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<sub>acc</sub>) were obtained in 22 subjects (10 males, 47 ± 17 years, hypertension: 50%) postprocessing and double integrating the accelerometric signals. carPP<sub>acc</sub> measurements were compared with tonometric assessments (carPP<sub>ton</sub>), and ultrasound-derived measurements (carPP<sub>US</sub>). Moreover, accelerometric carotid pressure waveforms (P<sub>acc</sub>) were contrasted in terms of shape to those obtained by tonometry (P<sub>ton</sub>) and ultrasound images elaboration (P<sub>US</sub>), calculating the root mean square error (RMSE<sub>ton</sub>, RMSE<sub>US</sub>) and the regression coefficients (r<sub>ton</sub> and r<sub>US</sub>). Moreover, both the repeatability and reproducibility analyses were performed. Results: carPP<sub>acc</sub> values (45.9 ± 10.6 mmHg) were significantly correlated with carPP<sub>ton</sub> (47.5 ± 11.3 mmHg) and carPP<sub>US</sub> (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 (RMSE<sub>ton</sub> = 5 ± 1.95 mmHg, RMSE<sub>US</sub> = 5.5 ± 2.3 mmHg, r<sub>ton</sub> = 0.94 ± 0.04, r<sub>US</sub> = 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.

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