Dilated cardiomyopathy: from epidemiologic to genetic phenotypes: A translational review of current literature

Astragalus polysaccharide protects against cardiac injury in a tnnt2a mutant zebrafish model of dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is a severe and irreversible heart disease characterized by dilated ventricles and decreased myocardial function. DCM has a poor prognosis and a very low survival rate, with a 5-year mortality rate ranging from 15 to 50%, and is an important cause of sudden cardiac death and heart failure. Genetic factors play important roles in the pathogenesis of DCM. Mutations in the cardiac troponin T (tnnt2) gene represent an important subset of known pathogenic variants that bind to DCM. However, few specific drugs are currently available to treat DCM caused by these gene mutations. Astragalus polysaccharide (APS), the main active ingredient of Astragalus mongholicus Bunge (Huangqi), is widely used in China to treat cardiovascular diseases, including DCM. This study explored drugs for the treatment of DCM caused by tnnt2a mutation and revealed the protective effect of APS on tnnt2a-mutant dilated cardiomyopathy.

METHODS

The tnnt2a-/- mutant zebrafish were used as a DCM model for comparison with the APS-treated group. The survival rate and the sinus venosus‒bulbus arteriosus (SV‒BA) distance were used to observe changes in cardiac output. Histopathological changes were observed via hematoxylin and eosin (HE) staining and TUNEL staining. The transcriptomes of the zebrafish in the DCM group and APS-treated group were investigated via RNA-seq. qRT‒PCR detection of apoptosis-related gene expression.

RESULTS

We found that APS markedly increased the heart rate and ATP content, and significantly inhibited the level of cardiac tissue edema, which are essential for improving the survival rate of tnnt2a-/-. Furthermore, APS modulates key muscle fiber-related genes (including ttnb and myom3) and significantly impacts multiple signaling pathways, including Rap1, PI3K-Akt, Jak-STAT, and Wnt signaling. The qRT‒PCR results revealed that APS decreased the expression of bax, caspase-3, and caspase-9 but increased the expression of bcl-2 in DCM zebrafish.

CONCLUSIONS

Our findings suggest that APS can improve the survival rate in dilated cardiomyopathy and has a positive protective effect on the myocardium in the tnnt2a mutant zebrafish model of DCM.

Identification of a rare variant in TNNT3 responsible for familial dilated cardiomyopathy through whole-exome sequencing and in silico analysis

BACKGROUND

Dilated cardiomyopathy (DCM) is a prevalent etiology of heart failure, distinguished by the gradual and frequently irreversible myocardial muscle impairment. Roughly 50% of DCM occurrences stem from hereditary rare variants. In this study, our aim was to identify the genetic cause of DCM in a pedigree with several affected individuals across four generations.

METHODS

Whole exome sequencing was performed on the proband, with variants filtered and analyzed using in silico tools. Co-segregation analysis was conducted using Sanger sequencing. Protein structure modeling and protein-protein interaction evaluations were performed using AlphaFold3 and HADDOCK2.4, respectively.

RESULTS

We identified a missense rare variant in the TNNT3 gene, leading to the p.Glu125Gly alteration in the Troponin T3 (TNNT3). This rare variant is strongly implicated as the causative factor for DCM in the pedigree. Several key factors underscore its significance: the rare variant co-segregates with the disease in the pedigree, is absent in 850 control samples, alters a conserved amino acid, is predicted to detrimentally affect protein function, and results in structural changes.

CONCLUSIONS

Our findings suggest that TNNT3 rare variants can induce DCM by weakening the binding energy between TNNT3 and Tropomyosin (TPM), leading to functional deficiencies in muscle contraction, as demonstrated by our structural modeling and docking studies. Troponin T is essential for the proper contraction of striated muscles and is related to cardiac development. Bioinformatics investigations have elucidated the involvement of TNNT3-related pathways, notably the Striated Muscle Contraction pathway and Cardiac Conduction. TNNT3 resides within loci previously implicated in cardiomyopathy. Given its crucial role in muscle contractile function, rare variants in TNNT3 hold the potential to be a significant contributing factor in the pathogenesis of DCM. A wealth of literature substantiates the correlation between troponin T and cardiac disorders. Our findings further corroborate this association.

Induced Pluripotent Stem Cells in Cardiomyopathy: Advancing Disease Modeling, Therapeutic Development, and Regenerative Therapy

Cardiomyopathies are a heterogeneous group of heart muscle diseases that can lead to heart failure, arrhythmias, and sudden cardiac death. Traditional animal models and in vitro systems have limitations in replicating the complex pathology of human cardiomyopathies. Induced pluripotent stem cells (iPSCs) offer a transformative platform by enabling the generation of patient-specific cardiomyocytes, thus opening new avenues for disease modeling, drug discovery, and regenerative therapy. This process involves reprogramming somatic cells into iPSCs and subsequently differentiating them into functional cardiomyocytes, which can be characterized using techniques such as electrophysiology, contractility assays, and gene expression profiling. iPSC-derived cardiomyocyte (iPSC-CM) platforms are also being explored for drug screening and personalized medicine, including high-throughput testing for cardiotoxicity and the identification of patient-tailored therapies. While iPSC-CMs already serve as valuable models for understanding disease mechanisms and screening drugs, ongoing advances in maturation and bioengineering are bringing iPSC-based therapies closer to clinical application. Furthermore, the integration of multi-omics approaches and artificial intelligence (AI) is enhancing the predictive power of iPSC models. iPSC-based technologies are paving the way for a new era of personalized cardiology, with the potential to revolutionize the management of cardiomyopathies through patient-specific insights and regenerative strategies.

Precision medicine applications in dilated cardiomyopathy: Advancing personalized care

Dilated cardiomyopathy (DCM) is a prevalent cardiac disorder affecting 1 in 250-500 individuals, characterized by ventricular dilation and impaired systolic function, leading to heart failure and increased mortality, including sudden cardiac death. DCM arises from genetic and environmental factors, such as drug-induced, inflammatory, and viral causes, resulting in diverse yet overlapping phenotypes. Advances in precision medicine are revolutionizing DCM management by leveraging genetic and molecular profiling for tailored diagnostic and therapeutic approaches. This review highlights comprehensive diagnostic evaluations, genetic discoveries, and multi-omics approaches integrating genomic, transcriptomic, proteomic, and metabolomic data to enhance understanding of DCM pathophysiology. Innovative risk stratification methods, including machine learning, are improving predictions of disease progression. Despite these advancements, the current one-size-fits-all management strategy contributes to persistently high morbidity and mortality. Emerging targeted therapies, such as CRISPR/Cas9 genome editing, aetiology-specific interventions, and pharmacogenomics, are reshaping treatment paradigms. Precision medicine holds promise for optimizing DCM diagnosis, treatment, and outcomes, aiming to reduce the burden of this debilitating condition.

Characteristics and pharmacological responsiveness in hiPSC models of inherited cardiomyopathy

Inherited cardiomyopathies are a major cause of heart failure in all age groups, often with an onset in adolescence or early adult life. More than a thousand variants in approximately one hundred genes are associated with cardiomyopathies. Interestingly, many genetic cardiomyopathies display overlapping phenotypical defects in patients, despite the diversity of the initial pathogenic variants. Understanding how the underlying pathophysiology of genetic cardiomyopathies leads to these phenotypes will improve insights into a patient's disease course, and creates the opportunity for conceiving treatment strategies. Moreover, therapeutic strategies can be used to treat multiple cardiomyopathies based on shared phenotypes. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) offer reliable, high-throughput models for studying molecular and cellular characteristics of hereditary cardiomyopathies. hiPSC-CMs are produced relatively easily, either by directly originating them from patients, or by introducing patient-specific genetic variants in healthy lines. This review evaluates 90 studies on 24 cardiomyopathy-associated genes and systematically summarises the morphological and functional phenotypes observed in hiPSC-CMs. Additionally, treatment strategies applied in cardiomyopathic hiPSC-CMs are compiled and scored for effectiveness. Multiple overlapping phenotypic defects were identified in cardiomyocytes with different variants, whereas certain characteristics were only associated with specific genetic variants. Based on these findings, common mechanisms, therapeutic prospects, and considerations for future research are discussed with the aim to improve clinical translation from hiPSC-CMs to patients.

Exploring the Familial Phenotypic Variability Associated With TTN Truncating Variants in Cardiomyopathies: Variant Spectrum, Genotype-Phenotype Correlation and Consequences in Genetic Counseling

Titin truncating variants (TTNtv) are the main genetic cause of dilated cardiomyopathies (DCMs). The phenotype and prognosis of probands have been evaluated in several large cohorts. However, few data are available on intrafamilial expressivity. To evaluate the phenotypical variability, we selected probands and family members carrying a unique TTN variant and recorded cardiac and genetic information. The cohort included 332 probands (314 TTNtv probands and 18 probands with in silico predicted in-frame exon skipping probands) and 191 relatives of TTNtv probands including 98 affected family members. Within TTNtv families, 96% of the affected relatives presented the same cardiomyopathy subtype as the proband, and 60% shared severity criteria (heart transplantation, implantable cardioverter-defibrillator, personal sudden death). Furthermore, we reported 18 probands that carry predicted in-frame exon skipping variants; they presented DCM (84%) as TTNtv patients but lower rate of rhythm disorders (0% vs. 29% respectively). In this work, we extend the genetic spectrum of TTNtv associated with DCM and show that within a family, and the cardiomyopathy phenotype is homogenous but the expressivity could vary. Such results are helpful for appropriate genetic counseling to better predict and manage the phenotype of mutation carriers.

Dilated Cardiomyopathy: A Novel BAG3 Mutation Associated with Aggressive Disease Progression and Ventricular Arrhythmias

We present the case of a 46-year-old man with a history of complex ventricular arrhythmias preceding the development of asymptomatic mild left ventricular dysfunction, who presented with acute-onset heart failure and was ultimately diagnosed with dilated cardiomyopathy. Genetic testing identified a novel, likely pathogenic mutation in exon 4 of the BAG3 gene (NM_004281, c.1128del, (p.(Ser377AlafsTer47)), not previously reported in the literature. Given the presence of multiple clinical features indicative of a poor prognosis, he underwent prophylactic placement of a subcutaneous implantable cardioverter-defibrillator. The clinical presentation of this novel BAG3 mutation suggests that it may be associated with a significant arrhythmic phenotype. This case underscores the importance of close follow-up and genetic testing in patients presenting with mild left ventricular dysfunction and ventricular arrhythmias.

Age at onset and clinical course of RBM20-mediated cardiomyopathy

Disease-causative variants in RBM20-encoded RNA-binding motif protein 20 cause a severe arrhythmogenic dilated cardiomyopathy (DCM). We aimed to characterize the clinical course of RBM20-mediated DCM in comparison to other familial and non-familial forms of DCM. The Mayo Clinic Genetic Arrhythmogenic Cardiomyopathy (ACM) Registry was used to identify RBM20- and TTNtv-positive individuals. Additionally, patients with idiopathic non-ischemic DCM were included in this study. Ventricular arrhythmic (VA) events were defined as sustained ventricular arrhythmia, sudden cardiac arrest (SCA), or ventricular tachycardia (VT)/ventricular fibrillation (VF)-terminating implantable cardioverter defibrillator (ICD) therapy and advanced heart failure (AHF) events defined as ventricular assist device implantation or heart transplantation. Overall, we identified 43 RBM20- (49% female) and 108 TTNtv- positive individuals (44% female). RBM20 variant-positive individuals were younger at time of diagnosis at 31 years vs. 45 years old for TTNtv-positive individuals (p < 0.0001). Additionally, RBM20 variant-positive individuals were more likely to have a family history of SCA (67% vs. 30%; p < 0.0001) and cardiomyopathy (88% vs. 61%; p = 0.0008). Interestingly, the prevalence of AHF (14% vs. 5%) events was higher in RBM20 variant-positive patients. RBM20 variant-positive individuals had earlier times to both VA (p = 0.007) and AHF (p = 0.0008) events. Findings were similar in comparison to idiopathic DCM. In this single center study, RBM20 patients had an earlier progressing disease with a higher prevalence of advanced heart failure compared with TTNtv patients. RBM20 patients progressed to VA and AHF endpoints earlier.

Cardiac Fibroblasts: Helping or Hurting

Cardiac fibroblasts (CFs) are the essential cell type for heart morphogenesis and homeostasis. In addition to maintaining the structural integrity of the heart tissue, muscle fibroblasts are involved in complex signaling cascades that regulate cardiomyocyte proliferation, migration, and maturation. While CFs serve as the primary source of extracellular matrix proteins (ECM), tissue repair, and paracrine signaling, they are also responsible for adverse pathological changes associated with cardiovascular disease. Following activation, fibroblasts produce excessive ECM components that ultimately lead to fibrosis and cardiac dysfunction. Decades of research have led to a much deeper understanding of the role of CFs in cardiogenesis. Recent studies using the single-cell genomic approach have focused on advancing the role of CFs in cellular interactions, and the mechanistic implications involved during cardiovascular development and disease. Arguably, the unique role of fibroblasts in development, tissue repair, and disease progression categorizes them into the friend or foe category. This brief review summarizes the current understanding of cardiac fibroblast biology and discusses the key findings in the context of development and pathophysiological conditions.

Biomimetic Approaches in the Development of Optimised 3D Culture Environments for Drug Discovery in Cardiac Disease

Cardiovascular disease remains the leading cause of death worldwide, yet despite massive investment in drug discovery, the progress of cardiovascular drugs from lab to clinic remains slow. It is a complex, costly pathway from drug discovery to the clinic and failure becomes more expensive as a drug progresses along this pathway. The focus has begun to shift to optimisation of in vitro culture methodologies, not only because these must be undertaken are earlier on in the drug discovery pathway, but also because the principles of the 3Rs have become embedded in national and international legislation and regulation. Numerous studies have shown myocyte cell behaviour to be much more physiologically relevant in 3D culture compared to 2D culture, highlighting the advantages of using 3D-based models, whether microfluidic or otherwise, for preclinical drug screening. This review aims to provide an overview of the challenges in cardiovascular drug discovery, the limitations of traditional routes, and the successes in the field of preclinical models for cardiovascular drug discovery. It focuses on the particular role biomimicry can play, but also the challenges around implementation within commercial drug discovery.

Ubiquitin-specific protease: an emerging key player in cardiomyopathy

Protein quality control (PQC) plays a vital role in maintaining normal heart function, as cardiomyocytes are relatively sensitive to misfolded or damaged proteins, which tend to accumulate under pathological conditions. Ubiquitin-specific protease (USP) is the largest deubiquitinating enzyme family and a key component of the ubiquitin proteasome system (UPS), which is a non-lysosomal protein degradation machinery to mediate PQC in cells. USPs regulate the stability or activity of the target proteins that involve intracellular signaling, transcriptional control of inflammation, antioxidation, and cell growth. Recent studies demonstrate that the USPs can regulate fibrosis, lipid metabolism, glucose homeostasis, hypertrophic response, post-ischemic recovery and cell death such as apoptosis and ferroptosis in cardiomyocytes. Since myocardial cell loss is an important component of cardiomyopathy, therefore, these findings suggest that the UPSs play emerging roles in cardiomyopathy. This review briefly summarizes recent literature on the regulatory roles of USPs in the occurrence and development of cardiomyopathy, giving us new insights into the molecular mechanisms of USPs in different cardiomyopathy and potential preventive strategies for cardiomyopathy.

Cardiac Magnetic Resonance to Reclassify Diagnosis and Detect Cardiomyopathies in Hospitalized Patients with Acute Presentation

BACKGROUND

Cardiomyopathies are a significant cause of heart failure, arrhythmia, and cardiac morbidity in the general population. Cardiovascular magnetic resonance (CMR) is a valuable tool for the diagnostic work-up of patients with acute cardiac events.

OBJECTIVES

This study evaluated the diagnostic value of CMR and the yield of cardiomyopathies in hospitalized cardiac patients with acute presentation.

METHODS

A retrospective analysis was conducted with 535 consecutive hospitalized patients who underwent CMR at Hippokration Hospital, Athens, Greece, to identify a subset of scans performed on an urgent basis of hospitalized patients. Demographic data, causes of admission, CMR findings, and plasma cardiac biomarkers (hs-Troponin I, NT-proBNP, and CRP) were systematically recorded.

RESULTS

Out of the initial 535 CMR scans evaluated, a further analysis was conducted with 104 patients who were in hospital and underwent CMR on an urgent basis. From the total population of hospitalized patients, 33% had CMR findings indicative of underlying cardiomyopathy, with dilated cardiomyopathy being the most common subtype (36%), followed by arrhythmogenic cardiomyopathy (27%), hypertrophic cardiomyopathy (15%), or other subtypes (e.g., cardiac amyloidosis, sarcoidosis, endomyocardial fibrosis, EGPA, or unclassified). CMR led to the reclassification of the initial diagnosis into that of underlying cardiomyopathy in 32% of cases. The highest reclassification rate was observed within the subgroup with heart failure (71%), followed by that of acute myocardial infarction/ischemic heart disease (24%) and myocarditis (22%).

CONCLUSIONS

CMR imaging effectively contributed to the differential diagnosis of hospitalized patients with acute cardiac events that remained without a definitive diagnosis after their initial work-up and uncovered underlying cardiomyopathy in almost one-third of this cohort.

Epigenome-wide association study for dilated cardiomyopathy in left ventricular heart tissue identifies putative gene sets associated with cardiac pathology and early indicators of cardiac risk

BACKGROUND

Methylation changes linked to dilated cardiomyopathy (DCM) affect cardiac gene expression. We investigate DCM mechanisms regulated by CpG methylation using multi-omics and causal analyses in the largest cohort of left ventricular tissues available.

METHODS

We mapped DNA methylation at ~ 850,000 CpG sites, performed array-based genotyping and conducted RNA sequencing on left ventricular tissue samples from failing and non-failing hearts across two independent DCM cohorts (discovery n = 329, replication n = 85). Summary-data-based Mendelian Randomisation (SMR) was applied to explore the causal contribution of sentinel CpGs to DCM. Fine-mapping of regions surrounding sentinel CpGs revealed additional signals for cardiovascular disease risk factors. Coordinated changes across multiple CpG sites were examined using weighted gene co-expression network analysis (WGCNA).

RESULTS

We identified 194 epigenome-wide significant CpGs associated with DCM (discovery P < 5.96E-08), enriched in active chromatin states in heart tissue. Amongst these, 32 sentinel CpGs significantly influenced the expression of 30 unique proximal genes (± 1 Mb). SMR suggested the causal contribution of two sentinel CpGs to DCM and two other sentinel CpGs to the expression of two unique proximal genes (P < 0.05). For one sentinel CpG, colocalisation analyses provided suggestive evidence for a single causal variant underlying the methylation-gene expression relationship. Fine-mapping revealed additional signals linked to cardiovascular disease-relevant traits, including creatinine levels and the Framingham Risk Score. Co-methylation modules were enriched in gene sets and transcriptional regulators related to cardiac physiological and pathological processes, as well as in transcriptional regulators whose cardiac relevance has yet to be determined.

CONCLUSIONS

Using the largest series of left ventricular tissue to date, this study investigates the causal role of cardiac methylation changes in DCM and suggests targets for experimental studies to probe DCM pathogenesis.

Systematic Review, Meta-Analysis, and Population Study to Determine the Biologic Sex Ratio in Dilated Cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) appears to be diagnosed twice as often in male than in female patients. This could be attributed to underdiagnosis in female patients or sex differences in susceptibility. Up to 30% of cases have an autosomal dominant monogenic cause, where equal sex prevalence would be expected. The aim of this systematic review, meta-analysis, and population study was to assess the sex ratio in patients with DCM, stratified by genetic status, and evaluate whether this is influenced by diagnostic bias.

METHODS

A literature search identified DCM patient cohorts with discernible sex ratios. Exclusion criteria were studies with a small (n<100), pediatric, or peripartum population. Meta-analysis and metaregression compared the proportion of female participants for an overall DCM cohort and the following subtypes: all genetic DCM, individual selected DCM genes (TTN and LMNA), and gene-elusive DCM. Population DCM sex ratios generated from diagnostic codes were also compared with those from sex-specific means using the UK Biobank imaging cohort; this established ICD coded, novel imaging-first, and genotype first determined sex ratios.

RESULTS

A total of 99 studies, with 37 525 participants, were included. The overall DCM cohort had a 0.30 female proportion (95% CI, 0.28-0.32), corresponding to a male:female ratio (M:F) of 2.38:1. This was similar to patients with an identified DCM variant (0.31 [95% CI, 0.26-0.36]; M:F 2.22:1; P=0.56). There was also no significant difference when compared with patients with gene-elusive DCM (0.30 [95% CI, 0.24-0.37]; M:F 2.29:1; P=0.81). Furthermore, the ratio within autosomal dominant gene variants was not significantly different for TTN (0.28 [95% CI, 0.22-0.36]; M:F 2.51:1; P=0.82) or LMNA (0.35 [95% CI, 0.27-0.44]; M:F 1.84:1; P=0.41). Overall, the sex ratio for DCM in people with disease attributed to autosomal dominant gene variants was similar to the all-cause group (0.34 [95% CI, 0.28-0.40]; M:F 1.98:1; P=0.19). In the UK Biobank (n=47 549), DCM defined by International Classification of Diseases, 10th revision, coding had 4.5:1 M:F. However, implementing sex-specific imaging-first and genotype-first diagnostic approaches changed this to 1.7:1 and 2.3:1, respectively.

CONCLUSIONS

This study demonstrates that DCM is twice as prevalent in male patients. This was partially mitigated by implementing sex-specific DCM diagnostic criteria. The persistent male excess in genotype-positive patients with an equally prevalent genetic risk suggests additional genetic or environmental drivers for sex-biased penetrance.

REGISTRATION

URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42023451944.

G protein regulation by RGS proteins in the pathophysiology of dilated cardiomyopathy

Regulators of G protein signaling (RGS) proteins fine-tune signaling via heterotrimeric G proteins to maintain physiologic homeostasis in various organ systems of the human body including the brain, kidney, heart, and vasculature. Impaired regulation of G protein signaling by RGS proteins is implicated in the pathogenesis of several human diseases including various forms of cardiomyopathy such as hypertrophic cardiomyopathy and dilated cardiomyopathy (DCM). Both genetic and nongenetic changes that impinge on G protein signaling in cardiomyocytes are implicated in the etiology of DCM, and there is accumulating evidence that such genetic and nongenetic changes affecting G protein signaling in cell types other than cardiomyocytes could serve as a DCM trigger in humans. This review discusses and highlights mammalian RGS proteins and their roles in cardiac physiology and disease, with a specific focus on the current understanding of the etiology of DCM and the pathogenic roles of RGS proteins that are prominently expressed in the cardiovascular system. Growing evidence suggests that defects in G protein regulation by RGS proteins in the cardiovascular system likely contribute to cardiomyocyte structural damage and decreased contractile function that hallmark DCM. Further studies that enhance the understanding of the dynamics of G protein regulation by RGS proteins in several cell types in the myocardium and the vasculature are critical to gaining more insight into the etiology of DCM and heart failure, and to the identification of novel therapeutic targets.

RBM20 p.Arg636Cys: A Pathogenic Variant Identified in a Family with Several Cases of Unexpected Sudden Deaths

Background: Dilated cardiomyopathy (DCM) can be an inherited condition related to premature sudden cardiac death (SCD). Pathogenic variants in some genes, like LMNA, SCN5A, FLNC or RBM20, have been linked to an increased risk of SCD. Although genetic study can help to stratify the arrhythmic risk, there are no specific guidelines for RBM20 carriers' management. We aimed to evaluate the genetic profile and clinical features of all DCM patients with pathogenic variants in RBM20.Methods: We identified all carriers of pathogenic variants in RBM20 in a single national center that specializes in inherited cardiac conditions. Forensic and molecular autopsies provided crucial information. Results: We identified a large family with inherited DCM due to RBM20 p.Arg636Cy and several SCDs. The proband was a 37-year-old male who suffered an unexpected SCD despite presenting a mild DCM phenotype with normal left ventricular ejection fraction. Family screening identified four other carriers, who were asymptomatic, but presented concealed mild DCM phenotypes. Family history revealed that six other relatives (two of them obligate carriers) had also suffered sudden deaths at young ages. Conclusions: We present an informative family with DCM, due to RBM20 p.Arg636Cys, and high rates of SCD, even in members with mild DCM phenotypes. ICD implantation to prevent SCD should be carefully evaluated in all RBM20 p.Arg636Cys carriers. Moreover, the frequent development of AF and HF progression requires specific awareness.

Identification and validation of diagnostic biomarkers and immune infiltration in dilated cardiomyopathies with heart failure and construction of diagnostic model

Dilated cardiomyopathy (DCM) is characterized by immune cell infiltration and can readily progress to heart failure (HF). In the study, differential expression analysis, enrichment analysis, and protein-protein interaction (PPI) network analysis were performed on DCM with HF-related datasets. The CytoHubba was used to identify hub genes. Diagnostic biomarkers were obtained by validating their expression and diagnostic value in another external dataset, and a diagnostic model was constructed. Finally, single-sample gene set enrichment analysis (ssGSEA) was used to predict immune cell infiltration in cardiac samples. The associations between diagnostic biomarkers and immune cells were investigated. The NetworkAnalyst and miRDB databases were used to predict transcription factors and microRNAs, followed by establishing regulatory networks. The DSigDB database was used to predict drug candidates. Subsequently, a mouse model of DCM with HF was used to validate the expression levels of these genes. The present study revealed that differentially expressed genes were enriched in the extracellular matrix organization, cardiac muscle hypertrophy, and other immune-related biological processes. OMD and THBS4 were finally identified, and the nomogram has satisfactory prediction and strong calibration ability. In addition, the two diagnostic biomarkers exhibited significant associations with multiple immune infiltrating cells. Finally, two TFs, 65 microRNAs, and 10 drug candidates were obtained. In animal experiments, two diagnostic biomarkers showed expression trends consistent with the results of bioinformatic analysis. OMD and THBS4 have been identified as hub immune-related diagnostic biomarkers for DCM with HF. Our research provides novel insights into the diagnosis and treatment of the disease.

BMP6, a potential biomarker of inflammatory fibrosis and promising protective factor for dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) stands as one of the most prevalent and severe causes of heart failure. Inflammation plays a pivotal role throughout the progression of DCM to heart failure, while age acts as a natural predisposing factor for all cardiovascular diseases. These two factors often interact, contributing to cardiac fibrosis, which is both a common manifestation and a pathogenic driver of adverse remodeling in DCM-induced heart failure.

METHOD

Bulk RNA-seq, single-cell RNA-seq, Mendelian randomization analysis, animal model construction, and BMP6 knockdown were utilized to identify and validate potential specific markers and targets for intervention in DCM heart failure.

RESULTS

We found that DCM hearts exhibit pronounced inflammatory cell infiltration and fibrosis. Both bulk RNA-seq and single-cell RNA-seq analyses revealed aberrant BMP6 expression specifically in fibroblasts. The ROC curve underscores the high specificity of BMP6 in relation to DCM, while Mendelian randomization analysis further confirms BMP6 as a protective factor against DCM. Notably, BMP6 knockdown led to a decrease in SMAD6 expression and a marked elevation in COL1A1 expression levels, indicating its antifibrotic role.

CONCLUSION

BMP6 emerges as a promising biomarker for DCM, and its functional role in exerting an antifibrotic effect underscores its potential as a therapeutic target.

RNA binding proteins: Mechanistic considerations and perspectives in controlling cardiovascular diseases

Cardiovascular diseases (CVDs) are becoming serious disease that endangering human health due to the increasing morbidity and mortality, and many molecular targets are involved in this complex pathologic process. Recently, RNA-binding proteins (RBPs) have received potential attention as a promising targets for preventing CVDs, including myocardial hypertrophy, dilated cardiomyopathy (DCM), myocardial fibrosis, and pulmonary hypertension (PH). As important regulators of RNA metabolism, RBPs play important roles in all steps of the gene expression cascade,and affect the occurrence and development of various diseases. In this review, we discuss the regulatory role of RBPs on various CVDs at the post transcriptional modification level based on current research. We also highlight the existing and potential RNA-based therapeutics that could impact future CVD treatments.

Mechanisms underlying dilated cardiomyopathy associated with FKBP12 deficiency

Dilated cardiomyopathy (DCM) is a highly prevalent and genetically heterogeneous condition that results in decreased contractility and impaired cardiac function. The FK506-binding protein FKBP12 has been implicated in regulating the ryanodine receptor in skeletal muscle, but its role in cardiac muscle remains unclear. To define the effect of FKBP12 in cardiac function, we generated conditional mouse models of FKBP12 deficiency. We used Cre recombinase driven by either the α-myosin heavy chain, (αMHC) or muscle creatine kinase (MCK) promoter, which are expressed at embryonic day 9 (E9) and E13, respectively. Both conditional models showed an almost total loss of FKBP12 in adult hearts compared with control animals. However, only the early embryonic deletion of FKBP12 (αMHC-Cre) resulted in an early-onset and progressive DCM, increased cardiac oxidative stress, altered expression of proteins associated with cardiac remodeling and disease, and sarcoplasmic reticulum Ca2+ leak. Our findings indicate that FKBP12 deficiency during early development results in cardiac remodeling and altered expression of DCM-associated proteins that lead to progressive DCM in adult hearts, thus suggesting a major role for FKBP12 in embryonic cardiac muscle.

Prognostic signature and therapeutic drug identification for dilated cardiomyopathy based on necroptosis via bioinformatics and experimental validation

Necroptosis, a type of programmed cell death, has been increasingly linked to cardiovascular disease development, yet its role in dilated cardiomyopathy (DCM) remains unclear. In this study, we analyzed the GSE5406 dataset from the GEO database to explore necroptosis-related prognostic signatures in DCM using LASSO regression. We identified five necroptosis-related genes (BID, CAMK2B, GLUL, HSP90AB1, CHMP5) that define a necroptosis-related signature with strong predictive value, evidenced by ROC curve areas of 0.852 and 0.957 in training and test sets, respectively. Our analyses, including GO and GSEA enrichment, focused on pathways associated with high necroptosis-related scores (NRS) and revealed significant immune cell infiltration. Notably, nTreg and iTreg cells were enriched in the high NRS group, while CD8 naive T cells and CD8 T cells positively correlated with NRS. Small molecule drugs fenofibrate, procyclidine, and tienilic acid emerged as potential therapeutic agents for high-risk patients, with fenofibrate showing efficacy in inhibiting DCM progression in an inflammatory animal model. These findings underscore the clinical relevance of necroptosis-related genes in assessing DCM progression and prognosis and highlight their potential for targeted therapeutic development.

An emerging double‑edged sword role of ferroptosis in cardiovascular disease (Review)

The pathophysiology of cardiovascular disease (CVD) is complex and presents a serious threat to human health. Cardiomyocyte loss serves a pivotal role in both the onset and progression of CVD. Among various forms of programmed cell death, ferroptosis, along with apoptosis, autophagy and pyroptosis, is closely linked to the advancement of CVD. Ferroptosis, a mechanism of cell death, is driven by the buildup of oxidized lipids and excess iron. This pathway is modulated by lipid, amino acid and iron metabolism. Key characteristics of ferroptosis include disrupted iron homeostasis, increased peroxidation of polyunsaturated fatty acids due to reactive oxygen species, decreased glutathione levels and inactivation of glutathione peroxidase 4. Treatments targeting ferroptosis could potentially prevent or alleviate CVD by inhibiting the ferroptosis pathway. Ferroptosis is integral to the pathogenesis of several types of CVD and inhibiting its occurrence in cardiomyocytes could be a promising therapeutic strategy for the future treatment of CVD. The present review provided an in‑depth analysis of advancements in understanding the mechanisms underlying ferroptosis. The present manuscript summarized the interplay between ferroptosis and CVDs, highlighting its dual roles in these conditions. Additionally, potential therapeutic targets within the ferroptosis pathway were discussed, alongside the current limitations and future directions of these novel treatment strategies. The present review may offer novel insights into preventive and therapeutic approaches for CVDs.

IL-17 affects the immune regulation of CD4+ T cells in dilated cardiomyopathy through JAK/STAT pathway

PURPOSE

Studying the effect of interleukin-17 (IL-17) on the mechanism of CD4+ T-cell immune regulation and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway may offer new ideas and methods for the therapy of dilated cardiomyopathy.

METHODS

Naive CD4+ T cells were isolated from mice using a magnetic bead sorting reagent and manipulated by overexpression or knockdown of IL-17. Protein levels of Janus kinase 2 (JAK2), phosphorylated JAK2 (p-JAK2), signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3 (p-STAT3), matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-9 (MMP-9) were determined by Western blotting. Quantitative polymerase chain reaction was used to assess the levels of JAK2, STAT3, MMP-2, and MMP-9. Expression of tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-4 (IL-4), and interferon-gamma (IFNγ) was determined by enzyme-linked immunosorbent assay test kits. TNF-α, IL-1β, IL-4, and IFNγ secretion was measured by flow cytometry.

RESULTS

In CD4+ T cells, IL-17 overexpression increased TNF-α, IL-1β, IL-4, IFNγ, p-JAK2, p-STAT3, MMP-2, MMP-9 levels, and apoptosis. Knockdown of IL-17 reduced the levels of TNF-α, IL-1β, IL-4, IFNγ, p-JAK2, p-STAT3, MMP-2, and MMP-9, as well as the level of apoptosis.

CONCLUSION

Through regulation of IL-17 expression in CD4+ T cells, this study reveals its crucial role in regulating the secretion of inflammatory factors, activation of the JAK/STAT signaling pathway, expression of matrix metalloproteinases, and apoptosis of CD4+ T cells.

Mendelian Randomization Study on the Associations Between Genetically Predicted Cardiovascular Disease Subtypes and the Risk of Developing Cardiomyopathies

Cardiomyopathies are commonly believed to have genetic origins; however, the connection between cardiomyopathies and cardiovascular diseases remains uncertain. Thus, we employed a Mendelian randomization (MR) approach to investigate the potential causal effects of specific cardiovascular disease subtypes on dilated and hypertrophic cardiomyopathies, focusing primarily on a European population. Summary-level data for cardiomyopathies and other cardiovascular diseases were obtained from public genome-wide association studies. Random-effects inverse-variance weighting was used as the primary analysis, whereas sensitivity analyses, including weighted median, MR-Egger, and multivariable MR methods, were also conducted. A genetic predisposition to atrial fibrillation [odds ratio (OR): 1.33; 95% confidence interval (CI): 1.18-1.50; P < 0.001], heart failure (OR: 3.22; 95% CI: 1.92-5.41; P < 0.001), and hypertension (OR: 1.50; 95% CI: 1.25-1.81; P < 0.001) were causally linked to an increased risk of developing dilated cardiomyopathy. However, there was no direct causal connection between genetically predicted coronary heart disease, pulmonary embolism, or ischemic stroke and the risk of developing dilated cardiomyopathy. In contrast, no significant associations were found between genetically predicted CVD subtypes and the risk of developing hypertrophic cardiomyopathy. Genetically predicted heart failure is significantly associated with the risk of developing dilated cardiomyopathy, underscoring the importance of effective heart failure management for risk prevention. Moreover, individuals with hypertension and atrial fibrillation might have an increased predisposition to dilated cardiomyopathy, highlighting crucial implications for management.

Comprehensive analysis of clinical characteristics, management, and prognosis in patients with dilated cardiomyopathy discharged from Spanish hospitals

OBJECTIVE

Dilated cardiomyopathy (DCM) is a leading cause of heart failure (HF) characterized by left ventricular dilatation and systolic dysfunction not explained by abnormal loading conditions. Despite its prevalence, DCM's epidemiology and prognosis remain poorly studied in our country.

METHODS

A retrospective observational study encompassed patients discharged from all Spanish public hospitals between 2016 and 2021 diagnosed with DCM. Data were extracted from the Minimum Basic Data Set. The study focused on hospital admissions, comorbidities, in-hospital mortality, and readmission rates for circulatory system diseases at 30 and 365 days.

RESULTS

Among 27,402 index episodes, DCM was the primary diagnosis in 12.4%, predominantly affecting men (72.5%). In-hospital mortality was 8.7%, with significant predictors including cardiogenic shock (OR: 12.4, 95% CI: 9.6-15.9), advanced or metastatic cancer (OR: 4.3, 95% CI: 3.8-5.0), renal failure (OR: 2.4, 95% CI: 2.2-2.7), and chronic liver disease (OR: 2.4, 95% CI: 2.1-2.8). Readmission rates were 7.9% at 30 days and 25.5% at 365 days, predominantly due to HF. Multivariate analysis identified age (IRR: 1.02, 95% CI: 1.01-1.02), female sex (IRR: 0.87, 95% CI: 0.79-0.96), severe hematological diseases (IRR: 2.12, 95% CI: 1.45-3.10), and metastatic cancer (IRR: 1.65, 95% CI: 1.31-2.07) as predictors of 30-day readmissions. At 365 days, predictors included age (IRR: 1.02, 95% CI: 1.01-1.02), female sex (IRR: 0.80, 95% CI: 0.74-0.86), severe hematological diseases (IRR: 2.43, 95% CI: 1.66-3.56), and renal failure (IRR: 1.42, 95% CI: 1.31-1.55).

CONCLUSION

This study highlights the substantial hospitalization burden and mortality risk among DCM patients, emphasizing the necessity for advanced management strategies and specialized cardiac care.

Association between comorbid COPD or chronic bronchitis and the prognosis of patients with Dilated cardiomyopathy

AIMS

Dilated cardiomyopathy (DCM) is characterized by unilateral or bilateral ventricular enlargement and reduced ventricular systolic function, with or without heart failure. In previous studies, we found that a history of chronic obstructive pulmonary disease (COPD) or chronic bronchitis is a high risk factor for DCM combined with pulmonary hypertension (PH). Therefore, we propose that the comorbidity of COPD or chronic bronchitis will increase the cardiogenic mortality of patients with DCM.

METHODS

Data were collected from patients with DCM who were admitted to The First Affiliated Hospital of Guangzhou University of Chinese Medicine from October 2008 to April 2020. The primary endpoint was cardiac death. Multivariable Cox regression analyses were employed to assess the associations between the comorbidities COPD or chronic bronchitis with the study endpoints. Different adjusting models were used to adjust for potential confounders.

RESULTS

A total of 305 DCM patients were ultimately enrolled, among whom 46 patients had COPD or chronic bronchitis. The median follow-up was 50 months. The rate of cardiac death in the COPD or chronic bronchitis group was significantly greater than that in the non-COPD or nonchronic bronchitis group (p < 0.001). The associations between comorbid COPD or chronic bronchitis and cardiac death remained robust after eliminating the possible effects of confounders. After grouping by PH, the risk difference was mainly derived from the intermediate- or high-probability PH group.

CONCLUSIONS

Comorbid COPD or chronic bronchitis increased the risk of cardiac death among DCM patients with an intermediate or high PH probability.

Unraveling the nexus of nesprin in dilated cardiomyopathy: From molecular insights to therapeutic prospects

Dilated cardiomyopathy is a complex and debilitating heart disorder characterized by the enlargement and weakening of the cardiac chambers, leading to impaired contractility and heart failure. Nesprins, a family of nuclear envelope spectrin repeat proteins that include isoforms Nesprin-1/-2, are integral components of the LInker of Nucleoskeleton and Cytoskeleton complex. They facilitate the connection between the nuclear envelope and the cytoskeleton, crucial for maintaining nuclear architecture, migration and positioning, and mechanical transduction and signaling. Nesprin-1/-2 are abundantly expressed in cardiac and skeletal muscles.They have emerged as key players in the pathogenesis of dilated cardiomyopathy. Mutations in synaptic nuclear envelope-1/-2 genes encoding Nesprin-1/-2 are associated with dilated cardiomyopathy, underscoring their significance in cardiac health. This review highlights the all known cases of Nesprin-1/-2 related dilated cardiomyopathy, focusing on their interactions with the nuclear envelope, their role in mechanical transduction, and their influence on gene expression. Moreover, it delves into the underlying mechanisms through which Nesprin dysfunction disrupts nuclear-cytoskeletal coupling, leading to abnormal nuclear morphology, impaired mechanotransduction, and altered gene regulation. The exploration of Nesprin's impact on dilated cardiomyopathy offers a promising avenue for therapeutic interventions aimed at ameliorating the disease. This review provides a comprehensive overview of recent advancements in understanding the pivotal role of Nesprins in dilated cardiomyopathy research.

Heart failure of very rare aetiology-haemochromatosis Type 3: a case report

Background

Haemochromatosis is a pathological condition characterized by the accumulation of iron in parenchymal organs, leading to toxic damage and dysfunction. Cardiac haemochromatosis represents one of the rare causes of severe heart failure (HF) that can be potentially prevented with targeted treatment.

Case Summary

We present the case of a 41-year-old female who was hospitalized for decompensated HF. Echocardiography revealed severe systolic dysfunction with a phenotype of dilated cardiomyopathy, accompanied by secondary moderate mitral regurgitation and severe tricuspid regurgitation (TR). To differentiate potential causes of HF, coronary angiography, cardiac magnetic resonance imaging (MRI), and endomyocardial biopsy were performed. Based on clinical findings, laboratory results, cardiac MRI, and endomyocardial biopsy data, a diagnosis of haemochromatosis was confirmed, and mutations in the TFR2 gene, responsible for haemochromatosis Type 3, were identified. The patient was treated in accordance with the latest European Society of Cardiology HF guidelines, and specific treatment for haemochromatosis, including therapeutic phlebotomy and iron chelation therapy, was initiated, resulting in a significant positive outcome.

Discussion

Investigating the aetiology of HF is essential, as even rare causes can be identified, and specific treatments are available that significantly improve prognosis and survival.

Three Novel Pathogenic Variants in Unrelated Vietnamese Patients with Cardiomyopathy

Background: Cardiomyopathy, including dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), is a major cause of heart failure (HF) and a leading indication for heart transplantation. Of these patients, 20-50% have a genetic cause, so understanding the genetic basis of cardiomyopathy will provide knowledge about the pathogenesis of the disease for diagnosis, treatment, prevention, and genetic counseling for families. Methods: This study collected nine patients from different Vietnamese families for genetic analysis at The Cardiovascular Center, E Hospital, Hanoi, Vietnam. The patients were diagnosed with cardiomyopathy based on clinical symptoms. Whole-exome sequencing (WES) was performed in the Vietnamese patients to identify variants associated with cardiomyopathy, and the Sanger sequencing method was used to validate the variants in the patients' families. The influence of the variants was predicted using in silico analysis tools. Results: Nine heterozygous variants were detected as a cause of disease in the patients, three of which were novel variants, including c.284C>G, p.Pro95Arg in the MYL2 gene, c.2356A>G, p.Thr786Ala in the MYH7 gene, and c.1223T>A, p.Leu408Gln in the DES gene. Two other variants were pathogenic variants (c.602T>C, p.Ile201Thr in the MYH7 gene and c.1391G>C, p.Gly464Ala in the PTPN11 gene), and four were variants of uncertain significance in the ACTA2, ANK2, MYOZ2, and PRKAG2 genes. The results of the in silico prediction software showed that the identified variants were pathogenic and responsible for the patients' DCM. Conclusions: Our results contribute to the understanding of cardiomyopathy pathogenesis and provide a basis for diagnosis, treatment, prevention, and genetic counseling.

Downregulation of miR-214 promotes dilated Cardiomyopathy Progression through PDE5A-Mediated cGMP regulation

Dilated cardiomyopathy (DCM) is a myocardial disorder resulting in a substantial decline in cardiac function and potentially leading to heart failure. This research combines bioinformatics analysis with empirical validation to explore the roles and mechanisms of miR-214 in DCM. Using the DEseq2 R package, a total of 125 differentially expressed circulating miRNAs (DE c-miRNAs) and 784 DE genes (DEGs) were identified. Cross-analysis between target genes of DE c-miRNAs and DEGs identified 124 common genes, and protein-protein interaction analysis of common genes identified 11 hub genes. Twelve DE c-miRNAs were further verified by quantifying their levels in the serum of DCM patients and healthy individuals. miR-214 levels were significantly decreased in serum from DCM patients, positively correlated with left ventricular ejection fraction and left ventricular fractional shortening. Further analysis showed that miR-214 directly targets and negatively regulates phosphodiesterase 5 A (PDE5A). Elevated PDE5A expression reduced cGMP levels; however, using sildenafil, a PDE5A inhibitor, reversed this effect, substantiating the regulatory mechanism of miR-214 on cGMP via PDE5A. These results provide new potential targets for the diagnosis and treatment of DCM.

Causal relationship between leukocyte telomere length and two cardiomyopathies based on a bidirectional Mendelian randomization approach

This study aims to employ the Mendelian randomization (MR) approach to investigate the relationship between leukocyte telomere length (TL) and 2 prevalent forms of cardiomyopathies. Using R software (4.3.1) for MR study, independent genetic variants associated with leukocyte TL were extracted from the Integrative Epidemiology Unit database, while cardiomyopathies data were pooled from FinnGen and European Bioinformatics Institute databases. Analytical methodologies included inverse-variance weighting, MR-Egger regression, and weighted median methods. Further analyses involved MR-Egger intercept and MR-PRESSO for handling horizontal pleiotropy and Cochran Q test for study heterogeneity. Our forward Mendelian randomization study indicates a positive correlation between longer leukocyte TL and the risk of 2 forms of cardiomyopathies: the longer the leukocyte telomere, the higher is the risk of cardiomyopathies. Specifically, for hypertrophic obstructive cardiomyopathy the OR is 2.23 (95% CI: 1.19-4.14, P = .01), for hypertrophic cardiomyopathy the OR is 1.80 (95% CI: 1.14-2.85, P = .01), and for dilated cardiomyopathy the OR is 1.32 (95% CI: 1.01-1.71, P = .04). In contrast, our reverse Mendelian randomization showed that cardiomyopathies were not directly associated with TL, and the inverse-variance-weighted test was not statistically significant for any of the 3 (P > .05). The reliability tests for the forward Mendelian randomization, including both MR-Egger intercept and MR-PRESSO tests, show no evidence of horizontal pleiotropy, and Cochran Q test indicates no heterogeneity. The "leave-one-out" sensitivity analysis revealed no outlier genes. The reliability tests for the reverse Mendelian randomization, including both MR-Egger intercept and MR-PRESSO tests, also indicate no genetic pleiotropy. Despite the heterogeneity shown in our study between hypertrophic cardiomyopathy and leukocyte TL, the sensitivity analysis did not identify any anomalies. Our Mendelian randomization study suggests that longer leukocyte TL is associated with an increased risk of hypertrophic obstructive cardiomyopathy, hypertrophic cardiomyopathy, and dilated cardiomyopathy. However, the onset of these 2 kinds of disease does not directly lead to changes in leukocyte TL.

Latrophilin-2 Deletion in Cardiomyocyte Disrupts Cell Junction, Leading to D-CMP

BACKGROUND

Latrophilin-2 (Lphn2), an adhesive GPCR (G protein-coupled receptor), was found to be a specific marker of cardiac progenitors during the differentiation of pluripotent stem cells into cardiomyocytes or during embryonic heart development in our previous studies. Its role in adult heart physiology, however, remains unclear.

METHODS

The embryonic lethality resulting from Lphn2 deletion necessitates the establishment of cardiomyocyte-specific, tamoxifen-inducible Lphn2 knockout mice, which was achieved by crossing Lphn2 flox/flox mice with mice having MerCreMer (tamoxifen-inducible Cre [Cyclization recombinase] recombinase) under the α-myosin heavy chain promoter.

RESULTS

Tamoxifen treatment for several days completely suppressed Lphn2 expression, specifically in the myocardium, and induced the dilated cardiomyopathy (D-CMP) phenotype with serious arrhythmia and sudden death in a short period of time. Transmission electron microscopy showed mitochondrial abnormalities, blurred Z-discs, and dehiscent myofibrils. The D-CMP phenotype, or heart failure, worsened during myocardial infarction. In a mechanistic study of D-CMP, Lphn2 knockout suppressed PGC-1α (Peroxisome proliferator-activated receptor gamma coactivator 1-alpha) and mitochondrial dysfunction, leading to the accumulation of reactive oxygen species and the global suppression of junctional molecules, such as N-cadherin (adherens junction), DSC-2 (desmocollin-2; desmosome), and connexin-43 (gap junction), leading to the dehiscence of cardiac myofibers and serious arrhythmia. In an experimental therapeutic trial, activators of p38-MAPK (p38 mitogen-activated protein kinases), which is a downstream signaling molecule of Lphn2, remarkably rescued the D-CMP phenotype of Lphn2 knockout in the heart by restoring PGC-1α and mitochondrial function and recovering global junctional proteins.

CONCLUSIONS

Lphn2 is a critical regulator of heart integrity by controlling mitochondrial functions and cell-to-cell junctions in cardiomyocytes. Its deficiency leads to D-CMP, which can be rescued by activators of the p38-MAPK pathway.

Dilated cardiomyopathy due to novel LMNA mutation: a case report

A case of a 44-year-old man presenting with a family history of LMNA mutation and cardiac symptoms (dizziness, weakness, palpitations, and shortness of breath) congruent with dilated cardiomyopathy. Genetic testing revealed a novel likely pathogenic mutation of the LMNA gene (c.513G>A, exon 2) not previously associated with dilated cardiomyopathy, and the patient underwent guideline direct treatment for dilated cardiomyopathy. In patients with LMNA mutations, VTA risk should be calculated to determine the need for prophylactic ICD placement.

Progression from cardiomyopathy to heart failure with reduced ejection fraction: A CORIN deficient course

Cardiomyopathies, encompassing hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), constitute a diverse spectrum of heart muscle diseases that often culminating in heart failure (HF). The inherent molecular heterogeneity of these conditions has implications for prognosis and therapeutic strategies. Publicly available microarray and RNA sequencing (RNA-seq) data sets of HCM (n = 106 from GSE36961) and DCM (n = 18 from GSE135055 and 166 from GSE141910) patients were employed for our analysis. The Non-negative Matrix Factorization (NMF) algorithm was applied to explore the molecular stratification within HCM and DCM, and enrichment analysis was performed to delineate their biological characteristics. By integrating bulk and single-nucleus RNA-seq (snRNA-seq) data, we identified a potential biomarker for HCM progression and cardiac fibrosis, which was subsequently validated using mendelian randomization and in vitro. Our application of NMF identified two distinct molecular clusters. Particularly, a profibrotic, heart failure with reduced ejection fraction (HFrEF)-resembling Cluster 1 emerged, characterized by diminished expression of CORIN and a high degree of fibroblast activation. This cluster also exhibited lower left ventricular ejection fraction (LVEF) and worse prognostic outcomes, establishing the significance of this molecular subclassification. We further found that overexpression of CORIN could mitigate TGFβ1-induced expression of col1a1 and α-SMA in neonatal rat cardiac fibroblasts. Our results indicated the heterogeneity of HCM population, and further evidenced the participation of corin in the progression of HCM, DCM and HFrEF. Nevertheless, our study is constrained by the lack of corresponding clinical data and experimental validation of the identified subtypes. Therefore, further studies are warranted to elucidate the downstream pathways of corin and to validate these findings in independent patient cohorts.

Plasma Olink Proteomics Reveals Novel Biomarkers for Prediction and Diagnosis in Dilated Cardiomyopathy with Heart Failure

In this study, we utilized the Olink Cardiovascular III panel to compare the expression levels of 92 cardiovascular-related proteins between patients with dilated cardiomyopathy combined with heart failure (DCM-HF) (n = 20) and healthy normal people (Normal) (n = 18). The top five most significant proteins, including SPP1, IGFBP7, F11R, CHI3L1, and Plaur, were selected by Olink proteomics. These proteins were further validated using ELISA in plasma samples collected from an additional cohort. ELISA validation confirmed significant increases in SPP1, IGFBP7, F11R, CHI3L1, and Plaur in DCM-HF patients compared to healthy controls. GO and KEGG analysis indicated that NT-pro BNP, SPP1, IGFBP7, F11R, CHI3L1, Plaur, BLM hydrolase, CSTB, Gal-4, CCL15, CDH5, SR-PSOX, and CCL2 were associated with DCM-HF. Correlation analysis revealed that these 13 differentially expressed proteins have strong correlations with clinical indicators such as LVEF and NT-pro BNP, etc. Additionally, in the GEO-DCM data sets, the combined diagnostic value of these five core proteins AUC values of 0.959, 0.773, and 0.803, respectively indicating the predictive value of the five core proteins for DCM-HF. Our findings suggest that these proteins may be useful biomarkers for the diagnosis and prediction of DCM-HF, and further research is prompted to explore their potential as therapeutic targets.

Exploring the etiology of dilated cardiomyopathy using Mendelian randomization

Background

Observational clinical studies suggest an association between dilated cardiomyopathy (DCM) and various factors including titin, cardiac troponin I (CTnI), desmocollin-2, the perinatal period, alcoholism, Behçet's disease, systemic lupus erythematosus, hyperthyroidism and thyrotoxicosis, hypothyroidism, carnitine metabolic disorder, and renal insufficiency. The causal nature of these associations remains uncertain. This study aims to explore these correlations using the Mendelian randomization (MR) approach.

Objective

To investigate the etiology of DCM through Mendelian randomization analysis.

Methods

Data mining was conducted in genome-wide association study databases, focusing on variant target proteins (titin, CTnI, desmocollin-2), the perinatal period, alcoholism, Behçet's disease, systemic lupus erythematosus, hyperthyroidism and thyrotoxicosis, hypothyroidism, carnitine metabolic disorder, and renal insufficiency, with DCM as the outcome. The analysis employed various regression models, namely, the inverse-variance weighted (IVW), MR-Egger, simple mode, weighted median, and weighted mode methods.

Results

The IVW results showed a correlation between titin protein and DCM, identifying titin as a protective factor [OR = 0.856, 95% CI (0.744-0.985), P = 0.030]. CTnI protein correlated with DCM, marking it as a risk factor [OR = 1.204, 95% CI (1.010-1.436), P = 0.040]. Desmocollin-2 also correlated with DCM and was recognized as a risk factor [OR = 1.309, 95% CI (1.085-1.579), P = 0.005]. However, no causal relationship was found between the perinatal period, alcoholism, Behçet's disease, systemic lupus erythematosus, hyperthyroidism and thyrotoxicosis, hypothyroidism, carnitine metabolic disorder, renal insufficiency, and DCM (P > 0.05). The MR-Egger intercept test indicated no pleiotropy (P > 0.05), affirming the effectiveness of Mendelian randomization in causal inference.

Conclusion

Titin, CTnI, and desmocollin-2 proteins were identified as independent risk factors for DCM. Contrasting with previous observational studies, no causal relationship was observed between DCM and the perinatal period, alcoholism, Behçet's disease, systemic lupus erythematosus, hyperthyroidism and thyrotoxicosis, hypothyroidism, carnitine metabolic disorder, or renal insufficiency.

The Pathogenic Mechanisms of and Novel Therapies for Lamin A/C-Related Dilated Cardiomyopathy Based on Patient-Specific Pluripotent Stem Cell Platforms and Animal Models

Variants (pathogenic) of the LMNA gene are a common cause of familial dilated cardiomyopathy (DCM), which is characterised by early-onset atrioventricular (AV) block, atrial fibrillation and ventricular tachyarrhythmias (VTs), and progressive heart failure. The unstable internal nuclear lamina observed in LMNA-related DCM is a consequence of the disassembly of lamins A and C. This suggests that LMNA variants produce truncated or alternative forms of protein that alter the nuclear structure and the signalling pathway related to cardiac muscle diseases. To date, the pathogenic mechanisms and phenotypes of LMNA-related DCM have been studied using different platforms, such as patient-specific induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs) and transgenic mice. In this review, point variants in the LMNA gene that cause autosomal dominantly inherited forms of LMNA-related DCM are summarised. In addition, potential therapeutic targets based on preclinical studies of LMNA variants using transgenic mice and human iPSC-CMs are discussed. They include mitochondria deficiency, variants in nuclear deformation, chromatin remodelling, altered platelet-derived growth factor and ERK1/2-related pathways, and abnormal calcium handling.

The Role of Ventricular Assist Devices in Patients With Heart Failure Due to Dilated Cardiomyopathy: A Systematic Review

Dilated cardiomyopathy (DCM) is a prevalent heart muscle disease characterized by ventricular dilation and systolic dysfunction, leading to severe heart failure (HF) and often requiring heart transplantation (HTx). This systematic review aimed to synthesize information regarding the role of ventricular assist devices (VADs) in managing HF patients due to DCM. A comprehensive search was conducted across PubMed, Embase, Scopus, Web of Science, and Cochrane databases for studies published between 2014 and 2024. Inclusion criteria were studies involving adult patients with HF due to DCM treated with VADs. Exclusion criteria included non-human studies, pediatric populations, and non-peer-reviewed articles. Thirty-one studies met the inclusion criteria. The included studies demonstrated that the use of VADs in patients with DCM resulted in significant improvements in left ventricular ejection fraction (LVEF), myocardial fibrosis reduction, and reverse ventricular remodeling. Studies reported enhanced survival rates, reduced symptoms, and better quality of life. VADs served as a critical bridge to HTx and, in some cases, as long-term destination therapy. However, complications such as thrombus formation, anemia, and kidney failure were noted, emphasizing the need for vigilant monitoring and management. Continuous advancements in VAD technology and patient management protocols were found to be essential for optimizing outcomes. We conclude that VADs play a crucial role in managing advanced HF due to DCM by providing mechanical circulatory support, improving cardiac function, and enhancing patient survival and quality of life. Despite associated complications, VADs are invaluable for patients with severe HF, offering both immediate and long-term therapeutic benefits. Future research should focus on minimizing complications and further improving VAD technology to enhance patient outcomes.

Prevalence of Genetically Associated Dilated Cardiomyopathy: A Systematic Literature Review and Meta-Analysis

Background

Dilated cardiomyopathy (DCM) is a leading cause of heart failure and cardiac transplantation globally. Disease-associated genetic variants play a significant role in the development of DCM. Accurately determining the prevalence of genetically associated DCM (genetic DCM) is important for developing targeted prevention strategies. This review synthesized published literature on the global prevalence of genetic DCM across various populations, focusing on two of the most common variants: titin (TTN) and myosin heavy chain 7 (MYH7).

Methods

MEDLINE® and Embase were searched from database inception to September 19, 2022 for English-language studies reporting the prevalence of genetic DCM within any population. Studies using family history as a proxy for genetic DCM were excluded.

Results

Of 2,736 abstracts, 57 studies were included. Among the global adult or mixed (mostly adults with few pediatric patients) DCM population, median prevalence was 20.2% (interquartile range (IQR): 16.3-36.0%) for overall genetic DCM, 11.4% (IQR: 8.2-17.8%) for TTN-associated DCM, and 3.2% (IQR: 1.8-5.2%) for MYH7-associated DCM. Global prevalence of overall pediatric genetic DCM within the DCM population was similar (weighted mean: 21.3%). Few studies reported data on the prevalence of genetic DCM within the general population.

Conclusions

Our study identified variable prevalence estimates of genetic DCM across different populations and geographic locations. The current evidence may underestimate the genetic contributions due to limited screening and detection of potential DCM patients. Epidemiological studies using long-read whole genome sequencing to identify structural variants or non-coding variants are needed, as well as large cohort datasets with genotype-phenotype correlation analyses.

Liver T1 Mapping Derived From Cardiac Magnetic Resonance Imaging: A Potential Prognostic Marker in Idiopathic Dilated Cardiomyopathy

BACKGROUND

Hepatic alterations are common aftereffects of heart failure (HF) and ventricular dysfunction. The prognostic value of liver injury markers derived from cardiac MRI studies in nonischemic dilated cardiomyopathy (DCM) patients is unclear.

PURPOSE

Evaluate the prognostic performance of liver injury markers derived from cardiac MRI studies in DCM patients.

STUDY TYPE

Prospective.

POPULATION

Three hundred fifty-six consecutive DCM patients diagnosed according to ESC guidelines (age 48.7 ± 14.2 years, males 72.6%).

FIELD STRENGTH/SEQUENCE

Steady-state free precession, modified Look-Locker inversion recovery T1 mapping and phase sensitive inversion recovery late gadolinium enhancement (LGE) sequences at 3 T.

ASSESSMENT

Clinical characteristics, conventional MRI parameters (ventricular volumes, function, mass), native myocardial and liver T1, liver extracellular volume (ECV), and myocardial LGE presence were assessed. Patients were followed up for a median duration of 48.3 months (interquartile range 42.0-69.9 months). Primary endpoints included HF death, sudden cardiac death, heart transplantation, and HF readmission; secondary endpoints included HF death, sudden cardiac death, and heart transplantation. Models were developed to predict endpoints and the incremental value of including liver parameters assessed.

STATISTICAL TESTS

Optimal cut-off value was determined using receiver operating characteristic curve and Youden method. Survival analysis was performed using Kaplan-Meier and Cox proportional hazard. Discriminative power of models was compared using net reclassification improvement and integrated discriminatory index. P value <0.05 was considered statistically significant.

RESULTS

47.2% patients reached primary endpoints; 25.8% patients reached secondary endpoints. Patients with elevated liver ECV (cut-off 34.4%) had significantly higher risk reaching primary and secondary endpoints. Cox regression showed liver ECV was an independent prognostic predictor, and showed independent prognostic value for primary endpoints and long-term HF readmission compared to conventional clinical and cardiac MRI parameters.

DATA CONCLUSIONS

Liver ECV is an independent prognostic predictor and may serve as an innovative approach for risk stratification for DCM.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Tail length and E525K dilated cardiomyopathy mutant alter human β-cardiac myosin super-relaxed state

Dilated cardiomyopathy (DCM) is a condition characterized by impaired cardiac function, due to myocardial hypo-contractility, and is associated with point mutations in β-cardiac myosin, the molecular motor that powers cardiac contraction. Myocardial function can be modulated through sequestration of myosin motors into an auto-inhibited "super-relaxed" state (SRX), which may be further stabilized by a structural state known as the "interacting heads motif" (IHM). Here, we sought to determine whether hypo-contractility of DCM myocardium results from reduced function of individual myosin molecules or from decreased myosin availability to interact with actin due to increased IHM/SRX stabilization. We used an established DCM myosin mutation, E525K, and characterized the biochemical and mechanical activity of wild-type and mutant human β-cardiac myosin constructs that differed in the length of their coiled-coil tail, which dictates their ability to form the IHM/SRX state. We found that short-tailed myosin constructs exhibited low IHM/SRX content, elevated actin-activated ATPase activity, and fast velocities in unloaded motility assays. Conversely, longer-tailed constructs exhibited higher IHM/SRX content and reduced actomyosin ATPase and velocity. Our modeling suggests that reduced velocities may be attributed to IHM/SRX-dependent sequestration of myosin heads. Interestingly, longer-tailed E525K mutants showed no apparent impact on velocity or actomyosin ATPase at low ionic strength but stabilized IHM/SRX state at higher ionic strength. Therefore, the hypo-contractility observed in DCM may be attributable to reduced myosin head availability caused by enhanced IHM/SRX stability in E525K mutants.

Emerging Concepts of Mechanisms Controlling Cardiac Tension: Focus on Familial Dilated Cardiomyopathy (DCM) and Sarcomere-Directed Therapies

Novel therapies for the treatment of familial dilated cardiomyopathy (DCM) are lacking. Shaping research directions to clinical needs is critical. Triggers for the progression of the disorder commonly occur due to specific gene variants that affect the production of sarcomeric/cytoskeletal proteins. Generally, these variants cause a decrease in tension by the myofilaments, resulting in signaling abnormalities within the micro-environment, which over time result in structural and functional maladaptations, leading to heart failure (HF). Current concepts support the hypothesis that the mutant sarcomere proteins induce a causal depression in the tension-time integral (TTI) of linear preparations of cardiac muscle. However, molecular mechanisms underlying tension generation particularly concerning mutant proteins and their impact on sarcomere molecular signaling are currently controversial. Thus, there is a need for clarification as to how mutant proteins affect sarcomere molecular signaling in the etiology and progression of DCM. A main topic in this controversy is the control of the number of tension-generating myosin heads reacting with the thin filament. One line of investigation proposes that this number is determined by changes in the ratio of myosin heads in a sequestered super-relaxed state (SRX) or in a disordered relaxed state (DRX) poised for force generation upon the Ca2+ activation of the thin filament. Contrasting evidence from nanometer-micrometer-scale X-ray diffraction in intact trabeculae indicates that the SRX/DRX states may have a lesser role. Instead, the proposal is that myosin heads are in a basal OFF state in relaxation then transfer to an ON state through a mechano-sensing mechanism induced during early thin filament activation and increasing thick filament strain. Recent evidence about the modulation of these mechanisms by protein phosphorylation has also introduced a need for reconsidering the control of tension. We discuss these mechanisms that lead to different ideas related to how tension is disturbed by levels of mutant sarcomere proteins linked to the expression of gene variants in the complex landscape of DCM. Resolving the various mechanisms and incorporating them into a unified concept is crucial for gaining a comprehensive understanding of DCM. This deeper understanding is not only important for diagnosis and treatment strategies with small molecules, but also for understanding the reciprocal signaling processes that occur between cardiac myocytes and their micro-environment. By unraveling these complexities, we can pave the way for improved therapeutic interventions for managing DCM.

Association between dietary selenium and zinc intake and risk of dilated cardiomyopathy in children: a case-control study

BACKGROUND

Dilated cardiomyopathy (DCMP) is characterized by the enlargement and weakening of the heart and is a major cause of heart failure in children. Infection and nutritional deficiencies are culprits for DCMP. Zinc is an important nutrient for human health due to its anti-oxidant effect that protects cell against oxidative damage. This case-control study aimed to investigate the relationship between dietary intake of zinc and selenium and the risk of DCMP in pediatric patients.

METHODS

A total of 36 DCMP patients and 72 matched controls were recruited, and their dietary intakes were assessed via a validated food frequency questionnaire. We used chi-square and sample T-test for qualitative and quantitative variables, respectively. Logistic regression analysis was applied to assess the relationship between selenium and zinc intake with the risk of DCMP.

RESULTS

After fully adjusting for confounding factors, analyses showed that selenium (OR = 0.19, CI = 0.057-0.069, P trend < 0.011) and zinc (OR = 0.12, CI = 0.035-0.046, P trend < 0.002) intake were strongly associated with 81% and 88% lower risk of pediatric DCMP, respectively.

CONCLUSIONS

This study highlights the protective role of adequate dietary intake of selenium and zinc in decreasing the risk of DCMP in children. Malnutrition may exacerbate the condition and addressing these micronutrient deficiencies may improve the cardiac function. Further studies are recommended to detect the underlying mechanisms and dietary recommendations for DCMP prevention.

Targeting ERBB2 and PIK3R1 as a therapeutic strategy for dilated cardiomyopathy: A single-cell sequencing and mendelian randomization analysis

Background

Dilated cardiomyopathy (DCM) is widely recognized as a significant contributor to heart failure. Nevertheless, the absence of pharmaceutical interventions capable of reversing disease progression and improving prognosis underscores the imperative for additional research in this area.

Methods

First, we identified and evaluated three gene sets, namely "SC-DCM", "EP-DCM" and "Drug", using big data and multiple bioinformatics analysis methods. Accordingly, drug-treatable ("Hub") genes in DCM were identified. Following this, four microarray expression profile datasets were employed to authenticate the expression levels and discriminatory efficacy of "Hub" genes. Additionally, mendelian randomization analysis was conducted to ascertain the causal association between the "Hub genes" and heart failure. Finally, the "DGIdb" was applied to identify "Hub" genes-targeted drugs. The "ssGSEA" algorithm assessed the level of immune cell infiltration in DCM.

Results

Enrichment analysis showed that the "SC-DCM" and "EP-DCM" gene sets were closely associated with DCM. PIK3R1 and ERBB2 were identified as drug-treatable genes in DCM. Additional analysis using MR supported a causal relationship between ERBB2 and heart failure, but not PIK3R1. Moreover, PIK3R1 was positively correlated with immune activation, while ERBB2 was negatively correlated. We found that everolimus was a pharmacological inhibitor for both PIK3R1 and ERBB2. However, no pharmacological agonist was found for ERBB2.

Conclusion

PIK3R1 and ERBB2 are drug-treatable genes in DCM. ERBB2 has a causal effect on heart failure, and its normal expression may play a role in preventing the progression of DCM to heart failure. In addition, there is a cross-expression of PIK3R1 and ERBB2 genes in both DCM and tumors. The adaptive immune system and PIK3R1 may be involved in DCM disease progression, while ERBB2 exerts a protective effect against DCM.

Identification of endocrine-disrupting chemicals targeting key DCM-associated genes via bioinformatics and machine learning

Dilated cardiomyopathy (DCM) is a primary cause of heart failure (HF), with the incidence of HF increasing consistently in recent years. DCM pathogenesis involves a combination of inherited predisposition and environmental factors. Endocrine-disrupting chemicals (EDCs) are exogenous chemicals that interfere with endogenous hormone action and are capable of targeting various organs, including the heart. However, the impact of these disruptors on heart disease through their effects on genes remains underexplored. In this study, we aimed to explore key DCM-related genes using machine learning (ML) and the construction of a predictive model. Using the Gene Expression Omnibus (GEO) database, we screened differentially expressed genes (DEGs) and performed enrichment analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to DCM. Through ML techniques combining maximum relevance minimum redundancy (mRMR) and least absolute shrinkage and selection operator (LASSO) logistic regression, we identified key genes for predicting DCM (IL1RL1, SEZ6L, SFRP4, COL22A1, RNASE2, HB). Based on these key genes, 79 EDCs with the potential to affect DCM were identified, among which 4 (3,4-dichloroaniline, fenitrothion, pyrene, and isoproturon) have not been previously associated with DCM. These findings establish a novel relationship between the EDCs mediated by key genes and the development of DCM.

The Prognostic Value of Serum Calcium Levels in Elderly Dilated Cardiomyopathy Patients

Background

It is unclear whether serum calcium on admission is associated with clinical outcomes in dilated cardiomyopathy (DCM). In this study, we conducted a retrospective study spanning a decade to investigate the prognostic value of baseline calcium in elderly patients with DCM.

Methods

A total of 1,089 consecutive elderly patients (age ≥60 years) diagnosed with DCM were retrospectively enrolled from January 2010 to December 2019. Univariate and multivariate analyses were performed to investigate the association of serum calcium with their clinical outcomes.

Results

In this study, the average age of the subjects was 68.36 ± 6.31 years. Receiver operating characteristic (ROC) curve analysis showed that serum calcium level had a great sensitivity and specificity for predicting in-hospital death, with an AUC of 0.732. Kaplan-Meier survival analysis showed that patients with a serum calcium >8.62 mg/dL had a better prognosis than those with a serum calcium ≤8.62 mg/dL (log-rank χ2 40.84, p < 0.001). After adjusting for several common risk factors, a serum calcium ≤8.62 mg/dL was related to a higher risk of long-term mortality (HR: 1.449; 95% CI: 1.115~1.882; p = 0.005).

Conclusions

Serum calcium level could be served as a simple and affordable tool to evaluate patients' prognosis in DCM.

Multimodal characterization of dilated cardiomyopathy: Geno- And Phenotyping of PrImary Cardiomyopathy (GrAPHIC)

AIMS

Cardiomyopathies (CMPs) are a heterogeneous group of diseases that are defined by structural and functional abnormalities of the cardiac muscle. Dilated cardiomyopathy (DCM), the most common CMP, is defined by left ventricular dilation and impaired contractility and represents a common cause of heart failure. Different phenotypes result from various underlying genetic and acquired causes with variable effects on disease development and progression, prognosis, and response to medical treatment. Current treatment algorithms do not consider these different aetiologies, due to lack of insights into treatable drivers of cardiac failure in patients with DCM. Our study aims to precisely phenotype and genotype the various subtypes of DCM and hereby lay the foundation for individualized therapy.

METHODS AND RESULTS

The Geno- And Phenotyping of PrImary Cardiomyopathy (GrAPHIC) is a currently ongoing prospective observational monocentric cohort study that recruits patients with DCM after exclusion of other causes such as coronary artery disease, valvular dysfunction, myocarditis, exposure to toxins, and peripartum CMP. Patients are enrolled at our heart failure outpatient clinic or during hospitalization at the University Hospital Hamburg. Clinical parameters, multimodal imaging and functional assessment, cardiac biopsies, and blood samples are obtained to enable an integrated genomic, functional, and biomarker analysis.

CONCLUSIONS

The GrAPHIC will contribute to a better understanding of the heterogeneous nature of primary CMPs focusing on DCM and provide improved prognostic approaches and more individualized therapies.

Development and validation of a risk model for intracardiac thrombosis in patients with dilated cardiomyopathy: a retrospective study

Intracardiac thrombosis is a severe complication in patients with non-ischemic dilated cardiomyopathy. This study aims to develop and validate an individualized nomogram to evaluate the risk of intracardiac thrombosis in patients with non-ischemic dilated cardiomyopathy. This retrospective study included patients diagnosed with dilated cardiomyopathy at first admission. Clinical baseline characteristics were acquired from electronic medical record systems. Multiple methods were applied to screen the key variables and generate multiple different variable combinations. Multivariable logistic regression was used to build the models, and the optimal model was chosen by comparing the discrimination. Then we checked the performance of the model in different thrombus subgroups. Finally, the model was presented using a nomogram and evaluated from the perspectives of discrimination, calibration, and clinical usefulness. Internal validation was performed by extracting different proportions of data for Bootstrapping. Ultimately, 564 eligible patients were enrolled, 67 of whom developed an intracardiac thrombosis. Risk factors included d-dimer, white blood cell count, high-sensitivity C-reactive protein, pulse pressure, history of stroke, hematocrit, and NT-proBNP in the optimal model. The model had good discrimination and calibration, and the area under the curve (AUC) was 0.833 (0.782-0.884), and the model's performance in each subgroup was stable. Clinical decision curve analysis showed that the model had clinical application value when the high-risk threshold was between 2% and 78%. The AUC of interval validation (30% and 70% data resampling) was 0.844 (0.765-0.924) and 0.833 (0.775-0.891), respectively. This novel intracardiac thrombosis nomogram could be conveniently applied to facilitate the individual intracardiac thrombosis risk assessment in patients with non-ischemic dilated cardiomyopathy.

Research Gaps in Pediatric Heart Failure: Defining the Gaps and Then Closing Them Over the Next Decade

Given the numerous opportunities and the wide knowledge gaps in pediatric heart failure, an international group of pediatric heart failure experts with diverse backgrounds were invited and tasked with identifying research gaps in each pediatric heart failure domain that scientists and funding agencies need to focus on over the next decade.