Ischaemic cardiomyopathy: pathophysiology, assessment and the role of revascularisation

Cocultured amniotic stem cells and cardiomyocytes in a 3-D acellular heart patch reduce the infarct size and left ventricle remodeling: promote angiogenesis in a porcine acute myocardial infarction model

BACKGROUND

Acute myocardial infarction (AMI) induces significant myocardial damage, ultimately leading to heart failure as the surrounding healthy myocardial tissue undergoes progressive deterioration due to excessive mechanical stress.

METHODS

This study aimed to investigate myocardial regeneration in a porcine model of AMI using an acellular amniotic membrane with fibrin-termed an amnion bilayer (AB) or heart patch-as a cellular delivery system using porcine amniotic stem cells (pASCs) and autologous porcine cardiomyocytes (pCardios). Fifteen pigs (aged 2-4 months, weighing 50-60 kg) were randomly assigned to three experimental groups (n = 5): control group (AMI induction only), pASC group (pASC transplantation only), and coculture group (pASC and pCardio transplantation). AMI was induced via posterior left ventricular artery ligation and confirmed through standard biomarkers. After eight weeks, histological and molecular analyses were conducted to assess myocardial regeneration.

RESULTS

Improvement in regional wall motion abnormality (RWMA) was observed in 60% of the coculture group, 25% of the pASC group, and none in the control group. Histological analysis of the control group revealed extensive fibrosis with pronounced lipomatosis, particularly at the infarct center. In contrast, pASC and coculture groups exhibited minimal fibrotic scarring at both the infarct center and border regions. Immunofluorescence analysis demonstrated positive α-actinin expression in both the pASC and coculture groups, with the coculture group displaying sarcomeric structures-an organization absent in control group. RNA expression levels of key cardiomyogenic markers, including cardiac troponin T (cTnT), myosin heavy chain (MHC), and Nkx2.5, were significantly elevated in the treatment groups compared to the controls, with the coculture group exhibiting the highest MHC expression. The expression of c-Kit was also increased in both treatment groups relative to the control. Conversely, apoptotic markers p21 and Caspase-9 were highest in the control group, while coculture group exhibited the lowest p53 expression.

CONCLUSION

Epicardial transplantation of an acellular amniotic heart patch cocultured with cardiomyocytes and pASCs demonstrated superior cardiomyogenesis after eight weeks compared to pASC transplantation alone or control conditions. The coculture system was found to enhance the cardiac regeneration process, as evidenced by improved RWMA, distinct sarcomeric organization, reduced fibrotic scarring, and lower apoptotic gene expression.

Optimizing Revascularization in Ischemic Cardiomyopathy: Comparative Evidence on the Benefits and Indications of CABG and PCI

Ischemic cardiomyopathy remains a leading cause of heart failure, yet the optimal revascularization approach for patients with reduced left ventricular function remains uncertain. This review synthesizes current evidence on coronary revascularization strategies, emphasizing real-world applicability and individualized treatment. It critically evaluates the benefits and limitations of coronary artery bypass grafting [CABG] and percutaneous coronary intervention [PCI], highlighting key knowledge gaps. Findings from the STICH trial demonstrate that CABG improves long-term survival despite an elevated early procedural risk, particularly in patients with extensive multivessel disease. In contrast, the REVIVED-BCIS2 trial suggests that PCI enhances quality of life but does not significantly reduce mortality compared to optimal medical therapy, making it a viable alternative for high-risk patients ineligible for surgery. This review underscores the role of advanced imaging techniques in myocardial viability assessment and emphasizes the importance of comprehensive risk stratification in guiding revascularization decisions. Special attention is given to managing high-risk patients unsuitable for CABG and the potential benefits of PCI in symptom relief despite uncertain survival benefits. A stepwise algorithm is proposed to assist clinicians in tailoring revascularization strategies, reinforcing the need for a multidisciplinary Heart Team approach to optimize outcomes.

Percutaneous Coronary Intervention for Heart Failure due to Coronary Artery Disease

The role of revascularization and percutaneous coronary intervention (PCI) in patients with acute coronary syndrome is well established. However, the incremental value of revascularization over guideline-directed medical therapy is controversial. Currently available data supports the use of PCI to improve angina and quality of life for chronic coronary disease and heart failure (HF). However, there is insufficient data to support revascularization with PCI to improve mortality, reduce cardiovascular events, or improve ejection fraction over medical therapy alone. Additional trials are necessary to identify HF patients who may benefit from revascularization, and the optimal revascularization strategy for this population.

Mitochondrial transplantation for cardioprotection and induction of angiogenesis in ischemic heart disease

To date, the regenerative potential of mitochondrial transplantation (MT) has been extensively investigated under several pathologies. Among various cardiovascular diseases, ischemic heart disease (IHD), the most prevalent pathological condition in human medicine, is induced by coronary artery narrowing, or occlusion, leading to bulk necrotic changes and fibrosis within the myocardium. Data associated with the pro-angiogenic activity of mitochondria have not been completely elucidated in terms of cardiac tissue regeneration. Here, we aimed to highlight the recent studies and advantages related to the application of mitochondrial mass in the ischemic myocardium. How and by which mechanisms, mitochondria can reduce aberrant myocardial tissue remodeling via different pathways such as angiogenesis and de novo blood formation was discussed in detail. We hope that data from the current review article help us understand the molecular and cellular mechanisms by which transplanted mitochondria exert their regenerative properties in the ischemic myocardium.

Proteomic and metabolomic analyses of the human adult myocardium reveal ventricle-specific regulation in end-stage cardiomyopathies

The left and right ventricles of the human heart are functionally and developmentally distinct such that genetic or acquired insults can cause dysfunction in one or both ventricles resulting in heart failure. To better understand ventricle-specific molecular changes influencing heart failure development, we first performed unbiased quantitative mass spectrometry on pre-mortem non-diseased human myocardium to compare the metabolome and proteome between the normal left and right ventricles. Constituents of gluconeogenesis, glycolysis, lipogenesis, lipolysis, fatty acid catabolism, the citrate cycle and oxidative phosphorylation were down-regulated in the left ventricle, while glycogenesis, pyruvate and ketone metabolism were up-regulated. Inter-ventricular significance of these metabolic pathways was then found to be diminished within end-stage dilated cardiomyopathy and ischaemic cardiomyopathy, while heart failure-associated pathways were increased in the left ventricle relative to the right within ischaemic cardiomyopathy, such as fluid sheer-stress, increased glutamine-glutamate ratio, and down-regulation of contractile proteins, indicating a left ventricular pathological bias.

Efficacy of catheter ablation for ventricular tachycardia in ischemic cardiomyopathy patients without an ICD implantation

BACKGROUND

The implantable cardioverter-defibrillator (ICD) prevents sudden cardiac death in patients with ischemic cardiomyopathy (ICM). Catheter ablation has been shown to effectively reduce ventricular tachycardia (VT) recurrence, yet its efficacy in patients without an ICD implantation remains uncertain.

OBJECTIVE

We aimed to investigate the outcomes of ablation for VT in patients with ICM without a backup ICD.

METHODS

Patients with ICM who received ablation for VT without an ICD implantation were included in this study. Ablation was guided by either activation mapping or substrate mapping. Endocardial ablation was the primary strategy; epicardial access was considered when endocardial ablation failed. The primary end point was VT recurrence during follow-up; secondary end points included cardiovascular rehospitalization, all-cause mortality, and a composite of these events.

RESULTS

A total of 114 patients were included, with the mean age of 58.2 ± 11.1 years, 102 of whom (89.5%) were male. Twelve patients (10.5%) underwent endo-epicardial ablation, whereas the rest received endocardial ablation. With a median follow-up of 53.8 months (24.8-84.2 months), VT recurred in 45 patients (39.5%), and 6 patients (5.3%) died, including 2 sudden cardiac deaths. The recurrence rate of VT was significantly lower in patients undergoing endo-epicardial ablation than in those with endocardial ablation only (8.3% vs 43.1%; log-rank P = .032). After multivariate adjustment, epicardial ablation remained associated with a reduced risk of VT recurrence (hazard ratio, 0.14; 95% confidential interval, 0.02-0.98; P = .048).

CONCLUSION

Patients with ICM undergoing VT ablation without a backup ICD experienced a notably low rate of arrhythmic death. Most recurrences proved nonlethal.

The Current State of Coronary Revascularization: Coronary Artery Bypass Graft Surgery Versus Percutaneous Coronary Interventions

PURPOSE OF REVIEW

The optimal revascularization strategy for coronary artery disease depends on various factors, such as disease complexity, patient characteristics, and preferences. Including a heart team in complex cases is crucial to ensure optimal outcomes. Decision-making between percutaneous coronary intervention and coronary artery bypass grafting must consider each patient's clinical profile and coronary anatomy. While current practice guidelines offer some insight into the optimal revascularization approach for the various phenotypes of coronary artery disease, the evidence to support either strategy continues to evolve and grow. Given the large amount of contemporary data on revascularization, this review aims to comprehensively summarize the literature on coronary artery bypass grafting and percutaneous coronary intervention in patients across the spectrum of coronary artery disease phenotypes.

RECENT FINDINGS

Contemporary evidence suggests that for patients with triple vessel disease, coronary artery bypass grafting is preferred over percutaneous coronary intervention due to better long-term outcomes, including lower rates of death, myocardial infarction, and target vessel revascularization. Similarly, for patients with left main coronary artery disease, both percutaneous coronary intervention and coronary artery bypass grafting can be considered, as they have shown similar efficacy in terms of major adverse cardiac events, but there may be a slightly higher risk of death with percutaneous coronary intervention. For proximal left anterior descending artery disease, both percutaneous coronary intervention and coronary artery bypass grafting are viable options, but coronary artery bypass grafting has shown lower rates of repeat revascularization and better relief from angina. The Synergy Between PCI with Taxus and Cardiac Surgery score can help in decision-making by predicting the risk of adverse events and guiding the choice between percutaneous coronary intervention and coronary artery bypass grafting. European and American guidelines both agree with including a heart team that can develop and lay out individualized, optimal treatment options with respect for patient preferences. The debate between coronary artery bypass grafting versus percutaneous coronary intervention in multiple different scenarios will continue to develop as technology and techniques improve for both procedures. Risk factors, pre, peri, and post-procedural complications involved in both revascularization strategies will continue to be mitigated to optimize outcomes for those patients for which coronary artery bypass grafting or percutaneous coronary intervention provide ultimate benefit. Methods to avoid unnecessary revascularization continue to develop as well as percutaneous technology that may allow patients to avoid surgical intervention when possible. With such changes, revascularization guidelines for specific patient populations may change in the coming years, which can serve as a limitation of this time-dated review.

Integrative Single-Cell Analysis of Cardiomyopathy Identifies Differences in Cell Stemness and Transcriptional Regulatory Networks among Fibroblast Subpopulations

Background

Cardiomyopathy encompasses a broad spectrum of diseases affecting myocardial tissue, characterized clinically by abnormalities in cardiac structure, heart failure, and/or arrhythmias. Clinically heterogeneous, major types include dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RM), ischemic cardiomyopathy (ICM), among which DCM is more prevalent, while ICM exhibits higher incidence and mortality rates. Myocardial injury during cardiomyopathy progression may lead to myocardial fibrosis. Failure to intervene early and inhibit the process of myocardial fibrosis may culminate in heart failure. Cardiac fibroblasts constitute crucial cellular components determining the extent and quality of myocardial fibrosis, with various subpopulations exerting diverse roles in cardiomyopathy progression. Despite this, understanding of the cellular plasticity and transcriptional regulatory networks of cardiac fibroblasts in cardiomyopathy remains limited. Therefore, in this study, we conducted comprehensive single-cell analysis of cardiac fibroblasts in cardiomyopathy to explore differences in cellular plasticity and transcriptional regulatory networks among fibroblast subpopulations, with the aim of providing as many useful references as possible for the diagnosis, prognosis, and treatment of cardiomyopathy.

Materials and Methods

Cells with mitochondrial gene expression comprising >20% of total expressed genes were excluded. Differential expression genes (DEGs) and stemness genes within cardiac fibroblast subpopulations were subjected to Gene Ontology (GO) analysis of biological processes (BP) and AUCell analysis. Monocle software was employed to analyze the pseudo-temporal trajectory of cardiac fibroblasts in cardiomyopathy. Additionally, the Python package SCENIC was utilized to assess enrichment of transcription factors and activity of regulators within cardiac fibroblast subpopulations in cardiomyopathy.

Results

Following batch effect correction, 179,927 cells were clustered into 32 clusters, designated as T_NK cells, endothelial cells, myeloid cells, fibroblasts, pericytes, SMCs, CMs, proliferating cells, EndoCs, and EPCs. Among them, 8148 fibroblasts were further subdivided into 4 subpopulations, namely C0 THBS4+ Fibroblasts, C1 LINC01133+ Fibroblasts, C2 FGF7+ Fibroblasts, and C3 AGT + Fibroblasts. Results from GO_BP and AUCell analyses suggest that C3 AGT + Fibroblasts may be associated with immune response activation, protein transport, and myocardial contractile function, correlating with disease progression in cardiomyopathy. Transcription factor enrichment analysis indicates that FOS is the most significant TF in C3 AGT + Fibroblasts, also associated with the M1 module, possibly implicated in protein hydrolysis, intracellular DNA replication, and cell proliferation. Moreover, correlation analysis of transcriptional regulatory activity between fibroblast subpopulations reveals a more pronounced heterogeneity within C3 AGT + Fibroblasts in cardiomyopathy.

Conclusion

C3 AGT + Fibroblasts exhibit increased sensitivity towards adverse outcomes in cardiomyopathy, such as myocardial fibrosis and impaired cardiac contractile function, compared to other cardiac fibroblast subpopulations. The differential cellular plasticity and transcriptional regulatory activity between C3 AGT + Fibroblasts and other subgroups offer new perspectives for targeting fibroblast subpopulation activity to treat cardiomyopathy. Additionally, stemness genes EPAS1 and MYC, along with the regulator FOS, may play roles in modulating the biological processes of cardiac fibroblasts in cardiomyopathy.

A treatment algorithm for ischemic cardiomyopathy

Treatment of ischemic cardiomyopathy has been the focus of increased attention by cardiologists due to recent evidence of an important outcome study comparing percutaneous coronary intervention (PCI) plus optimal medical treatment vs optimal medical treatment alone, concluding for the futility of myocardial revascularization by PCI. A relatively older trial of coronary artery bypass grafting (CABG) in the same condition, on the other hand, had concluded for some prognostic improvement at a long-term follow-up. This short manuscript addresses how to triage such patients, frequently encountered in medical practice and considering clinical presentation, imaging results, and surgical risk, to provide practical guidance to treatment.

Comparison of mid-term mortality after surgical, supported or unsupported percutaneous revascularization in patients with severely reduced ejection fraction: A direct and network meta-analysis of adjusted observational studies and randomized-controlled

INTRODUCTION

The optimal revascularization strategy in patients with heart failure with reduced ejection fraction (HFrEF) remains to be elucidated. The aim of this paper is to compare the mid-term mortality rate among patients with severely reduced ejection fraction (EF) and complex coronary artery disease who underwent coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI) with Impella support, or without.

METHODS

Randomized control trials and propensity-adjusted observational studies including patients with ischemic cardiomyopathy (ICM) and severe EF reduction undergoing revascularization were selected. Different revascularization strategies (CABG, supported PCI, and PCI without Impella) were compared in pairwise and network meta-analysis. The primary endpoint was mid-term mortality (within the first year after revascularization).

RESULTS

Fifteen studies, mostly observational (17,841 patients; 6779 patients treated with CABG, 8478 treated with PCI without Impella, and 2584 treated with Impella-supported PCI) were included in this analysis. The median age was 67.8 years (IQR 65-70.1), 21.2% (IQR 16.4-26%) of patients were female sex, and a high prevalence of cardiovascular risk factors was noted across the entire population. At pairwise analysis, CABG and PCI without Impella showed similar one-year all-cause mortality (10.6% [IQR 7.5-12.6%] vs 12% [IQR 8.4-11.5%]) RR 0.85 CI 0.67-1.09, while supported PCI reduced one-year all-cause mortality compared to PCI without Impella (9.4% [IQR 5.7-12.5%] vs 10.6% [IQR 8.9-10.7%]) RR 0.77 CI 0.6-0.89. At network meta-analysis, supported PCI showed better results (RR 0.75, 95% CI 0.59-0.94) compared to CABG.

CONCLUSION

Our analysis found that supported PCI may have a benefit over standard PCI in patients in direct comparison, and over CABG from indirect comparison, and with HFrEF undergoing revascularization. Further RCTs are needed to confirm this result. (PROSPERO CRD42023425667).

Incremental prognostic utility of left ventricular and left atrial strains in coronary artery disease patients with reduced systolic function

OBJECTIVE

This study aimed to investigate the predictive value of left ventricular global longitudinal strain (GLS) and left atrial reservoir strain (LARS) on adverse events in chronic coronary artery disease (CAD) patients with reduced systolic function.

METHODS

A total of 192 consecutive patients clinically diagnosed with chronic CAD and left ventricular ejection fraction (LVEF) ≤ 50% were finally included. Multiple strain parameters were analyzed with speckle tracking echocardiography. The composite endpoint included all-cause mortality, rehospitalization due to heart failure, myocardial infarction, and stroke.

RESULTS

Patients experiencing the endpoint showed lower LVEF, lower absolute GLS and LARS than those without events. Both GLS (AUC = 0.82 [GLS] vs. 0.58 [LVEF], p < 0.001) and LARS (AUC = 0.71 [LARS] vs. 0.58 [LVEF], p = 0.033) were superior to LVEF in predicting adverse events. Multivariate cox regression analysis showed that both GLS (hazard ratio, 0.71; 95% CI, 0.63-0.79; p < 0.001) and LARS (hazard ratio, 0.96; 95% CI, 0.93-0.98; p < 0.001) were independent predictors for the endpoint. The addition of LARS (global chi-squared, 35.7 vs. 17.4; p < 0.05), GLS (global chi-squared, 58.6 vs. 17.4; p < 0.05) or both LARS and GLS (global chi-squared, 79.6 vs. 17.4; p < 0.05) to LVEF in the prediction model significantly improved its performance. The same significant improvement was also shown in the subgroups of mild (30% < LVEF ≤ 50%) and severe (LVEF ≤ 30%) reduced systolic function.

CONCLUSIONS

Regarding CAD patients with reduced LVEF, both GLS and LARS are superior to LVEF in predicting adverse events, providing significant incremental value to LVEF.

Ischemic cardiomyopathy: epidemiology, pathophysiology, outcomes, and therapeutic options

Ischemic cardiomyopathy (ICM) is the most prevalent cause of heart failure (HF) in developed countries, with significant morbidity and mortality, despite constant improvements in the management of coronary artery disease. Current literature on this topic remains fragmented. Therefore, this review aimed to summarize the most recent data on ICM, focusing on its definition, epidemiology, outcomes, and therapeutic options. The most widely accepted definition is represented by a left ventricular dysfunction in the presence of significant coronary artery disease. The prevalence of ICM is largely influenced by age and sex, with older individuals and males being more affected. Its pathophysiology is characterized by plaque buildup, thrombus formation, hypoperfusion, ischemic cell death, and left ventricular remodeling. Despite improvements in therapy, ICM still represents a public health burden, with a 1-year mortality rate of 16% and a 5-year mortality rate of approximately 40% in the USA and Europe. Therefore, optimization of cardiovascular function, prevention of progressive remodeling, reduction of HF symptoms, and improved survival are the main goals of treatment. Therapeutic options for ICM include lifestyle changes, optimal medical therapy, revascularization, device therapy, mechanical circulatory support, and cardiac transplantation. Personalized management strategies and tailored patient care are needed to improve the outcomes of patients with ICM.

Clinical efficacy and safety of adjunctive treatment of chronic ischemic heart failure with Qishen Yiqi dropping pills: a systematic review and meta-analysis

Objectives

Our study was to evaluate the effect of Qishen Yiqi Dropping Pills(QSYQ) on the prognosis of chronic ischemic heart failure(CIHF) and its safety.

Methods

Databases including CNKI, Wanfang, VIP, CBM, PubMed, Web of Science, The Cochrane Library and EMbase were searched from their inception to April 2023 to screen relevant randomized controlled trials (RCTs). Primary indicators included readmission rates, rates of major adverse cardiovascular events (MACE), and all-cause mortality rates. The quality of the literature was assessed according to the Cochrane Reviewers' Handbook 5.0 and the Modified Jadad Scale (with a score of 4-7 rated as high quality). Meta-analysis was performed using the meta-package created by R software version 4.2.3, continuous data were compared using SMDs, and dichotomous and ordered data were compared using ORs; and the I2 test was used to assess the heterogeneity.

Results

Fifty-nine studies out of 1,745 publications were finally included, totalling 6,248 patients. Most studies were poorly designed and had some publication bias, with only 26 high-quality papers (Jadad score ≥4). Meta-analysis showed that the combined application of QSYQ was able to reduce the readmission rate [OR = 0.42, 95% CI (0.33, 0.53), P < 0.001], all-cause mortality rate [OR = 0.43, 95% CI (0.27, 0.68), P < 0.001], and the incidence of MACE [OR = 0.42, 95% CI (0.31, 0.56), P < 0.001]. Also, the treatment method can improve clinical effectiveness [OR = 2.25, 95% CI (1.97, 2.58), P < 0.001], increase 6-min walking distance (6MWD) [SMD = 1.87, 95% CI (1.33, 2.41), P < 0.0001] and left ventricular ejection fraction (LVEF) [SMD = 1.08, 95% CI (0.83, 1.33), P < 0.0001], and decrease the Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores [SMD = -2.03, 95% CI (-3.0, -1.07), P < 0.0001], BNP levels [SMD = -2.07, 95% CI (-2.81, -1.33), P < 0.0001] and NT-ProBNP levels [SMD = -2.77, 95% CI (-4.90, -0.63), P < 0.05]. A total of 21 studies (n = 2,742) evaluated their adverse effects, of which 13 studies reported no adverse effects and 8 studies reported minor adverse effects.

Conclusion

Our results suggest that the combined application of QSYQ can further improve patients' cardiac function and exercise tolerance, improve their quality of life, and ultimately improve patients' prognosis with a favorable safety profile. Nonetheless, limited by the quality and high heterogeneity of the literature, we must be conservative and cautious about the present results.

Systematic Review Registration

PROSPERO (CRD42023449251).

Ethyl ferulate suppresses post-myocardial infarction myocardial fibrosis by inhibiting transforming growth factor receptor 1

BACKGROUND

With an increasing number of myocardial infarction (MI) patients, myocardial fibrosis is becoming a widespread health concern. It's becoming more and more urgent to conduct additional research and investigations into efficient treatments. Ethyl ferulate (EF) is a naturally occurring substance with cardioprotective properties. However, the extent of its impact and the underlying mechanism of its treatment for myocardial fibrosis after MI remain unknown.

PURPOSE

The goal of this study was to look into how EF affected the signaling of the TGF-receptor 1 (TGFBR1) in myocardial fibrosis after MI.

METHODS

Echocardiography, hematoxylin-eosin (HE) and Masson trichrome staining were employed to assess the impact of EF on heart structure and function in MI-affected mice in vivo. Cell proliferation assay (MTS), 5-Ethynyl-2'-deoxyuridine (EdU), and western blot techniques were employed to examine the influence of EF on native cardiac fibroblast (CFs) proliferation and collagen deposition. Molecular simulation and surface plasmon resonance imaging (SPRi) were utilized to explore TGFBR1 and EF interaction. Cardiac-specific Tgfbr1 knockout mice (Tgfbr1ΔMCK) were utilized to testify to the impact of EF.

RESULTS

In vivo experiments revealed that EF alleviated myocardial fibrosis, improved cardiac dysfunction after MI and downregulated the TGFBR1 signaling in a dose-dependent manner. Moreover, in vitro experiments revealed that EF significantly inhibited CFs proliferation, collagen deposition and TGFBR1 signaling followed by TGF-β1 stimulation. More specifically, molecular simulation, molecular dynamics, and SPRi collectively showed that EF directly targeted TGFBR1. Lastly, knocking down of Tgfbr1 partially reversed the inhibitory activity of EF on myocardial fibrosis in MI mice.

CONCLUSION

EF attenuated myocardial fibrosis post-MI by directly suppressing TGFBR1 and its downstream signaling pathway.

Heart failure in patients is associated with downregulation of mitochondrial quality control genes

BACKGROUND

Mitochondrial dysfunction is one of key factors causing heart failure. We performed a comprehensive analysis of expression of mitochondrial quality control (MQC) genes in heart failure.

METHODS

Myocardial samples were obtained from patients with ischemic and dilated cardiomyopathy in a terminal stage of heart failure and donors without heart disease. Using quantitative real-time PCR, we analysed a total of 45 MQC genes belonging to mitochondrial biogenesis, fusion-fission balance, mitochondrial unfolded protein response (UPRmt), translocase of the inner membrane (TIM) and mitophagy. Protein expression was analysed by ELISA and immunohistochemistry.

RESULTS

The following genes were downregulated in ischemic and dilated cardiomyopathy: COX1, NRF1, TFAM, SIRT1, MTOR, MFF, DNM1L, DDIT3, UBL5, HSPA9, HSPE1, YME1L, LONP1, SPG7, HTRA2, OMA1, TIMM23, TIMM17A, TIMM17B, TIMM44, PAM16, TIMM22, TIMM9, TIMM10, PINK1, PARK2, ROTH1, PARL, FUNDC1, BNIP3, BNIP3L, TPCN2, LAMP2, MAP1LC3A and BECN1. Moreover, MT-ATP8, MFN2, EIF2AK4 and ULK1 were downregulated in heart failure from dilated, but not ischemic cardiomyopathy. VDAC1 and JUN were only genes that exhibited significantly different expression between ischemic and dilated cardiomyopathy. Expression of PPARGC1, OPA1, JUN, CEBPB, EIF2A, HSPD1, TIMM50 and TPCN1 was not significantly different between control and any form of heart failure. TOMM20 and COX proteins were downregulated in ICM and DCM.

CONCLUSIONS

Heart failure in patients with ischemic and dilated cardiomyopathy is associated with downregulation of large number of UPRmt, mitophagy, TIM and fusion-fission balance genes. This indicates multiple defects in MQC and represents one of potential mechanisms underlying mitochondrial dysfunction in patients with heart failure.

The Evolving Paradigm of Revascularization in Ischemic Cardiomyopathy: from Recovery of Systolic Function to Protection Against Future Ischemic Events

PURPOSE OF REVIEW

We aim to reevaluate how the assessment of myocardial viability can guide optimal treatment strategies for patients with ischemic cardiomyopathy (ICM) based on a more contemporary understanding of the mechanism of benefit of revascularization.

RECENT FINDINGS

The assessment of viability in left ventricular (LV) segments with diminished contraction has been proposed as key to predict the benefit of revascularization and, therefore, as a requisite for the selection of patients to undergo this form of treatment. However, data from prospective trials have diverged from earlier retrospective studies. Traditional binary viability assessment may oversimplify ICM's complexity and the nuances of revascularization benefits. A conceptual shift from the traditional paradigm centered on the assessment of viability as a dichotomous variable to a more comprehensive approach encompassing a thorough understanding of ICM's complex pathophysiology and the salutary effect of revascularization in the prevention of myocardial infarction and ventricular arrhythmias is required.

Echocardiography-based machine learning algorithm for distinguishing ischemic cardiomyopathy from dilated cardiomyopathy

BACKGROUND

Machine learning (ML) can identify and integrate connections among data and has the potential to predict events. Heart failure is primarily caused by cardiomyopathy, and different etiologies require different treatments. The present study examined the diagnostic value of a ML algorithm that combines echocardiographic data to automatically differentiate ischemic cardiomyopathy (ICM) from dilated cardiomyopathy (DCM).

METHODS

We retrospectively collected the echocardiographic data of 200 DCM patients and 199 ICM patients treated in the First Affiliated Hospital of Guangxi Medical University between July 2016 and March 2022. All patients underwent invasive coronary angiography for diagnosis of ICM or DCM. The data were randomly divided into a training set and a test set via 10-fold cross-validation. Four ML algorithms (random forest, logistic regression, neural network, and XGBoost [ML algorithm under gradient boosting framework]) were used to generate a training model for the optimal subset, and the parameters were optimized. Finally, model performance was independently evaluated on the test set, and external validation was performed on 79 patients from another center.

RESULTS

Compared with the logistic regression model (area under the curve [AUC] = 0.925), neural network model (AUC = 0.893), and random forest model (AUC = 0.900), the XGBoost model had the best identification rate, with an average sensitivity of 72% and average specificity of 78%. The average accuracy was 75%, and the AUC of the optimal subset was 0.934. External validation produced an AUC of 0.804, accuracy of 78%, sensitivity of 64% and specificity of 93%.

CONCLUSIONS

We demonstrate that utilizing advanced ML algorithms can help to differentiate ICM from DCM and provide appreciable precision for etiological diagnosis and individualized treatment of heart failure patients.

Comprehensive Characterization of Endogenous Phospholamban Proteoforms Enabled by Photocleavable Surfactant and Top-down Proteomics

Top-down mass spectrometry (MS)-based proteomics has become a powerful tool for analyzing intact proteins and their associated post-translational modifications (PTMs). In particular, membrane proteins play critical roles in cellular functions and represent the largest class of drug targets. However, the top-down MS characterization of endogenous membrane proteins remains challenging, mainly due to their intrinsic hydrophobicity and low abundance. Phospholamban (PLN) is a regulatory membrane protein located in the sarcoplasmic reticulum and is essential for regulating cardiac muscle contraction. PLN has diverse combinatorial PTMs, and their dynamic regulation has significant influence on cardiac contractility and disease. Herein, we have developed a rapid and robust top-down proteomics method enabled by a photocleavable anionic surfactant, Azo, for the extraction and comprehensive characterization of endogenous PLN from cardiac tissue. We employed a two-pronged top-down MS approach using an online reversed-phase liquid chromatography tandem MS method on a quadrupole time-of-flight MS and a direct infusion method via an ultrahigh-resolution Fourier-transform ion cyclotron resonance MS. We have comprehensively characterized the sequence and combinatorial PTMs of endogenous human cardiac PLN. We have shown the site-specific localization of phosphorylation to Ser16 and Thr17 by MS/MS for the first time and the localization of S-palmitoylation to Cys36. Moreover, we applied our method to characterize PLN in disease and reported the significant reduction of PLN phosphorylation in human failing hearts with ischemic cardiomyopathy. Taken together, we have developed a streamlined top-down targeted proteomics method for comprehensive characterization of combinatorial PTMs in PLN toward better understanding the role of PLN in cardiac contractility.

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Defining the Sarcomeric Proteoform Landscape in Ischemic Cardiomyopathy by Top-Down Proteomics

Ischemic cardiomyopathy (ICM) is a prominent form of heart failure, but the molecular mechanisms underlying ICM remain relatively understudied due to marked phenotypic heterogeneity. Alterations in post-translational modifications (PTMs) and isoform switches in sarcomeric proteins play important roles in cardiac pathophysiology. Thus, it is essential to define sarcomeric proteoform landscape to better understand ICM. Herein, we have implemented a top-down liquid chromatography (LC)-mass spectrometry (MS)-based proteomics method for the identification and quantification of sarcomeric proteoforms in the myocardia of donors without heart diseases (n = 16) compared to end-stage ICM patients (n = 16). Importantly, quantification of post-translational modifications (PTMs) and expression reveal significant changes in various sarcomeric proteins extracted from ICM tissues. Changes include altered phosphorylation and expression of cardiac troponin I (cTnI) and enigma homologue 2 (ENH2) as well as an increase in muscle LIM protein (MLP) and calsarcin-1 (Cal-1) phosphorylation in ICM hearts. Our results imply that the contractile apparatus of the sarcomere is severely dysregulated during ICM. Thus, this is the first study to uncover significant molecular changes to multiple sarcomeric proteins in the LV myocardia of the end-stage ICM patients using liquid chromatography-mass spectrometry (LC-MS)-based top-down proteomics. Raw data are available via the PRIDE repository with identifier PXD038066.

Identification MNS1, FRZB, OGN, LUM, SERP1NA3 and FCN3 as the potential immune-related key genes involved in ischaemic cardiomyopathy by random forest and nomogram

The immune molecular mechanisms involved in ischaemic cardiomyopathy (ICM) have not been fully elucidated. The current study aimed to elucidate the immune cell infiltration pattern of the ICM and identify key immune-related genes that participate in the pathologic process of the ICM. The differentially expressed genes (DEGs) were identified from two datasets (GSE42955 combined with GSE57338) and the top 8 key DEGs related to ICM were screened using random forest and used to construct the nomogram model. Moreover, the "CIBERSORT" software package was used to determine the proportion of infiltrating immune cells in the ICM. A total of 39 DEGs (18 upregulated and 21 downregulated) were identified in the current study. Four upregulated DEGs, including MNS1, FRZB, OGN, and LUM, and four downregulated DEGs, SERP1NA3, RNASE2, FCN3 and SLCO4A1, were identified by the random forest model. The nomogram constructed based on the above 8 key genes suggested a diagnostic value of up to 99% to distinguish the ICM from healthy participants. Meanwhile, most of the key DEGs presented prominent interactions with immune cell infiltrates. The RT-qPCR results suggested that the expression levels of MNS1, FRZB, OGN, LUM, SERP1NA3 and FCN3 between the ICM and control groups were consistent with the bioinformatic analysis results. These results suggested that immune cell infiltration plays a critical role in the occurrence and progression of ICM. Several key immune-related genes, including the MNS1, FRZB, OGN, LUM, SERP1NA3 and FCN3 genes, are expected to be reliable serum markers for the diagnosis of ICM and potential molecular targets for ICM immunotherapy.

Physician preferences for revascularization in patients with ischemic cardiomyopathy: Defining equipoise from web-based surveys

Background

The optimal revascularization approach in patients with heart failure with reduced ejection fraction (HFrEF) and ischemic heart disease ("ischemic cardiomyopathy") is unknown. Physician preferences regarding clinical equipoise for mode of revascularization and their willingness to consider offering enrollment in a randomized trial to patients with ischemic cardiomyopathy have not been characterized.

Methods

We conducted two anonymous online surveys: 1) a clinical case scenario-based survey to assess willingness to offer clinical trial enrollment for a patient with ischemic cardiomyopathy (overall response rate to email invitation 0.45 %), and 2) a Delphi consensus-building survey to identify specific areas of clinical equipoise (overall response rate to email invitation 37 %).

Results

Among 304 physicians responding to the clinical case scenario-based survey, the majority were willing to offer the opportunity for clinical trial enrollment to a prototypical patient with ischemic cardiomyopathy (92 %), and felt that a finding of non-inferiority for PCI vs. CABG would influence their clinical practice (78 %). Among 53 physicians responding to the Delphi consensus-building survey, the median appropriateness rating for CABG was significantly higher than that of PCI (p < 0.0001). In 17 scenarios (11.8 %), there was no difference in CABG or PCI appropriateness ratings, suggesting clinical equipoise in these settings.

Conclusions

Our findings demonstrate willingness to consider offering enrollment in a randomized clinical trial and areas of clinical equipoise, two factors that support the feasibility of a randomized trial to compare clinical outcomes after revascularization with CABG vs. PCI in selected patients with ischemic cardiomyopathy, suitable coronary anatomy and co-morbidity profile.

Identification and validation of ferroptosis-related genes and immune infiltration in ischemic cardiomyopathy

Background

Cardiomyocyte death is an important pathophysiological basis for ischemic cardiomyopathy (ICM). Many studies have suggested that ferroptosis is a key link in the development of ICM. We performed bioinformatics analysis and experiment validation to explore the potential ferroptosis-related genes and immune infiltration of ICM.

Methods

We downloaded the datasets of ICM from the Gene Expression Omnibus database and analyzed the ferroptosis-related differentially expressed genes (DEGs). Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and protein-protein interaction network were performed to analyze ferroptosis-related DEGs. Gene Set Enrichment Analysis was used to evaluate the gene enrichment signaling pathway of ferroptosis-related genes in ICM. Then, we explored the immune landscape of patients with ICM. Finally, the RNA expression of the top five ferroptosis-related DEGs was validated in blood samples from patients with ICM and healthy controls using qRT-PCR.

Results

Overall, 42 ferroptosis-related DEGs (17 upregulated and 25 downregulated genes) were identified. Functional enrichment analysis indicated several enriched terms related to ferroptosis and the immune pathway. Immunological analysis suggested that the immune microenvironment in patients with ICM is altered. The immune checkpoint-related genes (PDCD1LG2, LAG3, and TIGIT) were overexpressed in ICM. The qRT-PCR results showed that the expression levels of IL6, JUN, STAT3, and ATM in patients with ICM and healthy controls were consistent with the bioinformatics analysis results from the mRNA microarray.

Conclusion

Our study showed significant differences in ferroptosis-related genes and functional pathway between ICM patients and healthy controls. We also provided insight into the landscape of immune cells and the expression of immune checkpoints in patients with ICM. This study provides a new road for future investigation of the pathogenesis and treatment of ICM.

Left Main Coronary Artery Disease-Current Management and Future Perspectives

Due to its anatomical features, patients with an obstruction of the left main coronary artery (LMCA) have an increased risk of death. For years, coronary artery bypass grafting (CABG) has been considered as a gold standard for revascularization. However, notable advancements in the field of percutaneous coronary intervention (PCI) led to its acknowledgement as an important treatment alternative, especially in patients with low and intermediate anatomical complexity. Although recent years brought several random clinical trials that investigated the safety and efficacy of the percutaneous approach in LMCA, there are still uncertainties regarding optimal revascularization strategies. In this paper, we provide a comprehensive review of state-of-the-art diagnostic and treatment methods of LMCA disease, focusing on percutaneous methods.

Network Pharmacology Analysis and Experimental Verification Strategies Reveal the Action Mechanism of Danshen Decoction in Treating Ischemic Cardiomyopathy

Background

Danshen Decoction comprises Salvia miltiorrhiza, Santalum album, and Amomum villosum. It can promote blood circulation and remove blood stasis, and is commonly used in the treatment of gastric and duodenal ulcers, coronary heart disease, angina pectoris, etc. This research is based on network pharmacology and is experimentally verified to explore the potential mechanism of Danshen Decoction in the treatment of ischemic cardiomyopathy (ICM).

Methods

The effective components and targets of Danshen Decoction were firstly extracted from Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform, the drug-component-target-disease network was then constructed, the protein-protein interaction (PPI) network was constructed, the Gene Ontology (GO) enrichment analysis was carried out, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was analyzed in order to find the potential active components and therapeutic mechanisms. Finally, the in vitro hypoxia/reoxygenation model in H9c2 cells was established to verify the predicted active components and therapeutic mechanisms.

Results

The results showed that Danshen Decoction has 67 potential active components and 109 therapeutic targets in treating ICM. These targets were rich in a variety of gene functions and different signaling pathways; the main gene targets include TP53, c-Jun, and Akt1. Go enrichment analysis showed that response to drug, membrane raft, and G protein-coupled amine receiver activity rank first in each process, and the main signaling pathways include PI3K-Akt signaling pathway. Through molecular docking and experimental verification of the major active components and core therapeutic targets, the active components of Danshen Decoction demonstrated an ability to reduce the cell damage caused by hypoxia/reoxygenation in H9c2 cells by regulating the core therapeutic target including Akt1, c-Jun, and TP53.

Conclusion

Danshen Decoction has the effect of treating ICM in multiple ways, which is consistent with the results of network pharmacology. This laid a foundation for further study in exploring the active principles and pharmacological mechanism of Danshen Decoction.

DNMT3B System Dysregulation Contributes to the Hypomethylated State in Ischaemic Human Hearts

A controversial understanding of the state of the DNA methylation machinery exists in ischaemic cardiomyopathy (ICM). Moreover, its relationship to other epigenetic alterations is incomplete. Therefore, we carried out an in-depth study of the DNA methylation process in human cardiac tissue. We showed a dysregulation of the DNA methylation machinery accordingly with the genome-wide hypomethylation that we observed: specifically, an overexpression of main genes involved in the elimination of methyl groups (TET1, SMUG1), and underexpression of molecules implicated in the maintenance of methylation (MBD2, UHRF1). By contrast, we found DNMT3B upregulation, a key molecule in the addition of methyl residues in DNA, and an underexpression of miR-133a-3p, an inhibitor of DNMT3B transcription. However, we found many relevant alterations that would counteract the upregulation observed, such as the overexpression of TRAF6, responsible for Dnmt3b degradation. Furthermore, we showed that molecules regulating Dnmts activity were altered; specifically, SAM/SAH ratio reduction. All these results are in concordance with the Dnmts normal function that we show. Our analysis revealed genome-wide hypomethylation along with dysregulation in the mechanisms of addition, elimination and maintenance of methyl groups in the DNA of ICM. We describe relevant alterations in the DNMT3B system, which promote a normal Dnmt3b function despite its upregulation.

Depressive Symptoms and Incident Hospitalization for Heart Failure: Findings From the REGARDS Study

Background Depressive symptoms are risk factors for several forms of cardiovascular disease including coronary heart disease (CHD). However, it is unclear whether depressive symptoms are associated with incident heart failure (HF), including hospitalization for HF overall or by subtype: HF with preserved (HFpEF) or reduced ejection fraction (HFrEF). Methods and Results Among 26 268 HF-free participants in the REGARDS (Reasons for Geographic And Racial Differences in Stroke) study, a prospective biracial cohort of US community-dwelling adults ≥45 years, baseline depressive symptoms were defined as a score ≥4 on the 4-item Center for Epidemiologic Studies Depression scale. Incident HF hospitalizations were expert-adjudicated and categorized as HFpEF (EF ≥50%) and HFrEF, including mid-range EF (EF<50%). Over a median of 9.2 [IQR 6.2-10.9] years of follow-up, there were 872 incident HF hospitalizations, 526 among those without CHD and 334 among those with CHD. The age-adjusted HF hospitalization incidence rates per 1000 person-years were 4.9 (95% CI 4.0-5.9) for participants with depressive symptoms versus 3.2 (95% CI 3.0-3.5) for those without depressive symptoms (P<0.001). For overall HF, the elevated risk became attenuated after controlling for covariates. When HFpEF was assessed separately, depressive symptoms were associated with incident hospitalization after controlling for all covariates (hazard ratio [HR] 1.48, 95% CI 1.00-2.18) among those without baseline CHD. In contrast, depressive symptoms were not associated with incident HFrEF hospitalizations. Conclusions Among individuals free of CHD at baseline, depressive symptoms were associated with incident hospitalization for HFpEF, but not for HFrEF, or among those with baseline CHD.

Applications of Tissue Decellularization Techniques in Ventricular Myocardial Biofabrication

Ischemic heart disease is the leading cause of death around the world, and though the advent of coronary revascularization has revolutionized its treatment, many patients who sustain ischemic injury to the heart will go on to develop heart failure. Biofabrication of ventricular myocardium for replacement of irreversibly damaged ischemic myocardium is sought after as a potential therapy for ischemic heart failure, though challenges in reliably producing this biomaterial have limited its clinical application. One method that shows promise for generation of functional myocardium is the use of tissue decellularization to serve as a scaffold for biofabrication. This review outlines the methods, materials, challenges, and prospects of tissue decellularization techniques for ventricular myocardium biofabrication. Decellularization aims to preserve the architecture and composition of the extracellular matrix of the tissue it is applied to, allowing for the subsequent implantation of stem cells of the desired cell type. Decellularization can be achieved with multiple reagents, most of which have detergent properties. A variety of cell types can be implanted in the resulting scaffold, including cardiac progenitor cells, and embryonic or induced pluripotent stem cells to generate a range of tissue, from patches to beating myocardium. The future of this biofabrication method will likely emphasize patient specific tissue engineering to generate complex 3-dimensional constructs that can replace dysfunctional cardiac structures.

Catecholamine-induced cardiomyopathy: an endocrinologist's perspective

Although many endocrine diseases can be associated with acquired cardiomyopathy and heart failure, conditions except hypothyroidism, hyperthyroidism, phaeochromocytoma-paraganglioma (PPGL), and primary hyperaldosteronism are rare. PPGL is a rare catecholamine-secreting neuroendocrine tumour arising from the adrenal gland in 80-85% or extra-adrenal chromaffin cells of the autonomic neural ganglia in the remainder. The annual incidence of PPGL is 3-8 cases per million per year in the general population. Catecholamine-induced cardiomyopathy (CICMP) has got a prevalence of 8-11% among patients with PPGL. Hypertension, either sustained or episodic, is present in the vast majority (95%) of PPGL patients. However, among patients with CICMP, hypertension is present only in 65% of cases and the classical triad of paroxysmal headache, sweating, and palpitation is present only in 4%. Based on the cardiac remodelling in response to endogenous catecholamine excess, PPGL patients might present with one of the three CICMPs, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), or Takotsubo cardiomyopathy (TCM). Regardless of the subtypes, all CICMPs have many features in common - a dramatic clinical presentation, reversible cardiomyopathy, similar repolarisation electrocardiography changes, mild-moderate cardiac biomarker elevation, and normal coronary arteries on coronary angiography. CICMP should be suspected in patients with non-ischaemic, non-valvular forms of cardiomyopathy, even in those without definite features of catecholamine excess. PPGL associated TCM should be suspected in all acute coronary syndrome (ACS) patients exhibiting pronounced blood pressure variability with no culprit lesions on coronary angiography. This article will provide a review of the various CICMPs, their pathophysiology, clinical features, and the management options.

Analysis of Selected Cardiovascular Biomarkers in Takotsubo Cardiomyopathy and the Most Frequent Cardiomyopathies

Introduction: Among the causes of de novo diagnosed cardiomyopathy, Takotsubo cardiomyopathy (TTC) plays a minor role, with an occurrence of 50,000–100,000 cases per annum in the United States. In clinical practice, a differentiation of a TTC toward an ischemic cardiomyopathy (ICMP) or a dilatative cardiomyopathy (DCMP) appears to be challenging, especially in a subacute setting or in atypical types of TTC.

Methods: To investigate this issue, we analyzed serum levels of sST2, GDF-15, suPAR, HFABP, and clinical parameters including echocardiography in 51 patients with TTC, 52 patients with ischemic cardiomyopathy (ICMP) and 65 patients with dilated cardiomyopathy (DCMP).

Results: sST-2 seemed to be the most promising biomarker for prediction of a TTC in differential diagnosis to an ICMP (AUC: 0.879, p = < 0.001, Cut off values: 12,140.5 pg/ml) or to a DCMP (AUC: 0.881, p = < 0.001, cut off value: 14521.9 pg/ml). GDF-15 evidenced a slightly lower AUC for prediction of a TTC in differential diagnosis to an ICMP (AUC: 0.626, p = 0.028) and to a DCMP (AUC: 0.653, p = 0.007). A differential diagnostic value was found for H-FABP in the prediction of a DCMP compared to TTC patients (AUC: 0.686, p = < 0.001). In propensity score matching for left ventricular ejection fraction, sex, and cardiovascular risk factors, differences in the plasma levels of sST2 and H-FABP in the matched cohort of TTC vs. DCMP remained statistically significant. In the matched cohort of TTC vs. ICMP, differences in sST2 also remained statistically significant

Conclusion: As medical therapy, long term prognosis, interval of follow-ups, rehabilitation program and recommendations differ completely between TTC and ICMP/DCMP, biomarkers for differential diagnosis, or rather for confirmation of diagnosis, are warranted in cases of cardiomyopathies with unsure origin. sST-2, GDF-15 and H-FABP might facilitate the classification.

Identification of MYH6 as the potential gene for human ischaemic cardiomyopathy

The present study aimed to explore the potential hub genes and pathways of ischaemic cardiomyopathy (ICM) and to investigate the possible associated mechanisms. Two microarray data sets (GSE5406 and GSE57338) were downloaded from the Gene Expression Omnibus (GEO) database. The limma package was used to analyse the differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, Disease Ontology (DO) and Gene Ontology (GO) annotation analyses were performed. A protein‐protein interaction (PPI) network was set up using Cytoscape software. Significant modules and hub genes were identified by the Molecular Complex Detection (MCODE) app. Then, further functional validation of hub genes in other microarrays and survival analysis were performed to judge the prognosis. A total of 1065 genes were matched, with an adjusted p < 0.05, and 17 were upregulated and 25 were downregulated with|log₂ (fold change)|≥1.2. After removing the lengthy entries, GO identified 12 items, and 8 pathways were enriched at adjusted p < 0.05 (false discovery rate, FDR set at <0.05). Three modules with a score >8 after MCODE analysis and MYH6 were ultimately identified. When validated in GSE23561, MYH6 expression was lower in patients with CAD than in healthy controls (p < 0.05). GSE60993 data suggested that MYH6 expression was also lower in AMI patients (p < 0.05). In the GSE59867 data set, MYH6 expression was lower in CAD patients than in AMI patients and lower in heart failure (HF) patients than in non‐HF patients. However, there was no difference at different periods within half a year, and HF was increased when MYH6 expression was low (p < 0.05–0.01). We performed an integrated analysis and validation and found that MYH6 expression was closely related to ICM and HF. However, whether this marker can be used as a predictor in blood samples needs further experimental verification.

Human epididymis protein 4: a novel predictor of ischemic cardiomyopathy

Background

The prognostic value of human epididymis protein 4 (HE4) in patients with ischemic cardiomyopathy (ICM) is unknown.

Methods

A total of 103 patients with ICM were prospectively enrolled in this study from Hunan Provincial People’s Hospital between February 2019 and June 2019. All patients were tested for HE4 levels at baseline and follow-up. Endpoints of the study included cardiovascular death and heart failure-related hospitalization.

Results

A total of 96 patients with ICM were included for analysis. After a mean follow-up period of 263 (153–313) days, cardiovascular events were observed in 45 patients. Serum HE4 levels in patients with events were significantly higher than those in patients without events [188.70 (113.35–326.82) pmol/L versus 92.90 (61.50–123.20) pmol/L, P < 0.001]. Multivariate Cox regression analysis revealed that HE4 [χ²: 9.602, hazard ratio (HR): 1.003, 95% confidence interval (CI): 1.001–1.005, P = 0.002] and age [χ²: 4.55, HR: 1.044, 95% CI: 1.003–1.085, P = 0.033] were independent predictors of events. After adjusting for age and sex, the risk of events in patients with HE4 > 100.2 pmol/L was higher than that in patients with HE4 ≤ 100.2 pmol/L [HR: 3.372, 95% CI: 1.409–8.065, P < 0.001].

Conclusion

HE4 is an independent predictor of cardiovascular death and heart failure-related rehospitalization in patients with ICM.

Soluble fibrinogen‑like protein 2 levels are decreased in patients with ischemic heart failure and associated with cardiac function

Soluble fibrinogen‑like protein 2 (sFGL2), as a novel effector of regulatory T cells (Tregs), exhibits immune regulatory activity in several inflammatory diseases. Immune activation and persistent inflammation participate in the progression of ischemic heart failure (IHF). The present study aimed to determine serum sFGL2 levels in patients with IHF and explore the relationship between sFGL2 levels and cardiac function. A total of 104 patients with IHF and 32 healthy controls were enrolled. patients with IHF were further split into subgroups according to the New York Heart Association functional classification or left ventricular ejection fraction (LVEF). Serum sFGL2 levels and peripheral Tregs frequencies were analyzed by ELISA and flow cytometry, respectively. The suppressive function of Tregs was measured by proliferation and functional suppression assays. Serum levels of sFGL2 and circulating Tregs frequencies were significantly decreased in patients with IHF compared with healthy controls. In patients with IHF, sFGL2 levels and Tregs frequencies were decreased with the deterioration of cardiac function. Tregs from patients with IHF exhibited compromised ability to suppress CD4+CD25‑ T cells proliferation and inflammatory cytokines secretion. Specifically, sFGL2 levels and Tregs frequencies positively correlated with LVEF, whereas negatively correlated with left ventricular end‑diastolic dimension and N‑terminal pro‑brain natriuretic peptide. sFGL2 levels were positively correlated with Tregs frequencies. In conclusion, the reduction of serum sFGL2 levels are associated with the progression of IHF and sFGL2 could be used as a potential indicator for predicting disease severity.

Taohong siwu decoction attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via TGFBR1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Myocardial fibrosis after myocardial infarction (MI) leads to cardiac remodeling and loss of function. Taohong siwu decoction (THSWD), a well-known traditional Chinese medicinal prescription, has been clinically used to treat various cardiovascular and cerebrovascular diseases, but its potential functions in myocardial fibrosis after MI remain uncharacterized.

AIM OF THE STUDY

The purpose of current study was to explore the potential mechanism action and anti-myocardial fibrosis effects of treatment with THSWD in vivo and in vitro.

MATERIALS AND METHODS

Mouse underwent ligation of coronary artery to induce MI and divided equally into the sham group, model group and THSWD treatment groups. After 4 weeks, the effects of THSWD treatment on cardiac function were estimated by echocardiography. HE staining was used to detect the pathologic changes and Masson trichrome staining was used to estimate tissue fibrosis. To further explore the regulatory molecular mechanisms of THSWD, transcriptome analysis was performed. Furthermore, in vitro, we investigated the effect of THSWD on cell proliferation and collagen deposition in primary cardiac fibrosis cells and its possible mechanism of action. Overexpression of TGFBR1 was achieved by infection with an adenovirus vector encoding TGFBR1.

RESULTS

Treatment with THSWD significantly decreased myocardial fibrosis and recovered cardiac function in the post-MI mouse. The transcriptomics data imply that the TGF-β pathway might be a target in the anti-fibrosis effect of THSWD. THSWD inhibits TGF-β1-induced proliferation of primary cardiac fibroblasts. THSWD decreased collagen expression and TGFBR1 and Smad2/3 phosphorylation. Moreover, the inhibitory effect of THSWD on CFs proliferation and collagen deposition, as well as TGFBR1 signaling pathway-associated proteins expression was partially abrogated by overexpression of TGFBR1.

CONCLUSION

Collectively, the results implicate that THSWD attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via inhibiting TGFBR1, and might be a potential therapeutic agent for treatment of myocardial fibrosis post-MI.

Long-term Outcomes in Patients With Severely Reduced Left Ventricular Ejection Fraction Undergoing Percutaneous Coronary Intervention vs Coronary Artery Bypass Grafting

Importance

Data are lacking on the outcomes of patients with severely reduced left ventricular ejection fraction (LVEF) who undergo revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Objective

To compare the long-term outcomes in patients undergoing revascularization by PCI or CABG.

Design, Setting, and Participants

This retrospective cohort study performed in Ontario, Canada, from October 1, 2008, and December 31, 2016, included data from Ontario residents between 40 and 84 years of age with LVEFs less than 35% and left anterior descending (LAD), left main, or multivessel coronary artery disease (with or without LAD involvement) who underwent PCI or CABG. Exclusion criteria were concomitant procedures, previous CABG, metastatic cancer, dialysis, CABG and PCI on the same day, and emergency revascularization within 24 hours of a myocardial infarction (MI). Data analysis was performed from June 2, 2018, to December 28, 2018.

Exposures

Revascularization by PCI or CABG.

Main Outcomes and Measures

The primary outcome was all-cause mortality. Secondary outcomes were death from cardiovascular disease, major adverse cardiovascular events (MACE; defined as stroke, subsequent revascularization, and hospitalization for MI or heart failure), and each of the individual MACE.

Results

A total of 12 113 patients (mean [SD] age, 64.8 (11.0) years for the PCI group and 65.6 [9.7] years for the CABG group; 5084 (72.5%) male for the PCI group and 4229 (82.9%) male for the PCI group) were propensity score matched on 30 baseline characteristics: 2397 patients undergoing PCI and 2397 patients undergoing CABG. The median follow-up was 5.2 years (interquartile range, 5.0-5.3). Patients who received PCI had significantly higher rates of mortality (hazard ratio [HR], 1.6; 95% CI, 1.3-1.7), death from cardiovascular disease (HR 1.4, 95% CI, 1.1-1.6), MACE (HR, 2.0; 95% CI, 1.9-2.2), subsequent revascularization (HR, 3.7; 95% CI, 3.2-4.3), and hospitalization for MI (HR, 3.2; 95% CI, 2.6-3.8) and heart failure (HR, 1.5; 95% CI, 1.3-1.6) compared with matched patients who underwent CABG.

Conclusions and Relevance

In this study, higher rates of mortality and MACE were seen in patients who received PCI compared with those who underwent CABG. The findings may provide insight to physicians who are involved in decision-making for these patients.

High-Density Lipoprotein-Targeted Therapies for Heart Failure

The main and common constituents of high-density lipoproteins (HDLs) are apolipoprotein A-I, cholesterol, and phospholipids. Biochemical heterogeneity of HDL particles is based on the variable presence of one or more representatives of at least 180 proteins, 200 lipid species, and 20 micro RNAs. HDLs are circulating multimolecular platforms that perform divergent functions whereby the potential of HDL-targeted interventions for treatment of heart failure can be postulated based on its pleiotropic effects. Several murine studies have shown that HDLs exert effects on the myocardium, which are completely independent of any impact on coronary arteries. Overall, HDL-targeted therapies exert a direct positive lusitropic effect on the myocardium, inhibit the development of cardiac hypertrophy, suppress interstitial and perivascular myocardial fibrosis, increase capillary density in the myocardium, and prevent the occurrence of heart failure. In four distinct murine models, HDL-targeted interventions were shown to be a successful treatment for both pre-existing heart failure with reduced ejection fraction (HFrEF) and pre-existing heart failure with preserved ejection fraction (HFrEF). Until now, the effect of HDL-targeted interventions has not been evaluated in randomized clinical trials in heart failure patients. As HFpEF represents an important unmet therapeutic need, this is likely the preferred therapeutic domain for clinical translation.

Short-term and long-term outcomes of revascularization interventions for patients with severely reduced left ventricular ejection fraction: a meta-analysis

AIMS

This meta-analysis aimed to determine whether coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) should be preferred in patients with severely reduced left ventricular (LV) ejection fraction.

METHODS AND RESULTS

We searched the PubMed, EMBASE, and Cochrane Library databases from the conception of the databases till 1 May 2020 for studies on patients with severely reduced LV ejection fraction undergoing CABG and PCI. The primary clinical endpoints were 30 day and long-term mortalities. The secondary endpoints were 30 day and long-term incidences of myocardial infarction (MI) and stroke, long-term cardiovascular mortality, and repeat revascularization. Eighteen studies involving 11 686 patients were analysed. Compared with PCI, CABG had lower long-term mortality [hazard ratio (HR): 0.70, 95% confidence interval (CI): 0.61-0.80, P < 0.01], cardiovascular mortality (HR: 0.60, 95% CI: 0.43-0.85, P < 0.01), MI (HR: 0.51, 95% CI: 0.36-0.72, P < 0.01), and repeat revascularization (HR: 0.32, 95% CI: 0.23-0.47, P < 0.01) risk. Significant differences were not observed for long-term stroke (HR: 1.18, 95% CI: 0.74-1.87, P = 0.49), 30 day mortality (HR: 1.18, 95% CI: 0.89-1.56, P = 0.25), and MI (HR: 0.42, 95% CI: 0.16-1.11, P = 0.08) risk. CABG was associated with a higher risk of stroke within 30 days (HR: 2.88, 95% CI: 1.07-7.77, P = 0.04). In a subgroup analysis of propensity score-matched studies, CABG was associated with a higher long-term risk of stroke (HR: 1.61, 95% CI: 1.20-2.16, P < 0.01).

CONCLUSIONS

Among patients with severely reduced LV ejection fraction, CABG resulted in a lower mortality rate and an increased risk of stroke.

The efficacy of baroreflex activation therapy for heart failure: A meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of baroreflex activation therapy for heart failure is elusive. This meta-analysis aims to evaluate the impact of baroreflex activation therapy on treatment efficacy of heart failure.

METHODS

Several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases have been searched, and we include randomized controlled trials (RCTs) regarding the efficacy of baroreflex activation therapy for patients with heart failure.

RESULTS

This meta-analysis includes 4 RCTs. Baroreflex activation therapy shows significantly positive impact on the quality of life score (standard mean difference SMD = -4.61; 95% confidence interval CI = -6.24 to -2.98; P < .00001), 6-minute hall walk (6MHW) distance (SMD = 2.83; 95% CI = 1.44- 4.22; P < .0001), New York Heart Association (NYHA) Class (SMD = -3.23; 95% CI = -4.76 to -1.69; P < .0001), N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD = -1.24; 95% CI = -1.58 to -0.89; P < .00001) and the duration of hospitalization (SMD = -1.65; 95% CI = -2.90 to -0.39; P = .01) compared with control group for heart failure, but has no obvious effect on left ventricular ejection fraction (LVEF) (SMD = 1.43; 95% CI = -0.15-3.01; P = .08), or the number of hospitalization per year (SMD = -1.17; 95% CI = -2.56-0.22; P = .10).

CONCLUSIONS

Baroreflex activation therapy can improve the treatment efficacy for heart failure.

The Role of Non-coding RNAs in Ischemic Myocardial Reperfusion Injury

MicroRNAs (miRNA) are non-coding RNAs that regulate gene expression in up to 90% of the human genome through interactions with messenger RNA (mRNA). The expression of miRNAs varies and changes in diseased and healthy states, including all stages of myocardial ischemia-reperfusion and subsequent ischemia-reperfusion injury (IRI). These changes in expression make miRNAs an attractive potential therapeutic target. Herein, we review the differences in miRNA expression prior to ischemia (including remote ischemic conditioning and ischemic pre-conditioning), the changes during ischemia-reperfusion, and the changes in miRNA expression after IRI, with an emphasis on inflammatory and fibrotic pathways. Additionally, we review the effects of manipulating the levels of certain miRNAs on changes in infarct size, inflammation, remodeling, angiogenesis, and cardiac function after either ischemia-reperfusion or permanent coronary ligation. Levels of target miRNA can be increased using molecular mimics ("agomirs"), or can be decreased by using "antagomirs" which are antisense molecules that act to bind and thus inactivate the target miRNA sequence. Other non-coding RNAs, including long non-coding RNAs and circular RNAs, also regulate gene expression and have a role in the regulation of IRI pathways. We review the mechanisms and downstream effects of the miRNAs that have been studied as therapy in both permanent coronary ligation and ischemia-reperfusion models.

Combining Nanomaterials and Developmental Pathways to Design New Treatments for Cardiac Regeneration: The Pulsing Heart of Advanced Therapies

The research for heart therapies is challenged by the limited intrinsic regenerative capacity of the adult heart. Moreover, it has been hampered by the poor results obtained by tissue engineering and regenerative medicine attempts at generating functional beating constructs able to integrate with the host tissue. For this reason, organ transplantation remains the elective treatment for end-stage heart failure, while novel strategies aiming to promote cardiac regeneration or repair lag behind. The recent discovery that adult cardiomyocytes can be ectopically induced to enter the cell cycle and proliferate by a combination of microRNAs and cardioprotective drugs, like anti-oxidant, anti-inflammatory, anti-coagulants and anti-platelets agents, fueled the quest for new strategies suited to foster cardiac repair. While proposing a revolutionary approach for heart regeneration, these studies raised serious issues regarding the efficient controlled delivery of the therapeutic cargo, as well as its timely removal or metabolic inactivation from the site of action. Especially, there is need for innovative treatment because of evidence of severe side effects caused by pleiotropic drugs. Biocompatible nanoparticles possess unique physico-chemical properties that have been extensively exploited for overcoming the limitations of standard medical therapies. Researchers have put great efforts into the optimization of the nanoparticles synthesis and functionalization, to control their interactions with the biological milieu and use as a viable alternative to traditional approaches. Nanoparticles can be used for diagnosis and deliver therapies in a personalized and targeted fashion. Regarding the treatment of cardiovascular diseases, nanoparticles-based strategies have provided very promising outcomes, in preclinical studies, during the last years. Efficient encapsulation of a large variety of cargos, specific release at the desired site and improvement of cardiac function are some of the main achievements reached so far by nanoparticle-based treatments in animal models. This work offers an overview on the recent nanomedical applications for cardiac regeneration and highlights how the versatility of nanomaterials can be combined with the newest molecular biology discoveries to advance cardiac regeneration therapies.

Promoting Cardiac Regeneration and Repair Using Acellular Biomaterials

Ischemic heart disease is a common cause of end-stage heart failure and has persisted as one of the main causes of end stage heart failure requiring transplantation. Maladaptive myocardial remodeling due to ischemic injury involves multiple cell types and physiologic mechanisms. Pathogenic post-infarct remodeling involves collagen deposition, chamber dilatation and ventricular dysfunction. There have been significant improvements in medication and revascularization strategies. However, despite medical optimization and opportunities to restore blood flow, physicians lack therapies that directly access and manipulate the heart to promote healthy post-infarct myocardial remodeling. Strategies are now arising that use bioactive materials to promote cardiac regeneration by promoting angiogenesis and inhibiting cardiac fibrosis; and many of these strategies leverage the unique advantage of cardiac surgery to directly visualize and manipulate the heart. Although cellular-based strategies are emerging, multiple barriers exist for clinical translation. Acellular materials have also demonstrated preclinical therapeutic potential to promote angiogenesis and attenuate fibrosis and may be able to surmount these translational barriers. Within this review we outline various acellular biomaterials and we define epicardial infarct repair and intramyocardial injection, which focus on administering bioactive materials to the cardiac epicardium and myocardium respectively to promote cardiac regeneration. In conjunction with optimized medical therapy and revascularization, these techniques show promise to upregulate pathways of cardiac regeneration to preserve heart function.

The Role of Extracellular DNA and Histones in Ischaemia-Reperfusion Injury of the Myocardium

Despite an increase in the rates of survival in patients suffering myocardial infarction, as yet there is no therapy specifically targeting ischaemia and reperfusion injury of the myocardium. With a greater understanding of immune activation during infarction, more potential treatment targets are now being identified. The innate immune system is believed to play an important role in the myocardium after ischaemia-driven cardiomyocyte death. The release of intracellular contents including DNA into the extracellular space during necrosis and cell rupture is now believed to create a pro-inflammatory milieu which propagates the inflammatory process. DNA and DNA fragments have been shown to activate the innate immune system by acting as Danger-Associated Molecular Patterns (DAMPs), which act as ligands on toll-like receptors (TLRs). Stimulation of TLRs, in turn, can activate intracellular cell death pathways such as pyroptosis. Here, we review the role of DNA fragments during ischaemia and reperfusion, and assess their potential as a target in the quest to preserve cardiomyocyte viability following myocardial infarction.

Ankle-brachial index and incident heart failure with reduced versus preserved ejection fraction: The Multi-Ethnic Study of Atherosclerosis

This study investigated the relationship between ankle-brachial index (ABI) and risk for heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). ABI has previously been associated with mortality, cardiovascular disease (CVD), and overall HF but the relationship between ABI and risk of HF stratified by EF has not been well characterized. We analyzed data from 6553 participants (53% female; mean age 62 ± 10 years) enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA) who were free of known clinical CVD/HF at baseline (2000-2002) and had baseline ABI measured. Participants were classified as low (≤ 0.90), borderline-low (0.91-1.00), normal (1.01-1.40), and high (> 1.40) ABI. Incident hospitalized HF was determined over a median follow-up of 14 years; we classified HF events (n = 321) as HFrEF with EF < 50% (n = 155, 54%) or HFpEF with EF ⩾ 50% (n = 133, 46%). Low ABI was associated with incident HFrEF (hazard ratio (HR): 2.02, 95% CI 1.19-3.40, p = 0.01) and had no significant association with HFpEF (HR: 0.67, 95% CI 0.30-1.48, p = 0.32). Borderline-low and high ABI were not significantly associated with HFrEF or HFpEF. Cubic spline analyses showed association with both low and high ABI for HFrEF and high ABI for HFpEF. A 1 SD lower ABI (for ABI < 1.1) was associated with incident HFrEF in multivariable analysis (HR: 1.27, 95% CI 1.05-1.54) but was not significant after additionally adjusting for interim myocardial infarction (HR: 1.21, 95% CI 0.99-1.48). Low ABI was associated with higher risk for incident HFrEF but not HFpEF in persons free of known CVD. Future studies of a larger size are needed for high ABI analyses.

Shexiang Tongxin Dropping Pill Improves Peripheral Microvascular Blood Flow via Cystathionine-γ-Lyase

Background

To explore the protective effects of Shexiang Tongxin Dropping Pill (STP) in improving peripheral microvascular dysfunction in mice and to explore the involved mechanism.

Material/Methods

A peripheral microvascular dysfunction model was established by combined myocardial infarction (MI) and lipopolysaccharide (LPS) injection in mice. Then, the mice were randomized into a model group (n=10) or an STP group (n=10), which were treated with normal saline and STP, respectively. The cremaster muscle microvascular blood flow velocity and numbers of leukocytes adherent to the venular wall were evaluated before and after drug intervention. We assessed the expression of adhesion molecule CD11b and related transcript factor FOXO1 in leukocytes, cystathionine-γ-lyase (CSE) mRNA expression in the cremaster muscle, and mitochondrial DNA copy numbers.

Results

Compared with those of control mice, the cremaster microvascular blood flow velocity, cremaster CSE expression, and mitochondrial DNA copy number in mice from the model group were significantly lower and leukocyte adhesion and CD11b and FOXO1 expression were significantly higher. Intervention with STP could significantly increase the cremaster microvascular flow velocity (0.480±0.010 mm/s vs. 0.075±0.005 mm/s), mRNA expression of cremaster CSE, and mitochondrial DNA copy number, but it inhibited leukocyte adhesion and decreased leukocyte CD11b and FOXO1 expression.

Conclusions

STP significantly improved peripheral microcirculation, in which increased CSE expression might be the underlying mechanism.

Systemic Ventricular Dysfunction Between Stage One and Stage Two Palliation

Infants with a single ventricle can develop systemic ventricular dysfunction (SVD) after stage 1 operation, but available information is sparse. We reviewed our patients having Norwood, Sano, or hybrid procedures to better understand this problem. We conducted a retrospective, case-controlled cohort study of 267 patients having stage1 operation, examining outcomes between stages 1 and 2 (survival and subsequent cardiac surgeries), predictor variables, and histology of hearts explanted at transplantation. SVD developed in 32 (12%) patients and resolved in 13 (41%); mean age of onset was 3.0 ± 1.63 months; median = 2.79. SVD was not associated with cardiac anatomy, type of stage 1 procedure, weight, coronary abnormality, or atrioventricular valve regurgitation. The mean age of resolution = 12.1 ± 9.6 months; median = 6.3, and resolution may have been more likely with a systemic LV than RV (p = 0.067). Outcomes for the entire SVD group were less favorable than for those without, but patients with resolution of SVD had outcomes at least as good those without SVD. Myocardial histology (n = 4) suggested chronic ischemia. The risk of SVD after stage 1, while low, may be a fundamental feature of this patient population. SVD occurs with either a systemic RV or LV, although patients with a systemic LV may be more likely to have resolution than those with an RV. We identified no predictor variables, but histologic findings suggest chronic ischemia may be involved. Given the low incidence of SVD, multi-center studies will be required to better define predictors of onset and resolution.

Evaluation of telomere length in human cardiac tissues using cardiac quantitative FISH

Telomere length has been correlated with various diseases, including cardiovascular disease and cancer. The use of currently available telomere-length measurement techniques is often restricted by the requirement of a large amount of cells (Southern-based techniques) or the lack of information on individual cells or telomeres (PCR-based methods). Although several methods have been used to measure telomere length in tissues as a whole, the assessment of cell-type-specific telomere length provides valuable information on individual cell types. The development of fluorescence in situ hybridization (FISH) technologies enables the quantification of telomeres in individual chromosomes, but the use of these methods is dependent on the availability of isolated cells, which prevents their use with fixed archival samples. Here we describe an optimized quantitative FISH (Q-FISH) protocol for measuring telomere length that bypasses the previous limitations by avoiding contributions from undesired cell types. We have used this protocol on small paraffin-embedded cardiac-tissue samples. This protocol describes step-by-step procedures for tissue preparation, permeabilization, cardiac-tissue pretreatment and hybridization with a Cy3-labeled telomeric repeat complementing (CCCTAA)₃ peptide nucleic acid (PNA) probe coupled with cardiac-specific antibody staining. We also describe how to quantify telomere length by means of the fluorescence intensity and area of each telomere within individual nuclei. This protocol provides comparative cell-type-specific telomere-length measurements in relatively small human cardiac samples and offers an attractive technique to test hypotheses implicating telomere length in various cardiac pathologies. The current protocol (from tissue collection to image procurement) takes ∼28 h along with three overnight incubations. We anticipate that the protocol could be easily adapted for use on different tissue types.