(See Fig. 1.) Left ventricular strain-volume loops and diastolic dysfunction in suspected heart failure with preserved ejection fractionInternational Journal of CardiologyVol. 378PreviewPresence of left ventricular diastolic dysfunction (DD) is key in the pathogenesis of heart failure with preserved ejection fraction (HFpEF). However, non-invasive assessment of diastolic function is complex, cumbersome, and largely based on consensus recommendations. Novel imaging techniques may help detecting DD. Therefore, we compared left ventricular strain-volume loop (SVL) characteristics and diastolic (dys-)function in suspected HFpEF patients. Full-Text PDF Open Access

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Guidelines recommend replacement in patients with severe aortic stenosis (AS) who present with symptoms or left ventricular ejection fraction (LVEF) < 50%, both conditions representing a late stage of the disease. While global longitudinal strain (GLS) is load dependant but interesting for assessing prognosis, myocardial work has emerged. We aim to evaluate acute changes in myocardial work occurring in patients undergoing transcatheter aortic valve implantation (TAVI). Methods Patients who underwent TAVI were evaluated before and after by echocardiography. Complete echocardiographies were considered. Myocardial work indices (global work index (GWI), Global constructive work (GCW), Global work efficiency (GWE), Global wasted work (GWW)) were calculated integrating mean transaortic pressure-gradient and brachial-cuff systolic pressure. Results 125 patients underwent successful TAVI with significant decrease of the transaortic mean gradient (52.5 ± 16.1 to 12.2 ± 5.0, P<.0001). There was no significant change in LVEF post-TAVI. Myocardial work data post-TAVR showed a significant reduction of GWI (1389 ± 537 vs. 2014 ± 714, P<.0001), GCW (1693 ± 543 vs. 2379 ± 761, P<.0001) and GWE (85,0 ± 7,06 vs. 87,1 ± 5,98, P=0,0034). Decrease of GWI and GCW after TAVI was homogeneous among different sub-groups based on their GLS, LVEF of NYHA status before TAVI. We observed a significant association between GWI and GCW before TAVI and a GLS degradation after TAVI. Conclusion Myocardial work parameters show promising potential in best understanding the LV-myocardial consequences of AS and its correction. By their ability to discriminate NYHA status and GLS evolution, we can hypothesize on their clinical value.

The 2016 American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines for the evaluation of left ventricular diastolic function reported a new algorithm to assess diastolic function and to estimate left ventricular filling pressure (LVFP). At least five to six different parameters were necessary to conclude, each of them with their own inter-observer variability. This article examines the reproducibility of each parameter of the algorithm and its influence on the final decision of the clinician. Echocardiographic exams of 12 non-selected patients without any known cardiac disease or follow-up but addressed to the hospital for symptoms were analyzed by two readers (one junior and one senior) in five French cardiologic tertiary centers. Inter-observer reproducibility at each step of the algorithm and final decision were analyzed. There was mild agreement on the final decision. The main reasons of discrepancy were disagreement on the significance of mitral annular calcifications and measured values that are just around the cut-off (despite good reproducibility, a slight variation could lead to misclassification of a dichotomous choice between a normal measure and a pathologic measure). Without considering performance, this multicentric French study puts forward limits to the actual algorithm recommended for LVFP pattern assessment. Agreement is excellent in caricatural (easy) cases (left ventricular pressure clearly normal or clearly elevated) but a great discordance exists in the gray zone. Improvement in the algorithm and in the method for LVFP determination is proposed.

BACKGROUND:Heart failure with reduced ejection fraction (HFrEF) is a heterogeneous syndrome. In heart failure (HF) classifications, right ventricle (RV) function was for a long time unrecognized in favor of left ventricular ejection fraction (LVEF). The response to sacubitril/valsartan might differ according to phenotypes and the impact of right ventricular characteristics on this response remains controversial.OBJECTIVES:First, we applied clustering analysis in a HFrEF population undergoing sacubitril/valsartan treatment according to guidelines, to identify phenotypes and their associated clinical outcomes. Secondly, we evaluated RV-remodeling.MATERIAL AND METHODS:It is a prospective, observational, single-center study conducted on 108 symptomatic patients (mean age 66 ±12.8 years, 22.2% women). First, the clustering analysis was applied in a HFrEF population undergoing sacubitril/valsartan treatment, according to the guidelines, in order to identify phenotypes and clinical outcomes associated with them. Secondly, we evaluated RV-remodeling.RESULTS:Two distinct clusters were identified. Among the differences between phenotypes, RV (tricuspid annular plane systolic excursion (TAPSE) 16 ±4 mm compared to 19 ±4 mm, p < 0.001; RV free wall strain -19 ±5% compared to -21 ±4%, p = 0.046; RV fraction area change (FAC) 31 ±9% compared to 38 ±9%, p < 0.001), LV-filling pressure (E-wave deceleration time 138 (median: 41) ms compared to 180 (median: 94) ms, p < 0.001; E/e' 16.7 (median: 8.0) ms compared to 13.0 (median: 9.7) ms, p = 0.02) and creatinine level (106 ±34 μmol/L compared to 90 ±19 μmol/L, p = 0.002) were substantially different at the initiation of therapy. Major adverse cardiac events (MACEs) or death occurred in 38 out of 107 patients: 51.1% in cluster 1 compared to 24.2% in cluster 2 (p = 0.0074). A significant improvement in RV-functional parameters was observed under treatment. The TAPSE improved and correlated with the change in left ventricular (LV) function. Yet, it did not correlate with systolic pulmonary artery pressure (sPAP) and LV end-diastolic diameter.CONCLUSIONS:The HFrEF phenotype characterized by more severe RV dysfunction has a worse prognosis during sacubitril/valsartan therapy. Both RVand LV functions significantly improve when the patient is treated with sacubitril/valsartan.

AIMS Myocardial work (MW) 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. We sought to evaluate the performances of two distinct methods and to provide a quantitative comparison with invasive data. METHODS AND RESULTS Model-based and template-based methods were defined and applied for the evaluation of LV-pressures on 67 AS-patient. Global Constructive (GCW), Wasted (GWW), Positive (GPW), Negative (GNW) MW 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 (MPG) for estimating the LV-pressures vs. using a model-based and homemade software. A complete comparison was performed with invasive measurements. Patients were characterized by MPG of 49.8 ± 14.8 mmHg, the global longitudinal strain (GLS) was -15.0 ± 4.04%, GCW was 2107 ± 800 mmHg.% (model-based) and 2483 ± 1068 mmHg.% (template-based). The root mean square error (RMSE) and correlation were calculated for each patient and pressure estimation methods. The mean RMSE are 33.9 mmHg and 40.4 mmHg and the mean correlation coefficients are 0.81 and 0.72 for the model-based and template-based methods, respectively. The two methods present correlation coefficient r2 >0.75 for all the indices. CONCLUSION The two non-invasive methods of LV pressure estimation and work indices computation correlate with invasive measurements. Although the model-based approach requires less information and is associated with slightly better performances, the implementation of template-based method is easier and is appropriate for clinical practice.

AIMS:The left atrium (LA) has a pivotal role in cardiac performance and LA deformation is a well-known prognostic predictor in several clinical conditions including heart failure with reduced ejection fraction. The aim of this study is to investigate the effect of cardiac resynchronization therapy (CRT) on both LA morphology and function and to assess the impact of LA reservoir strain (LARS) on left ventricular (LV) systolic and diastolic remodelling after CRT.METHODS AND RESULTS:Two hundred and twenty-one CRT-candidates were prospectively included in the study in four tertiary centres and underwent echocardiography before CRT-implantation and at 6-month follow-up (FU). CRT-response was defined by a 15% reduction in LV end-systolic volume. LV systolic and diastolic remodelling were defined as the percent reduction in LV end-systolic and end-diastolic volume at FU. Indexed LA volume (LAVI) and LV-global longitudinal (GLS) strain were the main parameters correlated with LARS, with LV-GLS being the strongest determinant of LARS (r = -0.59, P < 0.0001). CRT induced a significant improvement in LAVI and LARS in responders (both P < 0.0001). LARS was an independent predictor of both LV systolic and diastolic remodelling at follow-up (r = -0.14, P = 0.049 and r = -0.17, P = 0.002, respectively).CONCLUSION:CRT induces a significant improvement in LAVI and LARS in responders. In CRT candidates, the evaluation of LARS before CRT delivery is an independent predictor of LV systolic and diastolic remodelling at FU.

This paper proposes a patient-specific model-based estimation of myocardial strain signals and the evaluation of echo-based parameters, adapted to patients with left bundle branch block (LBBB). The left ventricle (LV) was divided into 16 segments in order to evaluate concurrently different regions at the ventricular contraction process. For each LV segment, some parameters, associated with the active and passive components of the cardiac muscle, the electro-mechanical driving function and the electrical depolarization time, were identified using evolutionnary algorithms. The proposed approach was evaluated on data obtained from 3 LBBB patients. From patient-specific simulations, we also analysed electrical activation delay and myofiber contractility in LV segments. A close match was observed between experimental and simulated myocardial strain curves for all the subjects. The root mean square error (RMSE) is equal to 2.87(± 1.00), 2.49(± 0.55) and 3.63(± 0.81) for the anterior ischemic, the lateral ischemic and the non-ischemic LBBB patients, respectively. The proposed patient-specific model-based approach may be a useful tool for understanding LV mechanical dyssynchrony and identifying patients suitable for cardiac resynchronization therapy (CRT).

Abstract 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 < 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

The objective of this study is to propose a model-based method, adapted to patients with severe aortic stenosis (AS), in order to reproduce left ventricle (LV) pressure and volume from patient specific data. A formal sensitivity analysis is proposed, focused on left ventricle volume and pressure. The most influent parameters of this analysis are then selected to be identified in a parameter identification strategy and provide a patient specific pressure curve. This was implemented on 3 AS patients and a close match was observed between experimental and simulated pressure and volume curves. The global root mean square error (RMSE) for pressure and volume curves are respectively 21.8 $(\pm 1.8)$ mmHg and 14.8 $(\pm 9.4)ml$,. The model-based approach proposed shows promising results to generate accurate LV pressure and volume in AS case.

Non-invasive estimation of myocardial work by transthoracic echocardiography is a novel tool to analyse 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 analyses their utility in prediction of CRT-response. In total, 243 patients implanted by a CRT according to current recommendations were retrospectively included in hospital university of Rennes. All patients had a complete transthoracic 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 were analysed 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 Fig. 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 remodelling (best AUC 0.631 ± 0.040) after CRT-implantation. Left ventricular pressure estimation give useful information on top of strain curves for prediction for CRT-response.

Cardiac resynchronization therapy (CRT) is an implant-based therapy applied to patients with a specific heart failure (HF) profile. The identification of patients that may benefit from CRT is a challenging task and the application of current guidelines still induce a non-responder rate of about 30%. Several studies have shown that the assessment of left ventricular (LV) mechanics by speckle tracking echocardiography can provide useful information for CRT patient selection. A comprehensive evaluation of LV mechanics is normally performed using three different echocardioraphic views: 4, 3 or 2-chamber views. The aim of this study is to estimate the relative importance of strain-based features extracted from these three views, for the estimation of CRT response. Several features were extracted from the longitudinal strain curves of 130 patients and different methods of feature selection (out-of-bag random forest, wrapping and filtering) have been applied. Results show that more than 50% of the 20 most important features are calculated from the 4-chamber view. Although features from the 2- and 3-chamber views are less represented in the most important features, some of the former have been identified to provide complementary information. A thorough analysis and interpretation of the most informative features is also provided, as a first step towards the construction of a machine-learning chain for an improved selection of CRT candidates.

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 Ito 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. Al multivariable analysis corrected for clinical variables, QRS duration, mitral regurgitation. CRT-response and LV dyssynchrony, grade 1 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%a 2.10-9.06). Conclusions: The evaluation of DD in CRT candidates allows the prognostic stratification of patients, independently from CRT-response. (C) 2021 Elsevier B.V. All rights reserved.

Transthoracic echocardiography (TTE) is currently the gold standard in the routine evaluation of Left Ventricular Filling Pressure (LVFP) in patients with dyspnea and/or heart failure, which is guided by the 2016 American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines. Although, at least of 5 to 6 different parameters were necessary to conclude, each of them with their own intra- and interobserver variability. The present report examined the reproducibility of each parameter of the algorithm and its influence on the final decision of the clinician. We selected 12 adults admitted for dyspnea with a complete TTE. Each exam was analysed by two readers (one junior and one senior) in 5 French cardiologic tertiary centres. The methodology was always the same and replicated blinded. We focused on the reproducibility of the dichotomial choice for each value because of it's the only information needed for using the algorithm. As demonstrated in Fig. 1, only E/A ratio and LVEF status (preserved or not) had a substantial – but not perfect – agreement, LAVi had the poorest reproducibility. The final decision on left ventricular filling pressure pattern had a moderate agreement. Of note, the conclusion was identical for 5 patients for all readers. For the others, there was some discrepancy between readers, which was similar for seniors and juniors. Main discordance exists in considering mitral calcifications significant or not and for value which are around the cut-off. Without considering performance, this multicentric French study puts forward limits of actual algorithm recommended for left ventricular filling pressure pattern assessment. Agreement is excellent in caricatural (easy) cases (LV pressure clearly normal or clearly elevated), but a great discordance exists in grey zone. Improvement in the algorithm and in method for LVFP determination would be proposed.

The future of the diastolic function assessment will take advantage of the past and of the automatization Get access Erwan Donal, Erwan Donal Univ Rennes, CHU Rennes, Inserm, LTSI—UMR 1099, F-35033 Rennes, France Corresponding author. Tel: +33617708567; Fax: +33299282510. E-mail: erwan.donal@chu-rennes.fr https://orcid.org/0000-0003-2677-3389 Search for other works by this author on: Oxford Academic PubMed Google Scholar Marion Taconne, Marion Taconne Univ Rennes, CHU Rennes, Inserm, LTSI—UMR 1099, F-35033 Rennes, France Search for other works by this author on: Oxford Academic PubMed Google Scholar Arnaud Hubert, Arnaud Hubert Univ Rennes, CHU Rennes, Inserm, LTSI—UMR 1099, F-35033 Rennes, France Search for other works by this author on: Oxford Academic PubMed Google Scholar Virginie Le Rolle Virginie Le Rolle Univ Rennes, CHU Rennes, Inserm, LTSI—UMR 1099, F-35033 Rennes, France Search for other works by this author on: Oxford Academic PubMed Google Scholar European Heart Journal - Cardiovascular Imaging, Volume 22, Issue 5, May 2021, Pages 599–600, https://doi.org/10.1093/ehjci/jeab014 Published: 25 January 2021 Article history Received: 11 January 2021 Editorial decision: 12 January 2021 Accepted: 13 January 2021 Published: 25 January 2021

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

Background: The mechanisms of improvement of left ventricular (LV) function with cardiac resynchronization therapy (CRT) are not yet elucidated. The aim of this study was to characterize CRT responder profiles through clustering analysis, on the basis of clinical and echocardiographic preimplantation data, integrating automatic quantification of longitudinal strain signals. Methods: This was a multicenter observational study of 250 patients with chronic heart failure evaluated before CRT device implantation and followed up to 4 years. Clinical, electrocardiographic, and echocardiographic data were collected. Regional longitudinal strain signals were also analyzed with custom-made algorithms in addition to existing approaches, including myocardial work indices. Response was defined as a decrease of $15% in LV end-systolic volume. Death and hospitalization for heart failure at 4 years were considered adverse events. Seventy features were analyzed using a clustering approach (k-means clustering). Results: Five clusters were identified, with response rates between 50% in cluster 1 and 92.7% in cluster 5. These five clusters differed mainly by the characteristics of LV mechanics, evaluated using strain integrals. There was a significant difference in event-free survival at 4 years between cluster 1 and the other clusters. The quantitative analysis of strain curves, especially in the lateral wall, was more discriminative than apical rocking, septal flash, or myocardial work in most phenogroups. Conclusions: Five clusters are described, defining groups of below-average to excellent responders to CRT. These clusters demonstrate the complexity of LV mechanics and prediction of response to CRT. Automatic quantitative analysis of longitudinal strain curves appears to be a promising tool to improve the understanding of LV mechanics, patient characterization, and selection for CRT.

AbstractAimsStudies have demonstrated the reliability of B‐lines evaluated by lung ultrasonography to identify pulmonary congestion, but information is lacking about its utility as a prognostic marker of heart failure (HF). We sought to assess the prognostic midterm value of B‐lines in ambulatory patients presenting with dyspnoea, as an additive tool for patient management and to avoid acute HF exacerbations.Methods and resultsA total of 93 patients presenting with dyspnoea (New York Heart Association ≥2) were prospectively recruited in an outpatient clinic, and underwent clinical and echocardiographic evaluation, as well as B‐line evaluation with lung ultrasonography in eight zones. Primary endpoint was HF hospitalization at 1 year. A total of 88 patients were included, age 72.3 ± 9.6, with left ventricular ejection 47.7 ± 28.6%; E/e' 16.9 ± 10.9, left atrial volume 51.9 ± 22.5 mL/m2; peak tricuspid regurgitation velocity 2.6 ± 0.5 m/s, average B‐line count 7.7 ± 10. 8 (9%) patients were hospitalized for HF, seven of which had ≥6 B‐lines. B‐line cut‐off ≥6 (specificity = 66.2%; sensitivity = 87.5%) was predictive for HF hospitalization, with an odds ratio at 13.7 for HF hospitalization at 1 year [IC95% (1.6–117.4), P = 0.017].ConclusionsAmbulatory patients with ≥6 B‐lines have a higher risk of HF hospitalization at 1 year. This study highlights the prognostic value of B‐lines in evaluating HF risk in dyspnoeic patients.

Introduction: Simulation-based training in transesophageal echocardiography (TEE) seems promising. However, data are limited to non-randomized or single-center studies. To assess the impact of simulation-based vs. traditional teaching on TEE knowledge and performance for medical residents in cardiology.Materials and Methods: Nationwide prospective randomized multicenter study involving 43 centers throughout France allowing for the inclusion of >70% of all French cardiology residents. All cardiology residents naive from TEE will be included. Randomization with stratification by center will allocate residents to either a control group receiving theoretical knowledge by e-learning only, or to an intervention group receiving two simulation-based training sessions on a TEE simulator in addition.Results: All residents will undergo both a theoretical test (0–100 points) and a practical test on a TEE simulator (0–100 points) before and 3 months after the training. Satisfaction will be assessed by a 5-points Likert scale. The primary outcomes will be to compare the scores in the final theoretical and practical tests between the two groups, 3 months after the completion of the training.Conclusion: Data regarding simulation-based learning in TEE are limited to non-randomized or single-center studies. The randomized multicenter SIMULATOR study will assess the impact of simulation-based vs. traditional teaching on TEE knowledge and performance for medical residents in cardiology, and whether such an educational program should be proposed in first line for TEE teaching.

Fortuni et al.1Fortuni F. Butcher S.C. Van der Kley F. Lustosa R.P. Karalis I. de Weger A. et al.Left ventricular myocardial work in patients with severe aortic stenosis.J Am Soc Echocardiogr. 2020; Abstract Full Text Full Text PDF Scopus (17) Google Scholar have presented an interesting work in which they explored the potential use of myocardial work to better risk stratify patients with severe aortic stenosis (AS). This is a very interesting question with a real clinical impact. Indeed, the classical analysis of left ventricular (LV) function does not allow an optimal identification of asymptomatic AS patients who are at risk for development of heart failure or death if left untreated. Although global longitudinal strain has shown promising results,2Magne J. Cosyns B. Popescu B.A. Carstensen H.G. Dahl J. Desai M.Y. et al.Distribution and prognostic significance of left ventricular global longitudinal strain in asymptomatic significant aortic stenosis: an individual participant data meta-analysis.JACC Cardiovasc Imaging. 2019; 12: 84-92Crossref PubMed Scopus (104) Google Scholar strain, by definition, is afterload dependent. Thus, strain provides information on the intrinsic myocardial deformation as a function of afterload imposed by the stenotic aortic valve. As myocardial work is afterload independent, this tool could have an added value in risk stratification of patients with severe AS. Fortuni et al.1Fortuni F. Butcher S.C. Van der Kley F. Lustosa R.P. Karalis I. de Weger A. et al.Left ventricular myocardial work in patients with severe aortic stenosis.J Am Soc Echocardiogr. 2020; Abstract Full Text Full Text PDF Scopus (17) Google Scholar proposed in this study to use the original and commercial algorithm developed by Russell et al.3Russell K. Eriksen M. Aaberge L. Wilhelmsen N. Skulstad H. Remme E.W. et al.A novel clinical method for quantification of regional left ventricular pressure-strain loop area: a non-invasive index of myocardial work.Eur Heart J. 2012; 33: 724-733Crossref PubMed Scopus (280) Google Scholar The original motivation for the development of this tool was to better analyze LV mechanical dyssynchrony in order to improve prediction of CRT response.4Hubert A. Le Rolle V. Leclercq C. Galli E. Samset E. Casset C. et al.Estimation of myocardial work from pressure-strain loops analysis: an experimental evaluation.Eur Heart J Cardiovasc Imaging. 2018; 19: 1372-1379Crossref PubMed Scopus (98) Google Scholar In the initial study, Russell et al.3Russell K. Eriksen M. Aaberge L. Wilhelmsen N. Skulstad H. Remme E.W. et al.A novel clinical method for quantification of regional left ventricular pressure-strain loop area: a non-invasive index of myocardial work.Eur Heart J. 2012; 33: 724-733Crossref PubMed Scopus (280) Google Scholar used a canine model (dogs with normal heart, left bundle branch block, myocardial ischemia) and then a pool of patients. An average curve of LV pressure was calculated from this pool of patients with an invasive LV pressure measurement. This predefined LV pressure curve template was temporally adjusted and scaled in amplitude in order to fit the observed valvular timings and noninvasive systolic pressure value of a given patient. This template-based estimate is essential to the algorithm, and all measures are then derived from this curve. To the best of our knowledge, none of the patients used to establish this curve had severe AS. Consequently, the application of the commercial algorithm in patients with severe AS raises concerns. Moreover, a second degree of imprecision is that only the mean transaortic gradient is added to the systolic arterial pressure. The ventricular pressure, obtained from the method proposed by the authors, is not tested against invasive LV pressure curves. Although the results of this study are interesting and could correlate with invasive measures, it is worth pointing out the potential imprecision of the myocardial work estimation derived from an algorithm that was not originally developed for this purpose. We think that caution is needed when extrapolating the proposed algorithm to patients with severe AS and that readers should understand potential limitations of the conclusions. Of note, our team has proposed a model that has been developed with a group of patients having severe AS to estimate myocardial work noninvasively.5Owashi K.P. Hubert A. Galli E. Donal E. Hernandez A.I. Le Rolle V. Model-based estimation of left ventricular pressure and myocardial work in aortic stenosis.PLoS One. 2020; 15: e0229609Crossref PubMed Scopus (7) Google Scholar

Background: Despite all having systolic heart failure and broad QRS intervals, patients screened for cardiac resynchronization therapy (CRT) are highly heterogeneous, and it remains extremely challenging to predict the impact of CRT devices on left ventricular function and outcomes. The aim of this study was to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular remodeling and prognosis of CRT candidates by the application of machine learning approaches. Methods: One hundred ninety-three patients with systolic heart failure receiving CRT according to current recommendations were prospectively included in this multicenter study. A combination of the Boruta algorithm and random forest methods was used to identify features predicting both CRT volumetric response and prognosis. Model performance was tested using the area under the receiver operating characteristic curve. The k-medoid method was also applied to identify clusters of phenotypically similar patients. Results: From 28 clinical, electrocardiographic, and echocardiographic variables, 16 features were predictive of CRT response, and 11 features were predictive of prognosis. Among the predictors of CRT response, eight variables (50%) pertained to right ventricular size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with particularly good prediction of both CRT response (area under the curve, 0.81; 95% CI, 0.74-0.87) and outcomes (area under the curve, 0.84; 95% CI, 0.75-0.93). An unsupervised machine learning approach allowed the identification of two phenogroups of patients who differed significantly in clinical variables and parameters of biventricular size and right ventricular function. The two phenogroups had significantly different prognosis (hazard ratio, 4.70; 95% CI, 2.1-10.0; P < .0001; log-rank P < .0001). Conclusions: Machine learning can reliably identify clinical and echocardiographic features associated with CRT response and prognosis. The evaluation of both right ventricular size and functional parameters has pivotal importance for the risk stratification of CRT candidates and should be systematically performed in patients undergoing CRT. (J Am Soc Echocardiogr 2021;34:494-502.)