Association Between Echocardiographic Non-invasive Myocardial Work Indices and Myocardial Fibrosis in Patients With Dilated Cardiomyopathy

Effects of 12-week combined interval running and resistance training on cardiac structure and performance in patients with type 1 diabetes

Background

Exercise has been suggested to effectively improve cardiac performance in children with type 1 diabetes (T1D) by enhancing the glycemic control. The purpose of this study was to investigate (1) effects of a 12-week combined interval running and resistance training (CIRRT) and (2) 1 month of detraining on cardiac structure and myocardial performance in adolescent males with T1D.

Methods

A total of 72 participants, including 48 adolescent males with T1D (fasting blood glucose (FBG): 274.67 ± 52.99 mg/dL, age: 15.20 ± 1.78 years) and 24 healthy adolescents (FBG: 90.75 ± 5.47 mg/dL, age: 15.08 ± 1.67 years), were recruited to the study. Participants were allocated into diabetes exercise (DE), diabetes control (DC), and healthy controls (HC) groups. The DE group performed 12 weeks of a CIRRT program three times per week. Blood glucose profile, echocardiography (ECHO) indices, and peak oxygen consumption (VO2peak) were measured pre- and post-intervention and following 1-month detraining period. Repeated measures ANOVA was used for pre- and post-intervention comparisons within the DE group and across the three study groups. Significance level was set at p < 0.05.

Results

Exercise intervention resulted in decreased hemoglobin A1c (HbA1c% = Pre: 10.44 ± 2.03, Post: 9.38 ± 1.66, p < 0.05), FBG, left ventricular (LV) internal diameter, and both tricuspid and mitral deceleration time (DT) in the DE group. VO2peak, ejection fraction (EF% = Pre: 62.38 ± 1.6, Post: 64.08 ± 1.18, p < 0.05), fractional shortening, early tricuspid diastolic inflow E velocity, and tricuspid velocity during atrial contraction were also increased following the exercise training. HbA1c (Pre vs Follow-up: 9.83 ± 1.73, p < 0.05), EF (Pre vs Follow-up: 62.97 ± 1.56, p < 0.05), LV, and DT tricuspid remained significantly improved after detraining period compared to the baseline. In the baseline, the glycemic index and ECHO variable significantly differed in the DE and DC groups with the HC group (p < 0.05). However, after the intervention, the DC and HC groups did not change significantly (p > 0.05).

Conclusion

The CIRRT intervention was associated with improved cardiac structure and performance in male adolescents with T1D potentially due to exercise-induced adaptations. Meanwhile, the results indicate that most cardiac morphological and functional changes are reversible following periods of inactivity in patients with T1D.

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.

Application of the Left Ventricular Pressure-Strain Loop Technique in Monitoring Improvement Factors of Patients With Heart Failure Reduced Ejection Fraction

The left ventricular pressure-strain loop (PSL) is a new technique based on ultrasound for noninvasive quantitative evaluation of global and local myocardial work (MW). This study is aimed at evaluating improvement factors of patients with heart failure (HF) reduced ejection fraction (HFrEF) using the PSL technique. A total of 88 patients with HF were enrolled in this study, which had ≤ 40% left ventricular ejection fraction (LVEF). The EchoPAC workstation was used to obtain the global longitudinal strain (GLS) and MW parameters of the left ventricle. All patients have taken medicines for HF treatments for 6-12 months. The improvements of HF after therapies were evaluated according to the following recommended criteria. The clinical characteristics of patients with improved and nonimproved groups were stratified via univariate or multivariate logistic regression analysis, receiver operating characteristic (ROC), and the area under ROC (area under the curve (AUC)). There were no significant differences in general medical information, the underlying diseases, laboratory findings, myocardial enzyme activities, and taking medicines between the improved and nonimproved LVEF patients (p > 0.05). There were significant differences in LVEF of patients at admission, left ventricular end-diastolic diameter (LVEDD), interventricular septum thickness (IVST), early diastolic mitral flow peak velocity E (E peak), GLS, global myocardial work index (GWI), global myocardial constructive work (GCW), and global myocardial work efficiency (GWE) between the two groups (p < 0.05). Univariate and multivariate logistic regression analyses confirmed that GWI and GCW were critical predictive factors for LVEF improvement in patients with HF. ROC curve showed that the AUC of GWI and GCW were 0.796 and 0.779 at the cut-off of 741 mmHg% for GWI and 973.5 mmHg% for GCW, respectively. The sensitivities of GWI and GCW were 65% and 75%, and the specificities of GWI and GCW were 83.3% and 79.2% at given cut-off values. These results revealed that GWI and GCW were independent predictors of improvement of LVEF in patients with HFrEF.

Myocardial work by pressure-strain loop is associated with molecular imaging of fibroblast activation in hypertensive hearts using 99mTc-HFAPI SPECT

99mTc-HFAPI can visualize fibroblast activation in hypertensive hearts. Myocardial work (MW) reflects the cardiac mechanical properties after accounting for the afterload in hypertensive patients. We investigated whether MW was associated with increased uptake of 99mTc-HFAPI. A total of 97 hypertensive patients and 41 healthy volunteers were prospectively recruited. Global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were analyzed. According to whether myocardial uptake of FAPI was higher than the adjacent blood pool, hypertensive patients were divided into two groups, namely: FAPI + and FAPI- group, respectively. GWI, GCW and GWE of the FAPI + group were lower than the FAPI- group. The value of GWW in the FAPI + group was higher than in the FAPI- group. Multiple regression analyses revealed GWI, GWW and GWE were independently associated with early myocardial fibrosis. According to receiver operating characteristics (ROC) analysis, the best cutoff points for FAPI + of GWI, GWW and GWE were 1968.50 mmHg% (AUC: 0.687, 95% CI: 0.581-0.793, P = 0.002), 133.00 mmHg% (AUC: 0.778, 95% CI: 0.688-0.869, P < 0.001) and 95.07% (AUC: 0.813, 95% CI: 0.730-0.896, P < 0.001), respectively. GWI, GWW and GWE were impaired in hypertensive patients with cardiac 99mTc-HFAPI uptake and were associated with fibroblast activation in hypertensive hearts.

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.

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.

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.

Recent Progresses in the Multimodality Imaging Assessment of Myocardial Fibrosis

Myocardial fibrosis, a common pathophysiological consequence of various cardiovascular diseases, is characterized by fibroblast activation and excessive deposition of extracellular matrix (ECM) collagen. Accumulating evidence indicates that myocardial fibrosis contributes to ventricular stiffness, systolic and diastolic dysfunction, and ultimately leads to the development of heart failure (HF). Early detection and targeted treatment of myocardial fibrosis is critical to reverse ventricular remodeling and improve clinical outcomes in patients with cardiovascular diseases. However, despite considerable progresses made in understanding molecular mechanisms of myocardial fibrosis, non-invasive imaging to assess myocardial fibrosis and guide clinical treatment is still not widely available, limiting the development of innovative treatment strategies. This review summarizes recent progresses of imaging modalities for detecting myocardial fibrosis, with a focus on nuclear medicine, echocardiography and cardiac magnetic resonance (CMR).

The Presence, Location, and Degree of Late Gadolinium Enhancement in Relation to Myocardial Dysfunction and Poor Prognosis in Patients with Systemic Lupus Erythematosus

Patients with systemic lupus erythematosus (SLE) typically develop myocardial fibrosis. No studies have investigated the clinical significance of the presence, location, and degree of fibrosis in SLE patients. Seventy-four SLE patients were included. Thirty-seven non-autoimmune disease patients and thirty-seven healthy individuals were included as controls. Myocardial fibrosis was evaluated at cardiac magnetic resonance via a qualitative and quantitative assessment of late gadolinium enhancement (LGE). Myocardial function was measured via speckle-tracking echocardiography. All patients were followed up for the occurrence of major adverse cardiac events (MACE). The presence, locations, and degrees of LGE disturbed regional and global myocardial function. The presence of LGE, left ventricular free-wall LGE (LVFW LGE), and severe LGE were all independent predictors of MACE in SLE patients [LGE presence HR: 3.746 (1.434-9.79), p = 0.007; LVFW LGE HR: 2.395 (1.023-5.606), p = 0.044; severe LGE HR: 3.739 (1.241-11.266), p = 0.019]. LGE combined with SLE-related organ damage identified patients at high risk of MACE (p < 0.001). In conclusion, the presence, degree, and location of LGE were associated with myocardial dysfunction. The presence, location, and degree of LGE had the potential to independently predict poor prognosis and improve risk stratification in SLE patients.

Myocardial Work in Echocardiography

Myocardial work is an emerging tool in echocardiography that incorporates left ventricular afterload into global longitudinal strain analysis. Myocardial work correlates with myocardial oxygen consumption, and work efficiency can also be assessed. Myocardial work has been evaluated in a variety of clinical conditions to assess the added value of myocardial work compared to left ventricular ejection fraction and global longitudinal strain. This review showcases the current use of myocardial work in adult echocardiography and its possible role in cardiac pathologies.

Clinical Utility of Strain Imaging in Assessment of Myocardial Fibrosis

Myocardial fibrosis (MF) is a non-reversible process that occurs following acute or chronic myocardial damage. MF worsens myocardial deformation, remodels the heart and raises myocardial stiffness, and is a crucial pathological manifestation in patients with end-stage cardiovascular diseases and closely related to cardiac adverse events. Therefore, early quantitative analysis of MF plays an important role in risk stratification, clinical decision, and improvement in prognosis. With the advent and development of strain imaging modalities in recent years, MF may be detected early in cardiovascular diseases. This review summarizes the clinical usefulness of strain imaging techniques in the non-invasive assessment of MF.

Clinical research progress of myocardial work in assessment and prediction of coronary artery disease in noninvasive pressure-strain loop technique

Early identification and treatment of high-risk coronary artery disease (CAD) is the main goal of current cardiovascular disease treatments. Speckle-tracking ultrasound technology can quantify myocardial work using pressure-strain loops. Because myocardial work takes into account the effect of the left ventricular systolic function afterload, it can more objectively reflect left ventricular myocardial mechanical function than the overall left ventricular longitudinal strain. Therefore, this technique is more widely used in diseases caused by CAD. This article reviews the evaluation and prediction of different CAD types using a variety of myocardial work parameters and provides a new method for clinical research to assess myocardial function, which is expected to become a new prediction method for CAD.

Current and novel echocardiographic assessment of left ventricular systolic function in aortic stenosis-A comprehensive review

Aortic stenosis (AS) is a complex and progressive condition that can significantly reduce the quality of life and increase the incidence of premature mortality. Transthoracic echocardiography (TTE) is the gold standard imaging modality for the assessment of AS severity. While left ventricular ejection fraction (LVEF) derived from TTE is a very well-understood parameter, limitations such as high inter and intra-observer variability, insensitivity to sub-clinical dysfunction, and influence of loading conditions make LVEF a complicated and unreliable parameter. Myocardial deformation imaging has been identified as a promising parameter for identifying subclinical left ventricular dysfunction, however, this parameter is still afterload dependent. Myocardial Work is a promising novel assessment technique that accounts for afterload by combining the use of myocardial deformation imaging and non-invasive blood pressure to provide a more comprehensive assessment of mechanics beyond LVEF. This review evaluates the evidence for various echocardiographic assessment parameters used to quantify left ventricular function including myocardial work in patients with AS.

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.

Detection of myocardial fibrosis: Where we stand

Myocardial fibrosis, resulting from the disturbance of extracellular matrix homeostasis in response to different insults, is a common and important pathological remodeling process that is associated with adverse clinical outcomes, including arrhythmia, heart failure, or even sudden cardiac death. Over the past decades, multiple non-invasive detection methods have been developed. Laboratory biomarkers can aid in both detection and risk stratification by reflecting cellular and even molecular changes in fibrotic processes, yet more evidence that validates their detection accuracy is still warranted. Different non-invasive imaging techniques have been demonstrated to not only detect myocardial fibrosis but also provide information on prognosis and management. Cardiovascular magnetic resonance (CMR) is considered as the gold standard imaging technique to non-invasively identify and quantify myocardial fibrosis with its natural ability for tissue characterization. This review summarizes the current understanding of the non-invasive detection methods of myocardial fibrosis, with the focus on different techniques and clinical applications of CMR.

Echocardiographic Advances in Dilated Cardiomyopathy

Although the overall survival of patients with dilated cardiomyopathy (DCM) has improved significantly in the last decades, a non-negligible proportion of DCM patients still shows an unfavorable prognosis. DCM patients not only need imaging techniques that are effective in diagnosis, but also suitable for long-term follow-up with frequent re-evaluations. The exponential growth of echocardiography’s technology and performance in recent years has resulted in improved diagnostic accuracy, stratification, management and follow-up of patients with DCM. This review summarizes some new developments in echocardiography and their promising applications in DCM. Although nowadays cardiac magnetic resonance (CMR) remains the gold standard technique in DCM, the echocardiographic advances and novelties proposed in the manuscript, if properly integrated into clinical practice, could bring echocardiography closer to CMR in terms of accuracy and may certify ultrasound as the technique of choice in the follow-up of DCM patients. The application in DCM patients of novel echocardiographic techniques represents an interesting emergent research area for scholars in the near future.