Consistency of aortic distensibility and pulse wave velocity estimates with respect to the Bramwell-Hill theoretical model: A cardiovascular magnetic resonance study

Abstract

Background: Arterial stiffness is considered as an independent predictor of cardiovascular mortality, and is increasingly used in clinical practice. This study aimed at evaluating the consistency of the automated estimation of regional and local aortic stiffness indices from cardiovascular magnetic resonance (CMR) data. Results: Forty-six healthy subjects underwent carotid-femoral pulse wave velocity measurements (CF-PWV) by applanation tonometry and CMR with steady-state free-precession and phase contrast acquisitions at the level of the aortic arch. These data were used for the automated evaluation of the aortic arch pulse wave velocity (Arch-PWV), and the ascending aorta distensibility (AA-Distc, AA-Distb), which were estimated from ascending aorta strain (AA-Strain) combined with either carotid or brachial pulse pressure. The local ascending aorta pulse wave velocity AA-PWVc and AA-PWVb were estimated respectively from these carotid and brachial derived distensibility indices according to the Bramwell-Hill theoretical model, and were compared with the Arch-PWV. In addition, a reproducibility analysis of AA-PWV measurement and its comparison with the standard CF-PWV was performed. Characterization according to the Bramwell-Hill equation resulted in good correlations between Arch-PWV and both local distensibility indices AA-Distc (r = 0.71, p < 0.001) and AA-Distb (r = 0.60, p < 0.001); and between Arch-PWV and both theoretical local indices AA-PWVc (r = 0.78, p < 0.001) and AA-PWVb (r = 0.78, p < 0.001). Furthermore, the Arch-PWV was well related to CF-PWV (r = 0.69, p < 0.001) and its estimation was highly reproducible (inter-operator variability: 7.1%). Conclusions: The present work confirmed the consistency and robustness of the regional index Arch-PWV and the local indices AA-Distc and AA-Distb according to the theoretical model, as well as to the well established measurement of CF-PWV, demonstrating the relevance of the regional and local CMR indices. © 2011 Dogui et al; licensee BioMed Central Ltd.