Bucciarelli-Ducci, Chiara

Burchell, Amy E.

Dastidar, Amardeep Ghosh

Hamilton, Mark

Hart, Emma C.

MacIver, David H.

Manghat, Nathan E.

Nightingale, Angus K.

Paton, Julian F.

Ratcliffe, Laura E.

Rodrigues, Jonathan C.

Rohan, Stephen

Journal of Cardiovascular Magnetic Resonance

PubMed

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                          Rodrigues, J. C., Rohan, S., Dastidar, A. G., Burchell, A. E., Ratcliffe, L. E.,Hart, E. C., ... MacIver, D. H. (2015). Are systolic function and ejectionfraction interchangeable? New insights from cardiovascular magneticresonance and in-vivo validation of mathematical models of LV function.Journal of Cardiovascular Magnetic Resonance, 17(1), 1-2. [P325]. DOI:10.1186/1532-429X-17-S1-P325Publisher's PDF, also known as Version of recordLicense (if available):CC BYLink to published version (if available):10.1186/1532-429X-17-S1-P325Link to publication record in Explore Bristol ResearchPDF-documentThis is the final published version of the article (version of record). It first appeared online via BioMed Central at10.1186/1532-429X-17-S1-P325.University of Bristol - Explore Bristol ResearchGeneral rightsThis document is made available in accordance with publisher policies. Please cite only the publishedversion using the reference above. Full terms of use are available:http://www.bristol.ac.uk/pure/about/ebr-terms.htmlPOSTER PRESENTATION Open AccessAre systolic function and ejection fractioninterchangeable? New insights fromcardiovascular magnetic resonance and in-vivovalidation of mathematical models of LV functionJonathan C Rodrigues1,2*, Stephen Rohan3, Amardeep Ghosh Dastidar1, Amy E Burchell4, Laura E Ratcliffe4,Emma C Hart4,2, Angus K Nightingale4, Julian F Paton2,4, Chiara Bucciarelli-Ducci1, Mark Hamilton1,Nathan E Manghat1, David H MacIver5,6From 18th Annual SCMR Scientific SessionsNice, France. 4-7 February 2015BackgroundClinical studies have shown that many patients may haveabnormally reduced myocardial shortening despite pre-served ejection fraction (EF). Mathematical modelingexplains this apparent paradox by demonstrating, thatwhilst myocardial shortening determines radial strain (RS),it is absolute wall thickness (AWT) rather than RS thatdetermines EF. We sought in vivo cardiac MR (CMR) evi-dence to support the mathematical modeling theories.MethodsWe retrospectively analysed 39 CMR studies (28 hyperten-sive patients and 11 healthy volunteers [mean age: 47.4±13.0, male: 56.4%]) performed at 1.5T (Avanto, Siemens).Ventricular volumes and EF were measured using estab-lished CMR techniques. Left ventricular wall thicknesswas measured at end-diastole (ED) and end-systole (ES) inthe long- and short-axis cine views at the mid-cavity at thelevel of the papillary muscles. Measurements wererepeated twice, 1 day apart. Longitudinal strain (LS) wasestimated using a modified 6-point mean annular planesystolic excursion of the mitral valve from 3-chamber, 2-chamber and 4-chamber cines. Subgroup analysis was per-formed by EDWT (Group 1 <9mm [n= 19] and Group 2>9mm [n=20]). Continuous variables were compared byStudent t tests and categorical variables by Fisher exacttest (setting p<0.05 as significant).DefinitionsAWT = ES thickness - ED thickness.RS = (AWT / ED thickness) x 100.Midwall circumferential fractional shortening (mFS) =((LVIDd+EDWT)-(LVIDs+H))/(LVIDd+EDWT)x100(%), where H = ((LVIDd+EDWT)3-(LVIDd)3+(LVIDd)3/1/3-LVIDs, LVIDd = left ventricular internal dimensionin diastole, LVIDs = left ventricular internal dimensionin systole and EDWT = end diastolic wall thickness.ResultsIntra-observer variability for wall thickness measure-ments was good both both long-axis and short-axismeasurements (intra-class correlation coefficient=0.931).Significant positive correlation was demonstratedbetween EDWT and AWT (r2=0.42, p<0.0001). How-ever, significant negative correlations were demonstratedbetween EDWT and RS (r2=0.13, p<0.05), betweenEDWT and longitudinal strain (r2=0.62, p<0.0001) andbetween EDWT and mFS (r2=0.16, p<0.05). Subgroupanalysis by EDWT is demonstrated in Figure 1. Despitesignificant reductions in LS, mFS and trend towardslower RS, ejection fraction is significantly higher andindexed stroke volume is similar between in ventricleswith EDWT >9mm compared to those <9mm.ConclusionsMyocardial systolic function and ejection fraction arenot the same. Our study provides in-vivo validation ofmathematical modeling predictions that significant LV1CMR Unit, NIHR Cardiovascular Biomedical Research Unit, Bristol HeartInstitute, Bristol, UKFull list of author information is available at the end of the articleRodrigues et al. Journal of Cardiovascular MagneticResonance 2015, 17(Suppl 1):P325http://www.jcmr-online.com/content/17/S1/P325© 2015 Rodrigues et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.systolic impairment (in the form of impaired LS, RS andmFS) can be compensated for by significant increases inAWT thus maintaining indexed SV and EF. This findinghas implications for the understanding the pathophysiol-ogy of heart failure with preserved ejection fraction, andits potential treatment.FundingNIHR Bristol Cardiovascular Biomedical Research Unit,Bristol Heart Institute.JCLR: Clinical Society of Bath Postgraduate ResearchBursary.ECH: BHF grant IBSRF FS/11/1/28400.Authors’ details1CMR Unit, NIHR Cardiovascular Biomedical Research Unit, Bristol HeartInstitute, Bristol, UK. 2School of Physiology and Pharmacology, The Universityof Bristol, Bristol, UK. 3Medical School, The University of Bristol, Bristol, UK.4Cardionomics Research Group, Bristol Heart Institute, Bristol, UK. 5Cardiology,Taunton and Somerset Hospital, Taunton, UK. 6Biological Physics, TheUniversity of Manchester, Manchester, UK.Published: 3 February 2015doi:10.1186/1532-429X-17-S1-P325Cite this article as: Rodrigues et al.: Are systolic function and ejectionfraction interchangeable? New insights from cardiovascular magneticresonance and in-vivo validation of mathematical models of LVfunction. Journal of Cardiovascular Magnetic Resonance 2015 17(Suppl 1):P325.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitFigure 1 Subgroup analysis by end-diastolic wall thicknessRodrigues et al. Journal of Cardiovascular MagneticResonance 2015, 17(Suppl 1):P325http://www.jcmr-online.com/content/17/S1/P325Page 2 of 2

Are systolic function and ejection fraction interchangeable? New insights from cardiovascular magnetic resonance and in-vivo validation of mathematical models of LV function

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Are systolic function and ejection fraction interchangeable? New insights from cardiovascular magnetic resonance and in-vivo validation of mathematical models of LV function

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