The role of invasive diagnostics and its impact on the treatment of dilated cardiomyopathy: A systematic review

Molecular Pathways in Diabetic Cardiomyopathy and the Role of Anti-hyperglycemic Drugs Beyond Their Glucose Lowering Effect

Epidemiological evidence has shown that diabetes is associated with overt heart failure (HF) and worse clinical outcomes. However, the presence of a distinct primary diabetic cardiomyopathy (DCM) has not been easy to prove because the association between diabetes and HF is confounded by hypertension, obesity, microvascular dysfunction, and autonomic neuropathy. In addition, the molecular mechanisms underlying DCM are not yet fully understood, DCM usually remains asymptomatic in the early stage, and no specific biomarkers have been identified. Nonetheless, several mechanistic associations at the systemic, cardiac, and cellular/molecular levels explain different aspects of myocardial dysfunction, including impaired cardiac relaxation, compliance, and contractility. In this review, we focus on recent clinical and preclinical advances in our understanding of the molecular mechanisms of DCM and the role of anti-hyperglycemic agents in preventing DCM beyond their glucose lowering effect.

Beyond the beat: A pioneering investigation into exercise modalities for alleviating diabetic cardiomyopathy and enhancing cardiac health

Patients with preexisting cardiovascular disease or those at high risk for developing the condition are often offered exercise as a form of therapy. Patients with cancer who are at an increased risk for cardiovascular issues are increasingly encouraged to participate in exercise-based, interdisciplinary programs due to the positive correlation between these interventions and clinical outcomes following myocardial infarction. Diabetic cardiomyopathy (DC) is a cardiac disorder that arises due to disruptions in the homeostasis of individuals with diabetes. One of the primary reasons for mortality in individuals with diabetes is the presence of cardiac structural damage and functional abnormalities, which are the primary pathological features of DC. The aetiology of dilated cardiomyopathy is multifaceted and encompasses a range of processes, including metabolic abnormalities, impaired mitochondrial function, dysregulation of calcium ion homeostasis, excessive cardiomyocyte death, and fibrosis. In recent years, many empirical investigations have demonstrated that exercise training substantially impacts the prevention and management of diabetes. Exercise has been found to positively impact the recovery of diabetes and improve several metabolic problem characteristics associated with DC. One potential benefit of exercise is its ability to increase systolic activity, which can enhance cardiometabolic and facilitate the repair of structural damage to the heart caused by DC, leading to a direct improvement in cardiac health. In contrast, exercise has the potential to indirectly mitigate the pathological progression of DC through its ability to decrease circulating levels of sugar and fat while concurrently enhancing insulin sensitivity. A more comprehensive understanding of the molecular mechanism via exercise facilitates the restoration of DC disease must be understood. Our goal in this review was to provide helpful information and clues for developing new therapeutic techniques for motion alleviation DC by examining the molecular mechanisms involved.

Insight into the underlying molecular mechanism of dilated cardiomyopathy through integrative analysis of data mining, iTRAQ-PRM proteomics and bioinformatics

BACKGROUND

DCM is a common cardiomyopathy worldwide, which is characterized by ventricular dilatation and systolic dysfunction. DCM is one of the most widespread diseases contributing to sudden death and heart failure. However, our understanding of its molecular mechanisms is limited because of its etiology and underlying mechanisms. Hence, this study explored the underlying molecular mechanism of dilated cardiomyopathy through integrative analysis of data mining, iTRAQ-PRM proteomics and bioinformatics METHODS: DCM target genes were downloaded from the public databases. Next, DCM was induced in 20 rats by 8 weeks doxorubicin treatment (2.5 mg/kg/week). We applied isobaric tags for a relative and absolute quantification (iTRAQ) coupled with proteomics approach to identify differentially expressed proteins (DEPs) in myocardial tissue. After association analysis of the DEPs and the key target genes, subsequent analyses, including functional annotation, pathway enrichment, validation, were performed.

RESULTS

Nine hundred thirty-five genes were identified as key target genes from public databases. Meanwhile, a total of 782 DEPs, including 348 up-regulated and 434 down-regulated proteins, were identified in our animal experiment. The functional annotation of these DEPs revealed complicated molecular mechanisms including TCA cycle, Oxidative phosphorylation, Cardiac muscle contraction. Moreover, the DEPs were analyzed for association with the key target genes screened in the public dataset. We further determined the importance of these three pathways.

CONCLUSION

Our results demonstrate that TCA cycle, Oxidative phosphorylation, Cardiac muscle contraction played important roles in the detailed molecular mechanisms of DCM.

Non-ischaemic dilated cardiomyopathy: recognising the genetic links

The landscape of genetically related cardiac disease continues to evolve. Heritable genetic variants can be a primary cause of familial or sporadic dilated cardiomyopathy (DCM). There is also increasing recognition that genetic variation is an important determinant of susceptibility to acquired causes of DCM. Genetic forms of DCM can show a wide variety of phenotypic manifestations. Identifying patients who are most likely to benefit from genetic testing is paramount. The objective of this review is to highlight the importance of recognising genetic DCM, key genotype-phenotype correlations and the value of genetic testing in clinical management for both the individual and their family. This is likely to become more relevant as management strategies continue to be refined with genotype-specific recommendations and disease-modifying therapies.

Role of Endomyocardial Biopsy in Diagnostics of Myocarditis

Endomyocardial biopsy as the cornerstone of diagnostics has been re-evaluated throughout the years, leaving unanswered questions on the precedence of it. The reported incidence of myocarditis has increased during the pandemic of coronavirus disease 2019 (COVID-19), reinforcing discussions on appropriate diagnostics of myocarditis. By analysis of evidence-based literature published within the last demi-decade, we aimed to summarize the most recent information in order to evaluate the current role of endomyocardial biopsy in diagnostics and management of myocarditis. For the most part, research published over the last five years showed ongoing uncertainty regarding the use, informativeness, safety and necessity of performing a biopsy. Special circumstances, such as fulminant clinical course or failure to respond to empirical treatment, were reconfirmed as justified indications, with a growing applicability of non-invasive diagnostic approaches for most other cases. We concluded that endomyocardial biopsy, if performed properly and with adjunct diagnostic methods, holds a critical role for treatment correction in specific histological subtypes of myocarditis and for differential diagnosis between immune-mediated myocarditis and secondary infections due to immunosuppressive treatment. A high level of possible misdiagnosing was detected, indicating the need to review terminology used to describe findings of myocardial inflammation that did not meet Dallas criteria.

Cardiomyopathies in the Clinical Practice - an Overview

Cardiomyopathies are myocardial disorders with a structurally and functionally abnormal heart muscle. In this review, we describe pathophysiological aspects, clinical presentation, diagnosis, risk stratification and therapeutical concepts of the three most common forms of cardiomyopathy: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and arrhythmogenic cardiomyopathy (ACM).

NMR-Based Metabolomic Analysis of Sera in Mouse Models of CVB3-Induced Viral Myocarditis and Dilated Cardiomyopathy

Viral myocarditis (VMC) is an inflammatory heart condition which can induce dilated cardiomyopathy (DCM). However, molecular mechanisms underlying the progression of VMC into DCM remain exclusive. Here, we established mouse models of VMC and DCM by infecting male BALB/c mice with Coxsackievirus B3 (CVB3), and performed NMR-based metabonomic analyses of mouse sera. The mouse models covered three pathological stages including: acute VMC (aVMC), chronic VMC (cVMC) and DCM. We recorded ¹D ¹H-NMR spectra on serum samples and conducted multivariate statistical analysis on the NMR data. We found that metabolic profiles of these three pathological stages were distinct from their normal controls (CON), and identified significant metabolites primarily responsible for the metabolic distinctions. We identified significantly disturbed metabolic pathways in the aVMC, cVMC and DCM stages relative to CON, including: taurine and hypotaurine metabolism; pyruvate metabolism; glycine, serine and threonine metabolism; glycerolipid metabolism. Additionally, we identified potential biomarkers for discriminating a VMC, cVMC and DCM from CON including: taurine, valine and acetate for aVMC; glycerol, valine and leucine for cVMC; citrate, glycine and isoleucine for DCM. This work lays the basis for mechanistically understanding the progression from acute VMC to DCM, and is beneficial to exploitation of potential biomarkers for prognosis and diagnosis of heart diseases.

Diabetic cardiomyopathy: Clinical phenotype and practice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition of cardiac structure and function changes in diabetic patients without coronary artery disease, hypertension, and other types of heart diseases. DCM is not uncommon in people with diabetes, which increases the risk of heart failure. However, the treatment is scarce, and the prognosis is poor. Since 1972, one clinical study after another on DCM has been conducted. However, the complex phenotype of DCM still has not been fully revealed. This dilemma hinders the pace of understanding the essence of DCM and makes it difficult to carry out penetrating clinical or basic research. This review summarizes the literature on DCM over the last 40 years and discusses the overall perspective of DCM, phase of progression, potential clinical indicators, diagnostic and screening criteria, and related randomized controlled trials to understand DCM better.

Chemokines profile in patients with chronic heart failure treated with cardiac resynchronization therapy

PURPOSE

Inflammatory mechanisms have been suggested to play a role in the heart failure with reduced ejection fraction (HF-REF) development, but the role of chemokines is largely unknown. Cardiac resynchronization therapy (CRT) may reverse the HF-REF course. We aimed to evaluate selected chemokines concentrations in HF-REF patients and their relationship with disease severity and clinical response to CRT.

MATERIALS AND METHODS

The study included 37 patients (64.1 ± 11.04 years, 6 females) with HF-REF subjected to CRT, controlled prior to implantation and after 6 months. The control population included 26 healthy volunteers (63.9 ± 8.1 years, 8 females). Serum chemokines concentrations were determined using multiplex method.

RESULTS

HF-REF patients were characterized by the higher baseline MIF, NAP-2 and PF4 concentrations and lower Axl, BTC, IL-9, and IL-18 BPa concentrations comparing to controls. After 6 months of CRT only NAP-2 concentration decreased significantly in comparison to the baseline values.

CONCLUSIONS

HF-REF patients present altered chemokines profile compared to the control group. The CRT-related alleviation of HF-REF causes only slight changes in the chemokines concentrations especially in the platelet-associated ones. The precise chemokines role in the HF-REF pathogenesis and their prognostic value remains to be established.

[Systematic Analysis of the Roles of Trace Elements in the Prevention and Treatment of Chronic Heart Failure]

Systematic analysis of 3 728 publications on the relationship between microelement status and chronic heart failure (CHF) was carried out. Three main areas of research have been identified: 1) magnesium, electrolytes and CHF; 2) the transcriptional and antioxidant effects of zinc, selenium, copper; 3) iron-deficiency anemia and CHF. In this paper, we consider a complex of relationships between the magnesium insufficiency and CHF, the effect of magnesium on vascular tone, mitochondria, heart rhythm and the susceptibility of cardiomyocytes to adrenergic stimulation. Using magnesium orotate for the treatment of CHF is a feasible approach to compensate magnesium insufficiency in patients with CHF.

Genetic deletion of the alamandine receptor MRGD leads to dilated cardiomyopathy in mice

We have recently described a new peptide of the renin-angiotensin system, alamandine, a derivative of angiotensin-(1–7). Mas-related G protein-coupled receptor member D (MrgD) was identified as its receptor. Although similar cardioprotective effects of alamandine to those of angiotensin-(1–7) have been described, the significance of this peptide in heart function is still elusive. We aimed to evaluate the functional role of the alamandine receptor MrgD in the heart using MrgD-deficient mice. MrgD was localized in cardiomyocytes by immunofluorescence using confocal microscopy. High-resolution echocardiography was performed in wild-type and MrgD-deficient mice (2 and 12 wk old) under isoflurane anesthesia. Standard B-mode images were obtained in the right and left parasternal long and short axes for morphological and functional assessment and evaluation of cardiac deformation. Additional heart function evaluation was performed using Langendorff isolated heart preparations and inotropic measurements of isolated cardiomyocytes. Immunofluorescence indicated that the MrgD receptor is expressed in cardiomyocytes, mainly in the membrane and perinuclear and nuclear regions. Echocardiography showed left ventricular remodeling and severe dysfunction in MrgD-deficient mice. Strikingly, MrgD-deficient mice presented a pronounced dilated cardiomyopathy with a marked decrease in systolic function. Echocardiographic changes were supported by the data obtained in isolated hearts and inotropic measurements in cardiomyocytes. Our data add new evidence for a major role for alamandine/MrgD in the heart. Furthermore, our results indicate that we have identified a new gene implicated in dilated cardiomyopathy, unveiling a new target for translational approaches aimed to treat heart diseases.

NEW & NOTEWORTHY The renin-angiotensin system is a key target for cardiovascular therapy. We have recently identified a new vasodepressor/cardioprotective angiotensin, alamandine. Here, we unmasked a key role for its receptor, Mas-related G protein-coupled receptor member D (MrgD), in heart function. The severe dilated cardiomyopathy observed in MrgD-deficient mice warrants clinical and preclinical studies to unveil its potential use in cardiovascular therapy.

Listen to this article’s corresponding podcast at https://ajpheart.podbean.com/e/mrgd-deficiency-leads-to-dilated-cardiomyopathy/ .

Right ventricular dysfunction and remodeling in diabetic cardiomyopathy

The increasing prevalence of diabetic cardiomyopathy (DCM) is an important threat to health worldwide. While left ventricular (LV) dysfunction in DCM is well recognized, the accurate detection, diagnosis, and treatment of changes in right ventricular (RV) structure and function have not been well characterized. The pathophysiology of RV dysfunction in DCM may share features with LV diastolic and systolic dysfunction, including pathways related to insulin resistance and oxidant injury, although the RV has a unique cellular origin and composition and unique biomechanical properties and is coupled to the lower-impedance pulmonary vascular bed. In this review, we discuss potential mechanisms responsible for RV dysfunction in DCM and review the imaging approaches useful for early detection, protection, and intervention strategies. Additional data are required from animal models and clinical trials to better identify the onset and features of altered RV and pulmonary vascular structure and function during the onset and progression of DCM and to determine the efficacy of early detection and treatment of RV dysfunction on clinical symptoms and outcomes.

Prognostic value of fibrosis-related markers in dilated cardiomyopathy: A link between osteopontin and cardiovascular events

INTRODUCTION

Serum markers of fibrosis provide an insight into extracellular matrix (ECM) fibrosis in heart failure (HF) and dilated cardiomyopathy (DCM). However, their role as predictors of cardiovascular (CV) events in DCM is poorly understood.

METHODS

This is an observational, prospective cohort study. 70 DCM patients (48±12.1years, ejection fraction - EF 24.4±7.4) were recruited. Markers of collagen type I and III synthesis - procollagen type I and III carboxy- and amino-terminal peptides (PICP, PIIICP, PINP, PIIINP), fibrosis controlling factors - ostepontin (OPN), transforming growth factor (TGF1-β) and connective tissue growth factor (CTGF), and matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor (TIMP-1), were measured in serum. All patients underwent endomyocardial biopsy. The end-point was combined with CV death and urgent HF hospitalization. Patients were divided into two groups: those who did (group 1, n=45) and did not reach (group 2, n=25) an end-point.

RESULTS

Over a 12-month period of observation, 6 CV deaths and 19 HF hospitalizations occurred. Qualitative and quantitative measures of ECM fibrosis were similar in both groups. The levels of all of the markers of collagen synthesis, TGF1-β, MMP-9 and TIMP-1 were similar, however, OPN, CTGF and MMP-2 were significantly lower in group 1.

CONCLUSIONS

Invasively-determined fibrosis levels were not related with CV outcomes in DCM. Out of the 11 markers of fibrosis under study, only OPN was found to be related to CV outcomes. OPN is not only the pivotal protein controlling fibrosis, but may also serve as a biomarker associated with prognosis.

CCAAT/enhancer-binding protein β overexpression alleviates myocardial remodelling by regulating angiotensin-converting enzyme-2 expression in diabetes

Diabetic cardiomyopathy, a major cardiac complication, contributes to heart remodelling and heart failure. Our previous study discovered that CCAAT/enhancer-binding protein β (C/EBPβ), a transcription factor that belongs to a family of basic leucine zipper transcription factors, interacts with the angiotensin-converting enzyme 2 (ACE2) promoter sequence in other disease models. Here, we aimed to determine the role of C/EBPβ in diabetes and whether ACE2 expression is regulated by C/EBPβ. A type 1 diabetic mouse model was generated by an intraperitoneal injection of streptozotocin. Diabetic mice were injected with a lentivirus expressing either C/EBPβ or sh-C/EBPβ or treated with valsartan after 12 weeks to observe the effects of C/EBPβ. In vitro, cardiac fibroblasts and cardiomyocytes were treated with high glucose (HG) to investigate the anti-fibrosis, anti-apoptosis and regulatory mechanisms of C/EBPβ. C/EBPβ expression was down-regulated in diabetic mice and HG-induced cardiac neonatal cells. C/EBPβ overexpression significantly attenuated collagen deposition and cardiomyocyte apoptosis by up-regulating ACE2 expression. The molecular mechanism involved the binding of C/EBPβ to the ACE2 promoter sequence. Although valsartan, a classic angiotensin receptor blocker, relieved diabetic complications, the up-regulation of ACE2 expression by C/EBPβ overexpression may exert greater beneficial effects on patients with diabetic cardiomyopathy.

Dilated Cardiomyopathy: Genetic Determinants and Mechanisms

Nonischemic dilated cardiomyopathy (DCM) often has a genetic pathogenesis. Because of the large number of genes and alleles attributed to DCM, comprehensive genetic testing encompasses ever-increasing gene panels. Genetic diagnosis can help predict prognosis, especially with regard to arrhythmia risk for certain subtypes. Moreover, cascade genetic testing in family members can identify those who are at risk or with early stage disease, offering the opportunity for early intervention. This review will address diagnosis and management of DCM, including the role of genetic evaluation. We will also overview distinct genetic pathways linked to DCM and their pathogenetic mechanisms. Historically, cardiac morphology has been used to classify cardiomyopathy subtypes. Determining genetic variants is emerging as an additional adjunct to help further refine subtypes of DCM, especially where arrhythmia risk is increased, and ultimately contribute to clinical management.

Diagnostic approaches for diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a cardiac dysfunction which affects approximately 12% of diabetic patients, leading to overt heart failure and death. However, there is not an efficient and specific methodology for DCM diagnosis, possibly because molecular mechanisms are not fully elucidated, and it remains asymptomatic for many years. Also, DCM frequently coexists with other comorbidities such as hypertension, obesity, dyslipidemia, and vasculopathies. Thus, human DCM is not specifically identified after heart failure is established. In this sense, echocardiography has been traditionally considered the gold standard imaging test to evaluate the presence of cardiac dysfunction, although other techniques may cover earlier DCM detection by quantification of altered myocardial metabolism and strain. In this sense, Phase-Magnetic Resonance Imaging and 2D/3D-Speckle Tracking Echocardiography may potentially diagnose and stratify diabetic patients. Additionally, this information could be completed with a quantification of specific plasma biomarkers related to related to initial stages of the disease. Cardiotrophin-1, activin A, insulin-like growth factor binding protein-7 (IGFBP-7) and Heart fatty-acid binding protein have demonstrated a stable positive correlation with cardiac hypertrophy, contractibility and steatosis responses. Thus, we suggest a combination of minimally-invasive diagnosis tools for human DCM recognition based on imaging techniques and measurements of related plasma biomarkers.