Global Wasted Work Research Articles

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

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). 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. 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. 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.

Myocardial Work Appraisal in Transthyretin Cardiac Amyloidosis and Nonobstructive Hypertrophic Cardiomyopathy

Global left ventricular (LV) myocardial work (MW) indexes can be recognized at ultrasound imaging from the LV pressure/global longitudinal strain (GLS) loop analysis. A total of 4 indexes, global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), have been demonstrated to overcome the methodological limitations of GLS and provide useful information on myocardial dysfunction in some clinical settings. Although impaired MW indexes have been demonstrated in patients with transthyretin cardiac amyloidosis (ATTR) or with nonobstructive hypertrophic cardiomyopathy (HCM), there are no comparative studies at present. This study aimed to describe the characteristics of MW in both these clinical settings compared with patients with well-controlled hypertension (HTN). A total of 83 patients, 32 with ATTR (aged 70 ± 11years, 32% mutated, 68% wild-type, 72% men), 29 with HCM (aged 57 ± 17years), and 22 HTN controls (aged 56 ± 5.6years, 59% men) were prospectively enrolled at 2 clinical centers. All participants had New York Heart Association class I or II. Overall, the LV mass index was greater in both study groups than in HTN, whereas the LV ejection fraction (EF) was significantly lower in ATTR compared with other groups. Based on this finding, patients with ATTR were further divided into 2 subgroups: ATTR1 (LVEF ≤0.50), n=14 (44%) and ATTR2 (LVEF >0.50), n=18 (56%). Overall, the GWI and GCW were lower in all ATTR patients (mostly in ATTR1) than in the other groups (p <0.001), whereas only small differences in GWE and none in GWW were found among the groups. Of interest, the pairwise comparison and receiver operating characteristic analysis in preserved LVEF patients showed that GWI was a better discriminator of ATTR2 from HCM patients than GLS, with the cut-off value ≤1,419 mm Hg% (89% sensitivity; 55% specificity; p=0.013). In conclusion, MW analysis was confirmed to be a modern way to investigate myocardial function in patients with hypertrophic phenocopies. GWI and GCW were more impaired in patients with ATTR compared with HCM and HTN controls. Furthermore, this study likely revealed an additional discriminative value of GWI over GLS alone in preserved LVEF settings.

Left ventricular myocardial work for the prediction of postoperative outcomes in patients with bicuspid aortic stenosis.

Chronic elevation of left ventricular (LV) afterload contributes to adverse LV remodeling and myocardial impairment in bicuspid aortic valve (BAV) patients with severe aortic stenosis (AS). Incorporating LV afterload into global longitudinal strain (GLS) analysis, myocardial work facilitates early detection of LV dysfunction. The present study was to evaluate myocardial work in BAV patients with severe AS undergoing surgical aortic valve replacement (SAVR) and to evaluate its prognostic impact on early postoperative outcomes. Between January 2021 and March 2022, BAV patients with severe AS scheduled for SAVR were included and underwent comprehensive transthoracic echocardiography. Quantification of LV myocardial work was performed to obtain LV global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Clinical outcome was defined as a composite of major cardiovascular events including mortality, myocardial infarction, stroke, acute kidney injury, low cardiac output syndrome and vascular complications during hospitalization or within 30 days after operation. Among 103 BAV patients with severe AS undergoing SAVR (mean age of 65 ± 9 years, 57.3% male), 22 experienced postoperative major cardiovascular events. BAV patients with major cardiovascular events demonstrated lower LV GWI (P < 0.001) and GCW (P = 0.002) along with elder age (P = 0.030), decreased LVGLS (P = 0.026) and right ventricular longitudinal strain (P = 0.019), and higher prevalence of abnormal average E/e' ratio (P = 0.029) than those without major events. Decreased LV GWI and GCW was independently associated with the occurrence of major cardiovascular events (P < 0.01 for adjusted OR). Multivariable logistic regression model including LV GWI demonstrated superior power than the model including LVGLS and yielded best discrimination for BAV patients with and without major cardiovascular events during early postoperative period. Echocardiography-based LV myocardial work overcomes the limitations of LVGLS and presents as a promising novel index for the early detection of functional myocardial damage and the optimization of intervention timing among BAV patients with severe AS.

Indicators of global myocardial work of the left ventricle during exercise stress echocardiography in the diagnosis of stable coronary heart disease

Aim: To determine the possibility of identifying patients with significant coronary artery disease (CAD) by evaluation of the global left ventricular (LV) myocardial work indicators by constructing pressure-strain loops during exercise stress echocardiography.Material and Methods. The study included 136 patients aged 36 to 84 years, of which 97 (71%) men, with suspected or previously confirmed CAD, who underwent stress echocardiography on the treadmill according to the Bruce protocol. LV myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW) and global myocardial work efficiency (GWE) were evaluated using the technique of constructing pressure-strain loops at rest and at peak exercise. All patients underwent selective coronary angiography, according to the results of which they were divided into 3 groups: 51 patients without coronary artery lesions – the control group, 57 patients with single-vessel CAD and 28 patients with multi-vessel CAD. Significant lesion was defined as ≥ 70% artery luminal narrowing. All tests were two-sided and P-values &lt; 0.05 were considered statistically significant.Results. Compared with the control group, patients with single-vessel CAD at rest had significantly less GWE and more GWW. In these patients GWI, GCW and GWE at peak exercise were significantly lower, and GWW was significantly higher. In patients with multi-vessel CAD, all global LV myocardial work indicators significantly differed from the control group both at rest and at peak exercise. The optimal cutoff value of GWI at peak exercise to predict significant CAD was 2553 mmHg% with a sensitivity of 62% and a specificity of 95% (AUC 0.79 ± 0.05, p &lt; 0.001).Conclusions. The evaluation of global LV myocardial work indicators by constructing pressure-strain loops can be used in exercise stress echocardiography to improve the selection of patients requiring coronary intervention.

Determinants of myocardial work indices in women.

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. 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. 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. 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. 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.

Noninvasive left ventricular pressure-strain myocardial work in patients with well-functioning bicuspid aortic valves and aortic dilation: a preliminary study.

Noninvasive left ventricular pressure-strain myocardial work (MW) is a novel method for evaluating left ventricular function that integrates myocardial deformation and afterload and has certain advantages over global longitudinal strain (GLS). The study aimed to analyze MW in patients with well-functioning bicuspid aortic valve (BAV) and explore the influences of aortic dilation and arterial stiffness on left ventricular function. A total of 104 patients with well-functioning BAVs and 50 controls were enrolled in our study. Global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE), GLS, and aortic stiffness index were measured. Based on the ascending aortic diameter, patients with BAV were divided into 3 subgroups (nondilated, mildly dilated, and moderately dilated). GWI, GCW, GWW, and aortic stiffness index were significantly increased (P<0.001, P=0.023, P<0.001, and P<0.001, respectively), while GWE and GLS were significantly decreased among patients with BAV compared with controls (all P values <0.001). Patients with BAV and mildly and moderately dilated aortas had an increased GWW and aortic stiffness index but a decreased GWE compared with patients with BAV and nondilated aortas (all P values <0.05); meanwhile, GCW and GLS did not differ among the BAV subgroups (all P values >0.05). GWI was elevated in patients with BAV and moderately dilated aortas compared with patients with BAV and nondilated aortas (P<0.05). On multivariable analysis, the aortic stiffness index was an independent influencer of GWI, GCW, GWW, and GWE (P=0.025, P=0.049, P<0.001, and P=0.001, respectively). The aortic diameter was highly correlated with the aortic stiffness index (r=0.863; P<0.001). MW could assess early myocardial impairment in patients with well-functioning BAV. MW may help to differentiate the detrimental effect of aortic dilation on left ventricular function, whereas GLS may not.

Evaluation of global and regional myocardial work in hypertrophic cardiomyopathy patients by left ventricular pressure-strain loop

ObjectiveThis study aimed to investigate the value of left ventricular (LV) press-strain loop (PSL) in evaluating global and regional myocardial work (MW) in hypertrophic cardiomyopathy (HCM) patients.MethodsA total of 30 HCM patients with interventricular septum hypertrophy (HCM group) and 35 healthy subjects (control group) were selected from First Hospital of Qinhuangdao. The general clinical data and conventional ultrasound parameters of two groups were acquired. The MW parameters were analyzed using LV PSL. The regional MW parameters in the HCM group were compared between ventricular septum and the free walls of left ventricle.ResultsThe epicardial adipose tissue thickness of the HCM group was significantly greater than that of the control group (P < 0.05). Global work efficiency was significantly reduced, while global wasted work was increased in patients with HCM compared with controls (all P < 0.05). The HCM group was compared in the group, to be specific, in the HCM group, the work index, the work efficiency, and the longitudinal strain on the interventricular septum were lower than those on the free wall (all P < 0.05).ConclusionPSL is more effective than LVEF in assessing left ventricular systolic function in HCM and is able to quantify regional myocardial work in the ventricular septum in HCM patients with preserved LVEF, suggesting a novel idea for clinical diagnosis and assessment.

Left bundle branch pacing preserved left ventricular myocardial work in patients with bradycardia.

Left bundle branch pacing (LBBP) is an emerging physiological pacing modality. Left ventricular (LV) myocardial work (MW) incorporates afterload and LV global longitudinal strain to estimate global and segmental myocardial contractility. However, the effect of LBBP on LV MW remains unknown. This study aimed to evaluate the impact of LBBP on LV MW in patients receiving pacemaker for bradyarrhythmia. We prospectively enrolled 70 bradycardia patients with normal LV systolic function receiving LBBP (n = 46) and non-selective His-bundle pacing (NS-HBP) (n = 24). For comparative analysis, patients receiving right ventricular pacing (RVP) (n = 16) and control subjects (n = 10) were enrolled. Two-dimensional speckle tracking echocardiography was performed. The LV pressure-strain loop was non-invasively constructed to assess global LV MW. After 6-month follow-up, LBBP group (with >40% ventricular pacing during 6 months) had shorter peak strain dispersion (PSD) compared with RVP group, and higher LV global longitudinal strain compared with RVP group and NS-HBP group, but had no difference in left intraventricular mechanical dyssynchrony, including septal-to-posterior wall motion delay and PSD, compared with NS-HBP group. During ventricular pacing, LBBP group had higher global MW index (GWI) (2,189 ± 527 vs. 1,493 ± 799 mmHg%, P = 0.002), higher global constructive work (GCW) (2,921 ± 771 vs. 2,203 ± 866 mmHg%, P = 0.009), lower global wasted work (GWW) (211 ± 161 vs. 484 ± 281 mmHg%, P < 0.001) and higher global MW efficiency (GWE) (91.4 ± 5.0 vs. 80.9 ± 8.3%, P < 0.001) compared with RVP group, and had lower GWW (211 ± 161 vs. 406 ± 234 mmHg%, P < 0.001) and higher GWE (91.4 ± 5.0 vs. 86.4 ± 8.1%, P < 0.001) compared with NS-HBP group. In this study we found that in patients with mid-term (6-month) high ventricular pacing burden (>40%), LBBP preserved more LV MW compared with NS-HBP and RVP. Further studies are warranted to assess the association between LV MW and long-term clinical outcomes in LBBP with high ventricular pacing burden.

Assessment of left ventricular function in patients with type 2 diabetes mellitus by non-invasive myocardial work.

Diabetes mellitus (DM) is a chronic disease that poses a serious risk of cardiovascular diseases. Therefore, early detection of impaired cardiac function with non-invasive myocardial imaging is critical for improving the prognosis of patients with DM. This study aimed to assess the left ventricular (LV) function in patients with type 2 diabetes mellitus (T2DM) by non-invasive myocardial work technique. In all, 67 patients with T2DM and 28 healthy controls were included and divided into a DM group and a control group. Two-dimensional dynamic images of apical three-chamber view, apical two-chamber view, and apical four-chamber view were collected from all subjects, consisting of at least three cardiac cycles. LV myocardial strain parameters, including global longitudinal strain (GLS) and peak strain dispersion (PSD), as well as myocardial work parameters, including global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were obtained and analyzed. A total of 15 subjects were randomly selected to assess intra-observer and inter-observer consistency of myocardial work parameters and strain parameters, which showed excellent results (intra-class correlation coefficients: 0.856 - 0.983, P<0.001). Compared with the control group, the DM group showed significantly higher PSD (37.59 ± 17.18 ms vs. 27.72 ± 13.52 ms, P<0.05) and GWW (63.98 ± 43.63 mmHg% vs. 39.28 ± 25.67 mmHg%, P<0.05), and lower GWE (96.38 ± 2.02% vs. 97.72 ± 0.98%, P<0.001). Furthermore, the PSD was positively correlated with GWW (r = 0.565, P<0.001) and negatively correlated with GWE (r = -0.569, P<0.001). Uncoordinated LV myocardial strain, higher GWW, and lower GWE in patients with T2DM may serve as indicators for the early assessment of cardiac impairment in T2DM.

Association between epicardial adipose tissue and myocardial work by non-invasive left ventricular pressure-strain loop in people with suspected metabolic syndrome

Given the inconsistent results on the prognostic significance of epicardial adipose tissue (EAT), the purpose of the present study was to investigate the association of EAT thickness and myocardial work by non-invasive left ventricular pressure-strain loop in people with suspected metabolic syndrome (MS). A total of 194 participants imaged with echocardiography were evaluated. In accordance with the median EAT thickness, MS patients fell into thin EAT group and thick EAT group. Conventional echocardiographic parameters, global longitudinal strain (GLS) and the global myocardial work parameters obtained by pressure-strain loop analysis, comprising the global work index (GWI), global work efficiency (GWE), global constructive work (GCW) and global wasted work (GWW) were compared between the two groups. In comparison with the thin EAT group, thick EAT group achieved significantly higher values in interventricular septal thickness, end-diastolic left ventricular posterior wall thickness, left ventricular mass index and GWW (p < 0.05). while the absolute value of GLS, GWI, GCW, and GWE were notably lower in the thick EAT group (p < 0.001). EAT thickness showed a significant correlation with GWI and GCW (r = − 0.328, p = 0.001; r = − 0.253, p = 0.012), and also independently correlated with GWI and GCW in the multivariate regression analysis (β = − 0.310, p = 0.001; β = − 0.199, p = 0.049). EAT thickness is associated with left ventricular myocardial function in subjects with suspected metabolic syndrome, independently of other risk factors. Further studies are supposed to ensure the causal associations and related mechanisms.

Interrelationships between Peak Strain Dispersion, Myocardial Work Indices, Isovolumetric Relaxation and Systolic-Diastolic Coupling in Middle-Aged Healthy Subjects.

In echocardiography, peak strain dispersion (PSD) is the standard deviation of the time to peak longitudinal strain for each left ventricular (LV) segment during systole. It assesses the coordination and synchrony of LV segment contractility. Global work efficiency (GWE) and global wasted work (GWW) quantify LV myocardial work and, if impaired, the coupling between LV systolic contraction and early relaxation. Isovolumetric relaxation (IVRT) measures the duration of initial LV relaxation, while the ratio of early diastolic recoil to systolic excursion (E'VTI/S'VTI) describes systolic-diastolic coupling. We evaluated these parameters in 69 healthy subjects and found that PSD correlated negatively with GWE (r = -0.49, p < 0.0001) and E'VTI/S'VTI (r = -0.44, p = 0.0002), but positively with GWW (r = 0.4, p = 0.0007) and IVRT (r = 0.53, p < 0.0001). GWE correlated negatively with GWW (r = -0.94, p < 0.0001) and IVRT (r = -0.30, p = 0.0127), but positively with E'VTI/S'VTI (r = 0.3, p = 0.0132). In addition, E'VTI/S'VTI was negatively correlated with GWW (r = -0.35, p = 0.0032) and IVRT (r = -0.36, p = 0.0024). These associations remained significant after adjustment for sex, age and LV mass index of the subjects. In conclusion, there is an interaction between measures of LV asynchrony, myocardial work, diastolic function and its systolic-diastolic coupling in middle-aged healthy subjects. The clinical value of these interactions requires further investigation.

Myocardial work in patients with heart failure and ischemic cardiomyopathy according to the mode of coronary revascularization

BackgroundThe association of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) on myocardial function, as reflected in myocardial work (MyW) parameters, in patients with ischemic cardiomyopathy and heart failure (HF) is unknown. MethodsWe analyzed data from 68 patients who were hospitalized with chronic HF due to ischemic cardiomyopathy and stratified them according to the mode of revascularization. All patients underwent a 2D speckle tracking echocardiography exam performed by the same expert sonographer and had complete MyW data including global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). ResultsThe mean age of patients was 70 ± 10 years and 86.8% were men. The mean left ventricular ejection fraction (LVEF) in overall cohort was 31.6 ± 9.5%. Both subgroups did not significantly differ in terms of baseline LVEF, comorbidities, and pharmacotherapy. Compared with those who received PCI, patients revascularized with CABG had significantly greater GWI (821 vs. 555 mmHg%, p = 0.002), GCW (1101 vs. 794 mmHg%, p = 0.001), GWE (78 vs. 72.6%, p = 0.025), and global longitudinal strain (−8.7 vs. −6.7%, p = 0.004). Both patient subgroups did not significantly differ with respect to GWW (273 vs. 245 mmHg%, p = 0.410 for CABG and PCI, respectively) and survival during the median follow-up of 18 months (log-rank p = 0.813). ConclusionPatients with HF and ischemic cardiomyopathy revascularized with CABG had greater myocardial work performance when compared with those revascularized with PCI. This might suggest a higher degree of functional myocardial revascularization associated with the CABG procedure.

Incremental value of non-invasive myocardial work for the evaluation and prediction of coronary microvascular dysfunction in angina with no obstructive coronary artery disease.

Evidence suggests that patients suffering from angina with no obstructive coronary artery disease (ANOCA) experience coronary microvascular dysfunction (CMD). We aimed to understand the diagnosis value of noninvasive myocardial work indices (MWIs) with left ventricular pressure-strain loop (LV PSL) by echocardiography in ANOCA patients with CMD. 97 patients with ANOCA were recruited. All subjects underwent standard echocardiography with traditional ultrasound parameters, two-dimensional speckle-tracking echocardiography with global longitudinal strain (GLS), LV PSL with MWIs include global work index (GWI), global constructive work (GCW), global waste work (GWW) and global work efficiency (GWE). In addition, all enrolled cases underwent high-dose adenosine stress echocardiography (SE) with coronary flow velocity reserve (CFVR). CMD was defined as CFVR <2.0. Of the 97 patients with ANOCA, 52 were placed in the CMD group and 45 in the control group. GWI and GCW were decreased significantly in the CMD group compared with the control group (P < 0.001 for both). GWI and GCW were moderately correlated with CFVR (r = 0.430, P < 0.001 and r = 0.538, P < 0.001, respectively). In the multiple logistic regression analyses, GCW was identified as the only independent echocardiography parameter associated with CMD after adjusting for age and baseline APV [OR (95%CI) 1.009 (1.005-1.013); P < 0.001]. Moreover, the best predictor of CMD in patients with ANOCA using receiver operating characteristic (ROC) curve was GWI and GCW, with an area under the curve (AUC) of 0.800 and 0.832, sensitivity of 67.3% and 78.8%, specificity of 80.0% and 75.6%, respectively. MWIs with LV PSL is a new method to detect LV systolic function noninvasively in ANOCA patients with CMD.

Characterizing stenosis severity of coronary heart disease by myocardial work measurement in patients with preserved ejection fraction.

The novel echocardiographic parameter of myocardial work incorporates left ventricular pressure into the assessment of left ventricular systolic function and thereby corrects for afterload. We sought to investigate the diagnostic value of myocardial work to identify different grades of stenosis severity in coronary heart disease (CHD) patients with preserved left ventricular ejection fraction and without regional wall motion abnormalities. One hundred and seventeen consecutive subjects with preserved ejection fraction referred for coronary angiography were randomized and prospectively included in this study. Forty-six in the control group, and 25, 24, and 22 in each of the grade-1, grade-2, and grade-3 CHD groups as classified by the Gensini score. The following indices of myocardial work were assessed with a Vivid E95 Version 203 instrument: global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE). Both GWI (P<0.001) and GCW (P<0.001) decreased significantly in CHD grade-1, increased slightly in CHD grade-2 compared with CHD grade-1, and decreased significantly in CHD grade-3. GWW (P<0.001) increased significantly from CHD grade-1 to CHD grade-3, while GWE (P<0.001) decreased significantly from CHD grade-1 to CHD grade-3. Receiver operating characteristic curves analysis revealed good discrimination between the control group and CHD grade-3 for GWI [area under the curve (AUC): 0.810; 95% confidence interval (CI): 0.691-0.930], GCW (AUC: 0.758; 95% CI: 0.631-0.885), GWW (AUC: 0.754; 95% CI: 0.624-0.885) and GWE (AUC: 0.817; 95% CI: 0.709-0.926). The assessment of intraobserver and interobserver variability in the MW echocardiographic data documented good interclass correlation coefficients (all >0.85). Myocardial work incorporates left ventricular pressure into the assessment of left ventricular systolic function and thereby corrects for afterload. It identifies patients with incipient left ventricular dysfunction caused by chronic ischemia due to CHD. A gradual worsening of myocardial work parameters was observed when comparing patients with higher degrees of stenosis severity. Therefore, adding myocardial work when evaluating patients with suspected CHD may help increase diagnostic accuracy.

Assessing Myocardial Strain and Myocardial Work as a Marker for Hypertensive Heart Disease: A Meta-Analysis.

The main objective of this study was to determine whether myocardial strain and myocardial work are altered in hypertension and whether the strain is independent of hypertension-induced left ventricular hypertrophy. Two systematic literature searches were conducted using Medline and EMBASE through to June 30, 2022. In the first, search terms left ventricular strain or speckle tracking AND hypertension and left ventricular hypertrophy were used in conjunction with Boolean operators to identify articles reporting left ventricular strain in patients with hypertension. In the second, the terms Global cardiac or myocardial work AND hypertension were used to identify articles. Publication bias was assessed by examination of funnel plots and calculation of the Failsafe N and Duval and Tweedie's Trim and fill. The results were presented as Forrest plots. Global longitudinal strain (GLS) was significantly lower in patients with hypertension compared to those without hypertension with a mean difference of 2.0 0.1 (standard error of mean(SEM)) in the fixed effect model. Global circumferential strain (GCS) was significantly lower in hypertension. The mean difference between the hypertensive and non-hypertensive groups was 1.37 0.17. Global radial strain (GRS) was significantly (p 0.05) greater in hypertension. However, this difference was significant in only 3 and of borderline significance in 3 of 14 studies where GRS was measured. The mean difference between the hypertensive and non-hypertensive groups was 1.5 0.5 using the fixed effects model. There was a significant relationship between GLS and GCS as well as between GCS and GRS but no significant relationship between GLS and GRS. There was no significant difference in left ventricular ejection fraction (LVEF) between the hypertension and no hypertension groups. There was no significant relationship between LVEF and either GLS or GCS but a significant negative correlation was found between LVEF and GRS. GLS was further reduced in persons with hypertension and left ventricular hypertrophy (LVH) compared to hypertension without LVH. In contrast, there were no or minimal differences in GCS and GRS for individuals with hypertension and LVH compared to those without LVH. Global myocardial work index (GWI) and Global constructive work (GCW) were significantly greater in patients with hypertension compared to controls. Global wasted work (GWW) indicated significantly less wasted work in controls compared to hypertension. In contrast, Global work efficiency (GWE) was significantly lower in hypertension compared to the control. There was a significant reduction in GLS and GCS in hypertension while GRS was increased. The reduction in GLS in hypertension was not dependent on the presence of LVH. GLS was further reduced in persons with hypertension when LVH was present. In contrast, there were no or minimal differences in GCS and GRS for individuals with LVH compared to those without LVH. GLS was independent of left ventricle (LV) ejection fraction. GWI, GCW and GWW were greater in hypertension while GWE was lower in hypertension compared to controls. These data support the contention that GLS and indices of global work are early markers of hypertensive heart disease.

Non-Invasive Myocardial Work Indices in Infants Born to Mothers With Diabetes in Pregnancy.

This study used echocardiography to investigate non-invasive myocardial work (MCW) indices in infants born to mothers with diabetes mellitus (DM) in pregnancy (gestational DM: GDM), including those diagnosed under novel classification criteria and those with pre-existing DM. This single-centered, retrospective study included 25 infants born to mothers with GDM (termed "infant with GDM"), which was diagnosed by oral glucose tolerance test results during pregnancy or the presence of diabetes before the current pregnancy. We evaluated the relationship between the infant's MCW, such as global constructive work (GCW), global work index (GWI), global work efficiency (GWE), and global wasted work (GWW), and the mother's GDM maximal HbA1c during pregnancy. HbA1c level in GDM significantly negatively correlated with GWI* (r=-0.565) and GCW* (r=-0.641). In infants with GDM, GWI and GCW were significantly higher with <6.5% HbA1c than in those with >6.5% HbA1c GDM; however, the specific-layer global longitudinal strain analyses did not show any significant differences between the groups. The pressure-strain loop in infants with >6.5% HbA1c in GDM tended to be smaller than in those infants with <6.5% HbA1c GDM. The hyperglycemic environment of GDM leads to impaired MCW in the infants. MCW is useful for screening for cardiac illnesses among infants with GDM. Appropriate maternal blood glucose management while maintaining HbA1c <6.5% might be beneficial for the cardiac performance of infants with GDM.

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

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. 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. 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.

Prognostic value of left ventricular myocardial work indices in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement.

Left ventricular myocardial work (LVMW) is a novel echocardiographic-based method to assess left ventricular (LV) function using pressure-strain loops taking into account LV afterload. The aim of this study was to evaluate the prognostic value of LVMW indices in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). LV global work index (LV GWI), LV global constructive work (LV GCW), LV global wasted work (LV GWW), and LV global work efficiency (LV GWE) were calculated in 281 patients with severe AS [age 82, interquartile range (IQR) 78-85 years, 52% male] before the TAVR procedure. LV systolic pressure was derived non-invasively by adding the mean aortic gradient to the brachial systolic pressure to adjust for afterload and calculate LVMW indices. Overall, the average LV GWI was 1872 ± 753 mmHg%, GCW 2240 ± 797 mmHg%, GWW 200 (IQR 127-306) mmHg%, and GWE 89 (IQR 84-93)%. During a median follow-up of 52 (IQR 41-67) months, 64 patients died. While LV GWI was independently associated with all-cause mortality (Hazard ratio per-tertile-increase 0.639; 95%CI 0.463-0.883; P = 0.007), LV GCW, GWW, and GWE were not. When added to a basal model, LV GWI yielded a higher increase in predictivity compared to the left ventricular ejection fraction as well as LV global longitudinal strain and LV GCW, and also across the different haemodynamic categories (including low-flow low-gradient) of AS. LV GWI is independently associated with all-cause mortality in patients undergoing TAVR and has a higher prognostic value compared to both conventional and advanced parameters of LV systolic function.

Myocardial Work in Apical Hypertrophic Cardiomyopathy

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-apical HCM (non-ApHCM). This study aimed to (1) evaluate myocardial work indices in patients with ApHCM compared to 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 (CMR). 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 (GWW), and global work efficiency (GWE). We evaluated available CMR 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. Median GLS (-11% vs -18%, p < .001), GWI (966 mmHg% vs 1803 mmHg%, p < .001), and GCW (1050 mmHg% vs 1988 mmHg%, p < .001) were significantly impaired in patients with ApHCM compared to those with non-ApHCM. Increasing NT-ProBNP, abnormal ultra-sensitive troponin, and increasing maximal LV wall thickness were significantly associated with reduced GWI and GCW in patients with ApHCM (p < .05). GCW had only modest accuracy (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. Myocardial work indices are significantly impaired in patients with ApHCM compared to those with non-ApHCM and correlate with important clinical variables. GLS, GWI, and GCW are more strongly predictive of fibrosis in patients with non-ApHCM than ApHCM.

Association between resting myocardial work indices and stress myocardial perfusion in patients with angina and non-obstructive coronary artery disease.

Myocardial work (MW) indices and longitudinal strain (LS) are sensitive markers of early left ventricular systolic dysfunction. Stress computed tomography myocardial perfusion imaging (CT-MPI) can assess early myocardial ischemia. The association between resting MW indices and stress myocardial perfusion remains unclear. This study compares resting MW indices with LS to assess stress myocardial perfusion in angina patients with non-obstructive coronary artery disease (CAD). Eighty-four patients who underwent resting echocardiography, coronary computed tomography angiography, and stress CT-MPI were reviewed. Seventeen myocardial segments were divided into three regions according to the epicardial coronary arteries. Global indices included global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Regional indices included regional longitudinal strain (RLS), regional work index (RWI), and regional work efficiency (RWE). Reduced global perfusion was defined as an average stress myocardial blood flow (MBF) <116 mL/100 mL/min for the whole heart. Reduced regional perfusion was defined as an average stress MBF <116 mL/100 mL/min for the coronary territories. No patients demonstrated obstructions in the epicardial coronary arteries (stenosis diameter <50%). The MW indices and LS were compared. Receiver operating characteristic curves were constructed and logistic regression analyses were used to investigate the predictors of reduced myocardial perfusion. Patients with reduced stress perfusion demonstrated reduced GLS, GWI, GCW, and GWE (P<0.05) and increased GWW (P<0.05). After adjustment for age and sex, GWE was still independently associated with reduced myocardial perfusion (odds ratio =0.386, 95% confidence interval: 0.214-0.697; P<0.05). Receiver operating characteristic curves reflected the good diagnostic ability of GWE and its superiority to GLS (area under the curve: 0.858 vs. 0.741). The optimal cutoff GWE value was 95% (sensitivity, 70%; specificity, 90%). Regions with lower stress perfusion showed lower RLS, RWI, and RWE (P<0.05). The optimal cutoff value of RWE for predicting reduced regional perfusion was 95%, with an area under the curve of 0.780, a sensitivity of 62%, and a specificity of 83%. Resting MW indices perform well in assessing global and regional stress myocardial perfusion in angina patients with non-obstructive CAD, and GWE is superior to GLS in the global evaluations.