Sex Differences, Genetic and Environmental Influences on Dilated Cardiomyopathy

Integrative Analyses of Circulating Proteins and Metabolites Reveal Sex Differences in the Associations with Cardiac Function among DCM Patients

Dilated cardiomyopathy (DCM) is characterized by reduced left ventricular ejection fraction (LVEF) and left or biventricular dilatation. We evaluated sex-specific associations of circulating proteins and metabolites with structural and functional heart parameters in DCM. Plasma samples (297 men, 71 women) were analyzed for proteins using Olink assays (targeted analysis) or LC-MS/MS (untargeted analysis), and for metabolites using LC MS/MS (Biocrates AbsoluteIDQ p180 Kit). Associations of proteins (n = 571) or metabolites (n = 163) with LVEF, measured left ventricular end diastolic diameter (LVEDDmeasured), and the dilation percentage of LVEDD from the norm (LVEDDacc. to HENRY) were examined in combined and sex-specific regression models. To disclose protein-metabolite relations, correlation analyses were performed. Associations between proteins, metabolites and LVEF were restricted to men, while associations with LVEDD were absent in both sexes. Significant metabolites were validated in a second independent DCM cohort (93 men). Integrative analyses demonstrated close relations between altered proteins and metabolites involved in lipid metabolism, inflammation, and endothelial dysfunction with declining LVEF, with kynurenine as the most prominent finding. In DCM, the loss of cardiac function was reflected by circulating proteins and metabolites with sex-specific differences. Our integrative approach demonstrated that concurrently assessing specific proteins and metabolites might help us to gain insights into the alterations associated with DCM.

Cardiomyopathy in First-Degree Relatives of Patients Presenting With Acute Myocarditis: Prevalence and Prognostic Significance

BACKGROUND

Acute myocarditis has been genetically linked to dilated cardiomyopathy (DCM), but the clinical significance remains uncertain. We investigated the prevalence and long-term prognosis of DCM and heart failure (HF) among unselected patients hospitalized with acute myocarditis and their first-degree relatives compared with an age- and sex-matched cohort.

METHODS

This was an observational study utilizing the Danish nationwide registries, where all patients with a first-time myocarditis diagnosis from 1995 to 2018 were identified and matched (on birth year and sex) with 10 controls from the general population.

RESULTS

Totally 3176 patients with acute myocarditis and 31 760 controls were included (median age, 49.8 [Q1-Q3, 32.5-70.2] years; 35.6% female). At baseline, patients with myocarditis had a higher prevalence of DCM (7 [0.2%] versus 8 [0.0%]) and HF (336 [10.6%] versus 695 [2.2%]) than controls; P<0.0001 for both. Patients with myocarditis more often had siblings with DCM (12 [0.4%] versus 17 [0.05%]) or HF (36 [1.1%] versus 89 [0.3%]); P<0.0001, odds ratios 7.09 (3.38-14.85) and 2.92 (1.25-6.80), respectively, whereas parental DCM and HF did not differ among patients with myocarditis and controls. Patients with myocarditis had greater 20-year incidence of DCM, HF, and all-cause mortality (0.5% [0.3%-0.9%], 15% [13%-17%], and 47% [44%-50%]) compared with controls (0.06% [0.03%-0.11%], 6.8% [6.4%-7.3%], and 34% [33%-35%]; P<0.0001). Having a first-degree relative with DCM or HF was associated with increased long-term mortality among the patients with myocarditis (hazard ratio, 1.40 [1.11-1.77]) but not among the controls (hazard ratio, 0.90 [0.81-1.01]; Pdifference=0.0008).

CONCLUSIONS

Acute myocarditis aggregates with DCM within families, where it carries a worsened prognosis. A differential association between parents and siblings (with sibling preponderance) could suggest that additional environmental factors are important for myocarditis development even in predisposed individuals.

A systematic review and meta-analysis of mortality in chronic Chagas cardiomyopathy versus other cardiomyopathies: higher risk or fiction?

INTRODUCTION AND OBJECTIVES

Although multiple studies suggest that chronic Chagas cardiomyopathy (CCC) has higher mortality than other cardiomyopathies, the absence of meta-analyses supporting this perspective limits the possibility of generating robust conclusions. The aim of this study was to systematically evaluate the current evidence on mortality risk in CCC compared with that of other cardiomyopathies.

METHODS

PubMed/Medline and EMBASE were searched for studies comparing mortality risk between patients with CCC and those with other cardiomyopathies, including in the latter nonischemic cardiomyopathy (NICM), ischemic cardiomyopathy, and non-Chagas cardiomyopathy (nonCC). A random-effects meta-analysis was performed to combine the effects of the evaluated studies.

RESULTS

A total of 37 studies evaluating 17 949 patients were included. Patients with CCC had a significantly higher mortality risk compared with patients with NICM (HR, 2.04; 95%CI, 1.60-2.60; I2, 47%; 8 studies) and non-CC (HR, 2.26; 95%CI, 1.65-3.10; I2, 71%; 11 studies), while no significant association was observed compared with patients with ischemic cardiomyopathy (HR, 1.72; 95%CI, 0.80-3.66; I2, 69%; 4 studies) in the adjusted-measures meta-analysis.

CONCLUSIONS

Patients with CCC have an almost 2-fold increased mortality risk compared with individuals with heart failure secondary to other etiologies. This finding highlights the need for effective public policies and targeted research initiatives to optimally address the challenges of CCC.

De Novo p.Asp3368Gly Variant of Dystrophin Gene Associated with X-Linked Dilated Cardiomyopathy and Skeletal Myopathy: Clinical Features and In Silico Analysis

Dystrophin (DMD) gene mutations are associated with skeletal muscle diseases such as Duchenne and Becker Muscular Dystrophy (BMD) and X-linked dilated cardiomyopathy (XL-DCM). To investigate the molecular basis of DCM in a 37-year-old woman. Clinical and genetic investigations were performed. Genetic testing was performed with whole exome sequencing (WES) using the Illumina platform. According to the standard protocol, a variant found by WES was confirmed in all available members of the family by bi-directional capillary Sanger resequencing. The effect of the variant was investigated by using an in silico prediction of pathogenicity. The index case was a 37-year-old woman diagnosed with DCM at the age of 33. A germline heterozygous A>G transversion at nucleotide 10103 in the DMD gene, leading to an aspartic acid-glycine substitution at the amino acid 3368 of the DMD protein (c.10103A>G p.Asp3368Gly), was identified and confirmed by PCR-based Sanger sequencing of the exon 70. In silico prediction suggests that this variant could have a deleterious impact on protein structure and functionality (CADD = 30). The genetic analysis was extended to the first-degree relatives of the proband (mother, father, and sister) and because of the absence of the variant in both parents, the p.Asp3368Gly substitution was considered as occurring de novo. Then, the direct sequencing analysis of her 8-year-old son identified as hemizygous for the same variant. The young patient did not present any signs or symptoms attributable to DCM, but reported asthenia and presented with bilateral calf hypertrophy at clinical examination. Laboratory testing revealed increased levels of creatinine kinase (maximum value of 19,000 IU/L). We report an early presentation of dilated cardiomyopathy in a 33-year-old woman due to a de novo pathogenic variant of the dystrophin (DMD) gene (p.Asp3368Gly). Genetic identification of this variant allowed an early diagnosis of a skeletal muscle disease in her son.

The inflammatory spectrum of cardiomyopathies

Infiltration of the myocardium with various cell types, cytokines and chemokines plays a crucial role in the pathogenesis of cardiomyopathies including inflammatory cardiomyopathies and myocarditis. A more comprehensive understanding of the precise immune mechanisms involved in acute and chronic myocarditis is essential to develop novel therapeutic approaches. This review offers a comprehensive overview of the current knowledge of the immune landscape in cardiomyopathies based on etiology. It identifies gaps in our knowledge about cardiac inflammation and emphasizes the need for new translational approaches to improve our understanding thus enabling development of novel early detection methods and more effective treatments.

Association of MBL2 gene polymorphisms and MBL levels with dilated cardiomyopathy in a Chinese Han population

BACKGROUND

It has been reported that Mannose-binding lectin 2 (MBL2) gene polymorphisms and expression levels are related to dilated cardiomyopathy (DCM). This study aimed to investigate the potential association between MBL2 gene polymorphisms and the pathogenesis of DCM.

METHODS

Five single nucleotide polymorphisms (SNPs) of the MBL2 gene were genotyped in 440 DCM patients and 532 controls in Southwest China. A luciferase reporter assay was used to detect the transcriptional activity the different genotypes. MBL serum levels, left ventricle ejection fraction (LVEF) and lower left ventricular end-diastolic diameter (LVEDD) were measured.

RESULTS

The rs11003125 C allele increased the transcriptional activity of the MBL2 promoter compared with the rs11003125 G allele. The rs11003125 CC carriers had higher MBL serum levels, LVEF and LVEDD than the rs11003125 CG and GG carriers.

CONCLUSIONS

Our study first revealed that MBL2 polymorphisms and serum MBL levels were associated with DCM. Allele C in rs11003125 of MBL2 may upregulate the expression levels of MBL. High serum MBL levels may be a protective factor in DCM pathogenesis.

Comprehensive review on gene mutations contributing to dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common primary myocardial diseases. However, to this day, it remains an enigmatic cardiovascular disease (CVD) characterized by ventricular dilatation, which leads to myocardial contractile dysfunction. It is the most common cause of chronic congestive heart failure and the most frequent indication for heart transplantation in young individuals. Genetics and various other factors play significant roles in the progression of dilated cardiomyopathy, and variants in more than 50 genes have been associated with the disease. However, the etiology of a large number of cases remains elusive. Numerous studies have been conducted on the genetic causes of dilated cardiomyopathy. These genetic studies suggest that mutations in genes for fibronectin, cytoskeletal proteins, and myosin in cardiomyocytes play a key role in the development of DCM. In this review, we provide a comprehensive description of the genetic basis, mechanisms, and research advances in genes that have been strongly associated with DCM based on evidence-based medicine. We also emphasize the important role of gene sequencing in therapy for potential early diagnosis and improved clinical management of DCM.

Investigating the role of NPR1 in dilated cardiomyopathy and its potential as a therapeutic target for glucocorticoid therapy

Background: Dilated cardiomyopathy (DCM), a specific form of cardiomyopathy, frequently presents clinically with either left ventricular or biventricular enlargement, often leading to progressive heart failure. In recent years, the application of bioinformatics technology to scrutinize the onset, progression, and prognosis of DCM has emerged as a fervent area of interest among scholars globally. Methods: In this study, core genes closely related to DCM were identified through bioinformatics analysis, including weighted gene co expression network analysis (WGCNA) and single sample gene set enrichment analysis (ssGSEA) and so on. The correlation was verified through experiments on DCM patients, DCM rat models, and core gene knockout mice. Subsequently, the effects of glucocorticoids on DCM and the regulation of core genes were observed. Result: In the present study, natriuretic peptide receptor 1 (NPR1) was identified as a core gene associated with DCM through WGCNA and ssGSEA. Significant impairment of cardiac and renal function was observed in both DCM patients and rats, concomitant with a notable reduction in NPR1 expression. NPR1 KO mice displayed symptomatic manifestations of DCM, underscoring the pivotal role of NPR1 in its pathogenesis. Notably, glucocorticoid treatment led to substantial improvements in cardiac and renal function, accompanied by an upregulation of NPR1 expression. Discussion: These findings highlight the critical involvement of NPR1 in the pathophysiology of DCM and its potential as a key target for glucocorticoid-based DCM therapy. The study provides a robust theoretical and experimental foundation for further investigations into DCM etiology and therapeutic strategies.

Torsional and strain dysfunction precede overt heart failure in a mouse model of dilated cardiomyopathy pathogenesis

Detailed assessments of whole heart mechanics are crucial for understanding the consequences of sarcomere perturbations that lead to cardiomyopathy in mice. Echocardiography offers an accessible and cost-effective method of obtaining metrics of cardiac function, but the most routine imaging and analysis protocols might not identify subtle mechanical deficiencies. This study aims to use advanced echocardiography imaging and analysis techniques to identify previously unappreciated mechanical deficiencies in a mouse model of dilated cardiomyopathy (DCM) before the onset of overt systolic heart failure (HF). Mice lacking muscle LIM protein expression (MLP-/-) were used to model DCM-linked HF pathogenesis. Left ventricular (LV) function of MLP-/- and wild-type (WT) controls were studied at 3, 6, and 10 wk of age using conventional and four-dimensional (4-D) echocardiography, followed by speckle-tracking analysis to assess torsional and strain mechanics. Mice were also studied with RNA-seq. Although 3-wk-old MLP-/- mice showed normal LV ejection fraction (LVEF), these mice displayed abnormal torsional and strain mechanics alongside reduced β-adrenergic reserve. Transcriptome analysis showed that these defects preceded most molecular markers of HF. However, these markers became upregulated as MLP-/- mice aged and developed overt systolic dysfunction. These findings indicate that subtle deficiencies in LV mechanics, undetected by LVEF and conventional molecular markers, may act as pathogenic stimuli in DCM-linked HF. Using these analyses in future studies will further help connect in vitro measurements of the sarcomere function to whole heart function.NEW & NOTEWORTHY A detailed study of how perturbations to sarcomere proteins impact whole heart mechanics in mouse models is a major yet challenging step in furthering our understanding of cardiovascular pathophysiology. This study uses advanced echocardiographic imaging and analysis techniques to reveal previously unappreciated subclinical whole heart mechanical defects in a mouse model of cardiomyopathy. In doing so, it offers an accessible set of measurements for future studies to use when connecting sarcomere and whole heart function.

Cardiomyopathy: A New Perspective from Diagnostic Strategy

Cardiomyopathy entails a broad group of diseases, acquired or genetic, which result in a similar phenotype [...].

Sex and gender differences in myocarditis and dilated cardiomyopathy: An update

In the past decade there has been a growing interest in understanding sex and gender differences in myocarditis and dilated cardiomyopathy (DCM), and the purpose of this review is to provide an update on this topic including epidemiology, pathogenesis and clinical presentation, diagnosis and management. Recently, many clinical studies have been conducted examining sex differences in myocarditis. Studies consistently report that myocarditis occurs more often in men than women with a sex ratio ranging from 1:2-4 female to male. Studies reveal that DCM also has a sex ratio of around 1:3 women to men and this is also true for familial/genetic forms of DCM. Animal models have demonstrated that DCM develops after myocarditis in susceptible mouse strains and evidence exists for this progress clinically as well. A consistent finding is that myocarditis occurs primarily in men under 50 years of age, but in women after age 50 or post-menopause. In contrast, DCM typically occurs after age 50, although the age that post-myocarditis DCM occurs has not been investigated. In a small study, more men with myocarditis presented with symptoms of chest pain while women presented with dyspnea. Men with myocarditis have been found to have higher levels of heart failure biomarkers soluble ST2, creatine kinase, myoglobin and T helper 17-associated cytokines while women develop a better regulatory immune response. Studies of the pathogenesis of disease have found that Toll-like receptor (TLR)2 and TLR4 signaling pathways play a central role in increasing inflammation during myocarditis and in promoting remodeling and fibrosis that leads to DCM, and all of these pathways are elevated in males. Management of myocarditis follows heart failure guidelines and there are currently no disease-specific therapies. Research on standard heart failure medications reveal important sex differences. Overall, many advances in our understanding of the effect of biologic sex on myocarditis and DCM have occurred over the past decade, but many gaps in our understanding remain. A better understanding of sex and gender effects are needed to develop disease-targeted and individualized medicine approaches in the future.

VEZF1 loss-of-function mutation underlying familial dilated cardiomyopathy

Dilated cardiomyopathy (DCM), characteristic of left ventricular or biventricular dilation with systolic dysfunction, is the most common form of cardiomyopathy, and a leading cause of heart failure and sudden cardiac death. Aggregating evidence highlights the underlying genetic basis of DCM, and mutations in over 100 genes have been causally linked to DCM. Nevertheless, due to pronounced genetic heterogeneity, the genetic defects underpinning DCM in most cases remain obscure. Hence, this study was sought to identify novel genetic determinants of DCM. In this investigation, whole-exome sequencing and bioinformatics analyses were conducted in a family suffering from DCM, and a novel heterozygous mutation in the VEZF1 gene (coding for a zinc finger-containing transcription factor critical for cardiovascular development and structural remodeling), NM_007146.3: c.490A > T; p.(Lys164*), was identified. The nonsense mutation was validated by Sanger sequencing and segregated with autosome-dominant DCM in the family with complete penetrance. The mutation was neither detected in another cohort of 200 unrelated DCM patients nor observed in 400 unrelated healthy individuals nor retrieved in the Single Nucleotide Polymorphism database, the Human Gene Mutation Database and the Genome Aggregation Database. Biological analyses by utilizing a dual-luciferase reporter assay system revealed that the mutant VEZF1 protein failed to transactivate the promoters of MYH7 and ET1, two genes that have been associated with DCM. The findings indicate VEZF1 as a new gene responsible for DCM, which provides novel insight into the molecular pathogenesis of DCM, implying potential implications for personalized precisive medical management of the patients affected with DCM.

Identification of key immune-related genes in dilated cardiomyopathy using bioinformatics analysis

Dilated cardiomyopathy (DCM) is characterized by the left ventricular dilatation and impaired myocardial systolic dysfunction with high mortality and morbidity. However, the underlying mechanisms remain elusive. We first identified the differentially expressed genes (DEGs) between the DCM and control group using two expression profiles from GSE3585 and GSE84796. Enrichment analysis was conducted to explore the potential mechanisms underlying DCM. A total of four algorithms, including key module of MCODE, degree, maximum neighborhood component (MNC), and maximal clique centrality (MCC), were used to identify the hub genes within Cytoscape. The correlation between hub genes and infiltrated immune cells was evaluated to determine potential immune-related genes. The expression analysis and diagnosis value analysis of potential immune-related genes were performed. Finally, the expression analysis with GSE57338 and relationship analysis with the comparative toxicogenomics database (CTD) were performed to identify the key immune-related genes in DCM. A total of 80 DEGs were screened for DCM. Enrichment analysis revealed that DEGs were involved in the immune-related pathological process. Immune infiltration analysis indicated a potentially abnormal immune response in DCM. Four up-regulated genes (COL1A2, COL3A1, CD53, and POSTN) were identified as potential immune-related genes. Finally, three genes (COL1A2, COL3A1, and POSTN) were determined as the key immune-related genes in DCM via expression analysis with a validation set (GSE57338) and relationship analysis with CTD. Our study suggested that the upregulated COL1A2, COL3A1, and POSTN might be the key immune-related genes for DCM. Further studies are needed to validate the underlying mechanisms.

Sex and age differences in sST2 in cardiovascular disease

Aims

The goal of this study was to determine whether sex and age differences exist for soluble ST2 (sST2) for several cardiovascular diseases (CVDs).

Methods

We examined sST2 levels using an ELISA kit for myocarditis (n = 303), cardiomyopathy (n = 293), coronary artery disease (CAD) (n = 239), myocardial infarct (MI) (n = 159), and congestive heart failure (CHF) (n = 286) and compared them to controls that did not have CVDs (n = 234).

Results

Myocarditis occurred in this study in relatively young patients around age 40 while the other CVDs occurred more often in older individuals around age 60. We observed a sex difference in sST2 by age only in myocarditis patients (men aged 38, women 46, p = 0.0002), but not for other CVDs. Sera sST2 levels were significantly elevated compared to age-matched controls for all CVDs: myocarditis (p ≤ 0.0001), cardiomyopathy (p = 0.0009), CAD (p = 0.03), MI (p = 0.034), and CHF (p < 0.0001) driven by elevated sST2 levels in females for all CVDs except myocarditis, which was elevated in both females (p = 0.002) and males (p ≤ 0.0001). Sex differences in sST2 levels were found for myocarditis and cardiomyopathy but no other CVDs and were higher in males (myocarditis p = 0.0035; cardiomyopathy p = 0.0047). sST2 levels were higher in women with myocarditis over 50 years of age compared to men (p = 0.0004) or women under 50 years of age (p = 0.015). In cardiomyopathy and MI patients, men over 50 had significantly higher levels of sST2 than women (p = 0.012 and p = 0.043, respectively) but sex and age differences were not detected in other CVDs. However, women with cardiomyopathy that experienced early menopause had higher sST2 levels than those who underwent menopause at a natural age range (p = 0.02).

Conclusion

We found that sex and age differences in sera sST2 exist for myocarditis, cardiomyopathy, and MI, but were not observed in other CVDs including CAD and CHF. These initial findings in patients with self-reported CVDs indicate that more research is needed into sex and age differences in sST2 levels in individual CVDs.

Identification of BMP10 as a Novel Gene Contributing to Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM), characterized by left ventricular or biventricular enlargement with systolic dysfunction, is the most common type of cardiac muscle disease. It is a major cause of congestive heart failure and the most frequent indication for heart transplantation. Aggregating evidence has convincingly demonstrated that DCM has an underlying genetic basis, though the genetic defects responsible for DCM in a larger proportion of cases remain elusive, motivating the ongoing research for new DCM-causative genes. In the current investigation, a multigenerational family affected with autosomal-dominant DCM was recruited from the Chinese Han population. By whole-exome sequencing and Sanger sequencing analyses of the DNAs from the family members, a new BMP10 variation, NM_014482.3:c.166C > T;p.(Gln56*), was discovered and verified to be in co-segregation with the DCM phenotype in the entire family. The heterozygous BMP10 variant was not detected in 268 healthy volunteers enrolled as control subjects. The functional measurement via dual-luciferase reporter assay revealed that Gln56*-mutant BMP10 lost the ability to transactivate its target genes NKX2.5 and TBX20, two genes that had been causally linked to DCM. The findings strongly indicate BMP10 as a new gene contributing to DCM in humans and support BMP10 haploinsufficiency as an alternative pathogenic mechanism underpinning DCM, implying potential implications for the early genetic diagnosis and precision prophylaxis of DCM.

KLF13 Loss‐of‐Function Mutations Underlying Familial Dilated Cardiomyopathy

Background

Dilated cardiomyopathy (DCM), characterized by progressive left ventricular enlargement and systolic dysfunction, is the most common type of cardiomyopathy and a leading cause of heart failure and cardiac death. Accumulating evidence underscores the critical role of genetic defects in the pathogenesis of DCM, and >250 genes have been implicated in DCM to date. However, DCM is of substantial genetic heterogeneity, and the genetic basis underpinning DCM remains elusive in most cases.

Methods and Results

By genome‐wide scan with microsatellite markers and genetic linkage analysis in a 4‐generation family inflicted with autosomal‐dominant DCM, a new locus for DCM was mapped on chromosome 15q13.1–q13.3, a 4.77‐cM (≈3.43 Mbp) interval between markers D15S1019 and D15S1010, with the largest 2‐point logarithm of odds score of 5.1175 for the marker D15S165 at recombination fraction (θ)=0.00. Whole‐exome sequencing analyses revealed that within the mapping chromosomal region, only the mutation in the KLF13 gene, c.430G>T (p.E144X), cosegregated with DCM in the family. In addition, sequencing analyses of KLF13 in another cohort of 266 unrelated patients with DCM and their available family members unveiled 2 new mutations, c.580G>T (p.E194X) and c.595T>C (p.C199R), which cosegregated with DCM in 2 families, respectively. The 3 mutations were absent from 418 healthy subjects. Functional assays demonstrated that the 3 mutants had no transactivation on the target genes ACTC1 and MYH7 (2 genes causally linked to DCM), alone or together with GATA4 (another gene contributing to DCM), and a diminished ability to bind the promoters of ACTC1 and MYH7 . Add, the E144X‐mutant KLF13 showed a defect in intracellular distribution.

Conclusions

This investigation indicates KLF13 as a new gene predisposing to DCM, which adds novel insight to the molecular pathogenesis underlying DCM, implying potential implications for prenatal prevention and precision treatment of DCM in a subset of patients.

Construction of Immune-Related ceRNA Network in Dilated Cardiomyopathy: Based on Sex Differences

Background: Immune targeted therapy has become an attractive therapeutic approach for patients with dilated cardiomyopathy (DCM) recently. Genetic predisposition and gender play a critical role in immune-related responses of DCM. This study aimed to perform a bioinformatics analysis of molecular differences between male and female samples and identify immune-related ceRNA network in DCM.

Methods: The gene expression microarray and clinical features dataset of GSE19303 was downloaded from the GEO. The raw data were preprocessed, followed by identification of differentially expressed genes (DEGs) between male and female DCM samples. Crucial functions and pathway enrichment analysis of DEGs were investigated through GO analysis and KEGG pathway analysis, respectively. A lncRNA–miRNA–mRNA network was constructed and a central module was extracted from the ceRNA network.

Results: Compared with the female group, the male group benefits more from IA/IgG immunotherapy. Male patients of DCM had a significant positive correlation with the abundance of inflammatory cells (B cells, memory B cells, CD8⁺ Tem cells, and NK cells). Sex difference DEGs had a widespread impact on the signaling transduction, transcriptional regulation, and metabolism in DCM. Subsequently, we constructed an immune-related ceRNA network based on sex differences in DCM, including five lncRNAs, six miRNAs, and 29 mRNAs. Furthermore, we extracted a central module from the ceRNA network, including two lncRNAs (XIST and LINC00632), three miRNAs (miR-1-3p, miR-17-5p, and miR-22-3p), and six mRNAs (CBL, CXCL12, ESR1, IGF1R, IL6ST, and STC1). Among these DEGs, CBL, CXCL12, and IL6ST expression was considered to be associated with inflammatory cell infiltration in DCM.

Conclusions: The identified ceRNA network and their enriched pathways may provide genetic insights into the phenotypic diversity of female and male patients with DCM and may provide a basis for development of sex-related individualization of immunotherapy.

Identification and Verification of Feature Biomarkers Associated With Immune Cells in Dilated Cardiomyopathy by Bioinformatics Analysis

Objective: To explore immune-related feature genes in patients with dilated cardiomyopathy (DCM).

Methods: Expression profiles from three datasets (GSE1145, GSE21610 and GSE21819) of human cardiac tissues of DCM and healthy controls were downloaded from the GEO database. After data preprocessing, differentially expressed genes (DEGs) were identified by the ‘limma’ package in R software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were then performed to identify biological functions of the DEGs. The compositional patterns of stromal and immune cells were estimated using xCell. Hub genes and functional modules were identified based on protein-protein interaction (PPI) network analysis by STRING webtool and Cytoscape application. Correlation analysis was performed between immune cell subtypes and hub genes. Hub genes with |correlation coefficient| > 0.5 and p value <0.05 were selected as feature biomarkers. A logistic regression model was constructed based on the selected biomarkers and validated in datasets GSE5406 and GSE57338.

Results: A total of 1,005 DEGs were identified. Functional enrichment analyses indicated that extracellular matrix remodeling and immune and inflammation disorder played important roles in the pathogenesis of DCM. Immune cells, including CD8⁺ T-cells, macrophages M1 and Th1 cells, were proved to be significantly changed in DCM patients by immune cell infiltration analysis. In the PPI network analysis, STAT3, IL6, CCL2, PIK3R1, ESR1, CCL5, IL17A, TLR2, BUB1B and MYC were identified as hub genes, among which CCL2, CCL5 and TLR2 were further screened as feature biomarkers by using hub genes and immune cells correlation analysis. A diagnosis model was successfully constructed by using the three biomarkers with area under the curve (AUC) scores 0.981, 0.867 and 0.946 in merged dataset, GSE5406 and GSE57338, respectively.

Conclusion: The present study identified three immune-related genes as diagnostic biomarkers for DCM, providing a novel perspective of immune and inflammatory response for the exploration of DCM molecular mechanisms.

Racial Differences in Delivery Outcomes among Women with Peripartum Cardiomyopathy

Background

Peripartum cardiomyopathy (PPCM) is a rare idiopathic cardiomyopathy associated with pregnancy that occurs more frequently among Black women. However, less is known about the association of race/ethnicity with outcomes at the time of delivery in women with PPCM.

Methods

We used data from the 2016-2018 National Inpatient Sample (NIS) database to identify women with a diagnosis of PPCM based on International Classification of Diseases, 10th revision (ICD-10) codes. Using adjusted logistic regression, the association of race with PPCM and adverse cardiovascular (CV) outcomes with PPCM was evaluated across racial/ethnic groups (White, Black, Hispanic, Asian/Pacific Islander).

Results

Among 11,304,996 delivery hospitalizations, PPCM was present in 8735 (0.08%). After adjusting for CV risk factors (chronic hypertension, diabetes, and obesity) and socioeconomic factors (insurance status, hospital income, and residential income), Black and Native American women had greater adjusted odds of developing PPCM (adjusted odds ratio [aOR] 1.89; 95% confidence interval [CI] 1.66-2.15; aOR 1.60; 95% CI 1.02-2.50, respectively), compared with White women. In stratified analysis of CV events, however, Asian/Pacific Islander women with PPCM were the most likely to have CV complications (aOR 98; 95% CI 29-333 for pulmonary edema).

Conclusions

In the US, at the time of delivery hospitalization, Black and Native American women are the most likely to develop PPCM, despite adjustment for CV and socioeconomic risk factors, but Asian women have higher odds of having CV complications.