Noninvasive 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 (carPP(acc)) were obtained in 22 subjects (10 males, 47 +/- 17 years, hypertension: 50%) postprocessing and double integrating the accelerometric signals. carPP(acc) measurements were compared with tonometric assessments (carPP(ton)), and ultrasound-derived measurements (carPP(US)). Moreover, accelerometric carotid pressure waveforms (P-acc) were contrasted in terms of shape to those obtained by tonometry (P-ton) and ultrasound images elaboration (P-US), calculating the root mean square error (RMSEton, RMSEUS) and the regression coefficients (r(ton) and r(US)). Moreover, both the repeatability and reproducibility analyses were performed. Results: carPP(acc) values (45.9 +/- 10.6 mmHg) were significantly correlated with carPP(ton) (47.5 +/- 11.3 mmHg) and carPP(US) (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, r(ton) = 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 interoperator and intersession reproducibilities 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.