Purpose: Recently, the local aortic stiffness (AoStiff) can be evaluated using a non-invasive bioelectrical impedance (BI) technique. Herein, AoStiff is estimated from the measurement of two new BI variables: 1) The local aortic flow resistance (AoRes) exerted by the drag forces onto the flow 2) The local aortic wall distensibility (AoDist). We propose to compare these two indices with the reference pulse wave velocity (PWV) measurement and the direct assessment of the aortic drag forces (DF) and distensibility (DS) obtained by the magnetic resonance imaging technique (MRI).

Methods: PWV was measured by tonometry (Pulse Pen, Diatecne) on 98 patients (mean age ± years). Local aortic properties (DF and DS indices) were estimated from phase-contrast MRI data on 9 patients (mean age 58 ± 14 years). In both studies, AoRes and AoDist indices were evaluated by BI technique on patients at rest.

Results: A significant correlation was found between PWV and AoRes, AoDist respectively (r= 0.58, p<0.0001, 95% confidence interval: 0.43 to 0.70; r= −0.45, p<0.0001, 95% confidence interval: −0.60 to −0.27) as well as between AoRes and DF (r= 0.96, p=0.0002, spearman coefficient) and between AoDist and DS (r= 0.95, p=0.0004, spearman coefficient).

Conclusion: The local BI method relies on a differential analysis of AoStiff leading to two new indices (AoRes and AoDist) which show a higher and significant correlation with the parameters obtained with MRI technique than PWV method. Furthermore, a larger scale validation should be performed before considering these indices as a suitable alternative to standard methods.