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La régurgitation aortique est une pathologie valvulaire caractérisée par une mal coaptation d’une ou de plusieurs cuspides aortiques. Le résultat est un reflux du sang de l’aorte vers le ventricule gauche avec une surcharge de volume et de pression. En phase aiguë en présence d’une fuite aortique massive, le ventricule gauche évolue rapidement vers une défaillance terminale. Cependant en présence d’une fuite sévère, le ventricule s’adapte chroniquement par une série de mécanismes compensatoires :par l’augmentation de sa masse, du diamètre de la chambre de chasse et par une hypertrophie ventriculaire gauche. Cette dernière facilite la réduction de la tension pariétale résultante de la surcharge en pression et en volume afin finalement de réduire la consommation en oxygène. L’évolution est marquée par une détérioration progressive de la fonction ventriculaire qui en l’absence de traitement évolue vers l’insuffisance cardiaque. Le seul traitement actuel de la régurgitation aortique est le traitement chirurgical. À l’heure actuelle, il y a plusieurs drogues utilisées dans le traitement de l’insuffisance cardiaque mais leur point commun est la modification de l’homéostasie calcique, l’augmentation de la consommation d’oxygène avec un risque d’augmenter les arythmies, la morbidité et la mortalité. L’omecamtiv mecarbil est un activateur sélectif de la myosine cardiaque et est une nouvelle drogue en phase d’études cliniques pour son potentiel rôle dans le traitement l’insuffisance cardiaque systolique. Il active spécifiquement l'ATPase myocardique et améliore l'utilisation de l'énergie cardiaque. Il augmente le taux de libération de phosphate de la myosine, une fois que la myosine est liée à l'actine, elle reste liée beaucoup plus longtemps en présence d'omecamtiv mecarbil. Le résultat est une amélioration de la fonction systolique en augmentant la durée d'éjection systolique sans consommer plus d'énergie d’ATP, d'oxygène ou altérer les niveaux de calcium intracellulaire en, Doctorat en Sciences médicales (Médecine), info:eu-repo/semantics/nonPublished

Cardiovascular magnetic resonance (CMR) 2D feature tracking (FT) left ventricular (LV) myocardial strain has seen widespread use to characterize myocardial deformation. Yet, validation of CMR FT measurements remains scarce, particularly for regional strain. Therefore, we aimed to perform intervendor comparison of 3 different FT software against tagging. In 61 subjects (18 healthy subjects, 18 patients with chronic myocardial infarction, 15 with dilated cardiomyopathy, and 10 with LV hypertrophy due to hypertrophic cardiomyopathy or aortic stenosis) were prospectively compared global (G) and regional transmural peak-systolic Lagrangian longitudinal (LS), circumferential (CS) and radial strains (RS) by 3 FT software (cvi42, Segment, and Tomtec) among each other and with tagging at 3T. We also evaluated the ability of regional LS, CS, and RS by different FT software vs tagging to identify late gadolinium enhancement (LGE) in the 18 infarct patients. GLS and GCS by all 3 software had an excellent agreement among each other (ICC = 0.94-0.98 for GLS and ICC = 0.96-0.98 for GCS respectively) and against tagging (ICC = 0.92-0.94 for GLS and ICC = 0.88-0.91 for GCS respectively), while GRS showed inconsistent agreement between vendors (ICC 0.10-0.81). For regional LS, the agreement was good (ICC = 0.68) between 2 vendors but less vs the 3 (ICC 0.50-0.59) and moderate to poor (ICC 0.44-0.47) between all three FT software and tagging. Also, for regional CS agreement between 2 software was higher (ICC = 0.80) than against the 3rd (ICC = 0.58-0.60), and both better agreed with tagging (ICC = 0.70-0.72) than the 3rd (ICC = 0.57). Regional RS had more variation in the agreement between methods ranging from good (ICC = 0.75) to poor (ICC = 0.05). Finally, the accuracy of scar detection by regional strains differed among the 3 FT software. While the accuracy of regional LS was similar, CS by one software was less accurate (AUC 0.68) than tagging (AUC 0.80, p < 0.006) and RS less acc

SCOPUS: ar.j, info:eu-repo/semantics/published

Purpose: Because of its diagnostic and prognostic value, right ventricular strain assessed by speckle-tracking imaging (RVS) has been incorporated into echocardiographic guidelines. However, it suffers from limitations including the need of good image quality and of dedicated software with inter-vendor variability. We hypothesized that RV free wall longitudinal fractional shortening (LFS) could be used as a substitute to RVS, without suffering from the aforementioned limitations. Methods: We aimed to establish in a series of non-selected consecutive patients in sinus rhythm the value of LFS, calculated as [-(TAPSE/RVdiastolic length)] and of several common echocardiographic and Doppler parameters to predict an abnormal RV function, defined as RVS > − 20.2%. Results: Among 144 consecutive patients, poor image quality precluded the assessment of RVS and of LFS in 31 and 4 patients, respectively (P = 0.0018), resulting in a final study group of 113 patients. The intraclass correlation coefficients for inter- and intra-observer variability were 0.97 (95% CI 0.92; 0.98) and 0.93 (CI 0.92; 0.98) for LFS and RVS, respectively. Among all tested RV function indices, LFS best correlated with RVS (R 0.97, 95% CI 0.81; 0.91). Bland–Altman analysis for the comparison between LFS and RVS showed no systematic bias. The area under the ROC-curve of the various RV function indices to detect abnormal RVS was best for LFS (0.97, 95% CI 0.94–1), with sensitivity, specificity, negative and positive predictive value of 83%, 96%, 96%, and 83%, respectively. Conclusion: LFS performs reasonably well to predict abnormal RVS and is more often feasible than RVS., SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

OBJECTIVES: This study sought to compare the prognostic value of 2-dimensional (2D) right ventricular (RV) speckle tracking (STE) against cardiac magnetic resonance (CMR) RV ejection fraction (EF) and feature tracking (FT) and conventional echocardiographic parameters on overall and cardiovascular (CV) survival in patients with heart failure with reduced EF (HFrEF). BACKGROUND: Prior works showed that RV systolic function predicts prognosis in HFrEF. 2D RVSTE had recently been proposed as new echocardiographic method to evaluate RV dysfunction. METHODS: A total of 266 patients with HFrEF (mean LVEF 23 ± 7%, 60 ± 14 years of age; 29% women) underwent RV function assessment using CMR and 2D echocardiography and were followed for a primary endpoint of overall death and secondary endpoint of CV death. RESULTS: Average CMR-RVEF was 42 ± 15%, average STE RV global longitudinal strain (STE-RVGLS) was -18.0 ± 4.9%, and average CMR-FT-RVGLS was -11.8 ± 4.3%. After a median follow-up of 4.7 years, 102 patients died, 84 of a CV cause. RVEF, FT-RVGLS, tricuspid annulus plane systolic excursion (TAPSE), fractional area change (FAC), and STE-RVGLS were significant univariate predictors of overall and cardiac death. In multivariate Cox regression, age, ischemic etiology, diabetes, New York Heart Association functional class III to IV, and beta-blocker treatment were independent clinical predictors of overall mortality. CMR-RVEF (chi-square to enter = 3.9; p < 0.05), FT-RVGLS (chi-square to enter 3.7; p = 0.05), FAC (chi-square to enter 6.2; p = 0.02), and TAPSE (chi-square to enter = 4.1; p = 0.04) provided additional prognostic value over these baseline parameters, but the additional predictive value of STE-RVGLS (chi-square to enter = 10.8; p < 0.001) was significantly (p < 0.05) higher than the other tests. Additional hazard ratio to predict overall mortality was 2.5 (95% confidence interval [CI]: 1.6 to 3.9) for STE-RVGLS <-19%, 2.15 (95% CI: 1.34 to 3.43) for TAPSE >15 mm, 1.

OBJECTIVES: The present study aimed at investigating the respective contribution of afterload and myocardial fibrosis to pre- and post-operative left ventricular (LV) function by using stress-strain relationships. BACKGROUND: Separating the effect of myocardial dysfunction and afterload on pump performance has important implications for the prognosis and management of patients with severe aortic stenosis (AS). METHODS: A total of 101 patients with isolated severe AS (57% men; mean age 71 years) and 75 healthy control subjects underwent resting 2-dimensional and speckle-tracking echocardiography to measure global circumferential strain (GCS) and global longitudinal strain (GLS), as well as end-systolic wall stress (ESWS). Normal stress-strain relationships were constructed using control subjects' data and fitted to linear regression. End-systolic stress-strain indexes (the number of SDs from the mean regression line) were used as an afterload-independent index of myocardial function and compared with myocardial fibrosis, measured on transmural myocardial biopsies harvested at the time of surgery. RESULTS: GCS and GLS were afterload-dependent in both control subjects and patients. The GLS-ESWS relationship of patients was shifted downward compared with control subjects. Patients with reduced pre-operative end-systolic stress-strain indexes exhibited larger degrees of interstitial myocardial fibrosis than patients without (3.8 ± 2.9% vs. 8.3 ± 6.3%, p < 0.001; and 4.9 ± 4.4% vs. 9.5 ± 6.4%; p < 0.001, for GLS and GCS, respectively). By multivariate analysis, pre-operative end-systolic stress-strain indexes were the only predictors of post-operative longitudinal and circumferential end-systolic stress-strain indexes (ß = 0.49 and ß = 0.60, respectively; p < 0.001). CONCLUSIONS: Myocardial strains are afterload-dependent. In patients with severe AS, pre-operative stress-strain indexes allow identification of patients with increased myocardial fibrosis and predict the ext

The objective of this meta-analysis was to assess the predictive value of late gadolinium enhancement (LGE) and global systolic impairment for future major adverse cardiovascular events in left ventricular noncompaction (LVNC). The prognosis of patients with LVNC, with and without left ventricular dysfunction and LGE, is still unclear. A systematic review of published research and a meta-analysis reporting a combined endpoint of hard (cardiac death, sudden cardiac death, appropriate defibrillator firing, resuscitated cardiac arrest, cardiac transplantation, assist device implantation) and minor (heart failure hospitalization and thromboembolic events) events was performed. Four studies with 574 patients with LVNC and 677 with no LVNC and an average follow-up duration of 5.2 years were analyzed. In patients with LVNC, LGE was associated with the combined endpoint (pooled odds ratio: 4.9; 95% confidence interval: 1.63 to 14.6; p = 0.005) and cardiac death (pooled odds ratio: 9.8; 95% confidence interval: 2.44 to 39.5; p < 0.001). Preserved left ventricular systolic function was found in 183 patients with LVNC: 25 with positive LGE and 158 with negative LGE. In LVNC with preserved ejection fraction, positive LGE was associated with hard cardiac events (odds ratio: 6.1; 95% confidence interval: 2.1 to 17.5; p < 0.001). No hard cardiac events were recorded in patients with LVNC, preserved ejection fraction, and negative LGE. Patients with LVNC but without LGE have a better prognosis than those with LGE. When LGE is negative and global systolic function is preserved, no hard cardiac events are to be expected. Currently available criteria allow diagnosis of LVNC, but to further define the presence and prognostic significance of the disease, LGE and/or global systolic impairment must be considered for better risk stratification.

Myocardial tissue tracking imaging techniques have been developed for a more accurate evaluation of myocardial deformation (i.e. strain), with the potential to overcome the limitations of ejection fraction (EF) and to contribute, incremental to EF, to the diagnosis and prognosis in cardiac diseases. While most of the deformation imaging techniques are based on the similar principles of detecting and tracking specific patterns within an image, there are intra- and inter-imaging modality inconsistencies limiting the wide clinical applicability of strain. In this review, we aimed to describe the particularities of the echocardiographic and cardiac magnetic resonance deformation techniques, in order to understand the discrepancies in strain measurement, focusing on the potential sources of variation: related to the software used to analyse the data, to the different physics of image acquisition and the different principles of 2D vs. 3D approaches. As strain measurements are not interchangeable, it is highly desirable to work with validated strain assessment tools, in order to derive information from evidence-based data. There is, however, a lack of solid validation of the current tissue tracking techniques, as only a few of the commercial deformation imaging softwares have been properly investigated. We have, therefore, addressed in this review the neglected issue of suboptimal validation of tissue tracking techniques, in order to advocate for this matter.

The combination of aortic and mitral regurgitation is a typical example of a frequent yet understudied multiple valve disease scenario. The aetiology is often rheumatic or degenerative; less frequently it can be induced by drugs or radiation, or caused by infective endocarditis or congenital valvular lesions. Aortic regurgitation resulting in secondary mitral regurgitation is also not uncommon. There are limited data to guide the management of combined aortic and mitral regurgitation. Left ventricular dysfunction is frequent at initial presentation, and even more so postoperatively, suggesting that surgical management should not be delayed, particularly when symptoms occur or when there is evidence of even subtle left ventricular dysfunction. The decision to operate on one or both valves not only depends on the severity of each lesion, but also on several other factors, including age, co-morbidities and frailty, the increased operative risk of double valve surgery, the increased risk of long-term thrombotic and bleeding complications with multiple mechanical valves, the risk of leaving one valve unoperated and the probability of requiring redo surgery. The role of a multidisciplinary heart valve team is critical in this setting to optimize management and outcomes. The role of transcatheter approaches is currently limited, but technological advances will probably soon change the management paradigm., SCOPUS: re.j, info:eu-repo/semantics/published

AIMS: Although recommended by current guidelines, adoption of three-dimensional echocardiographic (3DE) chamber quantification in clinical practice has lagged because of time-consuming analysis. We recently validated an automated algorithm that measures left atrial (LA) and left ventricular (LV) volumes and ejection fraction (EF). This study aimed to determine the accuracy and reproducibility of these measurements in a multicentre setting. METHODS AND RESULTS: 180 patients underwent 3DE imaging (Philips) at six sites. Images were analysed using automated HeartModel (HM) software with endocardial border correction when necessary and by manual tracing. Measurements were performed by each site and by the Core Laboratory (CL) as the reference. Inter-technique comparisons included HM measurements by the sites against manual tracing by CL, and showed strong correlations (r-values: LVEDV: 0.97, LVESV: 0.97, LVEF: 0.88, LAV: 0.96), with the automated technique slightly underestimating LV volumes (biases: LVEDV: -14 ± 20 ml, LVESV: -6 ± 20 ml), LVEF (-2 ± 7%) and LAV (-9 ± 10 ml). Intra-technique comparisons included HM measurements by the sites against CL, with and without corrections. Corrections were unnecessary or minimal in most patients, and improved the measurements only modestly. Comparisons without corrections showed perfect agreement for all parameters. With corrections, correlations were better (r-values: LVEDV: 0.99, LVESV: 0.99, LVEF: 0.94, LAV: 0.99) and biases (LVEDV: -8 ± 12 ml, LVESV: -6 ± 12 ml, LVEF: 1 ± 5%, LAV: -10 ± 6 ml) smaller than in inter-technique comparison. All automated measurements with corrections were more reproducible than manual measurements. CONCLUSION: Automated 3DE analysis of left-heart chambers is an accurate alternative to conventional manual methodology, which yields almost the same values across laboratories and is more reproducible. This technique may contribute towards full integration of 3DE quantification into clinical routine.

BACKGROUND: In prior work, the authors demonstrated that two-dimensional speckle-tracking (2DST) correlated well but systematically overestimated global longitudinal strain (LS) and circumferential strain (CS) compared with two-dimensional cardiac magnetic resonance tagging (2DTagg) and had poor agreement on a segmental basis. Because three-dimensional speckle-tracking (3DST) has recently emerged as a new, more comprehensive evaluation of myocardial deformation, this study was undertaken to evaluate whether it would compare more favorably with 2DTagg than 2DST. METHODS: In a prospective two-center trial, 119 subjects (29 healthy volunteers, 63 patients with left ventricular dysfunction, and 27 patients with left ventricular hypertrophy) underwent 2DST, 3DST, and 2DTagg. Global, regional (basal, mid, and apical), and segmental (18 and 16 segments per patient) LS and CS by 2DST and 3DST were compared with 2DTagg using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Test-retest reproducibility of 3DST and 2DST was compared in 48 other patients. RESULTS: Both global LS and CS by 3DST agreed better with 2DTagg (ICC = 0.89 and ICC = 0.83, P < .001 for both; bias = 0.5 ± 2.3% and 0.2 ± 3%) than 2DST (ICC = 0.65 and ICC = 0.55, P < .001 for both; bias = -5.5 ± 2.5% and -7 ± 5.3%). Unlike 2DST, 3DST did not overestimate deformation at the regional and particularly the apical levels and at the segmental level had lower bias (LS, 0.8 ± 2.8% vs -5.3 ± 2.4%; CS, -0.01 ± 2.8% vs -7 ± 2.8%, respectively) but similar agreement with 2DST (LS: ICC = 0.58 ± 0.16 vs 0.56 ± 0.12; CS: ICC = 0.58 ± 0.12 vs 0.51 ± 0.1) with 2DTagg. Finally, 3DST had similar global LS, but better global CS test-retest variability than 2DST. CONCLUSIONS: Using 2DTagg as reference, 3DST had better agreement and less bias for global and regional LS and CS. At the segmental level, 3DST demonstrated comparable agreement but lower bias versus 2DTagg compared with 2DST. Also, test-retest vari

The aim of this paper is to describe an automated diagnostic pipeline which uses as input only ultrasound (US) data, but is at the same time informed by a training database of multimodal magnetic resonance (MR) and US image data. We create a multimodal cardiac motion atlas from 3D MR and 3D US data followed by multi-view machine learning algorithms to combine and extract the most meaningful cardiac descriptors for classification of dilated cardiomyopathy (DCM) patients using US data only. More specifically, we propose two algorithms based on: multi-view linear discriminant analysis (MLDA) and multi-view Laplacian support vector machines (MvLapSVM). Furthermore, a novel regional multi-view approach is proposed to exploit the regional relationships between the two modalities. We evaluate our pipeline on the classification task of discriminating between normals and DCM patients. Results show that the use of multi-view classifiers together with a cardiac motion atlas results in a statistically significant improvement in accuracy compared to classification without the multimodal atlas. MvLapSVM was able to achieve the highest accuracy for both the global approach (92.71%) and the regional approach (94.32%). Our work represents an important contribution to the understanding of cardiac motion, which is an important aid in the quantification of the contractility and function of the left ventricular myocardium. The intended workflow of the developed pipeline is to make use of the prior knowledge from the multimodal atlas to enable robust extraction of indicators from 3D US images for detecting DCM patients.

Increased myocardial fibrosis may play a key role in heart failure with preserved ejection fraction (HFpEF) pathophysiology. The study aim was to evaluate the presence, associations, and prognostic significance of diffuse fibrosis in HFpEF patients compared to age- and sex-matched controls. We prospectively included 118 consecutive HFpEF patients. Diffuse myocardial fibrosis was estimated by extracellular volume (ECV) quantified by cardiovascular magnetic resonance with the modified Look-Locker inversion recovery sequence. We determined an ECV age- and sex-adjusted cutoff value (33%) in 26 controls. Mean ECV was significantly higher in HFpEF patients versus healthy controls (32.9 ± 4.8% vs 28.2 ± 2.4%, P < 0.001). Multivariate logistic regression showed that body mass index (BMI) (odds ratio (OR) =0.92 [0.86-0.98], P = 0.011), diabetes (OR = 2.62 [1.11-6.18], P = 0.028), and transmitral peak E wave velocity (OR = 1.02 [1.00-1.03], P = 0.022) were significantly associated with abnormal ECV value. During a median follow-up of 11 ± 6 months, the primary outcome (all-cause mortality or first heart failure hospitalization) occurred in 38 patients. In multivariate Cox regression analysis, diabetes (hazard ratio (HR) =1.98 [1.04; 3.76], P = 0.038) and hemoglobin level (HR = 0.81 [0.67; 0.98], P = 0.028) were significant predictors of composite outcome. The ECV ability to improve this model added significant prognostic information. We then developed a risk score including diabetes, hemoglobin and ECV > 33% demonstrating significant prediction of risk and validated this score in a validation cohort of 53 patients. Kaplan-Meier curves showed a significant difference according to tertiles of the probability score (P < 0.001). Among HFpEF patients, high ECV, likely reflecting abnormal diffuse myocardial fibrosis, was associated with a higher rate of all-cause death and first HF hospitalization in short term follow up. Characterization of Heart Failure With Preserved Ejection

Understanding and describing the functional complexity of the heart has prompted the development of imaging modalities aiming for a more in-depth characterization of left ventricular mechanics by non-invasively evaluating the myocardial deformation, i.e. strain. Over the years, deformation imaging techniques have become extremely popular and have been applied to numerous research questions. In the contemporary framework of evolving tissue tracking technology, the present thesis contributes to the current state-of-the-art by addressing part of the gaps in evidence of validation and clinical application of deformation imaging modalities. Accordingly, this research work was focused on validating a widely used deformation imaging modality, 2D and 3D speckle tracking echocardiography and on investigating the clinical value of a new and promising tissue tracking modality, feature tracking cardiac magnetic resonance. This research work is therefore lining up to the efforts of standardization of strain measurement proposed by the imaging societies and contributes to the advancement in the field of clinical implementation., (MED - Sciences médicales) -- UCL, 2018

Although recommended by current guidelines, adoption of three-dimensional echocardiographic (3DE) chamber quantification in clinical practice has lagged because of time-consuming analysis. We recently validated an automated algorithm that measures left atrial (LA) and left ventricular (LV) volumes and ejection fraction (EF). This study aimed to determine the accuracy and reproducibility of these measurements in a multicentre setting. 180 patients underwent 3DE imaging (Philips) at six sites. Images were analysed using automated HeartModel (HM) software with endocardial border correction when necessary and by manual tracing. Measurements were performed by each site and by the Core Laboratory (CL) as the reference. Inter-technique comparisons included HM measurements by the sites against manual tracing by CL, and showed strong correlations (r-values: LVEDV: 0.97, LVESV: 0.97, LVEF: 0.88, LAV: 0.96), with the automated technique slightly underestimating LV volumes (biases: LVEDV: -14 ± 20 ml, LVESV: -6 ± 20 ml), LVEF (-2 ± 7%) and LAV (-9 ± 10 ml). Intra-technique comparisons included HM measurements by the sites against CL, with and without corrections. Corrections were unnecessary or minimal in most patients, and improved the measurements only modestly. Comparisons without corrections showed perfect agreement for all parameters. With corrections, correlations were better (r-values: LVEDV: 0.99, LVESV: 0.99, LVEF: 0.94, LAV: 0.99) and biases (LVEDV: -8 ± 12 ml, LVESV: -6 ± 12 ml, LVEF: 1 ± 5%, LAV: -10 ± 6 ml) smaller than in inter-technique comparison. All automated measurements with corrections were more reproducible than manual measurements. Automated 3DE analysis of left-heart chambers is an accurate alternative to conventional manual methodology, which yields almost the same values across laboratories and is more reproducible. This technique may contribute towards full integration of 3DE quantification into clinical routine.

BACKGROUND: The pathophysiology of paradoxical low-gradient (LG) severe aortic stenosis (SAS) remains controversial. As low transvalvular flow has been implicated, we sought to investigate the impact of left ventricular outflow tract (LVOT) ellipticity on the estimation of the LV stroke volume, the calculation of the aortic valve area (AVA) by use of the continuity equation and on AS severity grading. METHODS: We studied 190 consecutive patients (mean age: 72 ± 13 years; male: 57%) with SAS (indexed AVA < 0.6 cm2/m2) and preserved LV ejection fraction, including 120 patients with severe high gradient (HG) AS and 70 with severe paradoxical LG-AS. AS severity, LV volumes and LVOT ellipticity were assessed by 2D-Doppler echocardiography and cardiac magnetic resonance (CMR). RESULTS: The LVOT exhibited an elliptical shape on CMR images, with a shorter anterior-posterior than median-lateral diameter (2.2 ± 0.2 vs 2.8 ± 0.3 cm, p < 0.01). Accordingly, the LVOT area measured by planimetry was larger than by 2D-echocardiography, assuming a circular orifice (4.9 ± 0.9 cm2 vs 3.7 ± 0.8 cm2, p < 0.01). Inputting the elliptical LVOT area into the continuity equation resulted in a 29% increase in the indexed AVA (from 0.41 ± 0.09 cm2 to 0.54 ± 0.10 cm2). Accordingly, 30 (43%) patients with severe paradoxical LG-SAS were reclassified as having moderate AS. Similar results were obtained when considering 3D-echo for direct planimetry of the LVOT in a subset of 75 patients. CONCLUSIONS: Our results confirm that the LVOT is elliptical in shape and that taking this parameter into account in the calculation of the AVA results in reclassification of 43% of patients with severe paradoxical LG-AS into moderate AS.

Cardiac motion atlases provide a space of reference in which the motions of a cohort of subjects can be directly compared. Motion atlases can be used to learn descriptors that are linked to different pathologies and which can subsequently be used for diagnosis. To date, all such atlases have been formed and applied using data from the same modality. In this work we propose a framework to build a multimodal cardiac motion atlas from 3D magnetic resonance (MR) and 3D ultrasound (US) data. Such an atlas will benefit from the complementary motion features derived from the two modalities, and furthermore, it could be applied in clinics to detect cardiovascular disease using US data alone. The processing pipeline for the formation of the multimodal motion atlas initially involves spatial and temporal normalisation of subjects' cardiac geometry and motion. This step was accomplished following a similar pipeline to that proposed for single modality atlas formation. The main novelty of this paper lies in the use of a multi-view algorithm to simultaneously reduce the dimensionality of both the MR and US derived motion data in order to find a common space between both modalities to model their variability. Three different dimensionality reduction algorithms were investigated: principal component analysis, canonical correlation analysis and partial least squares regression (PLS). A leave-one-out cross validation on a multimodal data set of 50 volunteers was employed to quantify the accuracy of the three algorithms. Results show that PLS resulted in the lowest errors, with a reconstruction error of less than 2.3 mm for MR-derived motion data, and less than 2.5 mm for US-derived motion data. In addition, 1000 subjects from the UK Biobank database were used to build a large scale monomodal data set for a systematic validation of the proposed algorithms. Our results demonstrate the feasibility of using US data alone to analyse cardiac function based on a multimodal motion atlas.

BACKGROUND: Myocardial T1, T2 and T2* imaging techniques become increasingly used in clinical practice. While normal values for T1, T2 and T2* times are well established for 1.5 Tesla (T) cardiovascular magnetic resonance (CMR), data for 3T remain scarce. Therefore we sought to determine normal reference values relative to gender and age and day to day reproducibility for native T1, T2, T2* mapping and extracellular volume (ECV) at 3T in healthy subjects. METHODS: After careful exclusion of cardiovascular abnormality, 75 healthy subjects aged 20 to 90 years old (mean 56 ± 19 years, 47% women) underwent left-ventricular T1 (3-(3)-3-(3)-5 MOLLI)), T2 (8 echo- spin echo-imaging) and T2 * (8 echo gradient echo imaging) mapping at 3T CMR (Philips Ingenia 3T and computation of extracellular volume after administration of 0.2 mmol/kg Gadovist). Inter- and intra-observer reproducibility was estimated by intraclass correlation coefficient (ICC). Day to day reproducibility was assessed in 10 other volunteers. RESULTS: Mean myocardial T1 at 3T was 1122 ± 57 ms, T2 52 ± 6 ms, T2* 24 ± 5 ms and ECV 26.6 ± 3.2%. T1 (1139 ± 37 vs 1109 ± 73 ms, p < 0.05) and ECV (28 ± 3 vs 25 ± 2%, p < 0.001), but not T2 (53 ± 8 vs 51 ± 4, p = NS) were significantly greater in age matched women than in men. T1 (r = 0.40, p < 0.001) and ECV (r = 0.37, p = 0.001) increased, while T2 decreased significantly (r = -0.25, p < 0.05) with increasing age. T2* was not influenced by either gender or age. Intra and inter-observer reproducibility was high (ICC ranging between 0.81-0.99), and day to day coefficient of variation was low (6.2% for T1, 7% for T2, 11% for T2* and 11.5% for ECV). CONCLUSIONS: We provide normal myocardial T2, T2*,T1 and ECV reference values for 3T CMR which are significantly different from those reported at 1.5 Tesla CMR. Myocardial T1 and ECV values are gender and age dependent. Measurement had high inter and intra-observer reproducibility and good day-to-day reproducibility.

BACKGROUND: Despite widespread use to characterize and refine prognosis, validation data of two-dimensional (2D) speckle tracking (2DST) echocardiography myocardial strain measurement remain scarce. METHODS AND RESULTS: Global and regional subendocardial peak-systolic Lagrangian longitudinal (LS) and circumferential strain (CS) by 2DST and 2D-tagged (2DTagg) cardiac magnetic resonance imaging were compared against sonomicrometry in a dynamic heart phantom and among each other in 136 patients included prospectively at 2 centers. The ability of regional LS and CS 2DST and 2DTagg to identify late gadolinium enhancement was compared using receiver operating characteristics curves. In vitro, both LS-2DST and 2DTagg highly agreed with sonomicrometry (intraclass correlation coefficient [ICC], 0.89 and ICC, 0.90, both P<0.001 with -3±2.8% and 0.34±4.35% bias, respectively). In patients, both global LS and global CS 2DST agreed well with 2DTagg (ICC, 0.89 and ICC, 0.80; P<0.001); however, they provided systematically greater values (relative bias of -37±27% and -25±37% for global LS and global CS, respectively). On regional basis, however, ICC (from 0.17 to 0.81) and relative bias (from -9 to -98%) between 2DST and 2DTagg varied strongly among segments. Ability to discriminate infarcted versus noninfarcted segments by late gadolinium enhancement was similarly good for regional LS 2DTagg and 2DST (area under the curve, 0.66 versus 0.59; P=0.08), while it was lower for CS 2DST than 2DTagg (area under the curve, 0.61 versus 0.75; P<0.001). CONCLUSIONS: The high accuracy against sonomicrometry and good agreement of global LS and global CS by 2DST and 2DTagg confirm the overall validity of 2DST strain measurement. Yet, higher intertechnique segmental variability and lower ability for detecting infarct suggest that 2DST strain estimates may be less performant on regional than on global basis.

Background: The pathophysiology of low gradient severe aortic stenosis [SAS] despite normal ejection fraction also referred to as paradoxical low gradient [PLG]-SAS, is controversial. It has been suggested that PLG- SAS was associated with a higher degree of myocardial fibrosis and a worse outcome than high-gradient (HG)-SAS. Methods: To test this, we obtained myocardial biopsies and measured myocardial extravascular volume fraction (ECV, %) by use of cardiac magnetic resonance (Modified Look-Locker imaging T1 mapping at 3 T) in 142 consecutive patients with moderate to severe AS (22 moderate AS, 62 HG-SAS, 58 PLG-SAS, including 23 low flow [LF] and 35 normal flow [NF] PLG-SAS). ECV was also measured in 33 normal age-matched controls. Results: ECV correlated with the amount of interstitial fibrosis (IF) on histology (r=0.75, p<0.01). The amount of IF was similar in all subgroups (4±4% in NF-PLG- SAS, 5±3% in LF-PLG-SAS, 6±6% in HG-SAS) as were ECV values (29±4% in moderate AS, 29±6% in NF-LG-SAS, 29±3% in PLF-LG-SAS, 28± 6% in HG-SAS, p=0.9). No differences in ECV were found between SAS patients and controls (27±4%, p=0.33). The number of SAS patients with ECV values > 95% CI of controls was similar in each group (1/23 [4%] LF-PLG-SAS, 3/35 [9%] NF-PLG-SAS and 6/62 [10%] HG-SAS, p=ns; Figure). Conclusions: Our results demonstrate that the amount of IF, measured by histology or ECS is similar among controls and patients with SAS. These data do not support the contention that PLG-SAS is associated with higher degree of IF.

BACKGROUND: Limited data are available regarding the prognostic value of right ventricular (RV) systolic dysfunction (RVSD) in patients with coronary artery disease. Our objective was to evaluate the effect of RVSD assessed by cardiac magnetic resonance on survival of patients with low left ventricular (LV) ejection fraction (EF) undergoing coronary bypass grafting (CABG). METHODS: We prospectively assessed overall and cardiovascular death of 107 consecutive patients (94 men; age, 66 ± 10 years) undergoing CABG who had a LVEF of 0.35 or less by cardiac magnetic resonance before CABG. RESULTS: Mean LVEF was 0.25 ± 0.07, and mean RVEF was 0.46 ± 0.16. RVSD, defined by RVEF of 0.35 or less, was present in 32 patients (30%). In-hospital mortality rate (n = 8) was significantly higher in patients with RVSD (18.7% vs 2.7%, p = 0.004). Over a median follow-up of 4.7 years, 44 patients died, 33 of a cardiovascular cause. The primary end point of cardiovascular death was reached by 15 of 32 patients with RVSD and 18 of 75 patients without RVSD (47% vs 24%, p = 0.019). Univariate survival analysis showed that age, New York Heart Association Functional Classification, diabetes, estimated glomerular filtration rate, LVEF, LV indexed end-diastolic volume, RVEF, RV indexed end-diastolic volume, RV systolic function, and The Society of Thoracic Surgeons risk score were independent predictors of the primary end point of cardiovascular death. By multivariable analysis, the Society of Thoracic Surgeons risk score (hazard ratio, 1.32; 95% confidence interval, 1.13 to 1.55; p = 0.001) and RVSD (hazard ratio, 2.14; 95% confidence interval, 1.06 to 4.31; p = 0.034) remained significant independent predictors of cardiovascular death. CONCLUSIONS: RVSD strongly and independently predicts cardiovascular death in patients with coronary artery disease and low EF undergoing CABG. Evaluation of RV function should thus be part of preoperative evaluation of such patients.

Several studies have shown that increased myocardial fibrosis may play a key role in HFpEF pathophysiology. The aim of this study was to evaluate the presence and the determinants of diffuse fibrosis in HFpEF patients compared to age-matched volunteers. Methods: Between January 2015 and May 2016, we prospectively included 102 consecutive patients with HFpEF (78±9 years, 66% women) defined by LVEF≥ 50%, Framingham HF criteria, prior hospitalization for HF or NT-proBNP >350pg/ml. LV and RV functions were assessed by 2D echocardiography and cardiac magnetic resonance (cMR). Diffuse myocardial fibrosis was estimated by extra cellular volume (ECV) quantified by 3 Tesla cMR with the Modified Look-Locker Inversion Recovery sequence. We determined an ECV age-adjusted cutoff value (cutoff = 35%) corresponding to mean + 2 standard deviations in 27 age-matched volunteers (74±7years, 63% women) without previous cardiac history. Results: Fibrosis estimated by ECV was significantly higher in HFpEF patients than in volunteers (32±5% vs. 28±3%, p<0.0001). Twenty-two percent of HFpEF patients (n=23) had significant fibrosis considering the ECV cutoff of 35%. Compared to those with ECV<35%, these patients had a lower BSA, more diabetes, a higher indexed left atrial volume (LAiV), a higher E/e’ ratio, a lower tricuspid annular plane systolic excursion (TAPSE) and higher indexed end diastolic and end systolic RV volumes (Table). In multivariate logistic regression, only LAiV (OR= 1.02 [1.00-1.05], p=0.041), TAPSE (OR=0.90 [0.82-0.99], p=0.036) and diabetes (OR= 3.59 [1.32-9.78], p=0.013) were significant determinants of fibrosis. Conclusion: Among HFpEF patients, high levels of fibrosis were associated with LV diastolic function, decreased RV longitudinal systolic function and presence of diabetes. Yet, only 22% of HFpEF patients had high levels of fibrosis, suggesting that other mechanisms are involved in HFpEF pathophysiology.

Myocardial T1, T2 and T2* imaging techniques become more and more used in clinical practice. While normal values for T1, T2 and T2* times are well established for 1.5 Tesla (T) cardiac magnetic resonance (CMR), data for 3T remain scarce. Therefore we sought to determine normal reference values and inter and intraobserver reproducibility for native T1, T2, T2* mapping and extracellular volume (ECV) at 3T in healthy volunteers. 55 healthy volunteers aged 20 to 80 years old (mean age = 50±17 years, 62% men) underwent left-ventricular T1 (11 images, 18 heart-beats 3-(3)-3-(3)-5 steady state free precession Modified Look Locker Imaging (MOLLI)), T2 (spin echo-imaging with 8 echos ranging from 8 to 64ms) and T2 * (gradient echo imaging with 8 echos ranging from 2.5 to 15 ms) mapping at 3T CMR (Philips Ingenia 3T). T1 mapping by MOLLI was repeated 15 min after administration of 0.2 mmol/kg Gadovist . ECV was computed as = (1-Ht)* ((1/T1) myo-post – (1/T1) myo-pre)/ (1/T1) blood-post – (1/T1) blood-pre). T1, T2 and T2* times and ECV were measured by 2 observers in a region of interest (ROI) encompassing the whole mid-ventricular short axis slice as well as in a septal ROI . Inter- and intraobserver reproducibility were estimated by intraclass correlation coefficient (ICC). We provide normal myocardial T2, T2*,T1 and ECV reference values for 3T CMR. Myocardial T2, T2* and T1 had high inter and intraobserver reproducibility and were significantly different from those reported at 1.5 Tesla CMR. By contrast, ECV values in the whole myocardium were not significantly different from those reported at 1.5 T.