Alex J Barker

Florian von Knobelsdorff-Brenkenhoff

Henriette Gruettner

Jeanette Schulz-Menger

Michael Markl

Ralf F Trauzeddel

Journal of Cardiovascular Magnetic Resonance

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POSTER PRESENTATION Open AccessType of aortic valve replacement influencesascending aortic flow characteristics - a pilotstudy using 4D flow MRIFlorian von Knobelsdorff-Brenkenhoff1*, Ralf F Trauzeddel1, Alex J Barker2, Henriette Gruettner1, Michael Markl2,3,Jeanette Schulz-Menger1From 16th Annual SCMR Scientific SessionsSan Francisco, CA, USA. 31 January - 3 February 2013BackgroundProsthesis-related alterations of blood flow in theascending aorta after aortic valve replacement (AVR)may influence aortic remodeling. The study aimed atanalyzing ascending aortic flow characteristics after var-ious types of AVR.MethodsFlow-sensitive four-dimensional magnetic resonance ima-ging (4D-flow) was acquired in 38 AVR patients (n=9mechanical, n=8 stentless bioprosthesis, n=14 stented bio-prosthesis, n=7 autograft) and 9 healthy controls. Analysisincluded grading of vortex and helix flow (0-3 point scale),assessment of systolic flow eccentricity (1-3 point scale),and quantification of the segmental distribution of peaksystolic wall shear stress (WSSpeak) in the ascending aorta.ResultsCompared to controls, mechanical prostheses showedthe most distinct vorticity (2.7±0.5 vs. 0.7±0.7; p<0.001),while stented bioprostheses exhibited most distinct heli-city (2.6±0.7 vs. 1.6±0.5; p=0.002) (Figures 1 and 2).1Working Group Cardiovascular MRI, Experimental and Clinical ResearchCenter (Charite Medical Faculty and MDC) and HELIOS Clinics Berlin, Berlin,GermanyFull list of author information is available at the end of the articleFigure 1 Visualization of the blood flow in the ascending aorta using particle traces during peak systole: Each image is selected to berepresentative for the specific valve group.von Knobelsdorff-Brenkenhoff et al. Journal of CardiovascularMagnetic Resonance 2013, 15(Suppl 1):P245http://www.jcmr-online.com/content/15/S1/P245© 2013 von Knobelsdorff-Brenkenhoff et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms ofthe 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.Instead of a physiologic central flow, all stented, stent-less and mechanical prostheses showed eccentric flowjets mainly directed towards the right-anterior aorticwall. Stented and stentless prostheses showed an asym-metric distribution of WSSpeak along the aortic circum-ference, with significantly increased local WSSpeak wherethe flow jet impinged on the aortic wall. Local WSSpeakwas higher in stented (1.4±0.7N/m2) and stentless (1.3±0.7N/m2) compared to autografts (0.6±0.2N/m2;p=0.005 and p=0.008) and controls (0.7±0.1N/m2;p=0.017 and p=0.027). Autografts exhibited lower abso-lute WSSpeak than controls (0.4±0.1N/m2 vs. 0.7±0.2N/m2; p=0.003).ConclusionsThe flow characteristics in the ascending aorta in allAVR types were different from volunteers with nativeaortic valve, and they differed between the various typesof AVR.FundingFvKB is supported by the Else Kröner-Fresenius Stiftung(Bad Homburg, Germany). AJB is funded by the Whi-taker Postdoctoral and Fulbright Grants (New York,USA). MM is supported by the NMH Excellence inAcademic Medicine (EAM) Program ‘Advanced Cardio-vascular MRI Research Center’ (Chicago, USA).Author details1Working Group Cardiovascular MRI, Experimental and Clinical ResearchCenter (Charite Medical Faculty and MDC) and HELIOS Clinics Berlin, Berlin,Germany. 2Department of Radiology, Feinberg School of Medicine,Northwestern University, Chicago, IL, USA. 3Department of BiomedicalEngineering, McCormick School of Engineering, Northwestern University,Chicago, IL, USA.Published: 30 January 2013doi:10.1186/1532-429X-15-S1-P245Cite this article as: von Knobelsdorff-Brenkenhoff et al.: Type of aorticvalve replacement influences ascending aortic flow characteristics - apilot study using 4D flow MRI. Journal of Cardiovascular MagneticResonance 2013 15(Suppl 1):P245.Figure 2 Evaluation of vorticity, helicity and eccentricity of blood flow: The upper row shows the frequency of each score for the various AVRgroups and controls. The lower row depicts the mean ± SD scoring results. Please note that the order of the groups varies between the threecolumns. (* p<0.05 vs. stentless, autografts and controls; † p<0.05 vs. stentless, autografts and controls; ‡ <0.05 vs. controls; $ p<0.05 vs. stented,autografts, controls; | |p<0.05 vs. stentless, mechanical, autografts and controls).von Knobelsdorff-Brenkenhoff et al. Journal of CardiovascularMagnetic Resonance 2013, 15(Suppl 1):P245http://www.jcmr-online.com/content/15/S1/P245Page 2 of 2

Type of aortic valve replacement influences ascending aortic flow characteristics - a pilot study using 4D flow MRI

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Type of aortic valve replacement influences ascending aortic flow characteristics - a pilot study using 4D flow MRI

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