Discrepancies between cardiovascular magnetic resonance and Doppler echocardiography in the measurement of transvalvular gradient in aortic stenosis: the effect of flow vorticity

Journal of Cardiovascular Magnetic Resonance

Research

Emmanuel Gaillard¹  Lyes Kadem²  Éric Larose³  Philippe Pibarot³  Florent Le Ven³  Romain Capoulade³  Julio Garcia⁴ 

[1] Department of Mechanical Engineering, McGill University, Montréal, Canada;Laboratory of Cardiovascular Fluid Dynamics, Concordia University, Montréal, Canada;Québec Heart and Lung Institute, Laval University, Québec, Canada;Québec Heart and Lung Institute, Laval University, Québec, Canada;Laboratory of Cardiovascular Fluid Dynamics, Concordia University, Montréal, Canada;Department of Radiology, Northwestern University, Chicago, USA;

关键词: Aortic stenosis;    Echo-Doppler;    Cardiovascular magnetic resonance;    Mean pressure gradient;    Flow vorticity;   

DOI  :  10.1186/1532-429X-15-84

 received in 2013-05-06, accepted in 2013-09-03,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundValve effective orifice area EOA and transvalvular mean pressure gradient (MPG) are the most frequently used parameters to assess aortic stenosis (AS) severity. However, MPG measured by cardiovascular magnetic resonance (CMR) may differ from the one measured by transthoracic Doppler-echocardiography (TTE). The objectives of this study were: 1) to identify the factors responsible for the MPG measurement discrepancies by CMR versus TTE in AS patients; 2) to investigate the effect of flow vorticity on AS severity assessment by CMR; and 3) to evaluate two models reconciling MPG discrepancies between CMR/TTE measurements.MethodsEight healthy subjects and 60 patients with AS underwent TTE and CMR. Strouhal number (St), energy loss (EL), and vorticity were computed from CMR. Two correction models were evaluated: 1) based on the Gorlin equation (MPGCMR-Gorlin); 2) based on a multivariate regression model (MPGCMR-Predicted).ResultsMPGCMR underestimated MPGTTE (bias = −6.5 mmHg, limits of agreement from −18.3 to 5.2 mmHg). On multivariate regression analysis, St (p = 0.002), EL (p = 0.001), and mean systolic vorticity (p < 0.001) were independently associated with larger MPG discrepancies between CMR and TTE. MPGCMR-Gorlin and MPGTTE correlation and agreement were r = 0.7; bias = −2.8 mmHg, limits of agreement from −18.4 to 12.9 mmHg. MPGCMR-Predicted model showed better correlation and agreement with MPGTTE (r = 0.82; bias = 0.5 mmHg, limits of agreement from −9.1 to 10.2 mmHg) than measured MPGCMR and MPGCMR-Gorlin.ConclusionFlow vorticity is one of the main factors responsible for MPG discrepancies between CMR and TTE.

【 授权许可】

Unknown   
© Garcia et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.