWV measurements. Pearson's correlationwas performed.Results:
45 subjects were included: 18 healthy subjects and 27 patients with essential hypertension aged 32 ± 7 years and 58 ± 18 years respectively. The correlation between FT PWV and CF PWV was good and significant (r2 = 0.77; p < 0.0001). A better correlation was found in terms of transit time (r2 = 0.83; p < 0.0001). The Bland and Altman analysis, mean difference was 0.35 m/s p < 0.0001 versus -11 ms p < 0.0001, the standard deviation of the difference was 0.87 m/s versus 6.73 ms, classifying the device as good agreement with reference (Wilkinson, ARTERY RES 2010). A significant bias persisted with underestimation in older subjects.Conclusions:
pOpmètre® with optimized algorithm and procedure qualifies as excellent agreement with the reference technique for PWV assessement Compared to CF PWV, FT PWV is faster, simpler to perform and importantly, more acceptable to patients, however, outcome studies must confirm the value of this new device.