Left Ventricular Remodeling and Myocardial Work: Results From the Population-Based STAAB Cohort Study

The impact of hypercortisolism beyond metabolic syndrome on left ventricular performance: a myocardial work analysis

BACKGROUND AND AIMS

Endogenous Cushing's syndrome (CS) is characterized by an unfavorable cardiovascular (CV) and metabolic risk profile, but the potential adverse effects of hypercortisolism on myocardial function are not well known. Myocardial Work analysis is a new echocardiographic method that utilizes left ventricular pressure-strain loops to quantify cardiac performance independent of afterload.

METHODS AND RESULTS

In a cross-sectional analysis, we compared four groups: patients with overt endogenous CS (n = 31, mean age 47 ± 12 years, 71% women), patients with endogenous CS in long-term remission after medical cure (CS-LTR; n = 49, 53 ± 12 years, 78% women), healthy subjects (n = 439; 49 ± 11 years, 57% women), and individuals with metabolic syndrome (n = 305, 59 ± 10 years, 37% women). Both CS patient groups exhibited a CV risk pattern and metabolic profile worse than healthy subjects but better than individuals with metabolic syndrome. Analyses adjusted for sex and age revealed higher Wasted Work both in overt CS (median; quartiles: 105 mmHg%; 74, 147) and CS-LTR (97 mmHg%; 69, 158), respectively, when compared to healthy individuals (75 mmHg%; 54, 109, p < 0.01) or individuals with metabolic syndrome (95 mmHg%, 65, 136, p < 0.05), resulting in compromised Work Efficiency (p < 0.05).

CONCLUSION

Left ventricular performance is compromised in overt CS beyond alterations found in individuals with metabolic syndrome sharing equal CV risk factors and remains so despite biochemical remission during the LTR period. Myocardial Work analysis is suited to detect the subtle yet clinically relevant differences between different phenotypes of myocardial involvement.

Right ventricular myocardial work: proof-of-concept for the assessment of pressure-strain loops of patients with pre-capillary pulmonary hypertension

BACKGROUND

Right ventricular myocardial work (RVMW) assessed by transthoracic echocardiography allows to study the right ventricular (RV) function using RV pressure-strain loops. The assessment of these novel indexes of RVMW has not yet been exten sively studied, namely in pre-capillary pulmonary hypertension (PH) population.

OBJECTIVES

to evaluate the relationship between RVMW and invasive indices of right heart catheterization (RHC) in a cohort of patients with group I and group IV PH and to compare with a control group without PH.

METHODS

A prospective registry of pre-capillary PH patients was used and compared with a control group without PH. In both groups, patients underwent same day RHC and echocardiographic assessment. Dedicated software for left ventricle myocardial work was used for the RV. RV global work index (RVGWI) was calculated as the area of the RV pressure-strain loops. From RVGWI, RV global constructive work (RVGCW), RV global wasted work (RVGWW), and RV global work efficiency (RVGWE) were estimated.

RESULTS

25 pts were included: 17 pts with PH were compared with 8 pts without PH. RVGWI, RVGCW and RVGWW were significantly higher in PH patients than in controls (p < 0,05), while RVGWE was significantly lower (p < 0,05). Significant correlations were found between mean pulmonary artery pressure, cardiac index, venous oxygen saturation, NT-proBNP and RVGCW, RVGWW and RVGWE; between pulmonary vascular resistance, cardiac output, right ventricular stroke work and RVGWI, RVGCW, RVGWW and RVGWE; between stroke volume and RVGWW and RVGWE; between pulmonary artery pulsatility index and RVGWI, RVGCW and RVGWW; between RA pressure and RVGWE.

CONCLUSIONS

Patients with pre-capillary PH present significantly higher RVGWI, RVGCW and RVGWW and lower RVGWE than patients without PH. Echocardiographic RVMW-derived indexes show significant correlation with invasive measurements and NT-proBNP. Larger studies are needed to assess the prognostic value of these novel indexes.

Diagnostic value of combined maternal cardiac work and fetoplacental circulation parameters in detecting fetal intrauterine hypoxia in preeclamptic women

To investigate the correlation between fetoplacental circulation and maternal left ventricular myocardial work (MW) parameters in patients with preeclampsia (PE) and the prediction of fetal hypoxia. Seventy-eight PE patients (PE group) were assigned to intrauterine-hypoxia (27) and non-intrauterine-hypoxia (51) groups, and 45 healthy pregnant women were controls. The receiver operating characteristic (ROC) curve evaluated the diagnostic efficacy of each parameter for fetal intrauterine hypoxia. Relative to the controls and the non-intrauterine-hypoxia group, the umbilical artery (UA) S/D, PI, and RI, as well as the global work index (GWI), global effective work, and global ineffective work, increased in the PE group and intrauterine-hypoxia group (P < 0.05), respectively, while the cerebroplacental ratio (CPR) and global work efficiency decreased (P < 0.05). Relative to the controls group, the middle cerebral artery S/D, PI, and RI decreased in the PE group (P < 0.05). Correlation analysis showed that the fetoplacental circulation parameters were correlated with MW parameters (P < 0.05), and CPR achieved the highest correlation. ROC curves showed that UA-S/D, combined with GWI, produced the highest predictive value for fetal hypoxia in PE patients. There was a linear correlation between MW parameters and fetoplacental parameters, and CPR showed the highest correlation with MW. UA-S/D, combined with GWI, exhibited optimal diagnostic efficacy in predicting fetal intrauterine hypoxia in PE patients.

TUM4Health, a holistic student health promotion program. Screening of cardiovascular risk factors in university students

Cardio Vascular risk prevention in Germany has a gap between the ages of 20 and 30 years. We established a program for risk group identification in students and analyzed the screenings according to the ACCF/AHA Stages and NYHA functional classification. In a cross-sectional design, 596 participants completed a sports medical and motor performance check-up. We found 6% of the female subgroup in an underweight status. Low blood pressure in 5% of the male and 10% of the female group. Elevated blood pressure in 27% of the male and 12% of the female subgroup. According to ACCF/AHA classification, a percentage of 25.7% were clustered in Stage A, defined as having a high risk for heart failure (HF). Stage B consisted of participants with structural heart disease but without symptoms of HF, the prevalence of this group was 3.2%. In Stage C we assigned 0.7%, respectively four participants, with structural heart disease and prior symptoms (NYHA Stage C1 and C2). Screenings sensitize CV risk factors and detect HF risks at an early age; for freshmen at universities it seems to be the perfect time and place for secondary prevention. The gap in risk prevention can be closed, at least for students, who are an economically important target group. Moreover, we found a higher prevalence of Stage C in the sports-related study population compared to other studies. The risk for HF could be elevated in sports-related faculties. The high prevalence of underweight participants, especially in the female subgroup could also be a specific problem in sports-related groups. Even if not related to CV risks, the awareness of being underweight in combination with offers for a lifestyle change can prevent risks in the future. The same applies to low blood pressure in the female subgroup.

Clinical Applications of Myocardial Work in Echocardiography: A Comprehensive Review

Left ventricular (LV) global longitudinal strain (GLS) has recently garnered attention as a reliable and objective method for evaluating LV systolic function. One of the key advantages of GLS is its ability to detect subtle abnormalities even when the ejection fraction (EF) appears to be preserved. However, it is important to note that GLS, much like LVEF, is significantly influenced by load conditions. In recent years, researchers and clinicians have been exploring noninvasive myocardial work (MW) quantification as an innovative tool for assessing myocardial function. This method integrates measurements of strain and LV pressure, providing a comprehensive evaluation of the heart's performance. Notably, MW offers an advantage over GLS and LVEF because it provides a load-independent assessment of myocardial performance. The implementation of commercial echocardiographic software that facilitates the noninvasive calculation of MW has significantly broadened the scope of its application. This advanced technology is now being utilized in multiple clinical settings, including ischemic heart disease, valvular diseases, cardiomyopathies, cardio-oncology, and hypertension. One of the fundamental aspects of MW is its correlation with myocardial oxygen consumption, which allows for the assessment of work efficiency. Understanding this relationship is crucial for diagnosing and managing various cardiac conditions. The aim of this review is to provide an overview of the noninvasive assessment of myocardial by echocardiography, from basic principles and methodology to current clinical applications.

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.

Impact of Hypertension on Left Ventricular Geometry and Diastolic Function in Africa: Results from the Population-Based TAnve Health (TAHES) Cohort Study

High blood pressure leads to morphologic changes and functional alterations of the myocardial structure. Transthoracic echocardiography is of great clinical interest to evaluate these alterations, using reference values proposed by the American Society of Echocardiography/European Association of Cardiovascular Imaging, largely based on studies in Caucasian Whites. We aimed to assess the impact of hypertension on echocardiographic parameters in a sub-Saharan African community, using ethnic-specific reference values. This study is part of the TAnve HEalth Study, a population-based prospective cohort study initiated in 2015 in the district of Tanve, Republic of Benin. Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or currently taking antihypertensive medications. All participants had a transthoracic echocardiography. The patterns of diastolic dysfunction and left ventricular (LV) geometry were defined from 486 subjects in the cohort, free from cardiovascular disease, diabetes, and hypertension. Of all participants, 318 (65% women, median age 48 years) had hypertension. Systolic blood pressure correlated significantly (p <0.0001) with LV mass (r = 0.28), wall thickness (r = 0.25), isovolumic relaxation time (r = 0.27), E/A ratio (r = -0.35), lateral e' velocity (r= -0.41), and E/E' ratio (r = 0.39). Ventricular geometry was normal in only 22% of participants with hypertension when using the American Society of Echocardiography/European Association of Cardiovascular Imaging reference values, versus 69% with ethnic-specific reference ranges. The severity of hypertension was associated with ventricular geometry abnormalities. The prevalence of diastolic dysfunction was 14.5% (confidence interval 10.6% to 18.4%), including relaxation impairment (9%) and pseudonormal pattern (6%). Thus, correct assessment of the repercussions of hypertension on LV geometry in Black Africans requires ethnic-specific reference values.

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.

Exercise stress cardiac magnetic resonance imaging in the assessment of induced cardiovascular responses in cardiac patients: a scoping review protocol

OBJECTIVE

This scoping review will describe cardiac magnetic resonance imaging testing protocols used in combination with exercise (Ex-CMR) to assess cardiovascular responses. The review will document the advantages and limitations of these protocols in cardiac patients.

INTRODUCTION

Ex-CMR characterizes the heart, differentiating between normal and pathological cardiac remodeling with considerable accuracy. However, there is no review detailing existing Ex-CMR protocols. This is particularly important since not all Ex-CMR protocols seem to induce enough stress to effectively characterize cardiac remodeling, hence the need for a review to report on the current evidence.

INCLUSION CRITERIA

This review will consider studies that use Ex-CMR testing protocols to assess cardiovascular responses, revealing cardiac remodeling in patients whose age at the time of the study was ≥ 18 years.

METHODS

The review will be conducted in accordance with the JBI methodology for scoping reviews and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The following databases will be searched: PubMed, Embase, ISI Web of Science, OpenGrey, Grey Matters, and OAlster. Articles in English and French will be included and there will be no limitation set for the date of publication. Data will be extracted from papers included in the scoping review by 2 independent reviewers and will be classified in summary tables.

REVIEW REGISTRATION

Open Science Framework https://osf.io/hvn75/?view_only=f6cf8fc2112e498d89c39639dbce70d1 .

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.

Myocardial work: The analytical methodology and clinical utilities

The evaluation of left ventricular (LV) systolic function is an essential part of the clinical practice of cardiology. Although left ventricular ejection fraction (LVEF) is the most validated and widely used parameter, it has fundamental limitations. LV strain is more sensitive to detect subtle myocardial dysfunction when LVEF was preserved, but it is load-dependent. Invasive left ventricular pressure-volume loop (LV-PVL) is the reliable standard to evaluate cardiac function, but its wide clinical application is limited by the risk of invasive LV pressure detection. Until the advent of non-invasive LV pressure-strain loop (LV-PSL), things have changed. LV-PSL is in good agreement with regional myocardial oxygen consumption and metabolism. Compared with traditional echocardiographic parameters or LV strain, myocardial work (MW) derived from LV-PSL is a more advanced tool that combines deformation as well as hemodynamics through integration of global longitudinal strain and non-invasive LV systolic pressure. In recent years, researches on MW are going on in full swing and show many advantages of MW. This review described the method and discussed the applications, advantages, limitations, and prospects of MW in multiple cardiovascular diseases. The goal is to provide the readers new insights for evaluating LV systolic function and promote the incorporation of MW into daily practice.

Protective Effect of Shengmaiyin in Myocardial Hypertrophy-Induced Rats: A Genomic Analysis by 16S rDNA

Background

The gut-cardiac axis theory provides new insights into the complex mechanisms of cardiac hypertrophy and provides new therapeutic targets. Cardiac hypertrophy is a risk factor for heart failure. Shengmaiyin (SMY) is a traditional Chinese medicine formula with clear effects in the treatment and prevention of cardiac hypertrophy, but the mechanism by which it improves cardiac hypertrophy is still unclear. Therefore, this study aimed to investigate the protective effect and mechanism of SMY on isoproterenol (ISO)-induced myocardial hypertrophy in rats.

Methods

First, various pharmacodynamic methods were used to evaluate the therapeutic effect of SMY on ISO-induced myocardial hypertrophy in rats. Then, 16S rDNA amplicon sequencing technology was used to study the effect of SMY on the intestinal flora of rats with myocardial hypertrophy. Finally, the mechanism underlying the effect of SMY on cardiac hypertrophy was predicted by bioinformatics network analysis and verified by Western blotting.

Results

SMY increased ejection fraction (EF%) and left ventricular fractional shortening (FS%), ameliorated myocardial cell injury and fibrosis, regulated blood lipids and energy metabolism, and decreased cardiac hypertrophy marker gene expression. The gut microbiota of ISO-induced myocardial hypertrophy rats were significantly changed, while SMY effectively ameliorated the dysbiosis of the intestinal flora in rats with myocardial hypertrophy, especially Prevotella 9, Lactobacillus, and Clostridium. Mechanistic studies have shown that the anticardiac hypertrophy effect of SMY is related to the inhibition of the expression of HIF1α/PPAR signalling pathway-related proteins.

Conclusion

SMY significantly improves cardiac function, relieves myocardial cell fibrosis and necrosis, resists cardiac hypertrophy, improves blood lipid metabolism and energy metabolism, regulates intestinal microbial disturbance, and protects the heart.

Left ventricular myocardial work indices in pediatric hypertension: correlations with conventional echocardiographic assessment and subphenotyping

Myocardial work (MW) is a novel parameter that incorporates non-invasive estimates of left ventricular (LV) systolic pressure into the interpretation of strain, thus overcoming the limitations of load dependency traditionally encountered with LV fractional shortening (LVFS), ejection fraction (LVEF), and global longitudinal strain (GLS). However, data on MW in the pediatric population with hypertension are lacking. Conventional markers of LV function and MW indices were obtained from 88 echocardiographic examinations in 76 children with hypertension (47 males, 15.5 ± 2.96 years). When compared with a previously published cohort of 52 healthy controls, global work index (GWI) and global constructive work (GCW) were both significantly elevated while LVEF and GLS were not impaired but rather mildly increased. On multivariable analysis, GWI was correlated with systolic blood pressure (slope =  + 16, p < 0.001) and GLS (slope =  -100, p < 0.001), while GCW was correlated with systolic blood pressure (slope =  + 18, p < 0.001), GLS (slope =  -101, p < 0.001), male sex (slope =  -75, p = 0.016), and LV mass (slope =  -0.93, p < 0.001). Global wasted work (GWW) was correlated with age at echo visit (slope =  -4.5, p = 0.005) and GLS (slope =  + 5.5, p < 0.001). The opposite occurred for global work efficiency (GWE; slope =  + 0.20, p = 0.011, and slope =  -0.48, p < 0.001, respectively). Principal component analysis and k-means clustering revealed 4 subphenotypes which differed in terms of etiology, afterload, and compensation stage of the disease.    Conclusion: Non-invasive MW shows a good correlation with conventional markers of LV function and may help refine the assessment of hypertensive heart disease in children. What is Known: • Myocardial work (MW) is a novel parameter that incorporates non-invasive estimates of left ventricular (LV) systolic pressure into the interpretation of strain, thereby accounting for both deformation and afterload. • Although the usefulness of MW in the assessment of myocardial function beyond conventional markers has been demonstrated in various clinical populations, data in the pediatric population with hypertension are currently lacking. What is New: • Compared to normal values in healthy children, global work index and global constructive work were increased in those with hypertension, while LV ejection fraction and global longitudinal strain were not impaired. • Machine learning identified 4 subphenotypes which differed in terms of etiology, afterload, and compensation stage of the disease.

Normal Values for Myocardial Work Indices Derived From Pressure-Strain Loop Analyses: From the CCHS

BACKGROUND

Pressure-strain loop analyses is a noninvasive technique capable of evaluating myocardial work. Reference values are needed to benchmark these myocardial work indices for clinical practice.

METHODS

Healthy participants from a general population study were used to establish reference values for global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) measured by pressure-strain loop analyses. The relation to age and sex was examined. We furthermore examined the proportion of abnormal work indices according to low, intermediate, and high cardiovascular risk by the Framingham risk score.

RESULTS

The healthy sample consisted of 1827 participants (median age, 45 years; 39% men). Lower reference values were GWI, 1576 mm Hg%; GCW, 1708 mm Hg%; and GWE, 93.0% and upper reference value for GWW was 159 mm Hg%. Women exhibited significantly higher GWI, GCW, and GWW and lower GWE. Sex significantly modified the association between all indices and age (P for interaction: 0.001 for GWI, 0.009 for GCW, 0.003 for GWW, and 0.009 for GWE). For men, only GCW increased with age, whereas the other indices did not change with age. For women, GCW increased linearly with increasing age, whereas GWI, GWW, and GWE changed in a curvilinear fashion with age such that GWI increased in younger participants, GWW increased in elderly, and GWE declined concordantly. Abnormalities in myocardial work indices became more frequent with increasing Framingham risk score category (abnormal GWI: 2% versus 4% versus 5%, P=0.001; abnormal GCW: 2% versus 3% versus 4%, P=0.006; abnormal GWW: 3% versus 6% versus 11%, P<0.001; abnormal GWE: 3% versus 4% versus 11%, P<0.001).

CONCLUSIONS

Myocardial work indices differ between sexes and change with age in a sex-dependent manner. Accordingly, we established age- and sex-specific reference values from a general population sample. Abnormal work indices become more frequent with higher clinical risk.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02993172.

Quantitative Analysis of Myocardial Work by Non-invasive Left Ventricular Pressure-Strain Loop in Patients With Type 2 Diabetes Mellitus

Background: Type 2 diabetes mellitus (T2DM) is a common risk factor for cardiovascular diseases. The aims of this study were to evaluate the changes in the left ventricular myocardial work in T2DM patients using the left ventricular pressure-strain loop (PSL) technique, and to explore the risk factors for the left ventricular myocardial work impairment.

Methods: Fifty patients with T2DM and 50 normal controls (NCs) were included in the study. In addition to conventional echocardiography and two-dimensional speckle tracking echocardiography, the left ventricular myocardial work parameters were measured using PSL technology.

Results: The absolute value for global longitudinal strain (GLS), global work index (GWI) and, global constructive work (GCW) were significantly decreased in the T2DM group (P < 0.05), while the left ventricular ejection fraction (LVEF) was not significantly different between the T2DM and NC groups. Multivariable linear regression analysis showed that hemoglobin A1c (HbA1c) was independently related to GWI (β = −0.452, P < 0.05), while HbA1c and the diabetes duration were independently related to GCW (β = −0.393, P < 0.05 and β = −0.298, P < 0.05, respectively).

Conclusions: Changes in the left ventricular myocardial systolic function in T2DM patients were identified using PSL technology. HbA1c was shown to be an independent risk factor affecting GWI, while HbA1c and diabetes duration were demonstrated to be independent risk factors affecting GCW.

Dynamics of Left Ventricular Myocardial Work in Patients Hospitalized for Acute Heart Failure

BACKGROUND

The left ventricular ejection fraction (LVEF) is the most commonly used measure describing pumping efficiency, but it is heavily dependent on loading conditions and therefore not well-suited to study pathophysiologic changes. The novel concept of echocardiography-derived myocardial work (MyW) overcomes this disadvantage as it is based on LV pressure-strain loops. We tracked the in-hospital changes of indices of MyW in patients admitted for acute heart failure (AHF) in relation to their recompensation status and explored the prognostic utility of MyW indices METHODS AND RESULTS: We studied 126 patients admitted for AHF (mean 73 ± 12 years, 37% female, 40% with a reduced LVEF [<40%]), providing pairs of echocardiograms obtained both on hospital admission and prior to discharge. The following MyW indices were derived: global constructive and wasted work (GCW, GWW), global work index (GWI), and global work efficiency. In patients with HF with reduced ejection fraction with decreasing N-terminal prohormone B-natriuretic peptide levels during hospitalization, the GCW and GWI improved significantly, whereas the GWW remained unchanged. In patients with HF with preserved ejection fraction, the GCW and GWI were unchanged; however, in patients with no decrease or eventual increase in N-terminal prohormone B-natriuretic peptide, we observed an increase in GWW. In all patients with AHF, higher values of GWW were associated with a higher risk of death or rehospitalization within 6 months after discharge (per 10-point increment hazard ratio 1.035, 95% confidence interval 1.005-1.065).

CONCLUSIONS

Our results suggest differential myocardial responses to decompensation and recompensation, depending on the HF phenotype in patients presenting with AHF. The GWW predicted the 6-month prognosis in these patients, regardless of LVEF. Future studies in larger cohorts need to confirm our results and identify determinants of short-term and longer term changes in MyW.