Simplified pulse wave velocity measurement in children: Is the pOpmetre valid?

In population exposed to cardiovascular risk, aortic stiffness is an important marker which is assessed by carotid-to-femoral pulse wave velocity (PWV). In childhood, the validated applanation tonometer SphygmoCor (R) can be used to measure PWV, but is limited in routine practice by the child's cooperation and operator's experience. An alternative device, the pOpmetre (R) is validated in adults and rapidly measures finger-to-toe PWV using 2 oxymeter-like sensors. The aim of this study is to validate the pOpmetre (R) device in children aged between 4 and 8 years. We compared simultaneous PWV measurements of the two devices, SphygmoCor (R) and pOpmetre (R), in a training group, using the Bland-Altman method. Then we proposed an algorithm to correct pOpmetre (R) PWV (PWVpop). Finally, we validated this new algorithm in a validation group of children using the Bland-Altman method. This prospective study enrolled 26 children in the training group. Mean PWVpop was 3.919 +/- 0.587 m/s and mean SphygmoCor (R) PWV was 4.280 +/- 0.383 m/s, with a difference of -0.362(CI95%(-0.546;-0.178)) m/s. A new algorithm was defined using transit time (TTpop): corrected PWVpop (m/s) = 0.150/TTpop(s) + 1.381* Height(m) + 1.148. We enrolled 24 children in the validation group. Mean corrected PWVpop was 4.231 +/- 0.189 m/s and mean SphygmoCor (R) PWV was 4.208 +/- 0.296 m/s with a corrected difference of 0.023(CI95%(-0.086;0.131)) m/s. With this algorithm correction, we found an agreement between PWV measured by the SphygmoCor (R) and the pOpmetre (R), with a difference of less than 10%. Using this algorithm, the pOpmetre (R) could be used in clinical or research practice in young children exposed to cardiovascular risk. (This study was registered as NCT02991703).