Ischaemic cardiomyopathy. Pathophysiological insights, diagnostic management and the roles of revascularisation and device treatment. Gaps and dilemmas in the era of advanced technology

Prediction of major arrhythmic outcomes in ischaemic cardiomyopathy: value of hibernating myocardium in positron emission tomography/computed tomography

AIMS

Known predictors of major arrhythmic events (MAEs) in patients with ischaemic cardiomyopathy (ICM) include previous MAE and left ventricular ejection fraction (LVEF) ≤ 35%. Myocardial scars detected by perfusion imaging in ICM have been linked to MAE, but the prognostic significance of hibernating myocardium (HM) is unclear. The objective was to predict MAEs from combined 13N-ammonia (NH3) and 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in ICM.

METHODS AND RESULTS

Consecutive patients with ICM undergoing combined NH3- and FDG-PET/CT were included. HM was quantified in relation to total left ventricular myocardium (i.e. ≥7% is large). The primary outcome was MAEs [sudden cardiac death, implantable cardioverter defibrillator (ICD) therapy, and sustained ventricular tachycardia/fibrillation].Among 254 patients, median baseline LVEF was 35% [interquartile range (IQR) 28-45] and 10% had an ICD. PET/CT identified ischaemia in 94 (37%), scar in 229 (90%), and HM in 195 (77%) patients. Over a median follow-up of 5.4 (IQR 2.2-9.5) years, MAE occurred in 34 patients (13%). Large HM was associated with a lower incidence of MAE (hazard ratio 0.31, 95% confidence interval 0.1-0.8, P = 0.001). After multivariate adjustment for history of MAE, LVEF ≤35%, and scar ≥10%, large HM remained significantly associated with a lower incidence of MAE (P = 0.016). LVEF improved over time among patients with large HM (P = 0.006) but did not change in those without (P = 0.610) or small HM (P = 0.240).

CONCLUSION

HM conveys a lower risk of MAE in patients with ICM. This may be explained by an increase in LVEF when a large extent of HM is present.

The efficacy of revascularization in ischemic cardiomyopathy

Ischemic cardiomyopathy (ICM) is characterized by myocardial dysfunction due to myocardial ischemia, associated with the presence of significant coronary artery disease (CAD). We provide a comprehensive review of the current evidence for coronary revascularization in ICM, including consideration of the different modalities of coronary artery bypass grafting and percutaneous coronary intervention. In addition to a contemporary assessment of the literature, we aim to provide real-world insights and perspectives to guide clinical decision-making in this heterogeneous and complex patient population.

Nanomedicine: A great boon for cardiac regenerative medicine

Cardiovascular disease (CVD) represents a significant global health challenge, remaining the leading cause of illness and mortality worldwide. The adult heart's limited regenerative capacity poses a major obstacle in repairing extensive damage caused by conditions like myocardial infarction. In response to these challenges, nanomedicine has emerged as a promising field aimed at improving treatment outcomes through innovative drug delivery strategies. Nanocarriers, such as nanoparticles (NPs), offer a revolutionary approach by facilitating targeted delivery of therapeutic agents directly to the heart. This precise delivery system holds immense potential for treating various cardiac conditions by addressing underlying mechanisms such as inflammation, oxidative stress, cell death, extracellular matrix remodeling, prosurvival signaling, and angiogenic pathways associated with ischemia-reperfusion injury. In this review, we provide a concise summary of the fundamental mechanisms involved in cardiac remodeling and regeneration. We explore how nanoparticle-based drug delivery systems can effectively target the afore-mentioned mechanisms. Furthermore, we discuss clinical trials that have utilized nanoparticle-based drug delivery systems specifically designed for cardiac applications. These trials demonstrate the potential of nanomedicine in clinical settings, paving the way for future advancements in cardiac therapeutics through precise and efficient drug delivery. Overall, nanomedicine holds promise in revolutionizing the treatment landscape of cardiovascular diseases by offering targeted and effective therapeutic strategies that address the complex pathophysiology of cardiac injuries.

Injury-induced myosin-specific tissue-resident memory T cells drive immune checkpoint inhibitor myocarditis

Cardiac myosin-specific (MyHC) T cells drive the disease pathogenesis of immune checkpoint inhibitor-associated myocarditis (ICI-myocarditis). To determine whether MyHC T cells are tissue-resident memory T (TRM) cells, we characterized cardiac TRM cells in naive mice and established that they have a distinct phenotypic and transcriptional profile that can be defined by their upregulation of CD69, PD-1, and CXCR6. We then investigated the effects of cardiac injury through a modified experimental autoimmune myocarditis mouse model and an ischemia-reperfusion injury mouse model and determined that cardiac inflammation induces the recruitment of autoreactive MyHC TRM cells, which coexpress PD-1 and CD69. To investigate whether the recruited MyHC TRM cells could increase susceptibility to ICI-myocarditis, we developed a two-hit ICI-myocarditis mouse model where cardiac injury was induced, mice were allowed to recover, and then were treated with anti-PD-1 antibodies. We determined that mice who recover from cardiac injury are more susceptible to ICI-myocarditis development. We found that murine and human TRM cells share a similar location in the heart and aggregate along the perimyocardium. We phenotyped cells obtained from pericardial fluid from patients diagnosed with dilated cardiomyopathy and ischemic cardiomyopathy and established that pericardial T cells are predominantly CD69+ TRM cells that up-regulate PD-1. Finally, we determined that human pericardial macrophages produce IL-15, which supports and maintains pericardial TRM cells.

Consensus Clustering Analysis Identifies Ferroptosis-Related Patient Clusters and Predictive Signature Construction Based on Ferroptosis-Related Genes in Ischemic Cardiomyopathy

Background

Ischemic cardiomyopathy (ICM) significantly contributes to global disease burden, while the role of ferroptosis in ICM remains underexplored.

Methods

We identified differentially expressed ferroptosis-related genes (DEFRGs) by analyzing the GSE57338 dataset and cross-referencing with FerrDb. Consensus clustering was then used to identify ferroptosis-associated clusters within the ICM samples. A ferroptosis-specific predictive signature was developed using the least absolute shrinkage and selection operator (LASSO) method and validated with the GSE5406 dataset. Additionally, quantitative real-time PCR (qRT-PCR) experiments were performed to validate the 11 feature genes in a rat ICM model.

Results

We identified 15 DEFRGs in GSE57338, which distinguished two patient clusters with distinct ferroptosis gene expression, pathway enrichment profiles, and metabolic characteristics. All DEFRGs were upregulated in cluster 2. Potential therapeutic targets were also identified for different ICM patient clusters. The 11-gene predictive signature (TXNRD1, STEAP3, STAT3, SCL2A1, PLIN2, NQO1, NNMT, IL33, ENPP2, ARRDC3, ALOX5) showed robust predictive power in both training and validation sets. High-risk patients exhibited increased infiltration of CD8+ T cells, CD4+ naïve T cells, M0/M1 macrophages, and resting mast cells, along with significant enrichment in epithelial mesenchymal transition and interferon responses. Low-risk patients had higher infiltration of regulatory T cells and monocytes. Results of qPCR analysis confirmed the bioinformatic analysis, validating the expression of the 11 feature genes in the rat ICM model.

Conclusion

We identified two ferroptosis-related clusters in ICM patients and developed a predictive signature based on ferroptosis-related genes. Our findings highlight the importance of ferroptosis in ICM and offer new insights for its diagnosis and treatment.

Integrin beta-like 1 is regulated by DNA methylation and increased in heart failure patients

AIMS

Dynamic alterations in cardiac DNA methylation have been implicated in the development of heart failure (HF) with evidence of ischaemic heart disease (IHD); however, there is limited research into cell specific, DNA methylation sensitive genes that are affected by dysregulated DNA methylation patterns. In this study, we aimed to identify DNA methylation sensitive genes in the ischaemic heart and elucidate their role in cardiac fibrosis.

METHODS

A multi-omics integrative analysis was carried out on RNA sequencing and methylation sequencing on HF with IHD (n = 9) versus non-failing (n = 9) left ventricular tissue, which identified Integrin beta-like 1 (ITGBL1) as a gene of interest. Expression of Itgbl1 was assessed in three animal models of HF; an ischaemia-reperfusion pig model, a myocardial infarction mouse model and an angiotensin-II infused mouse model. Single nuclei RNA sequencing was carried out on heart tissue from angiotensin-II infused mice to establish the expression profile of Itgbl1 across cardiac cell populations. Subsequent in vitro analyses were conducted to elucidate a role for ITGBL1 in human cardiac fibroblasts. DNA pyrosequencing was applied to assess ITGBL1 CpG methylation status in genomic DNA from human cardiac tissue and stimulated cardiac fibroblasts.

RESULTS

ITGBL1 was >2-fold up-regulated (FDR adj P = 0.03) and >10-fold hypomethylated (FDR adj P = 0.01) in human HF with IHD left ventricular tissue compared with non-failing controls. Expression of Itgbl1 was up-regulated in three isolated animal models of HF and showed conserved correlation between increased Itgbl1 and diastolic dysfunction. Single nuclei RNA sequencing highlighted that Itgbl1 is primarily expressed in cardiac fibroblasts, while functional studies elucidated a role for ITGBL1 in cardiac fibroblast migration, evident in 50% reduced 24 h fibroblast wound closure occurring subsequent to siRNA-targeted ITGBL1 knockdown. Lastly, evidence provided from DNA pyrosequencing supports the theory that differential expression of ITGBL1 is caused by DNA hypomethylation.

CONCLUSIONS

ITGBL1 is a gene that is mainly expressed in fibroblasts, plays an important role in cardiac fibroblast migration, and whose expression is significantly increased in the failing heart. The mechanism by which increased ITGBL1 occurs is through DNA hypomethylation.

Ischaemic Cardiomyopathy Secondary to Asymptomatic Coronary Artery Disease: A Case Report

Ischaemic cardiomyopathy (ICM) represents a common complication of coronary artery disease (CAD). Ischaemia causes ventricular remodelling, leading to an irreversible loss of myocardial tissue and adequate contractility, primarily affecting the left ventricular ejection fraction (LVEF). We present the case of a 46-year-old male known as hypertensive presented to the hospital with a five-week history of progressive exertional dyspnoea, bilateral lower limb oedema subsequently involving his scrotum and penis. He reported reduced oral intake and occasional palpitations but denied chest pain, cough, fever, or haemoptysis. He had no personal history of cardiac disease, recent travels, or recreational drug use. Notably, he consumed approximately 12 units of alcohol weekly and was a non-smoker. On admission, he was treated for new-onset heart failure, and initial investigations showed acute kidney injury, raised troponin, and brain natriuretic peptide (BNP), and chest X-ray showed an enlarged heart size (cardiothoracic ratio (CTR), 0.56) with moderate right pleural effusion. Echocardiography revealed a severely dilated left ventricle with severely impaired systolic function (LVEF 16%), bi-atrial dilatation, borderline dilated right ventricle with impaired systolic function, and moderate tricuspid regurgitation. Cardiac MRI showed that the left ventricle was severely dilated with severely impaired systolic function with nonviable mid to apical inferior and inferoseptal transmural post-ischaemic scar with associated hypokinesia. Ischaemic cardiomyopathy may vary from asymptomatic to severely symptomatic, commonly when symptomatic patients will present with anginal chest pain and dyspnoea on exertion. In contrast, asymptomatic patients can sometimes have up to 80% of transient ischaemic events with no chest pain or associated symptoms. This case underscores the importance of considering asymptomatic coronary artery disease in clinical practice and highlights the need for novel interventions and markers for early ischemia detection.

Left ventricular recovery after total arterial coronary artery bypass grafting versus conventional coronary artery bypass grafting in patients with multivessel coronary artery disease and reduced left ventricular ejection fraction

BACKGROUND

We compared total arterial revascularization (TAR) versus conventional revascularization (CR) in terms of left ventricular function recovery in patients with multivessel coronary artery disease (CAD) and reduced left ventricular ejection fraction (LVEF).

METHODS

We conducted a retrospective cohort study of 162 consecutive patients with multivessel CAD and reduced LVEF who underwent isolated coronary artery bypass grafting at our institution between January 2013 and July 2022. We assessed left ventricular function by transthoracic echocardiography at admission, before discharge, and at follow-up of 3, 6, and 12 months, using LVEF, global longitudinal peak strain, end-diastolic volume index, and end-systolic volume index. We also evaluated mitral valve regurgitation and graft patency rate at 1 year.

RESULTS

The TAR group had a significantly higher increase in LVEF and global longitudinal peak strain, and a significantly lower decrease in end-diastolic volume index and end-systolic volume index than the CR group at 6 and 12 months after surgery. The TAR group also had a significantly lower degree of mitral valve regurgitation than the CR group at all-time points within 12 months after surgery. The TAR group had a significantly higher graft patency rate than the CR group at 12 months. There was no significant difference in hospital mortality or repeat revascularization between the groups.

CONCLUSIONS

TAR was associated with better recovery of left ventricular function than CR in patients with multivessel CAD and reduced LVEF. Further studies are needed to confirm these findings in this high-risk population.

The E2F family: a ray of dawn in cardiomyopathy

Cardiomyopathies are a group of heterogeneous diseases, characterized by abnormal structure and function of the myocardium. For many years, it has been a hot topic because of its high morbidity and mortality as well as its complicated pathogenesis. The E2Fs, a group of transcription factors found extensively in eukaryotes, play a crucial role in governing cell proliferation, differentiation, and apoptosis, meanwhile their deregulated activity can also cause a variety of diseases. Based on accumulating evidence, E2Fs play important roles in cardiomyopathies. In this review, we describe the structural and functional characteristics of the E2F family and its role in cardiomyocyte processes, with a focus on how E2Fs are associated with the onset and development of cardiomyopathies. Moreover, we discuss the great potential of E2Fs as biomarkers and therapeutic targets, aiming to provide a reference for future research.

Recent advancements and applications of deep learning in heart failure: Α systematic review

BACKGROUND

Heart failure (HF), a global health challenge, requires innovative diagnostic and management approaches. The rapid evolution of deep learning (DL) in healthcare necessitates a comprehensive review to evaluate these developments and their potential to enhance HF evaluation, aligning clinical practices with technological advancements.

OBJECTIVE

This review aims to systematically explore the contributions of DL technologies in the assessment of HF, focusing on their potential to improve diagnostic accuracy, personalize treatment strategies, and address the impact of comorbidities.

METHODS

A thorough literature search was conducted across four major electronic databases: PubMed, Scopus, Web of Science and IEEE Xplore, yielding 137 articles that were subsequently categorized into five primary application areas: cardiovascular disease (CVD) classification, HF detection, image analysis, risk assessment, and other clinical analyses. The selection criteria focused on studies utilizing DL algorithms for HF assessment, not limited to HF detection but extending to any attempt in analyzing and interpreting HF-related data.

RESULTS

The analysis revealed a notable emphasis on CVD classification and HF detection, with DL algorithms showing significant promise in distinguishing between affected individuals and healthy subjects. Furthermore, the review highlights DL's capacity to identify underlying cardiomyopathies and other comorbidities, underscoring its utility in refining diagnostic processes and tailoring treatment plans to individual patient needs.

CONCLUSIONS

This review establishes DL as a key innovation in HF management, highlighting its role in advancing diagnostic accuracy and personalized care. The insights provided advocate for the integration of DL in clinical settings and suggest directions for future research to enhance patient outcomes in HF care.

Exploring the molecular biology of ischemic cardiomyopathy based on ferroptosis‑related genes

Ischemic cardiomyopathy (ICM) is a serious cardiac disease with a very high mortality rate worldwide, which causes myocardial ischemia and hypoxia as the main damage. Further understanding of the underlying pathological processes of cardiomyocyte injury is key to the development of cardioprotective strategies. Ferroptosis is an iron-dependent form of regulated cell death characterized by the accumulation of lipid hydroperoxides to lethal levels, resulting in oxidative damage to the cell membrane. The current understanding of the role and regulation of ferroptosis in ICM is still limited, especially in the absence of evidence from large-scale transcriptomic data. Through comprehensive bioinformatics analysis of human ICM transcriptome data obtained from the Gene Expression Omnibus database, the present study identified differentially expressed ferroptosis-related genes (DEFRGs) in ICM. Subsequently, their potential biological mechanisms and cross-talk were analyzed, and hub genes were identified by constructing protein-protein interaction networks. Ferroptosis features such as reactive oxygen species generation, changes in ferroptosis marker proteins, iron ion aggregation and lipid oxidation, were identified in the H9c2 anoxic reoxygenation injury model. Finally, the diagnostic ability of Gap junction alpha-1 (GJA1), Solute carrier family 40 member 1 (SLC40A1), Alpha-synuclein (SNCA) were identified through receiver operating characteristic curves and the expression of DEFRGs was verified in an in vitro model. Furthermore, potential drugs (retinoic acid) that could regulate ICM ferroptosis were predicted based on key DEFRGs. The present article presents new insights into the role of ferroptosis in ICM, investigating the regulatory role of ferroptosis in the pathological process of ICM and advocating for ferroptosis as a potential novel therapeutic target for ICM based on evidence from the ICM transcriptome.

Hyaluronic acid stimulation of stem cells for cardiac repair: a cell-free strategy for myocardial infarct

BACKGROUND

Myocardial infarction (MI), a representative form of ischemic heart disease, remains a huge burden worldwide. This study aimed to explore whether extracellular vesicles (EVs) secreted from hyaluronic acid (HA)-primed induced mesenchymal stem cells (HA-iMSC-EVs) could enhance the cardiac repair after MI.

RESULTS

HA-iMSC-EVs showed typical characteristics for EVs such as morphology, size, and marker proteins expression. Compared with iMSC-EVs, HA-iMSC-EVs showed enhanced tube formation and survival against oxidative stress in endothelial cells, while reduced reactive oxygen species (ROS) generation in cardiomyocytes. In THP-1 macrophages, both types of EVs markedly reduced the expression of pro-inflammatory signaling players, whereas HA-iMSC-EVs were more potent in augmenting anti-inflammatory markers. A significant decrease of inflammasome proteins was observed in HA-iMSC-EV-treated THP-1. Further, phospho-SMAD2 as well as fibrosis markers in TGF-β1-stimulated cardiomyocytes were reduced in HA-iMSC-EVs treatment. Proteomic data showed that HA-iMSC-EVs were enriched with multiple pathways including immunity, extracellular matrix organization, angiogenesis, and cell cycle. The localization of HA-iMSC-EVs in myocardium was confirmed after delivery by either intravenous or intramyocardial route, with the latter increased intensity. Echocardiography revealed that intramyocardial HA-iMSC-EVs injections improved cardiac function and reduced adverse cardiac remodeling and necrotic size in MI heart. Histologically, MI hearts receiving HA-iMSC-EVs had increased capillary density and viable myocardium, while showed reduced fibrosis.

CONCLUSIONS

Our results suggest that HA-iMSC-EVs improve cardiac function by augmenting vessel growth, while reducing ROS generation, inflammation, and fibrosis in MI heart.

Intestinal microbiota and metabolome perturbations in ischemic and idiopathic dilated cardiomyopathy

BACKGROUND

Various clinical similarities are present in ischemic (ICM) and idiopathic dilated cardiomyopathy (IDCM), leading to ambiguity on some occasions. Previous studies have reported that intestinal microbiota appeared dysbiosis in ICM, whether implicating in the IDCM remains unclear. The aim of this study was to assess the alterations in intestinal microbiota and fecal metabolites in ICM and IDCM.

METHODS

ICM (n = 20), IDCM (n = 22), and healthy controls (HC, n = 20) were enrolled in this study. Stool samples were collected for 16S rRNA gene sequencing and gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

Both ICM and IDCM exhibited reduced alpha diversity and altered microbial community structure compared to HC. At the genus level, nine taxa including Blautia, [Ruminococcus]_torques_group, Christensenellaceae_R-7_group, UCG-002, Corynebacterium, Oceanobacillus, Gracilibacillus, Klebsiella and Citrobacter was specific to ICM, whereas one taxa Alistipes uniquely altered in IDCM. Likewise, these changes were accompanied by significant metabolic differences. Further differential analysis displayed that 18 and 14 specific metabolites uniquely changed in ICM and IDCM, respectively. The heatmap was generated to display the association between genera and metabolites. Receiver operating characteristic curve (ROC) analysis confirmed the predictive value of the distinct microbial-metabolite features in disease status. The results showed that microbial (area under curve, AUC = 0.95) and metabolic signatures (AUC = 0.84) were effective in discriminating ICM from HC. Based on the specific microbial and metabolic features, the patients with IDCM could be separated from HC with an AUC of 0.80 and 0.87, respectively. Furthermore, the gut microbial genus (AUC = 0.88) and metabolite model (AUC = 0.89) were comparable in predicting IDCM from ICM. Especially, the combination of fecal microbial-metabolic features improved the ability to differentiate IDCM from ICM with an AUC of 0.96.

CONCLUSION

Our findings highlighted the alterations of gut microbiota and metabolites in different types of cardiomyopathies, providing insights into the pathophysiological mechanisms of myocardial diseases. Moreover, multi-omics analysis of fecal samples holds promise as a non-invasive tool for distinguishing disease status.

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.

Impact of Positron Emission Tomography Viability Imaging: Guided Revascularizations on Clinical Outcomes in Patients With Myocardial Scar on Single-Photon Emission Computed Tomography Scans

BACKGROUND

Positron emission tomography (PET) viability scan is used to determine whether patients with a myocardial scar on single-photon emission computed tomography (SPECT) may need revascularization. However, the clinical utility of revascularization decision-making guided by PET viability imaging has not been proven yet. The purpose of this study was to investigate the impact of PET to determine revascularization on clinical outcomes.

METHODS

Between September 2012 and May 2021, 53 patients (37 males; mean age = 64 ± 11 years) with a myocardial scar on MIBI SPECT who underwent PET viability test were analyzed in this study. The primary outcome was a temporal change in echocardiographic findings. The secondary outcome was all-cause mortality.

RESULTS

Viable myocardium was presented by PET imaging in 29 (54.7%) patients. Revascularization was performed in 26 (49.1%) patients, including 18 (34.0%) with percutaneous coronary intervention (PCI) and 8 (15.1%) with coronary artery bypass grafting. There were significant improvements in echocardiographic findings in the revascularization group and the viable myocardium group. All-cause mortality was significantly lower in the revascularization group than in the medical therapy-alone group (19.2% vs. 44.4%, log-rank P = 0.002) irrespective of viable (21.4% vs. 46.7%, log-rank P = 0.025) or non-viable myocardium (16.7% vs. 41.7%, log-rank P = 0.046). All-cause mortality was significantly lower in the PCI group than in the medical therapy-alone group (11.1% vs. 44.4%, log-rank P < 0.001).

CONCLUSION

Revascularization improved left ventricular systolic function and survival of patients with a myocardial scar on SPECT scans, irrespective of myocardial viability on PET scans.

Ruscogenin Alleviates Myocardial Ischemia via Myosin IIA-Dependent Mitochondrial Fusion and Fission Balance

Ruscogenin (RUS), a major effective steroidal sapogenin derived from Ophiopogon japonicas, has been reported to alleviate myocardial ischemia (MI), but its cardioprotective mechanism is still not completely clear. In this study, we observed that RUS markedly reduced MI-induced myocardial injury, as evidenced by notable reductions in infarct size, improvement in biochemical markers, alleviation of cardiac pathology, amelioration of mitochondrial damage, and inhibition of myocardial apoptosis. Moreover, RUS notably suppressed oxygen-glucose deprivation (OGD)-triggered cell injury and apoptosis. Notably, RUS demonstrated a considerable decrease of the interaction between myosin IIA and F-actin, along with the restoration of mitochondrial fusion and fission balance. We further confirmed that the effects of RUS on MI were mediated by myosin IIA using siRNA and overexpression techniques. The inhibition of myosin IIA resulted in a significant improvement of mitochondrial fusion and fission imbalance, while simultaneously counteracting the beneficial effects of RUS. By contrast, overexpression of myosin IIA aggravated the imbalance between mitochondrial fusion and fission and partially weakened the protection of RUS. These findings suggest that myosin IIA is essential or even a key functional protein in the cardioprotection of RUS. Overall, our results have elucidated an undiscovered mechanism involving myosin IIA-dependent mitochondrial fusion and fission balance for treating MI. Furthermore, our study has uncovered a novel mechanism underlying the protective effects of RUS.

Cardiac Reverse Remodeling in Ischemic Heart Disease with Novel Therapies for Heart Failure with Reduced Ejection Fraction

Despite the improvements in the treatment of coronary artery disease (CAD) and acute myocardial infarction (MI) over the past 20 years, ischemic heart disease (IHD) continues to be the most common cause of heart failure (HF). In clinical trials, over 70% of patients diagnosed with HF had IHD as the underlying cause. Furthermore, IHD predicts a worse outcome for patients with HF, leading to a substantial increase in late morbidity, mortality, and healthcare costs. In recent years, new pharmacological therapies have emerged for the treatment of HF, such as sodium-glucose cotransporter-2 inhibitors, angiotensin receptor-neprilysin inhibitors, selective cardiac myosin activators, and oral soluble guanylate cyclase stimulators, demonstrating clear or potential benefits in patients with HF with reduced ejection fraction. Interventional strategies such as cardiac resynchronization therapy, cardiac contractility modulation, or baroreflex activation therapy might provide additional therapeutic benefits by improving symptoms and promoting reverse remodeling. Furthermore, cardiac regenerative therapies such as stem cell transplantation could become a new therapeutic resource in the management of HF. By analyzing the existing data from the literature, this review aims to evaluate the impact of new HF therapies in patients with IHD in order to gain further insight into the best form of therapeutic management for this large proportion of HF patients.

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.

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.

Targeting ferroptosis as a promising therapeutic strategy to treat cardiomyopathy

Cardiomyopathies are a clinically heterogeneous group of cardiac diseases characterized by heart muscle damage, resulting in myocardium disorders, diminished cardiac function, heart failure, and even sudden cardiac death. The molecular mechanisms underlying the damage to cardiomyocytes remain unclear. Emerging studies have demonstrated that ferroptosis, an iron-dependent non-apoptotic regulated form of cell death characterized by iron dyshomeostasis and lipid peroxidation, contributes to the development of ischemic cardiomyopathy, diabetic cardiomyopathy, doxorubicin-induced cardiomyopathy, and septic cardiomyopathy. Numerous compounds have exerted potential therapeutic effects on cardiomyopathies by inhibiting ferroptosis. In this review, we summarize the core mechanism by which ferroptosis leads to the development of these cardiomyopathies. We emphasize the emerging types of therapeutic compounds that can inhibit ferroptosis and delineate their beneficial effects in treating cardiomyopathies. This review suggests that inhibiting ferroptosis pharmacologically may be a potential therapeutic strategy for cardiomyopathy treatment.

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.

Therapeutic strategies in ischemic cardiomyopathy: Focus on mitochondrial quality surveillance

Despite considerable efforts to prevent and treat ischemic cardiomyopathy (ICM), effective therapies remain lacking, in part owing to the complexity of the underlying molecular mechanisms, which are not completely understood yet. It is now widely thought that mitochondria serve as “sentinel” organelles that are capable of detecting cellular injury and integrating multiple stress signals. These pathophysiological activities are temporally and spatially governed by the mitochondrial quality surveillance (MQS) system, involving mitochondrial dynamics, mitophagy, and biogenesis. Dysregulation of MQS is an early and critical process contributing to mitochondrial bioenergetic dysfunction and sublethal injury to cardiomyocytes during ICM. An improved understanding of the pathogenesis of ICM may enable the development of novel preventive and therapeutic strategies aimed at overcoming the challenge of myocardial ischemia and its cardiovascular sequelae. This review describes recent research on the protective effects of MQS in ICM and highlights promising therapeutic targets.

Nanomaterials-Mediated Therapeutics and Diagnosis Strategies for Myocardial Infarction

The alarming mortality and morbidity rate of myocardial infarction (MI) is becoming an important impetus in the development of early diagnosis and appropriate therapeutic approaches, which are critical for saving patients' lives and improving post-infarction prognosis. Despite several advances that have been made in the treatment of MI, current strategies are still far from satisfactory. Nanomaterials devote considerable contribution to tackling the drawbacks of conventional therapy of MI by improving the homeostasis in the cardiac microenvironment via targeting, immune modulation, and repairment. This review emphasizes the strategies of nanomaterials-based MI treatment, including cardiac targeting drug delivery, immune-modulation strategy, antioxidants and antiapoptosis strategy, nanomaterials-mediated stem cell therapy, and cardiac tissue engineering. Furthermore, nanomaterials-based diagnosis strategies for MI was presented in term of nanomaterials-based immunoassay and nano-enhanced cardiac imaging. Taken together, although nanomaterials-based strategies for the therapeutics and diagnosis of MI are both promising and challenging, such a strategy still explores the immense potential in the development of the next generation of MI treatment.

Integrated Strategies of Diverse Feature Selection Methods Identify Aging-Based Reliable Gene Signatures for Ischemic Cardiomyopathy

Objective: Ischemic cardiomyopathy (ICM) is a major cardiovascular state associated with prominently increased morbidity and mortality. Our purpose was to detect reliable gene signatures for ICM through integrated feature selection strategies.

Methods: Transcriptome profiles of ICM were curated from the GEO project. Classification models, including least absolute shrinkage and selection operator (LASSO), support vector machine (SVM), and random forest, were adopted for identifying candidate ICM-specific genes for ICM. Immune cell infiltrates were estimated using the CIBERSORT method. Expressions of candidate genes were verified in ICM and healthy myocardial tissues via Western blotting. JC-1 staining, flow cytometry, and TUNEL staining were presented in hypoxia/reoxygenation (H/R)-stimulated H9C2 cells with TRMT5 deficiency.

Results: Following the integration of three feature selection methods, we identified seven candidate ICM-specific genes including ASPN, TRMT5, LUM, FCN3, CNN1, PCNT, and HOPX. ROC curves confirmed the excellent diagnostic efficacy of this combination of previous candidate genes in ICM. Most of them presented prominent interactions with immune cell infiltrates. Their deregulations were confirmed in ICM than healthy myocardial tissues. TRMT5 expressions were remarkedly upregulated in H/R-stimulated H9C2 cells. TRMT5 deficiency enhanced mitochondrial membrane potential and reduced apoptosis in H/R-exposed H9C2 cells.

Conclusion: Collectively, our findings identified reliable gene signatures through combination strategies of diverse feature selection methods, which facilitated the early detection of ICM and revealed the underlying mechanisms.

Impact of frailty on all-cause mortality and major bleeding in patients with atrial fibrillation: A meta-analysis

BACKGROUND

Conflicting results have been reported on the impact of frailty on adverse outcomes in patients with atrial fibrillation (AF). The aim of this meta-analysis was to evaluate the impact of frailty on death and major bleeding in patients with AF.

METHODS

We comprehensively searched PubMed and Embase databases until June 30, 2021 for the relevant studies that investigated the impact of frailty on all-cause mortality and major bleeding in AF patients. Pooled multivariable-adjusted risk ratio (RR) and 95% confidence intervals (CI) was estimated for the frail vs. nonfrail patients using a random-effect model.

RESULTS

Ten studies involving 97,413 patients with AF satisfied the inclusion criteria. The prevalence of frailty in patients with AF ranged between 5.9% and 89.5%. Meta-analysis indicated that frailty was associated with higher risk of all-cause mortality (RR 2.77; 95% CI 1.68-4.57) and major bleeding (RR 1.83; 95% CI 1.24-2.71). Subgroup analysis showed that the impact of frailty on all-cause mortality was consistently found in each subgroup.

CONCLUSION

Frailty independently predicts all-cause mortality and major bleeding in patients with AF. Determination of frailty status may play an important role in risk classification of AF patients. However. lack of standardized definition of frailty is the most important limitations of this meta-analysis.

An antioxidant system through conjugating superoxide dismutase onto metal-organic framework for cardiac repair

Acute myocardial infarction (AMI) remains a dominant origin of morbidity, mortality and disability worldwide. Increases in reactive oxygen species (ROS) are key contributor to excessive cardiac injury after AMI. Here we developed an immobilized enzyme with Superoxide Dismutase (SOD) activity cross-link with Zr-based metal-organic framework (ZrMOF) (SOD-ZrMOF) for mitigate ROS-caused injury. In vitro and in vivo evidence indicates that SOD-ZrMOF exhibits excellent biocompatibility. By efficiently scavenging ROS and suppressing oxidative stress, SOD-ZrMOF can protect the function of mitochondria, reduce cell death and alleviate inflammation. More excitingly, long-term study using an animal model of AMI demonstrated that SOD-ZrMOF can reduce the infarct area, protect cardiac function, promote angiogenesis and inhibit pathological myocardial remodeling. Therefore, SOD-ZrMOF holds great potential as an efficacious and safe nanomaterial treatment for AMI.

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.

Coronary Revascularization in Patients With Stable Coronary Artery Disease: The Role of Imaging

In the last decades, the effective management of some cardiovascular risk factors in the general population has led to a progressive decrease in the prevalence of coronary artery disease (CAD). Nevertheless, coronary heart disease remains the major cause of death in developed and developing countries and chronic coronary syndromes (CCS) are still a major target of utilization of non-invasive cardiac imaging and invasive procedures. Current guidelines recommend the use of non-invasive imaging in patients with CCS to identify subjects at higher risk to be referred for invasive coronary angiography and possible revascularization. These recommendations are challenged by two opposite lines of evidence. Recent trials have somewhat questioned the efficacy of coronary revascularization as compared with optimal medical therapy in CCS. As a consequence the role of imaging in these patients and in in patients with ischemic cardiomyopathy is under debate. On the other hand, real-life data indicate that a consistent proportion of patients undergo invasive procedure and are revascularized without any previous non-invasive imaging characterization. On top of this, the impact of COVID-19 pandemic on the sanitary systems caused a change in the current management of patients with CAD. In the present review we will discuss these conflicting data analyzing the evidence which has been recently accumulated as well as the gaps of knowledge which should still be filled.

Bioinformatics Analysis and Identification of Genes and Pathways in Ischemic Cardiomyopathy

Purpose

Ischemic cardiomyopathy (ICM) is considered to be the most common cause of heart failure, with high prevalence and mortality. This study aimed to investigate the different expressed genes (DEGs) and pathways in the pathogenesis of ICM using bioinformatics analysis.

Methods

The control and ICM datasets GSE116250, GSE46224 and GSE5406 were collected from the gene expression omnibus (GEO) database. DEGs were identified using limma package of R software, and co-expressed genes were identified using Venn diagrams. Then, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to explore the biological functions and signaling pathways. Protein-protein interaction (PPI) networks were assembled with Cytoscape software to identify hub genes related to the pathogenesis of ICM. RT-PCR of Heart tissues (n=2 for non-failing controls and n=4 for ischemic cardiomyopathy patients) was used to validate the bioinformatic results.

Results

A total of 844 DEGs were screened from GSE116250, of which 447 were up-regulated genes and 397 were down-regulated genes, respectively. A total of 99 DEGs were singled out from GSE46224, of which 58 were up-regulated genes and 41 were down-regulated genes, respectively. Thirty DEGs were screened from GSE5406, including 10 genes with up-regulated expression and 20 genes with down-regulated expression. Five up-regulated and 3 down-regulated co-expressed DEGs were intersected in three datasets. GO and KEGG pathway analyses revealed that DEGs are mainly enriched in collagen fibril organization, protein digestion and absorption, AGE-RAGE signaling pathway and other related pathways. Collagen alpha-1(III) chain (COL3A1), collagen alpha-2(I) chain (COL1A2) and lumican (LUM) are the three hub genes in all three datasets through PPI network analysis. The expression of 5 DEGs (SERPINA3, FCN3, COL3A1, HBB, MXRA5) in heart tissues by qRT-PCR results was consistent with our GEO analysis, while expression of 3 DEGs (ASPN, LUM, COL1A2) was opposite with GEO analysis.

Conclusion

These findings from this bioinformatics network analysis investigated key hub genes, which contributed to better understanding the mechanism and new therapeutic targets of ICM.

Advances in Nanomaterials for Injured Heart Repair

Atherosclerotic cardiovascular disease (ASCVD) is one of the leading causes of mortality worldwide. Because of the limited regenerative capacity of adult myocardium to compensate for the loss of heart tissue after ischemic infarction, scientists have been exploring the possible mechanisms involved in the pathological process of ASCVD and searching for alternative means to regenerate infarcted cardiac tissue. Although numerous studies have pursued innovative solutions for reversing the pathological process of ASCVD and improving the effectiveness of delivering therapeutics, the translation of those advances into downstream clinical applications remains unsatisfactory because of poor safety and low efficacy. Recently, nanomaterials (NMs) have emerged as a promising new strategy to strengthen both the efficacy and safety of ASCVD therapy. Thus, a comprehensive review of NMs used in ASCVD treatment will be useful. This paper presents an overview of the pathophysiological mechanisms of ASCVD and the multifunctional mechanisms of NM-based therapy, including antioxidative, anti-inflammation and antiapoptosis mechanisms. The technological improvements of NM delivery are summarized and the clinical transformations concerning the use of NMs to treat ASCVD are examined. Finally, this paper discusses the challenges and future perspectives of NMs in cardiac regeneration to provide insightful information for health professionals on the latest advancements in nanotechnologies for ASCVD treatment.

Prognostic value of natriuretic peptides and restrictive filling pattern before surgical ventricular restoration

OBJECTIVE

Both increased natriuretic peptide levels and restrictive filling pattern (RFP) are important risk predictors in patients with heart failure. The aim of this study was to examine the role of the combined use of natriuretic peptide and RFP for the prognostic stratification of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration in the Biomarker Plus study.

METHODS

A total of 186 patients (aged 64 ± 10 years) underwent echocardiographic study and N-terminal pro-B-type natriuretic peptide assay at baseline (before surgical ventricular restoration). Patients were divided into 4 groups depending on baseline diastolic filling pattern (RFP/no RFP) and N-terminal pro-B-type natriuretic peptide level (less than or greater than or equal to the upper tertile value of 2003 ŋg/L). RFP was defined as E/A ratio ≥2. All-cause death or heart failure hospitalizations within 36-month follow-up were analyzed.

RESULTS

Despite similar ejection fraction, volumes, and mass, the 4 groups presented distinct clinical and structural pattern of presurgical ventricular restoration ventricular remodeling and significantly different clinical outcome after surgical unloading. During follow-up, 67 patients died or were hospitalized for heart failure (36%). High N-terminal pro-B-type natriuretic peptide levels and RFP, considered individually, were significantly associated with outcome (P < .0001). The combination of both was associated with the highest adjusted hazard of adverse events (hazard ratio, 3.63; 95% CI, 1.73-7.6; P < .0001).

CONCLUSIONS

The simultaneous use of 2 markers, 1 biological and 1 echocardiographic, may allow better prognostic stratification and characterization of the distinct structural and clinical phenotypes in a population of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration. This approach could be useful in the decision-making process to guide treatment choices in patients with ischemic cardiomyopathy.