How myocardial work could be relevant in patients with an aortic valve stenosis?

Funding Acknowledgements

Type of funding sources: None.

Background

Speckle tracking based myocardial work calculation is an attractive method to assess left ventricular (LV) myocardial function. In case of aortic stenosis (AS), assessment of work indices is challenging because it requires an accurate evaluation of LV-pressure curves. Therefore, we sought to evaluate the performances of two distinct methods for the estimation of myocardial work indices and to provide a quantitative comparison with invasively measured data.

Methods

Model-based and template-based methods were defined and applied for the evaluation of LV pressures on 67 AS patients. Global Constructive (GCW), Wasted (GWW), Positive (GPW), Negative (GNW) myocardial work and Global Work Efficiency (GWE) and Index (GWI) parameters were calculated using the available software computing the indices using brachial blood pressure and trans-aortic mean pressure gradient for estimating the LV pressures versus using a model-based and homemade software. A complete comparison was performed with invasive measurements.

Results

Patients were characterized by mean pressure gradient of 49.8 ± 14.8 mmHg, LV ejection fraction of 59 ± 8%, the global longitudinal strain was -15.0 ± 4.04%, GCW was 2107 ± 800mmHg.% (model-based method) and 2483 ± 1068mmHg.% (template-based method). The root mean square error (RMSE) and correlation were calculated for each patient and for each pressure estimation methods. The mean RMSE are 33.9mmHg and 40.4mmHg and the mean correlation coefficients are 0.81 and 0.72 for the model-based and template-based methods respectively. Correlation coefficient and Bland-Altman analysis were performed for the six work indices. The two methods present correlation coefficient r2 > 0.75 for almost all the indices.

Conclusion

The two non-invasive methods of LV pressure estimation and the work indices computation correlate with invasive measurements and computations for AS patients. Although the model-based approach requires less information and is associated with slightly better performances, the implementation of template-based method is easier and seems more appropriate in a clinical practice. Abstract Figure. SUMMARY

TET2 Drives 5hmc Marking of GATA6 and Epigenetically Defines Pancreatic Ductal Adenocarcinoma Transcriptional Subtypes

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) is characterized by advanced disease stage at presentation, aggressive disease biology, and resistance to therapy, resulting in an extremely poor 5-year survival rate of <10%. PDAC is classified into transcriptional subtypes with distinct survival characteristics, although how these arise is not known. Epigenetic deregulation, rather than genetics, has been proposed to underpin progression, but exactly why is unclear and is hindered by the technical limitations of analyzing clinical samples.

METHODS

We performed genome-wide epigenetic mapping of DNA modifications 5-methylcytosine and 5-hydroxymethylcytosine (5hmc) using oxidative bisulfite sequencing from formalin-embedded sections. We identified overlap with transcriptional signatures in formalin-fixed, paraffin-embedded tissue from resected patients, via bioinformatics using iCluster and mutational profiling and confirmed them in vivo.

RESULTS

We found that aggressive squamous-like PDAC subtypes result from epigenetic inactivation of loci, including GATA6, which promote differentiated classical pancreatic subtypes. We showed that squamous-like PDAC transcriptional subtypes are associated with greater loss of 5hmc due to reduced expression of the 5-methylcytosine hydroxylase TET2. Furthermore, we found that SMAD4 directly supports TET2 levels in classical pancreatic tumors, and loss of SMAD4 expression was associated with reduced 5hmc, GATA6, and squamous-like tumors. Importantly, enhancing TET2 stability using metformin and vitamin C/ascorbic acid restores 5hmc and GATA6 levels, reverting squamous-like tumor phenotypes and WNT-dependence in vitro and in vivo.

CONCLUSIONS

We identified epigenetic deregulation of pancreatic differentiation as an underpinning event behind the emergence of transcriptomic subtypes in PDAC. Our data showed that restoring epigenetic control increases biomarkers of classical pancreatic tumors that are associated with improved therapeutic responses and survival.

A new electron diffraction approach for structure refinement applied to Ca3Mn2O7

The digital large-angle convergent-beam electron diffraction (D-LACBED) technique is applied to Ca3Mn2O7 for a range of temperatures. Bloch-wave simulations are used to examine the effects that changes in different parameters have on the intensity in D-LACBED patterns, and atomic coordinates, thermal atomic displacement parameters and apparent occupancy are refined to achieve a good fit between simulation and experiment. The sensitivity of the technique to subtle changes in structure is demonstrated. Refined structures are in good agreement with previous determinations of Ca3Mn2O7 and show the decay of anti-phase oxygen octahedral tilts perpendicular to the c axis of the A21am unit cell with increasing temperature, as well as the robustness of oxygen octahedral tilts about the c axis up to ∼400°C. The technique samples only the zero-order Laue zone and is therefore insensitive to atom displacements along the electron-beam direction. For this reason it is not possible to distinguish between in-phase and anti-phase oxygen octahedral tilting about the c axis using the [110] data collected in this study.

A novel founder MSH2 deletion in Ethiopian Jews is mainly associated with early-onset colorectal cancer

Lynch syndrome is an inherited cancer predisposition syndrome caused by germline defects in any of the mismatch repair (MMR) genes. Diagnosis of carriers makes precision prevention, early detection, and tailored treatment possible. Herein we report a novel founder deletion of 18,758 bp, mediated by Alu repeats on both sides, detected in Ethiopian Jews. The deletion, which encompasses exon 9-10 of the MSH2 coding sequence, is associated mainly with early-onset MSH2/MSH6-deficient colorectal cancer (CRC) and liposarcoma. Testing of 35 members of 5 seemingly unrelated families of Ethiopian origin yielded 10/21 (48%) carriers, of whom 9 had CRC. Age at first tumor diagnosis ranged from 16 to 89 years. Carriers from the oldest generations were diagnosed after age 45 years (mean 57), and carriers from the younger generation were diagnosed before age 45 years (mean 30). Awareness of this founder deletion is important to improve patient diagnosis, institute surveillance from an early age, and refer patients for genetic counseling addressing the risk of bi-allelic constitutional MMR deficiency syndrome.

Prognostic role of myocardial work in patients with heart failure and reduced ejection fraction treated by sacubitril/valsartan

Funding Acknowledgements

Type of funding sources: None.

Background

the non-invasive assessment of myocardial work (MW) by pressure-strain loops analysis (PSL) is a relative new tool for the evaluation of myocardial performance. Sacubitril/Valsartan is a treatment for heart failure with reduced ejection fraction (HFrEF) which has a spectacular effect on the reduction of cardiovascular events (MACEs).

Purposes of this study were to evaluate 1) the short and medium term effect of Sacubitril/Valsartan treatment on MW parameters; 2) the prognostic value of MW in this specific group of patients.

Methods

79 patients with HFrEF (mean age: 66 ± 12 years; LV ejection fraction: 28 ± 9%) were prospectively included in the study and treated with Sacubitril/Valsartan. Echocardiographic examination was performed at baseline, and after 6- and 12-month of therapy with Sacubitril/Valsartan.

Results

Sacubitril/Valsartan significantly increased myocardial constructive work (CW) (1023 ± 449 vs 1424 ± 484 mmHg%, p &lt; 0.0001) and myocardial work efficiency (WE) [87 (78-90) vs 90 (86-95), p &lt; 0.0001]. During FU (2.6 ± 0.9 years), MACEs occurred in 13 (16%) patients. After correction for LV size, LVEF and WE, global myocardial constructive work (CW) was the only predictor of MACEs [HR 0.99 (0.99-1.00), p = 0.05]. (Table 1). A CW &lt; 910 mmHg (AUC = 0.81, p &lt; 0.0001, Figure 1, left panel) identified patients at particularly increase risk of MACEs [HR 11.09 (1.45-98.94), p = 0.002, log-rank test p &lt; 0.0001] (Figure 2, Right panel).

Conclusions

in patients with HFrEF who receive a comprehensive background beta-blocker and mineral-corticoid receptor antagonist therapy, Sacubitril/Valsartan induces a significant improvement of myocardial CW and WE. In this population, the estimation of CW before the initiation of Sacubitril/Valsartan therapy allows the prediction of MACEs.

Univariable analysis Multivariable analysis HR (95% CI) p-value HR (95% CI) p-value Age, per year 0.99 (0.95-1.04) 0.81 Ischemic cardiomyopathy 1.07 (0.36-3.21) 0.89 LVEDVi*, per ml/m2 1.01 (1.00-1.03) 0.03 LVESVi, per ml/m2 1.01 (1.00-1.03) 0.009 1.01 (0.99-1.02) 0.35 LVEF, per % 0.91 (0.85-0.98) 0.01 1.02 (0.93-1.12) 0.71 CW, per mmHg% 0.99 (0.99-1.00) 0.002 0.99 (0.99-1.00) 0.04 WE, per mmHg% 0.91 (0.86-0.96) 0.001 0.95 (0.88-1.02) 0.16 Predictors of MACEs at univariable and multivariable analysis Abstract Figure 1 A and B

Comparison of two methods to predict CRT-response

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Hospital university of Rennes INSERM - LTSI

Background

Non-invasive estimation of myocardial work by trans-thoracic echocardiography is a novel tool to analyze myocardial contraction efficiency during systole. Two methods are described, on using Left ventricular (LV) strain and a LV pressure estimation, and another with only LV strain integrals. The present study analyzes their utility in prediction of CRT-response.

Methods and results: 243 patients implanted by a CRT according to current recommendations were retrospectively included in hospital university of Rennes. All patients had a complete trans-thoracic echocardiography at implantation and at 6-moths follow-up. Responders were defined as having a 15% decrease in indexed LV end-systolic volume at follow-up compared to baseline. Baseline characteristics are described in table 1. 25.1% were non-responders. In this group, there were more men, more ischemic cardiomyopathies with more dilated LV. Strain signals ware analyzed only in the most informative loop, the apical 4 cavities. Myocardial work estimation with LV pressure estimation was previously described. The 3 different integral of strain signal were represented in figure 1. According to ROC curves, myocardial work (particularly wasted work in septal wall with AUC = 0.718 ± 0.04) estimated with LV pressure estimation is better than strain integrals to predict LV positive remodeling (best AUC 0.631 ± 0.040) after CRT-implantation.

Conclusion

Left ventricular pressure estimation give useful information on top of strain curves for prediction for CRT-response.

Table 1 Responders n = 182 Non-responders n = 61 Men (%) 109 (59.9%) 52 (85%) Ischemic cardiomyopathy (%) 42 (23.1%) 34 (55.7%) LVEF (%) 28 ± 6 28 ± 7 GLS (%) -9 ± 3 -7 ± 3 LVEDD (mm) 62 ± 8 67 ± 7 LVEDVi (ml/m2) 85 ± 34 88 ± 30 LVEF Left ventricular ejection fraction; GLS: global longitudinal strain; LVEDD: left ventricular end-diastolic diameter; LVEDVi: left ventricular end diastolic volume index Abstract Figure 1

Prospective validation of a non-invasive method to estimate myocardial work in aortic stenosis

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): ANR - Maestro project

Background

Stratification of aortic stenosis patients remains challenging and robust indices are required. Myocardial work assessment is a new afterload independent alternative to evaluate left ventricular function. Although, this method was developed in patients with normal aortic valve. We previously developed an integrated cardiovascular system simulated by a computational model to estimate non-invasively myocardial work in aortic stenosis patients* (figure 1A). In the present study, we tested our model in a prospective population of AS patients.

Method and results

9 patients with severe AS (aortic valve area &lt; 1cm2) were included. A complete trans-thoracic echocardiography with a non-invasive blood pressure by brachial artery cuff were realized immediately before a left heart catheterization to have an invasive left ventricular pressure. Myocardial work is then calculated with non-invasive and invasive LV pressure combined to LV strain curves. For constructive and wasted work, root mean squared between invasive and estimated measures were respectively r2 = 0.92 and r2 = 0.94 (figure 1B)

Conclusion

The proposed model is efficient to estimate non-invasively myocardial work indices in AS-patients. These afterload independent indices could permit in future to better stratify this population. 

*Owashi KP, Hubert A and al. Model-based estimation of left ventricular pressure and myocardial work in aortic stenosis. PlosOne 2020. Mar 3;15(3):e0229609

Abstract Figure 1

Importance of systematic right ventricular assessment in cardiac resynchronization therapy candidates: a machine-learning approach

Funding Acknowledgements

Type of funding sources: None.

Background

Despite having all a systolic heart failure and broad QRS, patients proposed for cardiac resynchronization therapy (CRT) are highly heterogeneous and it remains extremely complicated to predict the impact of the device on left ventricular (LV) function and outcomes.

Objectives

We sought to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular (LV) remodeling and prognosis of CRT-candidates by the application of machine learning (ML) approaches.

Methods

193 patients with systolic heart failure undergoing CRT according to current recommendations were prospectively included in this multicentre study. We used a combination of the Boruta algorithm and random forest methods to identify features predicting both CRT volumetric response and prognosis (Figure 1). The model performance was tested by the area under the receiver operating curve (AUC). We also applied the K-medoid method to identify clusters of phenotypically-similar patients.

Results

From 28 clinical, electrocardiographic, and echocardiographic-derived variables, 16 features were predictive of CRT-response; 11 features were predictive of prognosis.

Among the predictors of CRT-response, 7 variables (44%) pertained to right ventricular (RV) size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with a very good prediction of both CRT response (AUC 0.81, 95% CI: 0.74-0.87) and outcomes (AUC 0.84, 95% CI: 0.75-0.93) (Figure 1, Supervised Machine Learning Panel). An unsupervised ML approach allowed the identifications of two phenogroups of patients who differed significantly in clinical and parameters, biventricular size and RV function. The two phenogroups had significant different prognosis (HR 4.70, 95% CI: 2.1-10.0, p &lt; 0.0001; log –rank p &lt; 0.0001; Figure 1, Unsupervised Machine Learning Panel).

Conclusions

Machine learning can reliably identify clinical and echocardiographic features associated with CRT-response and prognosis. The evaluation of both RV-size and function parameters has pivotal importance for the risk stratification of CRT-candidates and should be systematically assessed in patients undergoing CRT.

Abstract Figure 1

Prognostic utility of the assessment of diastolic function in patients undergoing cardiac resynchronization therapy

Conflicting data exist about the relationship between cardiac resynchronization therapy (CRT) and diastolic function. Aims of the study are to assess diastolic patterns in patients undergoing CRT according to the 2016 recommendations of the American Society of Echocardiography/European Association of Cardiovascular Imaging and to evaluate the prognostic value of diastolic dysfunction (DD) in CRT candidates. METHODS AND RESULTS: One-hundred ninety-three patients (age: 67 ± 11 years, QRS width: 167 ± 21 ms) were included in this multicentre prospective study. Mitral filling pattern, mitral tissue Doppler velocity, tricuspid regurgitation velocity, and indexed left atrial volume were used to classify DD from grade I to III. CRT-response, defined as a reduction of left ventricular (LV) end-systolic volume > 15% at 6-month follow-up (FU), occurred in 132 (68%) patients. The primary endpoint was a composite of heart transplantation, LV assisted device implantation, or all-cause death during FU and occurred in 29 (15%) patients. CRT was associated with a degradation of DD in non-responders. At multivariable analysis corrected for clinical variables, QRS duration, mitral regurgitation, CRT-response and LV dyssynchrony, grade I DD was associated with a better outcome (HR 0.37, 95% CI: 0.14-0.96). Non-responders with grade II-III DD had the worse prognosis (HR 4.36, 95%CI: 2.10-9.06). CONCLUSIONS: The evaluation of DD in CRT candidates allows the prognostic stratification of patients, independently from CRT-response.

Non-invasive estimation of myocardial work in aortic stenosis from modelling approach

Background

The noninvasive assessment of myocardial work by pressure-strain loops (PSL) analysis is a recently introduced tool to estimate myocardial performance. PSL analysis cannot be applied to patients having an obstacle to LV ejection, as in the case of aortic stenosis (AS), because of the difficulty to estimate left ventricular (LV) pressure.

The purpose of this work is to propose a non-invasive model-based estimation of the left ventricular pressure curve in AS patients in order to evaluate myocardial work indices.

Methods

Twelve patients with moderate-to-severe AS underwent cardiac catheterization to acquire the LV pressure (Pexp-LV). All patients underwent a standard trans-thoracic echocardiography to extract regional myocardial strain curves and estimate the aortic valve area (AVA). Systolic and diastolic arterial pressures were also measured. The proposed cardiovascular system (CVS) model is composed of four main coupled sub-models simulating: i) cardiac electrical activities, ii) cardiac cavity, iii) the systemic and pulmonary circulation, and iv) cardiac valves (Figure 1, upper panel). A 2-step parameter identification strategy, based evolutionary algorithms, was implemented to learn LV parameters from Pexp-LV and to estimate patient-specific model-based LV pressure curves (Pmodel-LV) starting from parameters obtained from non-invasive hemodynamics. Global myocardial constructive work (GCW) and myocardial wasted work (GWW) were calculated using Pexp-LV and Pmodel-LV.

Results

A close match was observed between Pexp-LV and Pmodel-LV, with a mean total relative error of 12.27% (range 5.9% to 17.40%). When considering GCW and GWW, global correlation was equal to 0.92 (p&lt;0.0001). In BA analysis, mean bias was −2.9 mmHg.%, which corresponds to relative bias equal to 0.11% with respect to the mean value of work indices (Figure 1, lower panel).

Conclusions

A model-based approach can be used to estimate LV pressure and myocardial work indices in patients with AS, and be provide a promising tool for the assessment of myocardial performance in patients with AS

Funding Acknowledgement

Type of funding source: None

Mechanisms of angina in patients with biopsy-proven viral myocarditis: insights from intracoronary acetylcholine testing

Background

Patients with myocarditis often present with angina pectoris despite unobstructed coronary arteries. The underlying pathophysiological mechanism of angina in these patients remains to be elucidated. Coronary artery spasm is a well-known cause of angina in patients with unobstructed coronary arteries. In this study, we sought to assess the frequency of coronary vasomotor disorders in patients with biopsy-proven viral myocarditis.

Methods

In total, 700 consecutive patients who underwent endomyocardial biopsy for suspected myocarditis between 2008 and 2018 were retrospectively screened. Of these patients, viral myocarditis was confirmed in 303 patients defined as histological/immunohistological evidence of myocardial inflammation and presence of viral genome confirmed by PCR. Of these patients, 34 patients had angina despite unobstructed coronary arteries and underwent intracoronary acetylcholine (ACh) provocation testing in search of coronary spasm. Epicardial spasm was defined as acetylcholine-induced reproduction of the patient's symptoms associated with ischemic ECG changes and &gt;90% epicardial vasoconstriction. Microvascular spasm was defined as symptom reproduction and ECG changes in the absence of significant epicardial vasoconstriction.

Results

Patients were 49±16 years old, 62% were male and left ventricular ejection fraction was 54±16%. Most frequent viruses were parvovirus B19 (PVB19, 59%) and human herpes virus 6 (HHV6, 26%), 2 patients had combined PVB19/HHV6 infection and 3 patients other herpesviruses (CMV, EBV, VZV). Epicardial spasm was observed in 10 patients (29%) during ACh testing and microvascular spasm was found in 11 patients (32%). The rate of coronary spasm (epicardial and microvascular) was higher in the PVB19 subgroup compared to HHV6 (80% vs. 33%, p=0.031). In particular, there was a higher prevalence of microvascular spasm in PVB19 compared to HHV6 (45% vs. 0%, p=0.018).

Conclusion

We observed a high prevalence of microvascular and epicardial spasm in patients with biopsy-proven viral myocarditis suggesting coronary spasm as a potential underlying mechanism for angina in these patients. Microvascular spasm was most often observed in patients with PVB19-associated myocarditis.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Robert-Bosch-Stiftung; Berthold-Leibinger-Stiftung

Prognostic role of myocardial work in patients with heart failure and reduced ejection fraction treated by sacubitril/valsartan

Background

The non-invasive assessment of myocardial work (MW) by pressure-strain loops analysis (PSL) is a relative new tool for the evaluation of myocardial performance. Sacubitril/Valsartan is a treatment for heart failure with reduced ejection fraction (HFrEF) which has a spectacular effect on the reduction of cardiovascular events (MACEs).

Purposes of this study were to evaluate 1) the short and medium term effect of Sacubitril/Valsartan treatment on MW parameters; 2) the prognostic value of MW in this specific group of patients.

Methods

79 patients with HFrEF (mean age: 66±12 years; LV ejection fraction: 28±9%) were prospectively included in the study and treated with Sacubitril/Valsartan. Echocardiographic examination was performed at baseline, and after 6- and 12-month of therapy with Sacubitril/Valsartan.

Results

Sacubitril/Valsartan significantly increased global myocardial constructive work (CW) (1023±449 vs 1424±484 mmHg%, p&lt;0.0001) and myocardial work efficiency (WE) [87 (78–90) vs 90 (86–95), p&lt;0.0001]. During FU (2.6±0.9 years), MACEs occurred in 13 (16%) patients. After correction for LV size, LVEF and WE, CW was the only predictor of MACEs (Table 1). A CW&lt;910 mmHg (AUC=0.81, p&lt;0.0001, Figure 1A) identified patients at particularly increase risk of MACEs [HR 11.09 (1.45–98.94), p=0.002, log-rank test p&lt;0.0001] (Figure 1 B).

Conclusions

In patients with HFrEF who receive a comprehensive background beta-blocker and mineral-corticoid receptor antagonist therapy, Sacubitril/Valsartan induces a significant improvement of myocardial CW and WE. In this population, the estimation of CW before the initiation of Sacubitril/Valsartan therapy allows the prediction of MACEs.

Funding Acknowledgement

Type of funding source: None

Model-based analysis of myocardial strain in left bundle branch block patients

Background

Although patients with typical left bundle branch block (LBBB) show greater efficacy of cardiac resynchronization therapy (CRT), there is a wide range of responses to CRT with a subset of patients showing little or no improvement. Recently, it has been shown that combination of echo-based parameters of LV dyssynchrony and QRS duration helped to improve the prediction of the response to CRT. However, the interpretation of features extracted from echocardiography could be difficult due the complexity of mechanisms involved in cardiac contraction. Computational modelling could help to improve the interpretation of myocardial strains in LBBB patients before implantation.

Purpose

Purpose of the study is to propose a patient-specific model-based approach in order to assist the analysis of myocardial strains and to improve the interpretability of echo-based parameters.

Methods

The proposed model of the cardiovascular system integrates four main sub-models: 1) cardiac electrical system, 2) right and left atrium, 3) multi-segment right and left ventricles and 4) systemic and pulmonary circulations. Patient-specific simulations of myocardial strains were obtained by coupling the computational model and the clinical data to a parameter identification algorithm (Figure 1, upper panel). The proposed approach was evaluated on data obtained from 10 LBBB patients, including ischaemic (n=5) and non-ischaemic (n=5) cardiomyopathy. The localisation of scar was determined by cardiac MRI. Bull's-eye representations of the electrical activation time and contractility levels were analysed.

Results

The comparison between simulated and experimental strains for the 10 subjects reflects a satisfying adaptation of the model to different strain morphologies. The mean errors between real and synthesized signals are equal to 3.72±0.91. The lower panel of Figure 1 presents simulated (black line) and experimental (red line) myocardial strain signals for selected LBBB patients with a lateral ischaemia, anterior ischaemia and non-ischaemia. The bull's-eye representations of electrical activation delay and contractility levels, estimated from the model-based approach, for ischemic and non-ischemic LBBB is included in the figure. Contractility bull's-eye results allow ischaemic and non-ischaemic cases distinction, where low levels of contractility could be associated with damaged tissues.

Conclusion

Identified parameters show significant electrical conduction, mechanical activation delays for the LBBB patient. Hypocontractile myocardial segments were successfully localized from the model-based approach in both ischemic and non-ischemic patients.

Funding Acknowledgement

Type of funding source: None

Better diastolic function in CRT candidates is associated with improved survival after CRT implantation

Background

The relationship between diastolic dysfunction (DD) and outcome after CRT is debated.

Purpose

Purpose of this study was to evaluate the role of DD in predicting all-cause mortality in heart failure patients undergoing CRT.

Methods

One-hundred ninety-three patients (age: 67±11 years, QRS width: 167±21 ms, LVEF 28±8%) were included in this multicentre prospective study. Mitral filling pattern, mitral tissue Doppler velocity, tricuspid regurgitation velocity, and indexed left atrial volume were used to classify DD from grade I to III according to the 2016 recommendations of the American Society of Echocardiography/European Association of Cardiovascular Imaging. A reduction of LV end-systolic volume &gt;15% at 6-month follow-up (FU) identified CRT-responders and was observed in 132 (68%) patients.

Results

During a median 35 months FU, 29 (15%) patients died. Through multivariable analysis, coronary artery disease, NYHA functional class and grade I DD were shown to be independent predictors of prognosis (Table 1). Grade I DD was associated with a longer survival rate in both responders and non responders (Figure 1). Non responders with grade II-III DD had the worse outcome (HR 12.5 [3.56–44.04], p&lt;0.0001).

Conclusions

Better diastolic function at baseline is associated with an improved survival after CRT implantation, independently of CRT-response.

Funding Acknowledgement

Type of funding source: None

New expectations for diastolic function assessment in TTE based on a semi-automated computing of strain-volume loops

Background

Early diagnosis of heart failure with preserved ejection fraction (HFpEF) by determination of diastolic dysfunction is challenging. Strain-volume loop (SVL) is a new tool to analyze left ventricular function.

Purpose

We propose a new semi-automated method to calculate SVL area and explore the added value of this index for diastolic function assessment.

Methods

50 patients (25 amyloidosis, 25 HFpEF) were included in the study and compared with 25 healthy control subjects. All patients underwent standard echocardiography. SVL area were also assessed.

Results

Left ventricular ejection fraction was preserved and similar between groups. Classical indices of diastolic function were pathological in HFpEF and amyloidosis groups with greater left atrial volume index, greater mitral average E/e' ratio, faster tricuspid regurgitation (p&lt;0.0001 compared with controls). SVL analysis demonstrated a significant difference of the global area between groups, with the smaller area in amyloidosis group, the greater in controls and a mid-range value in HFpEF group (37 vs 120 vs 72 ml.%, respectively, p&lt;0.0001) (Table 1). Applying a Linear Discriminant Analysis (LDA) classifier, results show a mean area under the curve (AUC) of 0.89 for the comparison between HFpEF and amyloidosis groups (Figure 1).

Conclusion

Strain-volume loops area is efficient to identify patients with a diastolic dysfunction. This new semi-automated tool is very promising for future development of automated diagnosis with machine-learning algorithms.

Figure 1

Funding Acknowledgement

Type of funding source: None

101 Semi-automated volume-strain loops: a new tool in TTE to assess diastolic dysfunction

AIM

This work aims to evaluate a novel semi-automatic tool for the assessment of volume-strain loops by transthoracic echocardiography (TTE).

METHOD

17 patients with proved cardiac amyloidosis and 18 patients with heart failure with preserved ejection fraction (HFpEF) were compared to 19 controls, from a local database. All TTE were performed using Vivid E95 ultrasound system (General Electrics Healthcare, Horten, Norway). The complete method includes several steps: 1) extraction of LV strain full traces from apical 4 and 2 cavities views, 2) estimation of LV volume from these two traces by spline interpolations, 3) resampling of LV strain curves, determined for the same cardiac beat, (in apical 4-, 2- and 3- cavities views) as a function of pre-defined percentage increments of LV-volume and 4) calculation of the LV volume-strain loop area. (Figure 1, panel A)

RESULTS (Table 1): LVEF was similar between all groups whereas global longitudinal strain was significantly lower in amyloidosis group than controls (-14.4 vs -20.5%; p &lt; 0.001). HFpEF and amyloidosis groups had a worse diastolic function than controls with a greater left atrial volume index , a faster tricuspid regurgitation, a greater E/e’ ratio with a p &lt; 0.001 for all these indices. Simultaneously, the global area of volume-strain loop was significantly lower in HFpEF and amyloidosis group than controls (72 vs 36 vs 120.0 %.mL, respectively, p &lt; 0.0001) with an intermediate profile of HFpEF(Figure 1, panel B, HFpEF in green). This area was better correlated with mean e’ (r = 0.650, p &lt; 0.001) than all other indices.

CONCLUSION

LV volume-strain loop area appears a very promising new tool to assess semi-automatically diastolic function.

Main echocardiographic results Controls n = 19 HFpEF n = 18 Amyloidosis n = 17 p-value LVEDV (mL) 105 ± 15 103 ± 30 95 ± 93 0.476 LVEF (%) 65 ± 5 62 ± 7 62 ± 7 0.196 GLS (%) -20.5 ± 1.8 -18.4 ± 4.3 -14.4 ± 3.8 &lt;0.0001 LAVi (ml.m-2) 22 ± 5 51 ± 14 51 ± 22 &lt;0.0001 E/A ratio 2.1 ± 0.4 1.2 ± 0.7 1.7 ± 1.0 0.005 Mitral E/Ea average 5.9 ± 1.4 13.7 ± 5.8 17.3 ± 5.4 &lt;0.0001 Vmax TR (m/s) 2.0 ± 0.3 3.1 ± 0.4 2.7 ± 0.5 &lt;0.0001 V-S loop area (ml.%) 120 ± 54 72 ± 45 37 ± 21 &lt;0.0001

Abstract 101 Figure 1

P1779 Myocardial work is a predictor of exercise tolerance in patients with dilated cardiomyopathy and left ventricular dyssynchrony

Background

the assessment of myocardial work (MW) by pressure-strain loops is a recently introduced tool for the assessment of myocardial performance. Aim of the present study is to evaluate the relationship between myocardial work and exercise tolerance in patients with dilated cardiomyopathy (DCM)

Methods

51 patients with DCM (mean age 57 ± 13 years, left entricular ejection fraction : 32 ± 9%) underwent cardiopulmonary exercise test (CPET) to assess exercise performance. Trans-thoracic echocardiography (TTE) was performed CPET. The following indices of myocardial work (MW) were measured regionally and globally: constructive work (CW), wasted work (WW), and work efficiency (WE). Left ventricular (LV) dyssynchrony (DYS) was defined by the presence of septal flash or apical rocking at TTE.

Results

LV-DYS was observed in 16 (31%) patients and associated with lower LV ejection fraction (LVEF), GLS, global and septal WE, and higher global and septal WW (Table 1). In patients with LV-DYS, septal WE was the only predictor of exercise peak VO2max at multivariable analysis (Figure 1), whereas LVEF (β=0.47, p = 0.05) and age (β=-0.42, 47, p= 0.04) were predictors of exercise capacity in patients without LV-DYS.

Conclusions

In patients with DCM, LV-DYS is associated with an heterogeneous distribution of myocardial work. Septal WE is the best predictor of exercise performance in these patients.

Table 1 All n = 51 No-dyssynchrony n = 35 (69%) LV-Dyssynchrony n = 16 (31%) p-value LVEF, % 32 ± 9 34 ± 10 28 ± 7 0.04 GLS, % -12 ± 3 -13 ± 3 -10 ± 3 0.001 GCW, mmHg% 1325 ± 398 1342 ± 354 1287 ± 491 0.65 GWW, mmHg% 201 ± 147 154 ± 95 304 ±191 &lt;0.0001 GWE, % 85 ± 9 88 ± 7 78 ±10 &lt;0.0001 CWsept, mmHg% 1172 ± 459 1274 ± 398 949 ± 516 0.017 CWlat, mmHg% 1518 471 1472 ± 386 1620 ± 622 0.30 WWsept, mmHg% 283 ± 275 174 ± 98 522 ±376 &lt;0.0001 WWlat, mmHg% 135 ± 88 117 ± 81 176 ± 92 0.02 WEsept, % 78 ± 16 84 ± 9 62± 18* &lt;0.0001 WElat, % 90 ± 7 91 ± 7 88 ± 7 0.16

Abstract P1779 Figure.

539 Optimized multiparametric analysis of cardiac dyssynchrony: machine learning and prediction of response to cardiac resynchronization therapy based of the apical 4-chamber view

Conclusion

The high number of important features indicate the relevance of the 4-chamber as unique view for applying machine learning approaches on strain curves. Optimizing selection of patients for CRT should be possible just on the dataset coming from one apical 4-chamber view.

Abstract 539 Figure. fig1

557 Left ventricular diastolic function is a predictor of volumetric response to cardiac resynchronization therapy

Background

Conflicting data exist about the effects of cardiac resynchronization therapy (CRT) on diastolic function (DF). Aims of the study are: 1) to assess diastolic patterns in patients undergoing CRT; 2) to evaluate the role of DF in predicting CRT-response.

Methods

193 patients (age: 67 ± 11 ms, QRS width: 167 ± 21 ms, LVEF 28 ± 8%) were prospectively included in this multicentric study. 2D-standard echocardiography was performed before CRT and at 6-month follow-up (FU). DF was assessed according to recommendations from grade I to III. In case of data in the "grey zone", DF was defined as "indeterminate". A reduction of left ventricular (LV) end-systolic volume &gt;15% at FU identified CRT-responders (CRT-R).

Results

At 6-month FU, 132 patients (68%) were CRT-R. Figure 1 shows DF parameters in the overall population, CRT-R, and CRT-non responders (CRT-NR) before and after CRT. At multivariable analysis, grade I diastolic dysfunction at baseline was a significant independent predictor of CRT response (OR 3.02, p = 0.001) (Table 1). The addition of grade I diastolic dysfunction to a model including clinical (sex, NYHA class, ischemic cardiomyopathy) and echocardiographic parameters (LV size), significantly increase the model power for the prediction of CRT-response (χ2: 29 vs 44, p = 0.001).

Conclusions

Before CRT, DF parameters are significantly altered in CRT-NR with respect to CRT-R. Moreover, CRT-NR experience a significant deterioration of DF after CRT. In our population, grade I diastolic function at baseline was a significant independent predictor of positive response to CRT.

Table 1 Univariable analysis Multivariable analysis Age 1.01 (0.99-1.05) 0.25 Males 0.36 (0.17-0.76) 0.008 0.57 (0.22-1.47) 0.25 CAD 0.21 (0.11-0.40) &lt;0.001 0.31 (0.15-0.65) 0.002 NYHA 0.52 (0.31-0.88) 0.01 0.57 (0.22-1.47) 0.25 QRS 1.01 (0.99-1.02) 0.44 LVEDV 0.99 (0.99-1.00) 0.003 0.98 (0.97-1.01) 0.18 LVESV 0.99 (0.98-0.99) 0.005 1.01 (0.99-1.03) 0.28 LVEF 1.00 (0.97-1.05) 0.63 Grade I DD 4.13 (2.16-7.91) &lt;0.0001 3.02 (1.26-7.23) 0.001 Grade II DD 0.57 (0.40-0.80) 0.001 0.87 (0.35-2.19) 0.79 Grade III DD 0.76 (0.58-1.02) 0.06

Abstract 557 Figure.

424 Left ventricular function after correction of a proportionate mitral regurgitation: impact of the clipping approach

Method and results

Thirty-seven patients with severe secondary MR treated by PMVR were included and compared (according to indices of LV myocardial function) to nineteen patients with treated by OMT. Both groups were clinically comparable. At 6-month follow-up, only LV constructive work improve significantly in both groups (977 vs 1101 mmHg.%, p =0,003, 967 vs 1110 mmHg.%, p = 0,002 for PMVR and OMT groups, respectively) whereas left ventricular (LV) end-systolic volume index, LV ejection fraction and global longitudinal strain were not different. Compared to MITRA-FR and COAPT studies, our population had a proportionate MR (blue point in Figure 1, panel A). Figure 1-panel B demonstrate that only five patients of PMVR group had disproportionate MR (red points). Interestingly, these patients hadn’t any major event during 6 months FU.

Conclusion

Echocardiographic characteristics at 6-month follow-up are not different when compare PMVR and OMT for HF- patients with a severe proportionate secondary MR.

Main echocardiographic characteristics PMVR OMT Inclusion 6-month p Inclusion 6-month p NYHA 2.6 ± 0.6* 1.8 ± 0.7* &lt;0.0001 2.3 ± 0.5* 2.2 ± 0.4* 0.43 LVESVi(ml.m-2) 76 ± 36 75 ± 35 0.6 94 ± 32 90 ± 31 0.35 LVEF (%) 33 ± 6 33 ± 13 0.78 30 ± 8 31 ± 8 0.53 GLS (%) -9.8 ± 4 -9.9 ± 3.9 0.84 -10.0 ± 4 -10.3 ± 3.3 0.62 MR grade 3.4 ± 0.5 1.3 ± 1.0* &lt;0.0001 3.5 ± 0.5 2.8 ± 1.1* 0.007 Global work index (mmHg.%) 831 ± 370 933 ± 406 0.07 875 ± 314 939 ± 304 0.14 Constructive work (mmHg.%) 977 ± 366 1101 ± 404 0.003 967 ± 290 1110 ± 349 0.002 *symbols denote p &lt; 0.05 between both groups

Abstract 424 Figure.

P1486Semi-automated volume-strain loops: a new tool in TTE to assess diastolic dysfunction

Aim

This work aims to evaluate a novel semi-automatic tool for the assessment of volume-strain loops by transthoracic echocardiography (TTE). The proposed method was evaluated on a typical model of left ventricular (LV) diastolic dysfunction: the cardiac amyloidosis.

Method

18 patients with proved cardiac amyloidosis were compared to 19 controls, from a local database. All TTE were performed using Vivid E9 or E95 ultrasound system. The complete method includes several steps: 1) extraction of LV strain full traces from apical 4 and 2 cavities views, 2) estimation of LV volume from these two traces by spline interpolations, 3) resampling of LV strain curves, determined for the same cardiac beat, (in apical 4-, 2- and 3- cavities views) as a function of pre-defined percentage increments of LV-volume and 4) calculation of the LV volume-strain loop area. (Figure 1, panel B)

Results

(Table 1): LVEF was similar between both groups whereas global longitudinal strain was significantly lower in amyloidosis group (−14.4 vs −20.5%; p<0.001). Amyloidosis group had a worse diastolic function with a greater left atrial volume index (51 vs 22ml/m2), a faster tricuspid regurgitation (2.7 vs 2.0 m/s), a greater E/e' ratio (17.3 vs 5.9) with a p<0.001 for all these indices. Simultaneously, the global area of volume-strain loop was significantly lower in amyloidosis group (36.5 vs 120.0%.mL). This area was better correlated with mean e' with r=0.734 (p<0.001) than all other indices (Figure 1, panel A).

Table 1 Amyloidosis (N=18) Controls (N=19) p Global strain-volume loop area (%.mL) 36.5±21.3 120.0±54.2 <0.001 Global longitudinal strain (%) −14.4±3.8 −20.5±1.8 <0.001 Left ventricular ejection fraction (%) 62±7 65±5 0.08 Left atrial volume index (ml/m2) 51±22 22±5 <0.001 E/A 1.72±0.97 2.07±0.45 0.17 Mean e' 5.5±1.3 14.4±2.8 <0.001 Mean E/e' 17.3±5.4 5.9±1.4 <0.001 Tricuspid regurgitation velocity (m/s) 2.7±3.8 2.0±0.3 <0.001

Figure 1

Conclusion

LV volume-strain loop area appears a very promising new tool to assess semi-automatically diastolic function. Future applications will concern the integration of LV volume-strain loop area as novel feature in machine-learning approach.

The natural history of classic galactosemia: lessons from the GalNet registry

BACKGROUND

Classic galactosemia is a rare inborn error of carbohydrate metabolism, caused by a severe deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). A galactose-restricted diet has proven to be very effective to treat the neonatal life-threatening manifestations and has been the cornerstone of treatment for this severe disease. However, burdensome complications occur despite a lifelong diet. For rare diseases, a patient disease specific registry is fundamental to monitor the lifespan pathology and to evaluate the safety and efficacy of potential therapies. In 2014, the international Galactosemias Network (GalNet) developed a web-based patient registry for this disease, the GalNet Registry. The aim was to delineate the natural history of classic galactosemia based on a large dataset of patients.

METHODS

Observational data derived from 15 countries and 32 centers including 509 patients were acquired between December 2014 and July 2018.

RESULTS

Most affected patients experienced neonatal manifestations (79.8%) and despite following a diet developed brain impairments (85.0%), primary ovarian insufficiency (79.7%) and a diminished bone mineral density (26.5%). Newborn screening, age at onset of dietary treatment, strictness of the galactose-restricted diet, p.Gln188Arg mutation and GALT enzyme activity influenced the clinical picture. Detection by newborn screening and commencement of diet in the first week of life were associated with a more favorable outcome. A homozygous p.Gln188Arg mutation, GALT enzyme activity of ≤ 1% and strict galactose restriction were associated with a less favorable outcome.

CONCLUSION

This study describes the natural history of classic galactosemia based on the hitherto largest data set.

A Hydrothermal-Sedimentary Context for the Origin of Life

Critical to the origin of life are the ingredients of life, of course, but also the physical and chemical conditions in which prebiotic chemical reactions can take place. These factors place constraints on the types of Hadean environment in which life could have emerged. Many locations, ranging from hydrothermal vents and pumice rafts, through volcanic-hosted splash pools to continental springs and rivers, have been proposed for the emergence of life on Earth, each with respective advantages and certain disadvantages. However, there is another, hitherto unrecognized environment that, on the Hadean Earth (4.5-4.0 Ga), would have been more important than any other in terms of spatial and temporal scale: the sedimentary layer between oceanic crust and seawater. Using as an example sediments from the 3.5-3.33 Ga Barberton Greenstone Belt, South Africa, analogous at least on a local scale to those of the Hadean eon, we document constant permeation of the porous, carbonaceous, and reactive sedimentary layer by hydrothermal fluids emanating from the crust. This partially UV-protected, subaqueous sedimentary environment, characterized by physical and chemical gradients, represented a widespread system of miniature chemical reactors in which the production and complexification of prebiotic molecules could have led to the origin of life. Key Words: Origin of life-Hadean environment-Mineral surface reactions-Hydrothermal fluids-Archean volcanic sediments. Astrobiology 18, 259-293.

[Nutritional status in pediatric intermediate care: Assessment at admission, progression during the stay and after discharge]

INTRODUCTION

Malnutrition, known as a cause of morbidity, has not been studied in children admitted to pediatric intermediate care units. This study aimed to describe the association between patients' nutritional status and the relative severity of illness that characterizes this population.

PATIENTS AND METHODS

In this prospective longitudinal study, a dedicated nutrition support team assessed the nutritional status of all children, aged 5 days to 18 years, admitted to our university pediatric intermediate care unit (Hôpital Femme-Mère-Enfants, Lyon, France) over one year (2012-2013). Weight, height, body mass index, weight-for-age ratio, height-for-age ratio, and the analysis of growth curves were collected at admission. We monitored patients' weight, which allowed us to detect malnutrition occurrence during the stay, and its progression up to 3 months after discharge.

RESULTS

A total of 459 patients were enrolled. Based on the analysis integrating all nutritional indices and the progression of growth curves, malnutrition at admission was detected in 23.8% of children (20.5% and 6.8% suffered from acute and chronic malnutrition, respectively). Based only on the body mass index, malnutrition was detected in 15.5% of children. Chronic disease appeared as a risk factor for malnutrition at admission (P=0.0001) and young age for acute malnutrition (P=0.04). The incidence of acquired malnutrition during the stay (in children with a length of stay > 5 days) was up to 26%, and dyspnea was the only risk factor identified. This population recovered with a normal nutritional status late (66% after 2 months and 16% after 3 months).

CONCLUSIONS

The prevalence of malnutrition is high in our pediatric intermediate care unit. The occurrence of acquired malnutrition during the stay is frequent. All children should benefit from systematic nutritional assessment at admission as well as careful monitoring during the stay and after discharge, to adapt early and individualized nutritional support.

Validation of reference materials for uranium radiochronometry in the frame of nuclear forensic investigations

The results of a joint effort by expert nuclear forensic laboratories in the area of age dating of uranium, i.e. the elapsed time since the last chemical purification of the material are presented and discussed. Completely separated uranium materials of known production date were distributed among the laboratories, and the samples were dated according to routine laboratory procedures by the measurement of the (230)Th/(234)U ratio. The measurement results were in good agreement with the known production date showing that the concept for preparing uranium age dating reference material based on complete separation is valid. Detailed knowledge of the laboratory procedures used for uranium age dating allows the identification of possible improvements in the current protocols and the development of improved practice in the future. The availability of age dating reference materials as well as the evolvement of the age dating best-practice protocol will increase the relevance and applicability of age dating as part of the tool-kit available for nuclear forensic investigations.