Ezequiel Guzzetti1, Romain Capoulade2, Lionel Tastet1, Julio Garcia3, Florent Le Ven4, Marie Arsenault1, Elisabeth Bédard1, Eric Larose1, Marie-Annick Clavel1, Philippe Pibarot5. 1. Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada. 2. Institut du Thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France. 3. Department of Cardiac Sciences and Radiology, Stephenson Cardiac Imaging Centre, University of Calgary, Calgary, Alberta, Canada; Libin Cardiovascular Institute of Alberta, Stephenson Cardiac Imaging Centre, University of Calgary, Calgary, Alberta, Canada; Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada. 4. CHU Brest, Brest, France. 5. Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada. Electronic address: philippe.pibarot@med.ulaval.ca.
Abstract
BACKGROUND: In aortic stenosis, accurate measurement of left ventricular stroke volume (SV) is essential for the calculation of aortic valve area (AVA) and the assessment of flow status. Current American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines suggest that measurements of left ventricular outflow tract diameter (LVOTd) at different levels (at the annulus vs 5 or 10 mm below) yield similar measures of SV and AVA. The aim of this study was to assess the effect of the location of LVOTd measurement on the accuracy of SV and AVA measured on transthoracic echocardiography (TTE) compared with cardiovascular magnetic resonance (CMR). METHODS: One hundred six patients with aortic stenosis underwent both TTE and CMR. SV was estimated on TTE using the continuity equation with LVOTd measurements at four locations: at the annulus and 2, 5, and 10 mm below annulus. SV was also determined on CMR using phase contrast acquired in the aorta (SVCMR-PC), and a hybrid AVACMR-PC was calculated by dividing SVCMR-PC by the transthoracic echocardiographic Doppler aortic velocity-time integral. Comparison between methods was made using Bland-Altman analysis. RESULTS: Compared with the referent method of phase-contrast CMR for the estimation of SVCMR-PC and AVACMR-PC (SVCMR-PC 83 ± 16 mL, AVACMR-PC 1.27 ± 0.35 cm2), the best agreement was obtained by measuring LVOTd at the annulus or 2 mm below (P = NS), whereas measuring 5 and 10 mm below the annulus resulted in significant underestimation of SV and AVA by up to 15.9 ± 17.3 mL and 0.24 ± 0.28 cm2, respectively (P < .01 for all). Accuracy for classification of low flow was best at the annulus (86%) and 2 mm below (82%), whereas measuring 5 and 10 mm below the annulus significantly underperformed (69% and 61%, respectively, P < .001). CONCLUSIONS: Measuring LVOTd at the annulus or very close to it provides the most accurate measures of SV and AVA, whereas measuring LVOTd 5 or 10 mm below significantly underestimates these parameters and leads to significant overestimation of the severity of aortic stenosis and prevalence of low-flow status.
BACKGROUND: In aortic stenosis, accurate measurement of left ventricular stroke volume (SV) is essential for the calculation of aortic valve area (AVA) and the assessment of flow status. Current American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines suggest that measurements of left ventricular outflow tract diameter (LVOTd) at different levels (at the annulus vs 5 or 10 mm below) yield similar measures of SV and AVA. The aim of this study was to assess the effect of the location of LVOTd measurement on the accuracy of SV and AVA measured on transthoracic echocardiography (TTE) compared with cardiovascular magnetic resonance (CMR). METHODS: One hundred six patients with aortic stenosis underwent both TTE and CMR. SV was estimated on TTE using the continuity equation with LVOTd measurements at four locations: at the annulus and 2, 5, and 10 mm below annulus. SV was also determined on CMR using phase contrast acquired in the aorta (SVCMR-PC), and a hybrid AVACMR-PC was calculated by dividing SVCMR-PC by the transthoracic echocardiographic Doppler aortic velocity-time integral. Comparison between methods was made using Bland-Altman analysis. RESULTS: Compared with the referent method of phase-contrast CMR for the estimation of SVCMR-PC and AVACMR-PC (SVCMR-PC 83 ± 16 mL, AVACMR-PC 1.27 ± 0.35 cm2), the best agreement was obtained by measuring LVOTd at the annulus or 2 mm below (P = NS), whereas measuring 5 and 10 mm below the annulus resulted in significant underestimation of SV and AVA by up to 15.9 ± 17.3 mL and 0.24 ± 0.28 cm2, respectively (P < .01 for all). Accuracy for classification of low flow was best at the annulus (86%) and 2 mm below (82%), whereas measuring 5 and 10 mm below the annulus significantly underperformed (69% and 61%, respectively, P < .001). CONCLUSIONS: Measuring LVOTd at the annulus or very close to it provides the most accurate measures of SV and AVA, whereas measuring LVOTd 5 or 10 mm below significantly underestimates these parameters and leads to significant overestimation of the severity of aortic stenosis and prevalence of low-flow status.
Authors: Felix Troger; Ivan Lechner; Martin Reindl; Christina Tiller; Magdalena Holzknecht; Mathias Pamminger; Christian Kremser; Johannes Schwaiger; Sebastian J Reinstadler; Axel Bauer; Bernhard Metzler; Agnes Mayr; Gert Klug Journal: J Cardiovasc Magn Reson Date: 2022-01-06 Impact factor: 5.364
Authors: Patrick M Kozak; Min Pu; Katrina Swett; Martha L Daviglus; Mayank M Kansal; Daniela Sotres-Alvarez; Sonia G Ponce; Robert Kaplan; Mario Garcia; Carlos J Rodriguez Journal: Mayo Clin Proc Innov Qual Outcomes Date: 2022-07-31
Authors: Pier Pasquale Leone; Fabio Fazzari; Francesco Cannata; Jorge Sanz-Sanchez; Antonio Mangieri; Lorenzo Monti; Ottavia Cozzi; Giulio Giuseppe Stefanini; Renato Bragato; Antonio Colombo; Bernhard Reimers; Damiano Regazzoli Journal: Front Cardiovasc Med Date: 2021-06-04
Authors: Ezequiel Guzzetti; Jin Kyung Oh; Mylène Shen; Marc R Dweck; Kian Keong Poh; Amr E Abbas; Ramy Mando; Gregg S Pressman; Daniel Brito; Lionel Tastet; Tania Pawade; Mariano Luis Falconi; Diego Perez de Arenaza; William Kong; Edgar Tay; Philippe Pibarot; Jae-Kwan Song; Marie-Annick Clavel Journal: Eur Heart J Cardiovasc Imaging Date: 2022-04-18 Impact factor: 9.130