Assessment of wasted myocardial work: a novel method to quantify energy loss due to uncoordinated left ventricular contractions

Characteristic of myocardial work in mitral valve prolapse with versus without mitral annular disjunction: A propensity-matched study

BACKGROUND

Mitral annular disjunction (MAD) tends to coexist with mitral valve prolapse (MVP) and mitral regurgitation (MR), and is also highly associated with arrhythmias. Myocardial work (MW) analysis is dedicated to estimate myocardial performance by integrating strain analysis and afterload. We aimed to use MW analysis to investigate the cardiac remodeling and dysfunction in MAD, particularly the damage of some segments, and to enhance the understanding of the correlations between MW parameters and VAs within MVP patients.

METHODS

A total of 22 consecutive MVP patients with MAD (MAD+) and 44 consecutive MVP patients without MAD (MAD-) (50 ± 11yeas; 18% females) were screened by propensity score matching (PSM), and were divided into subgroups based on MR severity (MR+: Grade 2+; MR-: ≤1), GWI median (GWI ≤ 2079.5 mmHg%; GWI>2079.5 mmHg%), as well as the presence of VAs (VAs+; VAs-). MW parameters consist of global work efficiency (GWE), global work index (GWI), global constructive work (GCW) and global wasted work (GWW).

RESULTS

The MAD+ patients had larger LVEDD and LAVI, as well as lower GWE, GWI, and GCW (all P<0.05) compared to the MAD- patients, regardless of similar GLS and regurgitant volume(both P>0.05). When categorized by MR severity, GWI (P = 0.049) and GCW (P = 0.040) were diminished in the MR-MAD+ group. The regional analysis showed MAD+ patients had decreased MW index in the basal (posterior and inferior) and mid (posterior and inferior) segments. Multivariate linear regression showed MAD phenotype, but not MR severity, was independently associated with diminished GWE, GWI, and GCW (all P<0.05). When divided by GWI median, MAD phenotype [OR (95%CI): 5.189 (1.193-22.572), P = 0.028] was an independent predictor of decreased GCW. The receiver-operating characteristic curve identified bileaflet prolapse [AUC (95%CI): 0.664 (0.502-0.825), P = 0.045], and GWI for basal inferior [(AUC (95%CI): 0.679 (0.538-0.819), P = 0.020] as the predictors of the VAs.

CONCLUSION

MAD phenotype has the ability to compromise cardiac structure and function, irrespective of volume overload, as evidenced by dilated LV and impaired MW index in basal and mid segments. Excessively decreased regional MW index can identify patients with the high risk of VAs. MW analysis can be a valuable imaging marker for detecting myocardial impairment induced by MAD.

Intraoperative Assessment of Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing Aortic Valve Replacement

OBJECTIVE

Evaluation of noninvasive left ventricular (LV) myocardial work (MW) enables insights into cardiac contractility and efficacy beyond conventional echocardiography. However, there is limited intraoperative data on patients undergoing surgical aortic valve replacement (AVR). The aim of this study was to describe the feasibility and the intraoperative course of this technique of ventricular function assessment in these patients and compare it to conventional two (2D)- and three-dimensional (3D) echocardiographic measurements and strain analysis.

DESIGN

Prospective observational study.

SETTING

Single university hospital.

PARTICIPANTS

Twenty-five patients scheduled for isolated AVR with preoperative preserved left and right ventricular function, sinus rhythm, without significant other heart valve disease or pulmonary hypertension, and an uneventful intraoperative course.

INTERVENTIONS

Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Evaluation was performed in stable hemodynamics, in sinus rhythm or atrial pacing and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min.

MEASUREMENTS AND MAIN RESULTS

EchoPAC v206 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). Estimation of myocardial work was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF, GWI and GCW decreased significantly after AVR (T1 v T2, 1,647 ± 380 mmHg% v 1,021 ± 233 mmHg%, p < 0.001; T1 v T2, 2,095 ± 433 mmHg% v 1,402 ± 242 mmHg%, p < 0.001, respectively), while GWW remained unchanged (T1 v T2, 296 mmHg% [IQR 178-452) v 309 mmHg% [IQR 255-438), p = 0.97). This resulted in a decreased GWE directly after bypass (T1 v T2, 84% ± 6% v 78% ± 5%, p < 0.001), but GWE already improved at the end of surgery (T2 v T3, 78% ± 5% v 81% ± 5%, p = 0.003). There was no significant change in the values of GWI, GCW, or 2D and 3D LVEF before and after sternal closure (T2 v T3).

CONCLUSION

LV MW analysis showed a reduction of LV workload after bypass in our group of patients, which was not detected by conventional echocardiographic measures. This evolving technique provides deeper insights into cardiac energetics and efficiency in the perioperative course of aortic valve replacement surgery.

Myocardial Strain Imaging: Theory, Current Practice, and the Future

Myocardial strain imaging by echocardiography or cardiac magnetic resonance (CMR) is a powerful method to diagnose cardiac disease. Strain imaging provides measures of myocardial shortening, thickening, and lengthening and can be applied to any cardiac chamber. Left ventricular (LV) global longitudinal strain by speckle-tracking echocardiography is the most widely used clinical strain parameter. Several CMR-based modalities are available and are ready to be implemented clinically. Clinical applications of strain include global longitudinal strain as a more sensitive method than ejection fraction for diagnosing mild systolic dysfunction. This applies to patients suspected of having heart failure with normal LV ejection fraction, to early systolic dysfunction in valvular disease, and when monitoring myocardial function during cancer chemotherapy. Segmental LV strain maps provide diagnostic clues in specific cardiomyopathies, when evaluating LV dyssynchrony and ischemic dysfunction. Strain imaging is a promising modality to quantify right ventricular function. Left atrial strain may be used to evaluate LV diastolic function and filling pressure.

Evaluation of left ventricular systolic function in patients with iron deficiency anemia based on non-invasive left ventricular pressure-strain loops

BACKGROUND

Iron deficiency anemia (IDA) is a common health problem worldwide. The objective of this study was to noninvasively and quantitatively evaluate early changes in left ventricular systolic function in patients with IDA using the left ventricular press-strain loop (LV-PSL).

METHODS

Sixty-two patients with IDA were selected and divided into two groups based on hemoglobin (Hb) concentration: Group B with Hb > 9 g/dL and group C with 6 g/dL < Hb < 9 g/dL. Thirty-three healthy individuals were used as the control (Group A). The global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global waste work (GWW), global work efficiency (GWE) were derived using LV-PSL analysis. Receiver operating characteristic (ROC) curves were constructed for MW parameters to detect abnormal left ventricular systolic function in IDA patients.

RESULTS

Compared to group A, GWI and GCW were reduced in group B (both P < 0.01). Compared with groups B and A, GLS, GWI, GCW and GWE, and E/A were all diminished, and GWW, LVEDV, LVESV, and E/mean e' were all increased in group C (all P < 0.01). GLS was positively correlated with GWI, GCW, and GWE (r = 0.679, 0.681, and 0.447, all P < 0.01), and negatively associated with GWW (r = - 0.411, all P < 0.01). For GWI, area under the ROC curve (AUROC) was 0.783. The optimal GWI threshold for detecting abnormal LV systolic function in IDA was1763 mmHg%, with sensitivity of 0.71 and specificity of 0.78.

CONCLUSIONS

LV-PSL allows noninvasive quantitative assessment of early impaired LV systolic function in IDA patients with preserved LV ejection fraction, and GWI has high sensitivity and specificity compared with other parameters.

The clinical value of noninvasive left ventricular myocardial work in the diagnosis of myocardial ischemia in coronary heart disease: a comparative study with coronary flow reserve fraction

The prompt and precise identification of hemodynamically significant coronary artery lesions remains an ongoing challenge. This study investigated the diagnostic value of non-invasive global left ventricular myocardial work indices by echocardiography in functional status of coronary artery disease (CAD) patients with myocardial ischemia using fractional flow reserve (FFR) as the gold standard. A total of 77 consecutive patients with clinically suspected CAD were prospectively enrolled. All participants sequentially underwent echocardiography, invasive coronary angiography (ICA) and FFR measurement. According to the results of ICA, patients were divided into myocardial ischemia group (FFR ≤ 0.8, n = 27) and non-myocardial ischemia group (FFR > 0.8, n = 50). Myocardial work indices including global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE), global positive work (GPW), global negative work (GNW), global systolic constructive work (GSCW) and global systolic wasted work (GSWW) were obtained by using the non-invasive left ventricular pressure strain loop (PSL) technique. Compared with the non-myocardial ischemia group, GWI, GCW, GPW and GSCW were significantly decreased in the myocardial ischemia group at either the 18-segment level or the 12-segment level (P < 0.001). At the 18-segment level, GWI < 1783.6 mmHg%, GCW < 1945.4 mmHg%, GPW < 1788.7 mmHg% and GSCW < 1916.5 mmHg% were optimal cut-off value to detect myocardial ischemia with an FFR ≤ 0.8. Global left ventricular myocardial work indices by echocardiography exhibited a good diagnostic value in patients with CAD and may have a good clinical significance for the screening of suspected myocardial ischemia.

Myocardial Work Indices in Patients Recently Recovered from Mild-to-Moderate COVID-19

Background/Objectives: Persistent cardiovascular issues are common in COVID-19 survivors, making the detection of subtle myocardial injuries critical. This study evaluates myocardial work (MW) indices in patients recently recovering from mild-to-moderate COVID-19. Methods: A total of 105 recently recovered COVID-19 patients (who had a mean age of 52 years) underwent comprehensive laboratory testing and advanced echocardiographic assessments. The median time since their COVID-19 infections was 56 days (IQR: 42-71). The cohort was stratified based on high-sensitive troponin I (hs-TnI) levels: undetectable versus detectable. The echocardiographic analysis utilized pressure-strain loops to evaluate MW indices. Results: Detectable hs-TnI levels were observed in 42% of patients. The median values of MW indices for the entire group were slightly below normal values: global work index (GWI)-1834 mmHg% (IQR 1168-2054 mmHg%), global constructive work (GCW)-2130 mmHg% (IQR 2010-2398 mmHg%), global wasted work (GWW)-119 mmHg% (IQR 78-175 mmHg%), and global work efficiency (GWE)-94% (IQR 92-96%). Patients with detectable hs-TnI had higher GWW (168 vs. 97 mmHg%, p < 0.005) and lower GWE (93% vs. 95%, p < 0.005). In multiple regression analysis, strain dispersion (PSD) was the sole predictor for GWW (β = 0.67, p < 0.001), while for GWE, PSD (β = -0.67, p < 0.001) and LVEF (β = 0.16, p = 0.05) were significant predictors. Conclusions: Among patients recently recovering from mild-to-moderate COVID-19, elevated hs-TnI levels are linked with a reduction in GWE and an increase in GWW. PSD is an important predictor of myocardial inefficiency and wasted work. In this group, disruptions in the timing and coordination of cardiac muscle contractions may play a key pathophysiological role in reducing the efficiency of the heart's performance.

Improvements of myocardial strain and work in diabetes patients with normal ejection fraction after empagliflozin treatment

AIMS/INTRODUCTION

To assess the effect of empagliflozin treatment on left ventricular (LV), right ventricular (RV) and left atrial (LA) functions in diabetes patients with normal ejection fraction.

MATERIALS AND METHODS

The study included a total of 128 diabetes patients with multiple cardiovascular risk factors who were subjected to a 6-month follow up from the initiation of empagliflozin treatment. Before and after treatment with empagliflozin, LV, RV and LA strain, and noninvasive myocardial work parameters were evaluated by speckle tracking echocardiography.

RESULTS

In 128 diabetes patients (mean age 56 ± 8 years, 85 men) with multiple cardiovascular risk factors, myocardial strain and work parameters were impaired, despite the absence of significant clinical symptoms of heart failure. After 6-month treatment with empagliflozin, the absolute value of LV strain in all directions increased, represented by LV global longitudinal strain (-18.0 ± 1.7% to -19.2 ± 1.7% [mean ± SD]). The same trend in LV global work efficiency (93 [91-94] % to 94 [93-95] % [median (IQR)]), RV free-wall longitudinal strain (-24.0 ± 2.7% to -25.0 ± 2.8%), LA reservoir (31 ± 5% to 34 ± 5%) and conduit strain (-14 ± 4% to -16 ± 4%) was also observed. LV mass index (106.9 ± 16.8-103.6 ± 16.4 g/m2) and LV global wasted work (143 [111-185] mmHg% to 108 [88-141] mmHg%) decreased after treatment (P < 0.05 for all). LV volume and LA volume index remained unchanged after treatment. In the multivariable analysis, the change in LA reservoir strain (β = 0.050, P = 0.035) and baseline global longitudinal strain (β = -0.488, P < 0.001) were independent predictors of improvement in LV global longitudinal strain.

CONCLUSIONS

This study suggests that 6-month treatment with empagliflozin improved LV, RV and LA functions in diabetes patients with normal ejection fraction.

Prognostic relevance of global work index and global constructive work in patients with non-ischemic dilated cardiomyopathy

Myocardial work (MW) derived from pressure-strain loops is a novel non-invasive tool to assess left ventricular (LV) function, incorporating global longitudinal strain (GLS) by speckle tracking echocardiography and non-invasively assessed blood pressure. Studies on the role of MW in dilated cardiomyopathy (DCM) are still limited. Therefore, the aim of this study was to evaluate the potential value of MW for predicting adverse outcomes in patients with DCM. 116 consecutive patients with DCM who underwent heart catheterization were retrospectively recruited from June 2009 to July 2014. 34 patients (30%) met the composite endpoints for major adverse cardiac events (MACE) of cardiac transplantation, need for implantable cardioverter-defibrillator (ICD) therapy, heart failure hospitalization and all-cause mortality. Patients with DCM were followed up for a mean of 5.1 years (IQR: 2.2-9.1 years). Global work index (GWI) and global constructive work (GCW) were not only independent predictors but also provided incremental predictive values (Integrated discrimination improvement [IDI] > 0) of MACE in multivariate Cox models. Furthermore, Patients with GWI < 788 mm Hg% (HR 5.46, 95%CI 1.66-17.92, p = 0.005) and GCW < 1,238 mm Hg% (HR 4.46, 95%CI 1.53-12.98, p = 0.006) had higher risks of MACE. GWI and GCW assessed by strain imaging echocardiography may have an additional value beyond LV-EF and GLS for predicting adverse outcomes in DCM.

A Comparative Analysis of Apical Rocking and Septal Flash: Two Views of the Same Systole?

Heart failure (HF) is a complex medical condition characterized by both electrical and mechanical dyssynchrony. Both dyssynchrony mechanisms are intricately linked together, but the current guidelines for cardiac resynchronization therapy (CRT) rely only on the electrical dyssynchrony criteria, such as the QRS complex duration. This possible inconsistency may result in undertreating eligible individuals who could benefit from CRT due to their mechanical dyssynchrony, even if they fail to fulfill the electrical criteria. The main objective of this literature review is to provide a comprehensive analysis of the practical value of echocardiography for the assessment of left ventricular (LV) dyssynchrony using parameters such as septal flash and apical rocking, which have proven their relevance in patient selection for CRT. The secondary objectives aim to offer an overview of the relationship between septal flash and apical rocking, to emphasize the primary drawbacks and benefits of using echocardiography for evaluation of septal flash and apical rocking, and to offer insights into potential clinical applications and future research directions in this area. Conclusion: there is an opportunity to render resynchronization therapy more effective for every individual; septal flash and apical rocking could be a very useful and straightforward echocardiography resource.

A novel method for the evaluation of right ventricular dysfunction in acute pulmonary embolism: Myocardial work indices

PURPOSE

The presence of right ventricular dysfunction indicates a higher risk status in patients with pulmonary embolism (PE). The RV strain evaluated by speckle-tracking echocardiography seems to be more reliable method in the evaluation of RV dysfunction as compared to standard echocardiographic measures. In this study, we aimed to determine the value of myocardial-work indices in evaluating serial changes of RV function in acute PE.

METHODS

Our study comprised 83 consecutive acute PE patients who admitted to our tertiary cardiovascular hospital. Echocardiography was performed within the first 24-hours of hospitalization, and RV and LV myocardial-work parameters were obtained along with standard echocardiographic parameters. The change in the RV/LVr detected on tomography was selected as the primary outcome measure, and its' predictors were analyzed with classical linear regression and a generalized additive model (GAM).

RESULTS

Among the LV-RV strain and myocardial work parameters, the RV global longitudinal strain (GLS) has borderline statistical significance in predicting the RV/LVr change whereas the RV global work efficiency (RV-GWE) strongly predicted RV/LVr change (p: 0.049 and <0.001, respectively).

CONCLUSION

In this study, classical linear regression and GAM analyses showed that RV-GWE seems to offer a better prediction of RV/LVr change in patients with acute PE.

Successful Cardiac Resynchronization Therapy Reduces Negative Septal Work in Patient-Specific Models of Dyssynchronous Heart Failure

In patients with dyssynchronous heart failure (DHF), cardiac conduction abnormalities cause the regional distribution of myocardial work to be non-homogeneous. Cardiac resynchronization therapy (CRT) using an implantable, programmed biventricular pacemaker/defibrillator, can improve the synchrony of contraction between the right and left ventricles in DHF, resulting in reduced morbidity and mortality and increased quality of life. Since regional work depends on wall stress, which cannot be measured in patients, we used computational methods to investigate regional work distributions and their changes after CRT. We used three-dimensional multi-scale patient-specific computational models parameterized by anatomic, functional, hemodynamic, and electrophysiological measurements in eight patients with heart failure and left bundle branch block (LBBB) who received CRT. To increase clinical translatability, we also explored whether streamlined computational methods provide accurate estimates of regional myocardial work. We found that CRT increased global myocardial work efficiency with significant improvements in non-responders. Reverse ventricular remodeling after CRT was greatest in patients with the highest heterogeneity of regional work at baseline, however the efficacy of CRT was not related to the decrease in overall work heterogeneity or to the reduction in late-activated regions of high myocardial work. Rather, decreases in early-activated regions of myocardium performing negative myocardial work following CRT best explained patient variations in reverse remodeling. These findings were also observed when regional myocardial work was estimated using ventricular pressure as a surrogate for myocardial stress and changes in endocardial surface area as a surrogate for strain. These new findings suggest that CRT promotes reverse ventricular remodeling in human dyssynchronous heart failure by increasing regional myocardial work in early-activated regions of the ventricles, where dyssynchrony is specifically associated with hypoperfusion, late systolic stretch, and altered metabolic activity and that measurement of these changes can be performed using streamlined approaches.

Parameter subset reduction for imaging-based digital twin generation of patients with left ventricular mechanical discoordination

BACKGROUND

Integration of a patient's non-invasive imaging data in a digital twin (DT) of the heart can provide valuable insight into the myocardial disease substrates underlying left ventricular (LV) mechanical discoordination. However, when generating a DT, model parameters should be identifiable to obtain robust parameter estimations. In this study, we used the CircAdapt model of the human heart and circulation to find a subset of parameters which were identifiable from LV cavity volume and regional strain measurements of patients with different substrates of left bundle branch block (LBBB) and myocardial infarction (MI). To this end, we included seven patients with heart failure with reduced ejection fraction (HFrEF) and LBBB (study ID: 2018-0863, registration date: 2019-10-07), of which four were non-ischemic (LBBB-only) and three had previous MI (LBBB-MI), and six narrow QRS patients with MI (MI-only) (study ID: NL45241.041.13, registration date: 2013-11-12). Morris screening method (MSM) was applied first to find parameters which were important for LV volume, regional strain, and strain rate indices. Second, this parameter subset was iteratively reduced based on parameter identifiability and reproducibility. Parameter identifiability was based on the diaphony calculated from quasi-Monte Carlo simulations and reproducibility was based on the intraclass correlation coefficient ( ICC ) obtained from repeated parameter estimation using dynamic multi-swarm particle swarm optimization. Goodness-of-fit was defined as the mean squared error (χ 2 ) of LV myocardial strain, strain rate, and cavity volume.

RESULTS

A subset of 270 parameters remained after MSM which produced high-quality DTs of all patients (χ 2  < 1.6), but minimum parameter reproducibility was poor (ICC min  = 0.01). Iterative reduction yielded a reproducible (ICC min  = 0.83) subset of 75 parameters, including cardiac output, global LV activation duration, regional mechanical activation delay, and regional LV myocardial constitutive properties. This reduced subset produced patient-resembling DTs (χ 2  < 2.2), while septal-to-lateral wall workload imbalance was higher for the LBBB-only DTs than for the MI-only DTs (p < 0.05).

CONCLUSIONS

By applying sensitivity and identifiability analysis, we successfully determined a parameter subset of the CircAdapt model which can be used to generate imaging-based DTs of patients with LV mechanical discoordination. Parameters were reproducibly estimated using particle swarm optimization, and derived LV myocardial work distribution was representative for the patient's underlying disease substrate. This DT technology enables patient-specific substrate characterization and can potentially be used to support clinical decision making.

Scanning the Imaging Horizon for Hypertrophic Cardiomyopathy

In this article some of the recent advances in the use of noninvasive imaging applied to patients with hypertrophic cardiomyopathy (HCM) are discussed. Echocardiography and cardiac computed tomography are briefly discussed with respect to their power to detect apical aneurysmal disease. Echocardiographic phenotype-genotype correlations and the use of echocardiography to characterize myocardial work are reviewed. Positron emission tomography is reviewed in the context of ischemia imaging and also in the context of the use of a new tracer that might allow for recognition of early activation of the fibrosis pathway. Next, the technical capabilities of cardiovascular magnetic resonance to measure myocardial perfusion, oxygenation, and disarray are discussed as they apply to HCM. The application of radiomics to improve prediction of sudden cardiac death is touched upon. Finally, a deep learning approach to the recognition of HCM vs phenocopies is presented as a potential future diagnostic aid in the not-too-distant future.

Left Ventricle Myocardial Work Correlated with Functional Capacity in Severe Rheumatic Mitral Stenosis with Preserved Left Ventricular Ejection Fraction

Background and Aims

Functional capacity is reduced in mitral stenosis (MS) patients. Previous studies showed a correlation between left atrial strain and functional capacity in this population. However, currently, no left ventricle (LV) echocardiographic parameters were associated with functional capacity in patients with MS. Noninvasive LV pressure-strain loop analysis is a new echocardiographic method for evaluating LV function, integrating longitudinal strain from speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work (MW) that overcomes the preload-dependent characteristics conventional parameters by integrating afterload. This study aimed to evaluate the association between MW and functional capacity measured using exercise tests in patients with severe MS and preserved LV ejection fraction (LVEF).

Methods

Adult patients with symptomatic severe rheumatic MS (mitral valve area <1.5 cm2), and preserved LVEF (>50%) and sinus rhythm who underwent echocardiography and exercise stress test in our hospital from 2019 to 2021 were included. Exclusion criteria were suboptimal image quality for myocardial deformation analysis, significant mitral regurgitation or aortic valve lesions, coronary artery disease, intracardiac shunt, and atrial fibrillation. Standard echocardiographic parameters were measured, and all MW parameters were included. Exercise treadmill testing was performed using the modified Bruce protocol.

Results

A total of 33 individuals with isolated severe rheumatic MS in sinus rhythm (age 39.8 ± 9.8 years) were included in the study. Patients with severe isolated MS showed significantly impaired LV-global longitudinal strain values compared to normal reference values. Furthermore, patients with severe MS showed significantly lower values of global work index, global constructive work, and efficiency compared to normal values and higher wasted work. Global work efficiency was significantly correlated to the duration of exercise (P = 0.025, Pearson's r = 0.389).

Conclusions

In stable patients with isolated severe mitral stenosis, MW efficiency significantly correlated with functional capacity measured objectively through exercise testing.

Evolution and prognostic value of left ventricular deformation and myocardial work parameters in transthyretin amyloid cardiomyopathy

AIMS

Wild-type transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognized condition. It remains challenging to estimate the extent of disease and the prognosis for most patients. Myocardial work is a sensitive echocardiographic approach that improves the characterization of myocardial damage. We investigate the parameters of myocardial deformation and work in ATTR-CM patients and their changes over time.

METHODS AND RESULTS

We analysed clinical, electrocardiographic, biological, and echocardiographic characteristics in 113 patients [median age 82 (77-85), 90.4% male] diagnosed with wild-type ATTR-CM based on international consensus at a single centre. We compared the data at baseline and 18-month follow-up. Thirty-four patients died and 12 were hospitalized for heart failure at a median follow-up of 935 days (interquartile range 691-1159 days). Left ventricular end-diastolic diameter, left atrial strain during reservoir phase (LASRES), left ventricular longitudinal strain, global work index (GWI), global constructive work significantly decreased from baseline to 18 months, while left ventricular wall thickness increased. Left ventricular ejection fraction, right ventricular free wall strain (FWS), global wasted work (GWW), and global work efficiency did not alter significantly. Strain parameters were identified as prognostic on baseline evaluation using a multivariate analysis: GWI, GWW, FWS, and LASRES. They were significantly associated with the risk of death and hospitalization for heart failure.

CONCLUSION

Multi-chamber strain assessment may improve the surveillance of patients with ATTR-CM, and myocardial work parameters may improve clinical risk stratification in this population.

Quantitative assessment of left ventricular myocardial work in patients with different types of atrial fibrillation by non-invasive pressure-strain loop technique

OBJECTIVE

This study aimed to analyze myocardial work in patients with atrial fibrillation (AF) using a noninvasive pressure strain loop (PSL) technique to provide a basis for the quantitative assessment of left ventricular (LV) systolic function.

METHODS

LV myocardial work of 107 AF patients (56 with paroxysmal atrial fibrillation and 51 with persistent atrial fibrillation) and 55 healthy individuals were assessed by the noninvasive PSL and then compared.

RESULTS

Global longitudinal strain (GLS) in absolute values, global work index (GWI), global constructive work (GCW), and global work efficiency (GWE) were significantly lower in the AF group than control group, whereas peak strain dispersion (PSD) and global wasted work (GWW) were significantly higher (P < .05). Further subdivision according to the AF type revealed that, compared with the controls, GLS in absolute values and GWE decreased significantly; PSD and GWW increased significantly in the paroxysmal AF group (P < .05). Nevertheless, GWI and GCW were not significantly different between paroxysmal AF and control groups (P > .05). Compared to paroxysmal AF, persistent AF induced a further decrease in absolute GLS and GWE and a further increase in GWW (P < .05), but PSD did not increase further (P > .05). Multiple linear regression analysis showed that GWI and GCW were independently associated with systolic blood pressure. GWW was associated with types of AF and left atrial volume index (LAVI). GWE was correlated with age, types of AF, disease duration, and LAVI. Receiver operating characteristic curve analysis showed that the area under the curve predicting myocardial injury was higher for GWE and GWW than for GLS (area under the curve:  .880,  .846, and  .821, respectively).

CONCLUSIONS

Non-invasive PSL can quantitatively assess LV systolic function in patients with different kinds of AF and detect early subclinical myocardial injury in patients with paroxysmal AF. GWE and GWW outperform GLS and LV ejection fraction when assessing myocardial injury. Systolic blood pressure, type of AF, LVAI, disease duration, and age may be associated with myocardial injury in patients with AF.

Evaluation of subclinical left ventricular myocardial systolic dysfunction in type 2 diabetes mellitus patients with and without diabetes peripheral neuropathy by global myocardial work

AIMS

Speckle-tracking echocardiography can non-invasively estimate myocardial work (MW) to evaluate left ventricular (LV) myocardial systolic function. The present study evaluated whether MW may detect subclinical LV myocardial systolic dysfunction in type 2 diabetes mellitus (T2DM) patients with and without diabetes peripheral neuropathy (DPN).

METHODS

A total of 127 T2DM patients were included in the present study, including 67 T2DM patients with DPN. In addition, 73 sex- and age- matched healthy individuals served as normal controls. The global myocardial work index (GWI), global constructive work (GCW), global waste work (GWW), global positive work (GPW), global negative work (GNW), global work efficiency (GWE) and GCW/GWW were measured and analysed. Furthermore, the differences in MW parameters among normal controls, T2DM patients, and T2DM patients with DPN were analysed. Multiple regression models were built to explore for the independent influencing factors of GWI and GPW values in T2DM patients with DPN. Receiver operating characteristic curve analysis was performed to evaluate the sensitivity and specificity of MW in evaluating subclinical LV myocardial systolic dysfunction in T2DM patients with DPN.

RESULTS

The GWI, GCW and GPW of T2DM patients with DPN were significantly decreased compared with those of T2DM patients and normal controls (P < 0.001) and showed a significant decreasing trend overall (P trend < 0.001). GWE and GCW/GWW were significantly decreased in T2DM patients with DPN compared with normal controls (P < 0.05). Although GWW was not significantly different among the three groups, it showed an increasing trend (Ptrend = 0.033). High-density lipoprotein cholesterol (HDL-C) levels were independent influencing factor for decreased GWI (β = 0.21, P = 0.031) and GPW (β = 0.19, P = 0.043) values in T2DM patients with DPN. The combination of the GWI, GCW, GWE, GPW and GCW /GWW had good sensitivity (62.69%) and specificity (89.04%) when evaluating subclinical LV myocardial systolic dysfunction in T2DM patients with DPN.

CONCLUSIONS

Non-invasive evaluation of LV myocardial work can detect subclinical LV myocardial systolic dysfunction in T2DM patients with and without DPN. DPN has additive deleterious effects on LV myocardial systolic function in T2DM patients. The reduction of HDL-C levels may indicate the occurrence of subclinical LV myocardial systolic dysfunction in T2DM patients with DPN.

Association between myocardial work indices and cardiovascular events according to hypertension in the general population

AIMS

Pressure-strain loop (PSL) analysis is a novel echocardiographic tool capable of assessing myocardial work non-invasively. In this study, we aim to evaluate the prognostic value of myocardial work indices in the general population.

METHODS AND RESULTS

This was a prospective community-based cohort study (n = 4466). PSL analyses were performed to acquire global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency (GWE). The endpoint was a composite of heart failure or cardiovascular death (HF/CVD). Survival analysis was applied. A total of 3932 participants were included in this analysis (median age: 58 years, 43% men). Of these, 124 (3%) experienced the outcome during a median follow-up period of 3.5 years [interquartile range (IQR): 2.6-4.4 years]. Hypertension significantly modified the association between all work indices and outcome (P for interaction < 0.05), such that work indices posed a higher risk of outcome in non-hypertensive than in hypertensive participants. After adjusting for Atherosclerosis Risk in Communities (ARIC)-HF risk variables, all work indices predicted outcome in non-hypertensive participants, but only GWI, GCW, and GWE predicted outcome in hypertensive participants [GWI: hazard ratio (HR) = 1.12 (1.07-1.16), per 100 mmHg% decrease; GCW: HR = 1.12 (1.08-1.17), per 100 mmHg% decrease; GWE: HR = 1.08 (1.04-1.12), per 1% decrease]. Only GWE significantly increased C-statistics when added to ARIC-HF risk variables in hypertensive participants (C-stat 0.865 vs. 0.877, P for increment = 0.003).

CONCLUSION

Hypertension modifies the association between myocardial work indices and HF/CVD in the general population. All work indices are associated with outcome in normotensive participants. GWI, GCW, and GWE are independently associated with outcome in hypertension, but only GWE improves risk prediction.

Non-invasive left ventricular pressure-strain loop study on cardiac fibrosis in primary aldosteronism: a comparative study with cardiac magnetic resonance imaging

We investigated the potential diagnostic value of the myocardial work indices based on speckle tracking echocardiography for cardiac fibrosis in patients with primary aldosteronism. Our observational study included 48 patients with primary aldosteronism. We performed conventional echocardiography and the left ventricular pressure-strain loop analysis. We also performed cardiac magnetic resonance imaging to evaluate cardiac replacement fibrosis defined as late gadolinium enhancement (LGE). Patients with LGE (n = 30, 62.5%) had longer duration of hypertension and higher plasma NT-proBNP than those without LGE. Besides, they had a significantly (P ≤ 0.04) higher left ventricular mass index (121.3 ± 19.5 vs. 103.3 ± 20.0 g/m2) and global wasted work (205 ± 78 vs. 141 ± 36 mmHg%) and lower global longitudinal strain (-17.7 ± 1.8 vs. -19.0 ± 2.4%) and work efficiency (GWE, 90.9 ± 2.4 vs. 93.8 ± 1.5%). Receiver Operating Characteristics analysis showed that GWE ≤ 92% had a sensitivity and specificity of 76.7% and 83.3%, respectively, for LGE with the area under curve 0.85 (P < 0.001). In conclusion, both cardiac structure and function were impaired in patients with primary aldosteronism and cardiac fibrosis. The myocardial work index GWE showed significant value for the indication of cardiac fibrosis. Characterization of cardiac fibrosis in primary aldosteronism and the detective value of clinical and echocardiographic indices. Cardiac fibrosis was presented in 30 of the 48 analyzed primary aldosteronism patients with focal high signal intensity in mid-layer myocardium in limited segments as its characterization. The global work efficiency (GWE) had a significantly higher detective value for myocardial replacement fibrosis than other measurements such as left ventricular mass index (LVMI) and NT-proBNP.

Anthracycline-induced cardiotoxicity on regional myocardial work and left ventricular mechanical dispersion in adolescents and young adults in post-lymphoma remission

BACKGROUND

Myocardial work (MW) is a new echocardiographic tool with a high sensitivity to detect early and subtle alterations of myocardial function. We aimed to evaluate the late effects of anthracyclines by assessing the global and segmental MW and intraventricular mechanical dispersion from speckle tracking echocardiography in childhood lymphoma survivors (CLS).

METHODS

Thirty-one young adults including CLS and age-matched healthy controls were enrolled. All underwent echocardiography including an evaluation of left ventricular (LV) morphology and regional function. We assessed LV longitudinal (differentiating sub-endocardial and sub-epicardial layers), circumferential strains and twist, global and regional MW index (MWI). LV mechanical dispersion was assessed from the time dispersion of LV longitudinal strain, from myocardial wasted work (MWW) and myocardial work efficiency (MWE).

RESULTS

The longitudinal strains both at the level of the sub-endocardium and sub-epicardium were reduced in CLS compared to controls. The global MWI was also decreased (1668 ± 266 vs 1870 ± 264%.mmHg in CLS patients and controls, respectively, p < 0.05), especially on the apical segments. An increase of LV intraventricular mechanical dispersion was observed in CLS. MWW and MWE remained unchanged compared to controls.

CONCLUSION

Our results strongly support that cardiac remodeling is observed in CLS, characterized by a decrease in MW and an increase in LV mechanical dispersion. The apex is specifically altered, but its clinical significance remains uncertain. MW as a complement to strain seems interesting in cancer survivors to detect myocardial dysfunction at early stage and adapt their follow-up.

How to assess and treat right ventricular electromechanical dyssynchrony in post-repair tetralogy of Fallot: insights from imaging, invasive studies, and computational modelling

BACKGROUND AND AIMS

Right bundle branch block (RBBB) and resulting right ventricular (RV) electromechanical discoordination are thought to play a role in the disease process of subpulmonary RV dysfunction that frequently occur post-repair tetralogy of Fallot (ToF). We sought to describe this disease entity, the role of pulmonary re-valvulation, and the potential added value of RV cardiac resynchronization therapy (RV-CRT).

METHODS

Two patients with repaired ToF, complete RBBB, pulmonary regurgitation, and significantly decreased RV function underwent echocardiography, cardiac magnetic resonance, and an invasive study to evaluate the potential for RV-CRT as part of the management strategy. The data were used to personalize the CircAdapt model of the human heart and circulation. Resulting Digital Twins were analysed to quantify the relative effects of RV pressure and volume overload and to predict the effect of RV-CRT.

RESULTS

Echocardiography showed components of a classic RV dyssynchrony pattern which could be reversed by RV-CRT during invasive study and resulted in acute improvement in RV systolic function. The Digital Twins confirmed a contribution of electromechanical RV dyssynchrony to RV dysfunction and suggested improvement of RV contraction efficiency after RV-CRT. The one patient who underwent successful permanent RV-CRT as part of the pulmonary re-valvulation procedure carried improvements that were in line with the predictions based on his Digital Twin.

CONCLUSION

An integrative diagnostic approach to RV dysfunction, including the construction of Digital Twins may help to identify candidates for RV-CRT as part of the lifetime management of ToF and similar congenital heart lesions.

Non-invasive estimation of left ventricular systolic peak pressure: a prerequisite to calculate myocardial work in hypertrophic obstructive cardiomyopathy

AIMS

Myocardial work (MyW) is an echocardiographically derived parameter to estimate myocardial performance. The calculation of MyW utilizes pressure strain loops from global longitudinal strain and brachial blood pressure (BP) as a surrogate of left ventricular systolic pressure (LVSP). Since LVSP cannot be equated with BP in hypertrophic obstructive cardiomyopathy (HOCM), we explored whether LVSP can be derived non-invasively by combining Doppler gradients and BP.

METHODS AND RESULTS

We studied 20 consecutive patients (8 women, 12 men; mean age 57.0 ± 13.9 years; NYHA 2.1 ± 0.8; maximal septal thickness 24.7 ± 6.3 mm) with indication for first alcohol septal ablation. All measurements were performed simultaneously in the catheterization laboratory (CathLab)-invasively: ascending aortic and LV pressures; non-invasively: BP, maximal (CWmax) and mean (CWmean) Doppler gradients.LVSP was 188.9 ± 38.5 mmHg. Mean gradients of both methods were comparable (CathLab 34.3 ± 13.4 mmHg vs. CW 31.0 ± 13.7 mmHg). Maximal gradient was higher in echocardiography (64.5 ± 28.8 mmHg) compared with CathLab (54.8 ± 24.0 mmHg; P < 0.05). Adding BP (143.1 ± 20.6 mmHg) to CWmax resulted in higher (207.7 ± 38.0 mmHg; P < 0.001), whereas adding BP to CWmean in lower (174.1 ± 26.1 mmHg; P < 0.01) derived LVSP compared with measured LVSP. However, adding BP to averaged CWmax and CWmean resulted in comparable results for measured and derived LVSP (190.9 ± 31.6 mmHg) yielding a favourable correlation (r = 0.87, P < 0.001) and a good level of agreement in the Bland-Altman plot.

CONCLUSION

Non-invasive estimation of LVSP in HOCM is feasible by combining conventional BP and averaged CWmean and CWmax gradients. Hereby, a more reliable estimation of MyW in HOCM may be feasible.

Non-invasive myocardial work in aortic stenosis: validation and improvement in left ventricular pressure estimation

AIMS

The non-invasive myocardial work index (MWI) has been validated in patients without aortic stenosis (AS). A thorough assessment of methodological limitations is warranted before this index can be applied to patients with AS.

METHODS AND RESULTS

We simultaneously measured left ventricular pressure (LVP) by using a micromanometer-tipped catheter and obtained echocardiograms in 20 patients with severe AS. We estimated LVP curves and calculated pressure-strain loops using three different models: (i) the model validated in patients without AS; (ii) the same model, but with pressure at the aortic valve opening (AVO) adjusted to diastolic cuff pressure; and (iii) a new model based on the invasive measurements from patients with AS. Valvular events were determined by echocardiography. Peak LVP was estimated as the sum of the mean aortic transvalvular gradient and systolic cuff pressure. In same-beat comparisons between invasive and estimated LVP curves, Model 1 significantly overestimated early systolic pressure by 61 ± 5 mmHg at AVO compared with Models 2 and 3. However, the average correlation coefficients between estimated and invasive LVP traces were excellent for all models, and the overestimation had limited influence on MWI, with excellent correlation (r = 0.98, P < 0.001) and good agreement between the MWI calculated with estimated (all models) and invasive LVP.

CONCLUSION

This study confirms the validity of the non-invasive MWI in patients with AS. The accuracy of estimated LVP curves improved when matching AVO to the diastolic pressure in the original model, mirroring that of the AS-specific model. This may sequentially enhance the accuracy of regional MWI assessment.

Longitudinal strain and myocardial work in symptomatic patients having recovered from COVID-19 and possible associations with the severity of the disease

COVID-19 may have residual consequences in multiple organs, including the cardiovascular system. The purpose of the present investigation is to quantify myocardial function in symptomatic individuals with long COVID and investigate the association between illness severity and myocardial function. A retrospective cross-sectional study was conducted in which symptomatic individuals with previous COVID-19 underwent echocardiographic analysis of left ventricle global longitudinal strain (LVGLS) and myocardial work (MW). Individuals also performed cardiopulmonary testing (CPX) to assess peak oxygen uptake (VO2peak). Differences between illness severity subgroups were analyzed by the Mann-Whitney test. Correlations were calculated using the Spearman correlation test. Multilinear regressions were performed to evaluate the influences of COVID-19 severity, body mass index, age, and sex on MW. Fifty-six individuals were included (critical subgroup: 17; moderate/severe subgroup: 39), 59% females; median age: 56 years (IQR: 43-63). CPX revealed a substantial reduction in VO2peak (median of 53% of predicted values). LVGLS were not statistically different between subgroups. Global wasted work (GWW) was higher in the critical subgroup [146 (104-212) versus 121 (74-163) mmHg%, p = 0.01], and global work efficiency (GWE) was lower in this subgroup [93 (91-95) versus 94 (93-96), p = 0.03]. Illness severity was the only independent predictor of GWW and GWE (GWW: r2 = 0.167; p = 0.009; GWE: r2 = 0.172; p = 0.005) in multilinear regressions. In our study with long COVID-19 individuals, despite having a similar LVGLS, patients had subclinical LV dysfunction, demonstrated only by an increase in GWW and a decrease in GWE.

Echocardiographic Myocardial Work: A Novel Method to Assess Left Ventricular Function in Patients with Coronary Artery Disease and Diabetes Mellitus

Myocardial ischemia caused by coronary artery disease (CAD) and the presence of metabolic abnormalities and microvascular impairments detected in patients with diabetes mellitus (DM) are a common cause of left ventricular (LV) dysfunction. Transthoracic echocardiography is the most-used, non-invasive imaging method for the assessment of myocardial contractility. The accurate evaluation of LV function is crucial for identifying patients who are at high risk or may have worse outcomes. Myocardial work (MW) is emerging as an alternative tool for the evaluation of LV systolic function, providing additional information on cardiac performance when compared to conventional parameters such as left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) because it incorporates deformation and load into its analysis. The potential of MW in various conditions is promising and it has gained increased attention. However, larger studies are necessary to further investigate its role and application before giving an answer to the question of whether it can have widespread implementation into clinical practice. The aim of this review is to summarize the actual knowledge of MW for the analysis of LV dysfunction caused by myocardial ischemia and hyperglycemia.

Current Role of Electrocardiographic Imaging in Patient Selection for Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is a recognized therapy for heart failure with altered ejection fraction and abnormal left ventricular activation time. Since the introduction of the therapy, a 30% rate of non-responders is observed and unchanged. The 12-lead ECG remains the only recommended tool for patient selection to CRT. The 12-lead ECG is, however, limited in its inability to provide a precise pattern of regional electrical activity. Electrocardiographic imaging (ECGi) provides a non-invasive detailed mapping of cardiac activation and therefore appears as a promising tool for CRT candidates. The non-invasive ventricular activation maps acquired by ECGi have been primarily explored for the diagnosis and guidance of therapy in patients with atrial or ventricular tachyarrhythmia. However, the accuracy of the system in this field is lacking and needs further improvement before considering a clinical application. On the other hand, its use for patient selection for CRT is encouraging. In this review, we introduce the technical considerations and we describe how ECGi can precisely characterize ventricular activation, especially in patients with left bundle branch block, thus identifying the electrical substrate responsive to CRT.

Coronary Microvascular Dysfunction in Patients With Heart Failure: Characterization of Patterns in HFrEF Versus HFpEF

BACKGROUND

Coronary microvascular dysfunction (CMD) is involved in heart failure (HF) onset and progression, independently of HF phenotype and obstructive coronary artery disease. Invasive assessment of CMD might provide insights into phenotyping and prognosis of patients with HF. We aimed to assess absolute coronary flow, absolute microvascular resistance, myocardial perfusion, coronary flow reserve, and microvascular resistance reserve in patients with HF with preserved ejection fraction and HF with reduced ejection fraction (HFrEF).

METHODS

Single-center, prospective study of 56 consecutive patients with de novo HF with nonobstructive coronary artery disease divided into HF with preserved ejection fraction (n=21) and HFrEF (n=35). CMD was invasively assessed by continuous intracoronary thermodilution and defined as coronary flow reserve <2.5. Left ventricular and left anterior descending artery-related myocardial mass was quantified by echocardiography and coronary computed tomography angiography. Myocardial perfusion (mL/min per g) was calculated as the ratio between absolute coronary flow and left anterior descending artery-related mass.

RESULTS

Patients with HFrEF showed a higher left ventricular and left anterior descending artery-related myocardial mass compared with HF with preserved ejection fraction (P<0.010). Overall, 52% of the study population had CMD, with a similar prevalence between the 2 groups. In HFrEF, CMD was characterized by lower absolute microvascular resistance and higher absolute coronary flow at rest (functional CMD; P=0.002). CMD was an independent predictor of a lower rate of left ventricular reverse remodeling at follow-up. In patients with HF with preserved ejection fraction, CMD was mainly due to higher absolute microvascular resistance and lower absolute coronary flow during hyperemia (structural CMD; P≤0.030).

CONCLUSIONS

Continuous intracoronary thermodilution allows the definition and characterization of patterns with distinct CMD in patients with HF and could identify patients with HFrEF with a higher rate of left ventricular reverse remodeling at follow-up.

Study of stress-strain loops on cardiotoxicity related to immune checkpoint inhibitors

OBJECTIVE

To evaluate the effect of immune checkpoint inhibitors (ICIs) on left ventricular myocardial work by pressure-strain loop (PSL).

METHODS

Forty-three immunotherapy patients were enrolled in the case group, and another 43 healthy volunteers were enrolled in the control group. They were examined by echocardiography before immunotherapy (T0 phase), after three cycles of treatment (T3 phase) and after six cycles of treatment (T6 phase). Conventional echocardiographic parameters, left ventricular global longitudinal strain (GLS), and myocardial work indices, including global work index (GWI), global constructive work (GCW), global work waste (GWW), and global work efficiency (GWE), were collected for analysis to compare the results of the different immunotherapy cycles.

RESULTS

There were no statistically significant differences of baseline characteristics, conventional echocardiographic parameters, left ventricular strain, and myocardial work indices between T0 phase and control group (all p > .05). There were no statistically significant differences in LVEF between T0, T3, and T6 phase (all p > .05). GLS, GWI, GCW, and GWE were decreased and GWW was increased in T3 and T6 phase. There were no statistically significant difference between GLS in T3 and T0 phase (q = .9057, p > .05). The difference was statistically significant between GLS in T6 and T0 phase (q = 5.5651, p < .01). The difference was statistically significant between GLS in T3 and T6phase(q = 4.6594, p < .01). There were statistically significant difference in GWI, GCW, GWE, and GWW in the T3 and T6 phase compared with the T0 phase (p < .01).

CONCLUSION

PSL can effectively evaluate the effect of ICIs on left ventricular myocardial work, to provide a new method for the early clinical detection of ICIs-related cardiotoxicity.

Global and regional myocardial function assessment in symptomatic patients with chronic coronary syndrome using longitudinal strain and noninvasive myocardial work

Speckle tracking echocardiography (STE) derived longitudinal strain (LS) and noninvasive pressure-strain loop (PSL) derived myocardial work (MW) are more sensitive than conventional echocardiographic parameters in quantitative assessment of early myocardial dysfunction. The aim of this study was to assess left ventricular (LV) global and regional myocardial function in symptomatic chronic coronary syndrome (CCS) patients using the two promising methods. Transthoracic echocardiography was performed on patients with angina or equivalent symptoms before coronary angiography. STE-based LS and PSL-based MW analysis were carried out on each patient for global and regional myocardial function assessment. A total of 102 patients were classified into significant and nonsignificant coronary artery stenosis (CAS) groups. Among global myocardial function parameters, LS had the biggest area under the curve (AUC) of 0.735, with cutoff value of 18.4% (sensitivity, 79.6%; specificity, 72.9%), but remained statistically alike with all MW indices in predicting significant CAS (P>0.05 for all). Among regional myocardial function parameters, both LS and MW indices had predictive value for significant left anterior descending artery (LAD) or left circumflex artery (LCX) stenosis, while only myocardial work efficiency (MWE) for right coronary artery (RCA) stenosis. Both global and regional LS and MW have predictive value for significant CAS, but their value of regionalized assessment varies with specific coronary artery involvement.

Cardiac reverse remodelling by imaging parameters with recent changes to guideline medical therapy in heart failure

Recently established heart failure therapies, including sodium glucose co-transporter 2 inhibitors, angiotensin-neprilysin inhibitors, and cardiac resynchronization therapy, have led to both clinical and structural improvements. Reverse remodelling describes the structural and functional responses to therapy and has been shown to correlate with patients' clinical response, acting as a biomarker for treatment success. The introduction of these new therapeutic agents in addition to advances in non-invasive cardiac imaging has led to an expansion in the evaluation and the validation of cardiac reverse remodelling. Methods including volumetric changes as well as strain and myocardial work have all been shown to be non-invasive end-points of reverse remodelling, correlating with clinical outcomes. Our review summarizes the current available evidence on reverse remodelling in heart failure by the non-invasive cardiac imaging techniques, in particular transthoracic echocardiography.

Determinants of myocardial work indices in women

OBJECTIVE

By incorporating myocardial deformation and afterload, novel echocardiographic myocardial work indices appear to be advantageous compared to load-dependent left ventricular (LV) deformation analyses. As such, these indices may provide a more accurate and, above all, load-independent estimation of LV function in patients with chronically increased afterload. To date however, data on the relation of these indices to clinical and conventional echocardiographic parameters are scarce.

PURPOSE

Our aim was to evaluate the relationship between myocardial work indices and age, body mass index (BMI), NTproBNP, the clinical history of arterial hypertension and diastolic dysfunction as well as selected conventional echocardiographic parameters in women.

METHODS

We analyzed echocardiographic data of women included in the Berlin Female Risk Evaluation (BEFRI) trial. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. The impact of selected clinical and echocardiographic characteristics on myocardial work parameters was investigated by uni- and multivariate regression analyses.

RESULTS

A total of 224 women were included in the final analysis. 155 of them were normotensive and 69 had a history of arterial hypertension. Diastolic dysfunction was more prevalent in subjects with arterial hypertension. Study participants with arterial hypertension showed higher GWI and GCW whereas GWW and GWE did not significantly differ between groups. GCW and GWW were lower and GWE higher in the presence of normal diastolic function. In multivariate regression analyses, arterial hypertension, LV GLS, and interventricular septal thickness were significantly associated with GWI. GCW showed significant associations with the clinical history of arterial hypertension, LV GLS, age and IVRT. Similarly, LV GLS, IVRT and mitral inflow E wave deceleration time were identified to be significant determinants of GWW and GWE.

CONCLUSION

Our data confirm that, in a randomly selected sample of the general urban female population, myocardial work parameters are predominantly determined by LV GLS. In addition, the presence of arterial hypertension was identified to be a significant determinant of GWI and GCW, but not for GWW and GWE. Finally, a prolonged LV relaxation time was significantly associated with GWW and GWE, suggesting more wasted myocardial work and lower GWE values with increasing LV relaxation time.

Assessment of subclinical left ventricular myocardial systolic dysfunction in type 2 diabetes mellitus patients with or without hypertension by global and segmental myocardial work

OBJECTIVE

The research was aimed to evaluate the subclinical left ventricular (LV) myocardial systolic dysfunction in T2DM patients with or without hypertension (HT) by global and segmental myocardial work (MW).

METHODS

A total of 120 T2DM patients (including 60 T2DM patients with HT) and 70 sex- and age- matched normal controls were included. The global and segmental variables of work index (WI), constrictive work (CW), waste work (WW), work efficiency (WE), and CW/WW were analysed by non-invasive pressure-strain loop. Receiver operating characteristic (ROC) analysis was performed for detection the subclinical LV systolic dysfunction in T2DM patients with and without HT.

RESULTS

The global work index (GWI), global CW (GCW), global WE (GWE), and GCW/global WW (GWW) of T2DM and T2DM patients with HT were significantly lower than normal controls (p < 0.05). The WI, CW, WE, and CW/WW of the LV anterior wall in T2DM and T2DM patients with HT were significantly lower when compared with those of the normal controls (p < 0.05). ROC analysis showed that the value of area under the curve (AUC) in combined GWI, GCW, GWE, and GCW/GWW was significantly higher than the AUCs of the individual indices (p < 0.05).

CONCLUSIONS

MW can non-invasively and accurately evaluate subclinical global and segmental LV myocardial systolic dysfunction in T2DM patients with and without HT. Regulating total cholesterol levels and controlling blood pressure in T2DM patients with and without HT might reduce the impairment of LV myocardial systolic function.

State-of-the-Art: Noninvasive Assessment of Left Ventricular Function Through Myocardial Work

The assessment of myocardial work (MW) using noninvasive pressure-strain loop analysis is a novel echocardiographic method that provides a more precise assessment of cardiac performance by considering the left ventricular loading condition. By integrating various MW components such as index, efficiency, and constructive and wasted work, an extensive analysis of left ventricular mechanics and energetics can be achieved. This approach offers a more comprehensive assessment of global cardiac function and performance, surpassing conventional surrogate indices. In this review, we aim to summarize the existing knowledge on MW and its distinctive characteristics in various cardiac pathologies.

Myocardial Work in Apical Hypertrophic Cardiomyopathy

BACKGROUND

Pressure-strain loop analysis is a novel echocardiographic technique to calculate myocardial work indices that has not been applied to patients with apical hypertrophic cardiomyopathy (ApHCM). We hypothesized that myocardial work indices differ between patients with ApHCM and those with non-ApHCM. This study aimed to (1) evaluate myocardial work indices in patients with ApHCM compared with those with non-ApHCM, (2) describe associations with relevant clinical variables, and (3) examine associations with significant late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging.

METHODS

We retrospectively identified 48 patients with ApHCM and 69 with non-ApHCM who had measurements of global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency. We evaluated available cardiac magnetic resonance imaging data on 34 patients with ApHCM and 51 with non-ApHCM. Multivariable regression models correcting for traditional cardiac risk factors were used to evaluate the associations of myocardial work indices with relevant clinical variables.

RESULTS

Median GLS (-11% vs -18%, P < .001), GWI (966 mm Hg% vs 1803 mm Hg%, P < .001), and GCW (1,050 mm Hg% vs 1,988 mm Hg%, P < .001) were significantly impaired in patients with ApHCM compared with those with non-ApHCM. Increasing N-terminal pro b-type natriuretic peptide, abnormal ultrasensitive troponin, and increasing maximal left ventricular wall thickness were significantly associated with reduced GWI and GCW in patients with ApHCM (P < .05). Global constructive work had only modest accuracy (area under the curve [AUC] = 0.70) to predict LGE in patients with ApHCM. However, in patients with non-ApHCM, GLS was the strongest predictor of LGE (AUC = 0.91), with a -17% cutoff yielding 81% sensitivity and 80% specificity.

CONCLUSION

Myocardial work indices are significantly impaired in patients with ApHCM compared to those with non-ApHCM and correlate with important clinical variables. Global longitudinal strain, GWI, and GCW are more strongly predictive of fibrosis in patients with non-ApHCM than ApHCM.

Echocardiographic pressure-strain loop-derived stroke work of the right ventricle: validation against the gold standard

AIMS

Commercially available integrated software for echocardiographic measurement of stroke work (SW) is increasingly used for the right ventricle, despite a lack of validation. We sought to assess the validity of this method [echo-based myocardial work (MW) module] vs. gold-standard invasive right ventricular (RV) pressure-volume (PV) loops.

METHODS AND RESULTS

From the prospectively recruiting EXERTION study (NCT04663217), we included 42 patients [34 patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) and 8 patients with absence of cardiopulmonary disease] with RV echocardiography and invasive PV catheterization. Echocardiographic SW was assessed as RV global work index (RVGWI) generated via the integrated pressure-strain MW software. Invasive SW was calculated as the area bounded by the PV loop. An additional parameter derived from the MW module, RV global wasted work (RVGWW), was correlated with PV loop measures. RVGWI significantly correlated with invasive PV loop-derived RV SW in the overall cohort [rho = 0.546 (P < 0.001)] and the PAH/CTEPH subgroup [rho = 0.568 (P < 0.001)]. Overall, RVGWW correlated with invasive measures of arterial elastance (Ea), the ratio of end-systolic elastance (Ees)/Ea, and end-diastolic elastance (Eed) significantly.

CONCLUSIONS

Integrated echo measurement of pressure-strain loop-derived SW correlates with PV loop-based assessment of RV SW. Wasted work correlates with invasive measures of load-independent RV function. Given the methodological and anatomical challenges of RV work assessment, evolution of this approach by incorporating more elaborated echo analysis data and an RV reference curve might improve its reliability to mirror invasively assessed RV SW.

Global Left Ventricular Myocardial Work Efficiency in Patients With Severe Rheumatic Mitral Stenosis and Preserved Left Ventricular Ejection Fraction

BACKGROUND

Assessment of left ventricular (LV) function plays a pivotal role in the management of patients with valvular heart disease, including those caused by rheumatic heart disease. Noninvasive LV pressure-strain loop analysis is emerging as a new echocardiographic method to evaluate global LV systolic function, integrating longitudinal strain by speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work. The aim of this study was to characterize global LV myocardial work efficiency in patients with severe rheumatic mitral stenosis (MS) with preserved ejection fraction (EF).

METHODS

We retrospectively included adult patients with severe rheumatic MS with preserved EF (> 50%) and sinus rhythm. Healthy individuals without structural heart disease were included as a control group. Global LV myocardial work efficiency was estimated with a proprietary algorithm from speckle-tracking strain analyses, as well as noninvasive blood pressure measurements.

RESULTS

A total of 45 individuals with isolated severe rheumatic MS with sinus rhythm and 45 healthy individuals were included. In healthy individuals without structural heart disease, the mean global LV myocardial work efficiency was 96% (standard deviation [SD], 2), Compared with healthy individuals, median global LV myocardial work efficiency was significantly worse in MS patients (89%; SD, 4; p < 0.001) although the LVEF was similar.

CONCLUSIONS

Individuals with isolated severe rheumatic MS and preserved EF, had global LV myocardial work efficiencies lower than normal controls.

Subtle Changes in Myocardial Work Indices Assessed by 2D-Speckle Tracking Echocardiography Are Linked with Pathological LV Remodeling and MACEs Following an Acute Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention

The goal of this study was to assess whether subtle changes in myocardial work indices may predict left ventricular (LV) remodeling and major cardiac events (MACEs) in patients with a first ST-elevation acute myocardial infarction (STEMI) and preserved LVEF after successful myocardial revascularization with PCI. Methods. Consecutive STEMI patients in sinus rhythm and with an LV ejection fraction ≥ 50% following a successful PCI were recruited. Conventional and two-dimensional speckle tracking echocardiography (2D-STE) was conducted within 36 h of the PCI and 3 months later. Patients having an increase of more than 20% in LV diastolic volume were included in the LV remodeling group. MACEs were noted throughout a four-year period of follow-up. Results: The study comprised 246 STEMI patients with a mean age of 66; 72% of whom were men. In 24% (58) of the patients, LV remodeling developed. These patients were older, more frequently hypertensive, and had a smoking history. They also exhibited significantly lower baseline and 3-month values for the myocardial global index (GWI), global constructive work (GCW), and global myocardial efficiency (GWE). The cut-off values of 1670 mmHg% for GWI and 83% for GWE were predictive of LV remodeling (p < 0.0001). During the four-year follow-up period, 19% of STEMI patients experienced a MACE, involving 15% from non-LV remodelers and 34% from LV remodelers (p = 0.01). The cut-off values for baseline GWI of 1680 mmHg% and baseline GWE of 84% had the best accuracy in predicting MACEs. In conclusion, non-invasive myocardial work indices offered a reproducible and accurate method to predict post-MI LV remodeling and MACEs.

Phenotyping heart failure by echocardiography: imaging of ventricular function and haemodynamics at rest and exercise

Traditionally, congestive heart failure (HF) was phenotyped by echocardiography or other imaging techniques according to left ventricular (LV) ejection fraction (LVEF). The more recent echocardiographic modality speckle tracking strain is complementary to LVEF, as it is more sensitive to diagnose mild systolic dysfunction. Furthermore, when LV systolic dysfunction is associated with a small, hypertrophic ventricle, EF is often normal or supernormal, whereas LV global longitudinal strain can reveal reduced contractility. In addition, segmental strain patterns may be used to identify specific cardiomyopathies, which in some cases can be treated with patient-specific medicine. In HF with preserved EF (HFpEF), a diagnostic hallmark is elevated LV filling pressure, which can be diagnosed with good accuracy by applying a set of echocardiographic parameters. Patients with HFpEF often have normal filling pressure at rest, and a non-invasive or invasive diastolic stress test may be used to identify abnormal elevation of filling pressure during exercise. The novel parameter LV work index, which incorporates afterload, is a promising tool for quantification of LV contractile function and efficiency. Another novel modality is shear wave imaging for diagnosing stiff ventricles, but clinical utility remains to be determined. In conclusion, echocardiographic imaging of cardiac function should include LV strain as a supplementary method to LVEF. Echocardiographic parameters can identify elevated LV filling pressure with good accuracy and may be applied in the diagnostic workup of patients suspected of HFpEF.

Multiaxial pressure-strain analysis of regional myocardial work in the setting of graded coronary stenoses and dobutamine stress

We present a detailed analysis of regional myocardial blood flow and work to better understand the effects of coronary stenoses and low-dose dobutamine stress. Our analysis is based on a unique open-chest model in anesthetized canines that features invasive hemodynamic monitoring, microsphere-based blood flow analysis, and an extensive three-dimensional (3-D) sonomicrometer array that provides multiaxial deformational assessments in the ischemic, border, and remote vascular territories. We use this model to construct regional pressure-strain loops for each territory and quantify the loop subcomponent areas that reflect myocardial work contributing to the ejection of blood and wasted work that does not. We demonstrate that reductions in coronary blood flow markedly alter the shapes and temporal relationships of pressure-strain loops, as well as the magnitudes of their total and subcomponent areas. Specifically, we show that moderate stenoses in the mid-left anterior descending coronary artery decrease regional midventricle myocardial work indices and substantially increase indices of wasted work. In the midventricle, these effects are most pronounced along the radial and longitudinal axes, with more modest effects along the circumferential axis. We further demonstrate that low-dose dobutamine can help to restore or even improve function, but often at the cost of increased wasted work. This detailed, multiaxial analysis provides unique insight into the physiology and mechanics of the heart in the presence of ischemia and low-dose dobutamine, with potential implications in many areas, including the detection and characterization of ischemic heart disease and the use of inotropic support for low cardiac output.NEW & NOTEWORTHY Our unique experimental model assesses cardiac pressure-strain relationships along multiple axes in multiple regions. We demonstrate that moderate coronary stenoses decrease regional myocardial work and increase wasted work and that low-dose dobutamine can help to restore myocardial function, but often with further increases in wasted work. Our findings highlight the significant directional variation of cardiac mechanics and demonstrate potential advantages of pressure-strain analyses over traditional, purely deformational measures, especially in characterizing physiological changes related to dobutamine.

Evaluating the characteristics of myocardial work by two-dimensional echocardiography during pre-eclampsia pregnancy

This study aimed to analyze the changes in myocardial work (MyW) properties and the correlation of MyW with cardiovascular and clinical indices during the pre-eclampsia (PE) pregnancy. Standard two-dimensional and speckle-tracking echocardiography were sequentially performed on 77 women with PE and 89 with normal pregnancy. Four components of MyW: global myocardial work index (GWI), constructive work (GCW), wasted work (GWW), and work efficiency (GWE) were measured. The significant increased GWI, GCW and GWW were observed, while GWW elevated more than GCW with consequently resulting the decline in GWE among PE cases. Although there was a diverse relationship between MyW components and LV morphological as well as functional indices, MyW parameters were significantly correlated with the grades of arterial hypertension and the incidence of adverse outcome of PE. With the hypertension stages, GWI, GCW and GWW gradually increased but GWE decreased. Meanwhile, the higher GWI and GCW and the lower GWE, the more adverse events occurred in PE group. In conclusion, during the PE pregnancy, GWI, GCW and GWW increase, while GWW elevates more than GCW, which leads to the decrease in GWE. Moreover, the changes in MyW are associated with the hypertension grades and the poor prognosis in PE. The non-invasive manner for MyW assessment provides a new perspective on the myocardial biomechanics, cardio-metabolic conditions and pathophysiological changes in the condition of PE.

Myocardial work in children with Wolff-Parkinson-White syndrome

Wolff-Parkinson-White Syndrome (WPW) has been associated with reduced local myocardial deformation, and when left ventricular dysfunction is present, catheter ablation of the accessory pathway may be required, even in asymptomatic patients. We aimed to evaluate the diagnostic value of non-invasive myocardial work in predicting subtle abnormalities in myocardial performance in children with WPW.Seventy-five paediatric patients (age 8.7 ± 3.5 years) were retrospectively recruited for the study: 25 cases with manifest WPW and 50 age- and sex- matched controls (CTR). Global myocardial work index (MWI) was measured as the area of the left ventricle (LV) pressure-strain loops. From MWI, global Myocardial Constructive Work (MCW), Wasted Work (MWW), and Work Efficiency (MWE) were estimated. In addition, standard echocardiographic parameters of LV function were evaluated. Despite normal LV ejection fraction (EF) and global longitudinal strain (GLS), children with WPW had worse MWI, MCW, MWW, and MWE. At multivariate analysis, MWI and MCW were associated with GLS and systolic blood pressure, and QRS was the best independent predictor of low MWE and MWW. In particular, a QRS > 110 ms showed good sensitivity and specificity for worse MWE and MWW values. In children with WPW, myocardial work indices were found significantly reduced, even in the presence of normal LV EF and GLS. This study supports the systematic use of myocardial work during the follow-up of paediatric patients with WPW. Myocardial work analysis may represent a sensitive measure of LV performance and aid in decision-making.

Left Bundle Branch Area Pacing versus Right Ventricular Pacing in Patients with Atrioventricular Block: An Observational Cohort Study

Objective

We aim to conduct a comparison of the safety and effectiveness performance between left bundle branch area pacing (LBBAP) and right ventricular pacing (RVP) regimens for patients with atrioventricular block (AVB).

Methods

This observational cohort study included patients who underwent pacemaker implantations with LBBAP or RVP for AVB indications from the 1st of January 2018 to the 18th of November 2021 at West China Hospital. The primary composite outcome included all-cause mortality, lead failure, or heart failure hospitalization (HFH). The secondary outcome included periprocedure complication, cardiac death, or recurrent unexplained syncope. A 1 : 1 propensity score-matched cohort was conducted for left ventricular (LV) function analysis.

Results

A total of 903 patients met the inclusion criteria and completed clinical follow-up. After adjusting for the possible confounders, LBBAP was independently associated with a lower risk of the primary outcome (OR 0.48, 95% CI 0.28 to 0.83, p = 0.009), including a lower risk of all-cause mortality and HFH. No significant difference in the secondary outcome was detected between the groups except that LBBAP was independently associated with a lower risk of recurrent unexplained syncope. In the propensity-score matching cohort of echocardiographic analysis, the LV systolic dyssynchrony index was lower in LBBAP compared with that in RVP (5.68 ± 1.92 vs. 6.50 ± 2.28%, p = 0.012).

Conclusions

Compared to conventional RVP, LBBAP is a feasible novel pacing model associated with a significant reduction in the primary composite outcome. Moreover, LBBAP significantly reduces the risk of recurrent unexplained syncope and improves LV systolic synchrony. This study is registered with ClinicalTrials.gov NCT05722379.

Segmental and global myocardial work in hypertensive patients with different left ventricular ejection fraction: what's the role of the apex played?

We investigated myocardial work in hypertension (HT) among patients with different left ventricular ejection fraction (LVEF) to analyze the contribution of segmental myocardial work to global myocardial work. 114 patients with HT were divided into 4 groups: HTsnEF ("supra-normal" EF, > 65%); HTnEF ("normal" EF, 60-65%); HTmEF (designed as "middle" EF, 50-60%, within an abnormal LV geometry); HTrEF (reduced EF, < 50%). Longitudinal strain (LS) and myocardial work indices were obtained by echocardiography: myocardial work index (MWI), constructive work (MCW), wasted work (MWW), myocardial work efficiency (MWE), and percentages of apical work were calculated (PApi-MWI, PApi-MCW). Global LS (GLS) and global MWE (GWE) decreased in HTmEF and HTrEF groups. Global MWI(GWI) and MCW(GCW) increased in HTsnEF and HTnEF groups, and subsequently decreased, particularly in HTrEF group (P < 0.05). GWW increased in all HT subgroups. All segmental MWI and MCW were elevated or preserved initially in HTsnEF and HTnEF groups, and subsequently decreased, obviously in basal and middle segments in HTrEF group (P < 0.05). All segmental MWW increased and MWE decreased in HTmEF and HTrEF groups (P < 0.05). PApi-MWI and PApi-MCW increased initially, and subsequently decreased in HTmEF group, and elevated significantly in HTrEF group. Correlation analysis revealed a close connection of GLS and myocardial work parameters with LVEF. Apical myocardial work increased at the early stages of hypertensive systolic dysfunction, as a compensatory mechanism. Segmental myocardial work analysis added value to explore the distribution of myocardial impairment.

Segmental and global myocardial work in hypertensive patients with different left ventricular geometry

BACKGROUND

Myocardial work acquired by echocardiography has emerged as a novel method to evaluate myocardial function. We investigated global and segmental myocardial work in hypertension (HT) among patients with different patterns of left ventricular (LV) geometry in order to analyze the contribution of segmental myocardial work to global myocardial work.

METHODS AND RESULTS

One hundred twenty-five patients with HT were divided into 4 groups: normal geometry (NG), concentric remodeling (CR), concentric hypertrophy (CH) and eccentric hypertrophy (EH). Longitudinal strain (LS) and the following indices were obtained by echocardiography: myocardial work index (MWI), myocardial constructive work (MCW), myocardial wasted work (MWW), and myocardial work efficiency (MWE). The global longitudinal strain (GLS) decreased gradually among the groups: NG, CR, CH and EH (P < 0.001). Global MWI (GWI) and global MCW (GCW) did not change across the different LV remodeling groups. Global MWW (GWW) increased and global MWE (GWE) decreased in both CH and EH group (P < 0.001). The LS of basal and middle regions reduced gradually in all HT subgroups, while apical LS decreased only in the CH and EH groups (P < 0.001). Basal MWI and MCW decreased in the CH and EH groups (P = 0.025, 0.007, respectively). Apical MWI and MCW increased in the NG and CR groups (P = 0.015, 0.044, respectively), with a decreasing trend in the CH and EH groups. All segmental MWW elevated and MWE reduced significantly in the CH and EH groups (P < 0.001). Univariate and multivariate logistic regression analyses demonstrated a significant association between left atrial volume index (LAVI), GLS, GWE and LV hypertrophy. At the receiver operating characteristic (ROC) analysis, optimal cutoff values of GLS, Apical LS, GWE and Apical MWE discriminating LV hypertrophy were 0.9072, 0.8049, 0.8325 and 0.7414, respectively.

CONCLUSION

Apical myocardial work increases in the early stages of LV remodeling, likely as a compensatory mechanism to maintain normal global myocardial work. Segmental myocardial work analysis offers a reliable means to explore the distribution of myocardial impairment in hypertensive patients at different LV remodeling stages.

Strain Imaging and Ventricular Arrhythmia

Ventricular arrhythmia is one of the main causes of sudden cardiac death. Hence, identifying patients at risk of ventricular arrhythmias and sudden cardiac death is important but can be challenging. The indication for an implantable cardioverter defibrillator as a primary preventive strategy relies on the left ventricular ejection fraction as a measure of systolic function. However, ejection fraction is flawed by technical constraints and is an indirect measure of systolic function. There has, therefore, been an incentive to identify other markers to optimize the risk prediction of malignant arrhythmias to select proper candidates who could benefit from an implantable cardioverter defibrillator. Speckle-tracking echocardiography allows for a detailed assessment of cardiac mechanics, and strain imaging has repeatedly been shown to be a sensitive technique to identify systolic dysfunction unrecognized by ejection fraction. Several strain measures, including global longitudinal strain, regional strain, and mechanical dispersion, have consequently been proposed as potential markers of ventricular arrhythmias. In this review, we will provide an overview of the potential use of different strain measures in the context of ventricular arrhythmias.

Shifting from Left Ventricular Ejection Fraction to Strain Imaging in Aortic Stenosis

Adverse ventricular remodeling is an inflexion point of disease progression in aortic stenosis (AS) and a major determinant of prognosis. Intervention before irreversible myocardial damage is of paramount importance to sustain favorable post-operative outcomes. Current guidelines recommend a left ventricular ejection fraction (LVEF)-based strategy to determine the threshold for intervention in AS. However, LVEF has several pitfalls: it denotes the left ventricular cavity volumetric changes and it is not suited to detecting subtle signs of myocardial damage. Strain has emerged as a contemporary imaging biomarker that describes intramyocardial contractile force, providing information on subclinical myocardial dysfunction due to fibrosis. A large body of evidence advocates its use to determine the switch from adaptive to maladaptive myocardial changes in AS, and to refine thresholds for intervention. Although mainly studied in echocardiography, studies exploring the role of strain in multi-detector row computed tomography and cardiac magnetic resonance are emerging. This review, therefore, summarizes contemporary evidence on the role of LVEF and strain imaging in AS prognosis, aiming to move from an LVEF-based to a strain-based approach for risk stratification and therapeutic decision-making in AS.

Impact of arterial stiffness on echocardiographic myocardial work indices in patients with isolated bicuspid aortic valve

OBJECTIVE

Data related to the existence of left ventricular (LV) abnormalities in normal functional bicuspid aortic valve (BAV) disease is scarce. In addition, the impact of afterload and the involved mechanisms are unclear. In this work, we study the relationship between LV function assessed with myocardial work index (MWI) and arterial stiffness in a cohort of normal functioning BAV patients.

METHODS

In this study, we included a total of 38 consecutive patients with isolated BAV and 44 age- and gender-matched control subjects with tricuspid aortic valve. All participants underwent transthoracic echocardiography to assess conventional parameters and global longitudinal strain (GLS). In addition, MWI was measured by the noninvasive LV pressure-strain cycle method. Aortic pulse wave velocity (PWV) and wave reflection were evaluated by applanation tonometry.

RESULTS

The mean aortic PWV was significantly higher in BAV patients (6.4 ± 0.80, 7.02 ± 0.1.2, p = .01, respectively). LV-MWI related parameters such as global work efficiency (GWE) (96.261.69 and 97.051.27, p = .02) and global wasted work (GWW) (78.232.1 and 61.824.4, p = .01) were found significantly different between the BAV and control groups. However, global working index and global constructive working were not different between groups (1969 ± 259 and 2014 ± 278, p = .45; 2299 ± 290 and 2359 ± 345, p = .39, respectively). Multivariable ordinary least squares regression analysis revealed that BAV (ß = 8.4; 95% CI: 1.5-15.3; p = .04) and PVW (ß = 5.6; 95% CI: 0.7-10.5; p = .01) were significant predictors of GWV.

CONCLUSION

GWW is increased and GWE is decreased in patients with BAV compared with controls, and these changes are related to arterial stiffness. The relationship between aortic PWV and GWW may help to explain the exact mechanism of subclinical myocardial dysfunction in patients with isolated BAV.

Impact of gliflozins on cardiac remodeling in patients with type 2 diabetes mellitus & reduced ejection fraction heart failure: a pilot prospective study. GLISCAR Study

AIMS

Type 2 diabetes mellitus (T2DM) and heart failure are closely related entities and together determine an increased risk of mortality compared to patients suffering from only one of these diseases. Sodium-glucose co-transporter type 2 inhibitors (SGLT-2i) have shown favorable effects on cardiovascular system, particularly on heart failure. Aim of this study is to verify whether in individuals with T2DM and heart failure with reduced ejection fraction (HFrEF) treated with SGLT-2i, echocardiographic signs of favorable reverse remodeling follow longitudinal observation.

METHODS

31 subjects with T2DM and HFrEF were finally included. All individuals performed clinical visit, medical history, blood sampling and echocardiography at time 0' and at the end of 6 months of follow-up on SGLT-2i treatment.

RESULTS

After 6 months follow-up, left ventricular ejection fraction (LVEF), global work index (GWI), global work efficiency (GWE), global longitudinal strain (GLS), left atrial expansion index (LAEI) and total left atrial emptying fraction (TLAEF), tricuspid annular plane systolic excursion (TAPSE), septal thickness (St), pulmonary artery systolic pressures (PASP) and TAPSE/PASP ratio significantly improved.

CONCLUSIONS

Despite the lack of a favorable effect on cardiac remodeling, SGLT-2i treatment significantly improved LV systolic and diastolic function, left atrial (LA) reservoir and total emptying function, RV systolic function and pulmonary artery pressure.