Non-invasive Assessment of Carotid Pulse Pressure Values: an Accelerometric-based Approach

Objective: Central pulse pressure (cPP) is increasingly investigated as possible independent predictor of cardiovascular risk and carotid pulse pressure (carPP) can be used as a surrogate of cPP. Despite its importance, carPP measurement remains challenging in clinical practice. The aim of this study was to introduce a new easier-to-use method for noninvasive carPP evaluation based on the use of a MEMS accelerometer. Methods: carPP values (carPPacc) were obtained in 22 subjects (10 males, 47±17 years, hypertension: 50%) postprocessing and double integrating the accelerometric signals. carPPacc measurements were compared with tonometric assessments (carPPton,) and ultrasound-derived measurements (carPPUS). Moreover, accelerometric carotid pressure waveforms (Pacc) were contrasted in terms of shape to those obtained by tonometry (Pton) and ultrasound images elaboration (PUS), calculating the root mean square error (RMSEton, RMSEUS) and the regression coefficients (rton and rUS). Moreover, both repeatability and reproducibility analysis were performed. Results: carPPacc values (45.9±10.6 mmHg) were significantly correlated with carPPton (47.5±11.3 mmHg) and carPPUS (43.3±8.4 mmHg) assessments (R=0.94, p<0.0001 and R=0.80, p<0.0001, respectively). The validity of the accelerometric approach was confirmed by morphological parameters (RMSEton=5±1.95 mmHg; RMSEUS=5.5±2.3 mmHg; rton=0.94±0.04; rUS=0.93±0.04). Coefficient of variation (CV) was equal to 6.2% for the repeatability analysis, while CV values for inter-operator and inter-session reproducibility were 8.9% and 9.4%, respectively. Conclusion: The proposed approach, providing an easier and more available measurement, could represent a valid alternative to existing and used technique for carPP assessment.