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ASSESSMENT OF AORTIC MORPHOMETRY AND PEAK VELOCITY BASED ON 4D FLOW MRI
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uncertain or discordant findings at echocardiography. However, among younger patients with BAV, some may have a hemodynamically significant stenosis with no/minimal AVC. The results of CT AVC should thus be interpreted cautiously in this subset of patients.
583 ASSESSMENT OF AORTIC MORPHOMETRY AND PEAK VELOCITY BASED ON 4D FLOW MRI
Canadian Journal of Cardiology Volume 31 2015
group (r¼0.55, p<0.001 and r¼0.45, p<0.001, respectively). CONCLUSION: The aorta morphometric and hemodynamic differences can be detected using a single 4D flow MRI acquisition in the entire aorta except the SOV regions. The association of aortic diameter with age and PV were driven by the control group. The BAV significantly impacted PV, while no significant difference was found in ascending aorta diameter between the BAV and TAV.
J Garcia, A Barker, I Murphy, K Jarvis, A Powell, S Schnell, J Collins, J Carr, M Markl Chicago, Illinois BACKGROUND:
Aortic dimensions and peak velocity (PV) are clinically important metrics for the characterization of aortopathies. The purpose of this study was to apply 4D flow MRI for the simultaneous assessment of aorta diameter and PV along the entire aorta. We hypothesized that: 1) 4D flow can detect differences in aortic dimensions and PV based on a single acquisition; 2) maximal aortic diameter is associated with age and PV. METHODS: 165 subjects (65 controls, 50 patients with bicuspid aortic valve (BAV), and 50 patients with tricuspid aortic valve (TAV) both with aortic dilatation) underwent a 4D flow MRI exam. Data analysis included the calculation of a 3D phase-contrast (PC) angiogram (MRA) from the 4D flow data followed by 3D segmentation of the aortic lumen and a volume centerline (Fig. 1A, 1B). Centerline was used to extract diameter and PV (Fig. 1C, 1D). Standardized anatomic landmarks (Fig. 1B) were used to normalize the measurements along the aorta centerline distance. Diameter validation was performed in 20 controls by comparing 4D flow derived diameter with manual diameter measurements obtained from standard contrast enhanced (CE) MRA. The CE-MRA data underwent 3D segmentation and extraction of diameter along the centerline. RESULTS: For CE-MRA, the manually measured diameters at landmarks have an absolute difference of 22 % with centerline based calculations. However, 4D flow derived diameter differed to CE MRA in the aortic sinus region (Fig. 1E). For the remainder of the aorta a very good agreement for diameter between CE MRA and 4D flow MRI was found (mean difference¼0.1 mm, limits of agreement¼2.2mm, absolute error¼54 %). Significant differences between controls, BAV and TAV groups were found throughout the aorta for aortic diameter and PV (p<0.05 and p<0.05, respectively, Fig. 1F, 1G). Maximum PV was located within the aortic sinus section and showed a significant difference (p<0.05) between all groups. Significant correlations of maximal diameter with age (r¼0.52, p<0.001) and aortic PV (r¼0.44. p<0.001) were found. However, independent group correlations showed that these associations were driven by the control
584 IMPACT OF AORTIC VALVE REPAIR AND VALVE-SPARING PROCEDURES ON THE MITRAL ANNULAR GEOMETRY ASSESSED BY 3-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY M Pagé, M Laflamme, C De Meester, L De Kerchove, G El-Khoury, A Pasquet, J Vanoverschelde Montréal, Québec BACKGROUND:
Annular non-planarity, referred to as the “saddle-shape” of the mitral valve (MV) annulus, is thought to play a role in minimizing leaflet stress and preserving adequate valve function. Aortic valve (AV) repair and sparing procedures are increasingly used to treat young patients with severe aortic regurgitation (AR). However, the impact of these procedures on MV annular geometry and function is unknown. METHODS: 2D and 3D transesophageal echocardiography (TEE) of the MV apparatus was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n¼10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation (Tirone-David procedure); Group 2 (n¼10): tricuspid AV undergoing AV repair and Tirone-David procedure; Group 3 (n¼10): patients undergoing isolated AV cusp repair and external ring annuloplasty without root replacement) and in 10 controls
uncertain or discordant findings at echocardiography. However, among younger patients with BAV, some may have a hemodynamically significant stenosis with no/minimal AVC. The results of CT AVC should thus be interpreted cautiously in this subset of patients.
583 ASSESSMENT OF AORTIC MORPHOMETRY AND PEAK VELOCITY BASED ON 4D FLOW MRI
Canadian Journal of Cardiology Volume 31 2015
group (r¼0.55, p<0.001 and r¼0.45, p<0.001, respectively). CONCLUSION: The aorta morphometric and hemodynamic differences can be detected using a single 4D flow MRI acquisition in the entire aorta except the SOV regions. The association of aortic diameter with age and PV were driven by the control group. The BAV significantly impacted PV, while no significant difference was found in ascending aorta diameter between the BAV and TAV.
J Garcia, A Barker, I Murphy, K Jarvis, A Powell, S Schnell, J Collins, J Carr, M Markl Chicago, Illinois BACKGROUND:
Aortic dimensions and peak velocity (PV) are clinically important metrics for the characterization of aortopathies. The purpose of this study was to apply 4D flow MRI for the simultaneous assessment of aorta diameter and PV along the entire aorta. We hypothesized that: 1) 4D flow can detect differences in aortic dimensions and PV based on a single acquisition; 2) maximal aortic diameter is associated with age and PV. METHODS: 165 subjects (65 controls, 50 patients with bicuspid aortic valve (BAV), and 50 patients with tricuspid aortic valve (TAV) both with aortic dilatation) underwent a 4D flow MRI exam. Data analysis included the calculation of a 3D phase-contrast (PC) angiogram (MRA) from the 4D flow data followed by 3D segmentation of the aortic lumen and a volume centerline (Fig. 1A, 1B). Centerline was used to extract diameter and PV (Fig. 1C, 1D). Standardized anatomic landmarks (Fig. 1B) were used to normalize the measurements along the aorta centerline distance. Diameter validation was performed in 20 controls by comparing 4D flow derived diameter with manual diameter measurements obtained from standard contrast enhanced (CE) MRA. The CE-MRA data underwent 3D segmentation and extraction of diameter along the centerline. RESULTS: For CE-MRA, the manually measured diameters at landmarks have an absolute difference of 22 % with centerline based calculations. However, 4D flow derived diameter differed to CE MRA in the aortic sinus region (Fig. 1E). For the remainder of the aorta a very good agreement for diameter between CE MRA and 4D flow MRI was found (mean difference¼0.1 mm, limits of agreement¼2.2mm, absolute error¼54 %). Significant differences between controls, BAV and TAV groups were found throughout the aorta for aortic diameter and PV (p<0.05 and p<0.05, respectively, Fig. 1F, 1G). Maximum PV was located within the aortic sinus section and showed a significant difference (p<0.05) between all groups. Significant correlations of maximal diameter with age (r¼0.52, p<0.001) and aortic PV (r¼0.44. p<0.001) were found. However, independent group correlations showed that these associations were driven by the control
584 IMPACT OF AORTIC VALVE REPAIR AND VALVE-SPARING PROCEDURES ON THE MITRAL ANNULAR GEOMETRY ASSESSED BY 3-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY M Pagé, M Laflamme, C De Meester, L De Kerchove, G El-Khoury, A Pasquet, J Vanoverschelde Montréal, Québec BACKGROUND:
Annular non-planarity, referred to as the “saddle-shape” of the mitral valve (MV) annulus, is thought to play a role in minimizing leaflet stress and preserving adequate valve function. Aortic valve (AV) repair and sparing procedures are increasingly used to treat young patients with severe aortic regurgitation (AR). However, the impact of these procedures on MV annular geometry and function is unknown. METHODS: 2D and 3D transesophageal echocardiography (TEE) of the MV apparatus was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n¼10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation (Tirone-David procedure); Group 2 (n¼10): tricuspid AV undergoing AV repair and Tirone-David procedure; Group 3 (n¼10): patients undergoing isolated AV cusp repair and external ring annuloplasty without root replacement) and in 10 controls