Myocardial Expression of Fas and Recovery of Left Ventricular Function in Patients With Recent-Onset Cardiomyopathy

Sex-based differences in the phenotypic expression and prognosis of idiopathic non-ischaemic cardiomyopathy: a cardiovascular magnetic resonance study

AIMS

We sought to characterize sex-related differences in cardiovascular magnetic resonance-based cardiovascular phenotypes and prognosis in patients with idiopathic non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Patients with NICM enrolled in the Cardiovascular Imaging Registry of Calgary (CIROC) between 2015 and 2021 were identified. Z-score values for chamber volumes and function were calculated as standard deviation from mean values of 157 sex-matched healthy volunteers, ensuring reported differences were independent of known sex-dependencies. Patients were followed for the composite outcome of all-cause mortality, heart failure admission, or ventricular arrhythmia. A total of 747 patients were studied, 531 (71%) males. By Z-score values, females showed significantly higher left ventricular (LV) ejection fraction (EF; median difference 1 SD) and right ventricular (RV) EF (difference 0.6 SD) with greater LV mass (difference 2.1 SD; P < 0.01 for all) vs. males despite similar chamber volumes. Females had a significantly lower prevalence of mid-wall striae (MWS) fibrosis (22% vs. 34%; P < 0.001). Over a median follow-up of 4.7 years, 173 patients (23%) developed the composite outcome, with equal distribution in males and females. LV EF and MWS were significant independent predictors of the outcome (respective HR [95% CI] 0.97 [0.95-0.99] and 1.6 [1.2-2.3]; P = 0.003 and 0.005). There was no association of sex with the outcome.

CONCLUSION

In a large contemporary cohort, NICM was uniquely expressed in females vs. males. Despite similar chamber dilation, females demonstrated greater concentric remodelling, lower reductions in bi-ventricular function, and a lower burden of replacement fibrosis. Overall, their prognosis remained similar to male patients with NICM.

Role of immune cells in the pathogenesis of myocarditis

Myocarditis is an inflammatory heart disease that mostly affects young people. Myocarditis involves a complex immune network; however, its detailed pathogenesis is currently unclear. The diversity and plasticity of immune cells, either in the peripheral blood or in the heart, have been partially revealed in a number of previous studies involving patients and several kinds of animal models with myocarditis. It is the complexity of immune cells, rather than one cell type that is the culprit. Thus, recognizing the individual intricacies within immune cells in the context of myocarditis pathogenesis and finding the key intersection of the immune network may help in the diagnosis and treatment of this condition. With the vast amount of cell data gained on myocarditis and the recent application of single-cell sequencing, we summarize the multiple functions of currently recognized key immune cells in the pathogenesis of myocarditis to provide an immune background for subsequent investigations.

Myocardial Recovery

In this paper, the feasibility of myocardial recovery is analyzed through a literature review. First, the phenomena of remodeling and reverse remodeling are analyzed, approached through the physics of elastic bodies, and the terms myocardial depression and myocardial recovery are defined. Continuing, potential biochemical, molecular, and imaging markers of myocardial recovery are reviewed. Then, the work focuses on therapeutic techniques that can facilitate the reverse remodeling of the myocardium. Left ventricular assist device (LVAD) systems are one of the main ways to promote cardiac recovery. The changes that take place in cardiac hypertrophy, extracellular matrix, cell populations and their structural elements, β-receptors, energetics, and several biological processes, are reviewed. The attempt to wean the patients who experienced cardiac recovery from cardiac assist device systems is also discussed. The characteristics of the patients who will benefit from LVAD are presented and the heterogeneity of the studies performed in terms of patient populations included, diagnostic tests performed, and their results are addressed. The experience with cardiac resynchronization therapy (CRT) as another way to promote reverse remodeling is also reviewed. Myocardial recovery is a phenomenon that presents with a continuous spectrum of phenotypes. There is a need for algorithms to screen suitable patients who may benefit and identify specific ways to enhance this phenomenon in order to help combat the heart failure epidemic.

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.

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.

Disparities in Cardio-oncology: Effects On Outcomes and Opportunities for Improvement

Purpose of Review

The purpose of this article is to provide a comprehensive review of available data on health disparities and the interconnected social determinants of health (SDOH) in cardio-oncology. We identify the gaps in the literature and suggest areas for future research. In addition, we propose strategies to address these disparities at various levels.

Recent Findings

There has been increasing recognition of health disparities and the role of SODH on an individual’s access to health care, quality of care, and outcomes of the illness. There is growing evidence of sex and race-based differences in cancer therapy-related cardiotoxicity. Recent studies have shown how access and quality of health care are affected by financial stability and rurality. Our recent study utilizing the social vulnerability index (SVI) and county-level patient data found graded increase in county-level cardio-oncology mortality with greater social vulnerability. The incremental impact of social vulnerability was higher for cardio-oncology mortality than for mortality related to either cancer or CVD alone. The mortality rates in these patients were higher in rural areas compared to urban areas regardless of social vulnerability. Additionally, for those within the counties within highest social vulnerability, Black individuals had significantly higher cardio-oncology mortality compared with White individuals.

Summary

Disparities in the cardio-oncology population are deep-rooted and widespread, leading to poor quality of life and increased mortality. It is crucial to integrate SDOH, not only in clinical care delivery but also in future research, and registry data to improve our understanding and the outcomes in our unique subset of cardio-oncology patients.

Changes in the Left Ventricular Eicosanoid Profile in Human Dilated Cardiomyopathy

Objective

Metabolites derived from N−3 and N−6 polyunsaturated fatty acids (PUFAs) have both beneficial and detrimental effects on the heart. However, contribution of these lipid mediators to dilated cardiomyopathy (DCM)-associated mitochondrial dysfunction remains unknown. This study aimed to characterize DCM-specific alterations in the PUFA metabolome in conjunction with cardiac mitochondrial quality in human explanted heart tissues.

Methods

Left ventricular tissues obtained from non-failing control (NFC) or DCM explanted hearts, were assessed for N−3 and N−6 PUFA metabolite levels using LC-MS/MS. mRNA and protein expression of CYP2J2, CYP2C8 and epoxide hydrolase enzymes involved in N−3 and N−6 PUFA metabolism were quantified. Cardiac mitochondrial quality was assessed by transmission electron microscopy, measurement of respiratory chain complex activities and oxygen consumption (respiratory control ratio, RCR) during ADP-stimulated ATP production.

Results

Formation of cardioprotective CYP-derived lipid mediators, epoxy fatty acids (EpFAs), and their corresponding diols were enhanced in DCM hearts. These findings were corroborated by increased expression of CYP2J2 and CYP2C8 enzymes, as well as microsomal and soluble epoxide hydrolase enzymes, suggesting enhanced metabolic flux and EpFA substrate turnover. DCM hearts demonstrated marked damage to mitochondrial ultrastructure and attenuated mitochondrial function. Incubation of fresh DCM cardiac fibers with the protective EpFA, 19,20-EDP, significantly improved mitochondrial function.

Conclusions

The current study demonstrates that increased expressions of CYP-epoxygenase enzymes and epoxide hydrolases in the DCM heart correspond with enhanced PUFA-derived EpFA turnover. This is accompanied by severe mitochondrial functional impairment which can be rescued by the administration of exogenous EpFAs.

Sex Differences, Genetic and Environmental Influences on Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is characterized by dilatation of the left ventricle and impaired systolic function and is the second most common cause of heart failure after coronary heart disease. The etiology of DCM is diverse including genetic pathogenic variants, infection, inflammation, autoimmune diseases, exposure to chemicals/toxins as well as endocrine and neuromuscular causes. DCM is inherited in 20–50% of cases where more than 30 genes have been implicated in the development of DCM with pathogenic variants in TTN (Titin) most frequently associated with disease. Even though male sex is a risk factor for heart failure, few studies have examined sex differences in the pathogenesis of DCM. We searched the literature for studies examining idiopathic or familial/genetic DCM that reported data by sex in order to determine the sex ratio of disease. We found 31 studies that reported data by sex for non-genetic DCM with an average overall sex ratio of 2.5:1 male to female and 7 studies for familial/genetic DCM with an overall average sex ratio of 1.7:1 male to female. No manuscripts that we found had more females than males in their studies. We describe basic and clinical research findings that may explain the increase in DCM in males over females based on sex differences in basic physiology and the immune and fibrotic response to damage caused by mutations, infections, chemotherapy agents and autoimmune responses.

NOGEA: A Network-oriented Gene Entropy Approach for Dissecting Disease Comorbidity and Drug Repositioning

Rapid development of high-throughput technologies has permitted the identification of an increasing number of disease-associated genes (DAGs), which are important for understanding disease initiation and developing precision therapeutics. However, DAGs often contain large amounts of redundant or false positive information, leading to difficulties in quantifying and prioritizing potential relationships between these DAGs and human diseases. In this study, a network-oriented gene entropy approach (NOGEA) is proposed for accurately inferring master genes that contribute to specific diseases by quantitatively calculating their perturbation abilities on directed disease-specific gene networks. In addition, we confirmed that the master genes identified by NOGEA have a high reliability for predicting disease-specific initiation events and progression risk. Master genes may also be used to extract the underlying information of different diseases, thus revealing mechanisms of disease comorbidity. More importantly, approved therapeutic targets are topologically localized in a small neighborhood of master genes on the interactome network, which provides a new way for predicting drug-disease associations. Through this method, 11 old drugs were newly identified and predicted to be effective for treating pancreatic cancer and then validated by in vitro experiments. Collectively, the NOGEA was useful for identifying master genes that control disease initiation and co-occurrence, thus providing a valuable strategy for drug efficacy screening and repositioning. NOGEA codes are publicly available at https://github.com/guozihuaa/NOGEA.

Sex-Related Differences in Dilated Cardiomyopathy with a Focus on Cardiac Dysfunction in Oncology

PURPOSE OF REVIEW

The aim of this report is to describe the main aspects of sex-related differences in non-ischemic dilated cardiomyopathies (DCM), focusing on chemotherapy-induced heart failure (HF) and investigating the possible therapeutic implications and clinical management applications in the era of personalized medicine.

RECENT FINDINGS

In cardio-oncology, molecular and multimodality imaging studies confirm that sex differences do exist, affecting the therapeutic cardioprotective strategies and, therefore, the long-term outcomes. Interestingly, compelling evidences suggest that sex-specific characteristics in drug toxicity might predict differences in the therapeutic response, most likely due to the tangled interplay between cancer and HF, which probably share common underlying mechanisms. Cardiovascular diseases show many sex-related differences in prevalence, etiology, phenotype expression, and outcomes. Complex molecular mechanisms underlie this diverse pathological manifestations, from sex-determined differential gene expression to sex hormone interaction with their receptors in the heart. Non-ischemic DCM is an umbrella definition that incorporates several etiologies, including chemotherapy-induced cardiomyopathies. The role of sex as a risk factor for cardiotoxicity is poorly explored. However, understanding the various features of disease manifestation and outcomes is of paramount importance for a prompt and tailored evaluation.

Sex-specific influence on cardiac structural remodeling and therapy in cardiovascular disease

Background

Cardiovascular diseases (CVDs) culminating into heart failure (HF) are major causes of death in men and women. Prevalence and manifestation, however, differ between sexes, since men mainly present with coronary artery disease (CAD) and myocardial infarction (MI), and post-menopausal women predominantly present with hypertension. These discrepancies are probably influenced by underlying genetic and molecular differences in structural remodeling pathways involved in hypertrophy, inflammation, fibrosis, and apoptosis. In general, men mainly develop eccentric forms, while women develop concentric forms of hypertrophy. Besides that, women show less inflammation, fibrosis, and apoptosis upon HF. This seems to emerge, at least partially, from the fact that the underlying pathways might be modulated by estrogen, which changes after menopause due to declining of the estrogen levels.

Conclusion

In this review, sex-dependent alterations in adverse cardiac remodeling are discussed for various CVDs. Moreover, potential therapeutic options, like estrogen treatment, are reviewed.

Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a clinical diagnosis characterized by left ventricular or biventricular dilation and impaired contraction that is not explained by abnormal loading conditions (for example, hypertension and valvular heart disease) or coronary artery disease. Mutations in several genes can cause DCM, including genes encoding structural components of the sarcomere and desmosome. Nongenetic forms of DCM can result from different aetiologies, including inflammation of the myocardium due to an infection (mostly viral); exposure to drugs, toxins or allergens; and systemic endocrine or autoimmune diseases. The heterogeneous aetiology and clinical presentation of DCM make a correct and timely diagnosis challenging. Echocardiography and other imaging techniques are required to assess ventricular dysfunction and adverse myocardial remodelling, and immunological and histological analyses of an endomyocardial biopsy sample are indicated when inflammation or infection is suspected. As DCM eventually leads to impaired contractility, standard approaches to prevent or treat heart failure are the first-line treatment for patients with DCM. Cardiac resynchronization therapy and implantable cardioverter-defibrillators may be required to prevent life-threatening arrhythmias. In addition, identifying the probable cause of DCM helps tailor specific therapies to improve prognosis. An improved aetiology-driven personalized approach to clinical care will benefit patients with DCM, as will new diagnostic tools, such as serum biomarkers, that enable early diagnosis and treatment.

Value of SOFA, APACHE IV and SAPS II scoring systems in predicting short-term mortality in patients with acute myocarditis

Acute myocarditis is an uncommon and potentially life-threatening disease. Scoring systems are essential for predicting outcome and evaluating the therapy effect of adult patients with acute myocarditis. The aim of this study was to determine the value of the Sequential Organ Failure Assessment (SOFA), Acute Physiology and Chronic Health Evaluation IV (APACHE IV) and second Simplified Acute Physiology Score (SAPS II) scoring systems in predicting short-term mortality of these patients. We retrospectively analyzed data from 305 adult patients suffering from acute myocarditis between April 2005 and August 2016. The association between the value of admission SOFA, APACHE IV and SAPS II scores and risk of short-term mortality was determined. Multivariate Cox analysis showed that SOFA, APACHE IV and SAPS II scores were independent risk factors of death in patients with acute myocarditis. For each scoring system, Kaplan–Meier analysis showed that the cumulative short-term mortality was significantly higher in patients with higher admission scores compared with those with lower admission scores. For the prediction of short-term mortality in a patient with acute myocarditis, SAPS II had the highest accuracy followed by the APACHE IV and SOFA scores.

Identification of genomic biomarkers for anthracycline-induced cardiotoxicity in human iPSC-derived cardiomyocytes: an in vitro repeated exposure toxicity approach for safety assessment

The currently available techniques for the safety evaluation of candidate drugs are usually cost-intensive and time-consuming and are often insufficient to predict human relevant cardiotoxicity. The purpose of this study was to develop an in vitro repeated exposure toxicity methodology allowing the identification of predictive genomics biomarkers of functional relevance for drug-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The hiPSC-CMs were incubated with 156 nM doxorubicin, which is a well-characterized cardiotoxicant, for 2 or 6 days followed by washout of the test compound and further incubation in compound-free culture medium until day 14 after the onset of exposure. An xCELLigence Real-Time Cell Analyser was used to monitor doxorubicin-induced cytotoxicity while also monitoring functional alterations of cardiomyocytes by counting of the beating frequency of cardiomyocytes. Unlike single exposure, repeated doxorubicin exposure resulted in long-term arrhythmic beating in hiPSC-CMs accompanied by significant cytotoxicity. Global gene expression changes were studied using microarrays and bioinformatics tools. Analysis of the transcriptomic data revealed early expression signatures of genes involved in formation of sarcomeric structures, regulation of ion homeostasis and induction of apoptosis. Eighty-four significantly deregulated genes related to cardiac functions, stress and apoptosis were validated using real-time PCR. The expression of the 84 genes was further studied by real-time PCR in hiPSC-CMs incubated with daunorubicin and mitoxantrone, further anthracycline family members that are also known to induce cardiotoxicity. A panel of 35 genes was deregulated by all three anthracycline family members and can therefore be expected to predict the cardiotoxicity of compounds acting by similar mechanisms as doxorubicin, daunorubicin or mitoxantrone. The identified gene panel can be applied in the safety assessment of novel drug candidates as well as available therapeutics to identify compounds that may cause cardiotoxicity.

Antiviral and myocyte protective effects of IL-28A in coxsackievirus B3-induced myocarditis

OBJECTIVE

This study aimed to investigate whether interleukin-28A (IL-28A) plays a role in murine myocarditis induced by coxsackievirus B3 (CVB3), and to explore its possible mechanism involved.

METHODS

Male BALB/c mice both infected and not infected by CVB3 were randomly divided into four groups (n=40), untreated or treated with different doses of IL-28A for 4 days, and then sacrificed on days 4 and 7 post-infection. The heart samples were collected for histopathologic examination. Cardiac viral load was determined by a plaque assay. Additionally, immunoblot analysis, TUNEL assay, and immunohistochemistry were performed to examine the expression of signal transducer, activator of transcription 1 and 2 (STAT1 and STAT2), CVB3-induced apoptosis and the expression of Bcl-2, BAX and Caspase-3.

RESULTS

Compared to uninfected mice, the CVB3 infected mice exhibited higher mortality rate (p<0.001), apparent inflammation and myocardial lesion (p<0.01), and higher cardiac viral load (p<0.01). After CVB3 infection, IL-28A treated mice presented no death (p<0.001), reduced inflammation and myocardial lesion (p<0.01), and lower viral load (p<0.01) compared to untreated mice. Besides, treatment with IL-28A markedly increased the expressions of STAT1 and STAT2, and inhibited CVB3-induced apoptosis in myocardial cells with increased ratio of Bcl-2/BAX.

CONCLUSION

The antiviral and myocyte protective effects of IL-28A in CVB3-induced myocarditis are regulated by STAT1 and STAT2.

Sex and gender differences in myocarditis and dilated cardiomyopathy

Heart failure due to nonischemic dilated cardiomyopathy (DCM) contributes significantly to the global burden of cardiovascular disease. Myocarditis is, in turn, a major cause of acute DCM in both men and women. However, recent clinical and experimental evidence suggests that the pathogenesis and prognosis of DCM differ between the sexes. This seminar provides a contemporary perspective on the immune mediators of myocarditis, including interdependent elements of the innate and adaptive immune response. The heart's acute response to injury is influenced by sex hormones that appear to determine the subsequent risk of chronic DCM. Preliminary data suggest additional genetic variations may account for some of the differences in epidemiology, left ventricular recovery, and survival between men and women. We highlight the gaps in our knowledge regarding the management of women with acute DCM and discuss emerging therapies, including bromocriptine for the treatment of peripartum cardiomyopathy.

Implantable cardiac defibrillators and sudden death in recent onset nonischemic cardiomyopathy: results from IMAC2

BACKGROUND

Given the potential for recovery in recent onset nonischemic cardiomyopathy (ROCM), the timing and need for implantable cardioverter-defibrillator (ICDs) remains controversial. We examined the utilization of ICDs and the impact on survival for subjects with ROCM.

METHODS AND RESULTS

An National Heart, Lung, and Blood Institute sponsored registry enrolled 373 subjects with ROCM, all with a left ventricular ejection fraction (LVEF) ≤0.40 and ≤6 months of symptoms. The mean age was 45 ± 14 years, 38% were female, 21% black, 75% New York Heart Association II/III, and the mean LVEF was 0.24 ± 0.08. Survival was comparable for subjects with an ICD within 1 month of entry (n = 43, 1/2/3 year % survival = 97/97/92) and those with no ICD at 1 month (n = 330, % survival = 98/97/95, P = .30) and between those with and without an ICD at 6 months (ICD, n = 73, 1/2/3 year % survival = 98/98/95; no ICD, n = 300, % survival = 98/96/95, P = .95). There were only 6 sudden cardiac deaths (SCD) noted (% survival free from SCD = 99/98/97) and these occurred in 1.9% of subjects without ICD and 0.9% of those with a device (P = .50).

CONCLUSIONS

In a multicenter cohort of ROCM the risk of SCD was low at 1% per year. Early ICD placement did not impact survival and can be deferred while assessing potential for myocardial recovery.

Variants of Toll-like receptor 4 predict cardiac recovery in patients with dilated cardiomyopathy

The clinical course of patients with dilated cardiomyopathy (DCM) varies from cardiac recovery to end stage heart failure. The etiology of this variability is largely unknown. In this study, we investigated the impact of coding polymorphisms of the innate immune protein Toll-like receptor 4 (TLR4) on left ventricular performance in patients with DCM. Two variants of TLR4 (rs4986790, TLR4 c.1187A→G, p.299D→G and rs4986791,TLR4 c.1487C→T, p.T399I) were investigated in 158 patients with DCM. Other reasons for heart failure were excluded by coronary angiography, myocardial biopsy, and echocardiography. Risk factors, age, gender, or treatment did not differ among the groups. At the follow-up evaluation (median 4.0-5.4 months), patients carrying the TLR4 wild type gene displayed cardiac recovery under intense medical heart failure therapy indexed by reduced left ventricular dilation, improved left ventricular ejection fraction, and reduced NT-probrain natriuretic peptide blood level when compared with the initial evaluation. In contrast, patients carrying both the rs4986790 and the rs4986791 variant showed significantly reduced improvement of left ventricular ejection fraction (p = 0.006) and left ventricular dilation (p = 0.015) at the follow-up evaluation when compared with carriers of the wild type gene under the same treatment conditions. In addition, NT-probrain natriuretic peptide level in carriers of both TLR4 variants did not change significantly at the follow up when compared with the first evaluation. Among patients with DCM, the presence of the TLR4 variants rs4986790 and rs4986791 predicts impaired cardiac recovery independently of medical treatment or cardiac risk factors.

Clinical and demographic predictors of outcomes in recent onset dilated cardiomyopathy: results of the IMAC (Intervention in Myocarditis and Acute Cardiomyopathy)-2 study

OBJECTIVES

We sought to determine clinical and demographic predictors of recovery of left ventricular function for subjects with recent onset cardiomyopathy (ROCM).

BACKGROUND

Although ROCM is a frequent reason for consultation and transplantation referral, its prognosis and natural history on contemporary therapy are unknown.

METHODS

In the multicenter IMAC (Intervention in Myocarditis and Acute Cardiomyopathy)-2 study, subjects with a left ventricular ejection fraction (LVEF) of ≤0.40, fewer than 6 months of symptom duration, and an evaluation consistent with idiopathic dilated cardiomyopathy or myocarditis were enrolled. LVEF was reassessed at 6 months, and subjects were followed up for 4 years. LVEF and event-free survival were compared by race, sex, and clinical phenotype.

RESULTS

The cohort of 373 persons was 38% female and 21% black, with a mean age of 45 ± 14 years. At entry, 91% were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and 82% were receiving beta-blockers, which increased to 92% and 94% at 6 months. LVEF was 0.24 ± 0.08 at entry and 0.40 ± 0.12 at 6 months (mean increase: 17 ± 13 ejection fraction units). Transplant-free survival at 1, 2, and 4 years was 94%, 92%, and 88%, respectively; survival free of heart failure hospitalization was 88%, 82%, and 78%, respectively. In analyses adjusted for sex, baseline LVEF, and blood pressure, LVEF at 6 months was significantly lower in blacks than in nonblacks (p = 0.02). Left ventricular end-diastolic diameter at presentation was the strongest predictor of LVEF at 6 months (p < 0.0001).

CONCLUSIONS

Outcomes in ROCM are favorable but differ by race. Left ventricular end-diastolic diameter by transthoracic echo at presentation was most predictive of subsequent myocardial recovery. (Genetic Modulation of Left Ventricular Recovery in Recent Onset Cardiomyopathy; NCT00575211).

Inflammatory markers and cytokines in peripartum cardiomyopathy: a delicate balance

Acute peripartum cardiomyopathy, a unique form of heart failure with onset in the last phase of pregnancy or shortly postpartum, has demonstrated evidence of an inflammatory process characterized by cytokine imbalance. Cytokines serve as inducers of repair mechanisms and promoters of both inflammatory and anti-inflammatory immune responses. Elevated plasma C-reactive protein, a marker of an inflammatory process, is co-expressed in the heart with the pro-inflammatory cytokine, TNF-alpha. Both pro-inflammatory and anti-inflammatory cytokines are involved in an intricate balance in response to injury to the heart. This article discusses potential and identified imbalances in levels of cytokines in peripartum cardiomyopathy that have led to clinical trials aimed at the modulation of select number of cytokines, some of which have been shown to have significant clinical benefit. Continuing investigation in this area is important since restoration of critical cytokine balance may be an area that holds promise for therapy. At the same time, one must be cautious in the timing of any intervention that alters cytokine balance.

Myocardial Fas and cytokine expression in end-stage heart failure: impact of LVAD support

Left ventricular assist device (LVAD) support may facilitate myocardial recovery. We evaluated the impact of LVAD support on Fas expression in a cohort with end-stage heart failure. Myocardial gene expression was assessed pre- and post-LVAD by RNase protection assay and compared to control donor hearts. The expression of Fas is markedly elevated at the time of LVAD support and is tightly correlated with TNF expression. While interleukin (IL)-6 was significantly reduced by LVAD support, the impact of support on Fas was highly variable and tightly linked to tumor necrosis factor (TNF). The role of Fas in predicting recovery after LVAD support requires further investigation.

Myocarditis

Myocarditis is an uncommon, potentially life-threatening disease that presents with a wide range of symptoms in children and adults. Viral infection is the most common cause of myocarditis in developed countries, but other etiologies include bacterial and protozoal infections, toxins, drug reactions, autoimmune diseases, giant cell myocarditis, and sarcoidosis. Acute injury leads to myocyte damage, which in turn activates the innate and humeral immune system, leading to severe inflammation. In most patients, the immune reaction is eventually down-regulated and the myocardium recovers. In select cases, however, persistent myocardial inflammation leads to ongoing myocyte damage and relentless symptomatic heart failure or even death. The diagnosis is usually made based on clinical presentation and noninvasive imaging findings. Most patients respond well to standard heart failure therapy, although in severe cases, mechanical circulatory support or heart transplantation is indicated. Prognosis in acute myocarditis is generally good except in patients with giant cell myocarditis. Persistent, chronic myocarditis usually has a progressive course but may respond to immunosuppression.

Left ventricular remodeling and myocardial recovery on mechanical circulatory support

BACKGROUND

Myocardial recovery after ventricular assist devices (VAD) is rare but appears more common in nonischemic cardiomyopathies (NICM). We sought to evaluate left ventricular (LV) end diastolic diameter (LVEDD) for predicting recovery after VAD.

METHODS AND RESULTS

NICM patients receiving long-term mechanical support between 1996 and 2008 were reviewed. Subjects were divided into 3 groups: mild, moderate, and severe dilation (Group A: LVEDD <6.0 cm [n = 22]; Group B: 6.0-7.0 cm [n = 32]; Group C: >7.0 cm [n = 48], respectively). Overall, recovery (successful explant without transplantation) occurred in 14 of 102 subjects (14%). Of these, 2 died and 2 required transplantation within 1 year. Recovery was more common in patients without LV dilation (Groups A/B/C = 32%/22%/0%, P < .001), as was sustained recovery (alive and transplant free 1 year after explant; A/B/C = 27%/10%/0%, P = .001). Of the recovery patients in Group A, 6/7 (86%) had sustained recovery versus 3/6 (50%) in Group B.

CONCLUSIONS

Recovery occurred in 32% of NICM patients without significant LV dilation at time of VAD, the majority of whom experienced significant sustained recovery. Recovery was not evident in those with severe LV dilation. Routine echocardiography at the time of implant may assist in targeting patients for recovery after VAD.

Apoptosis in patients with acute myocarditis

Acute myocarditis is an acute inflammatory syndrome characterized by acute myocardial damage and dysfunction followed by a variable recovery over time with some patients progressing toward severe dilated cardiomyopathy. Cardiomyocyte apoptosis, a key pathologic feature of heart failure, may play a critical role in functional recovery in patients with acute myocarditis. The aim of the study was to investigate whether apoptosis predicts functional recovery in patients with acute myocarditis. Sixteen patients with biopsy-documented acute myocarditis were followed for 1 year with serial transthoracic echocardiography. Functional recovery was defined as 12-month left ventricular ejection fraction >40%. Cardiomyocyte apoptosis, leukocyte infiltration, and cell proliferation was assessed in all samples. A group of cases in which the diagnosis of acute myocarditis was made after death was also selected for comparison, and morphologically normal hearts from patients who died from a noncardiac cause were selected as controls. Six patients (38%) had functional recovery at 12 months, whereas 10 (62%) did not. The 2 groups had similar characteristics except for lower baseline left ventricular ejection fraction in the group with functional recovery. Apoptotic rate was found to be significantly higher in patients with acute myocarditis than in control hearts, and, unexpectedly, patients with functional recovery had significantly higher apoptotic rates than patients without recovery (3.2% vs 0.5%, p = 0.001). None of the patients with apoptotic rates below the median had functional recovery versus 86% of patients with apoptotic rates above the median (p <0.001). In conclusion, higher rates of cardiomyocyte apoptosis in patients with acute myocarditis are associated with functional recovery at 1 year.

Is the Fas/Fas-L pathway a promising target for treating inflammatory heart disease?

The elucidation of the intricate molecular network of costimulus and regulatory pathways of the immune system led to the design of molecular therapies that specifically inactivate some cellular responses and ameliorate some autoimmune and inflammatory diseases. This innovative concept opens a new class of therapies, and one of the central components that could be targeted in future molecular therapies is the Fas-based pathway. Both soluble and membrane-bound Fas and Fas-L molecules exert a wide range of proinflammatory functions through the secretion of cytokines and chemokines, cellular chemotaxis, transcriptional regulation, cellular death, and others. Accordingly, many chronic inflammatory diseases, including myocarditis, are attenuated in mice lacking either molecule. Although it is tempting to speculate that the Fas/Fas-L pathway could be targeted for in vivo myocarditis therapy, the plurality of Fas/Fas-L functions can be an obstacle, leading to important side effects. In this review, we suggest that the injection of nonagonistic antibodies raised against the Fas molecule or the inactivation of downstream Fas-1,4,5-inositol triphosphate cascade are possible targets for myocarditis treatment.

Myocarditis

Myocarditis may present with a wide range of symptoms, ranging from mild dyspnea or chest pain that resolves without specific therapy to cardiogenic shock and death. Dilated cardiomyopathy with chronic heart failure is the major long-term sequela of myocarditis. Most often, myocarditis results from common viral infections; less commonly, specific forms of myocarditis may result from other pathogens, toxic or hypersensitivity drug reactions, giant-cell myocarditis, or sarcoidosis. The prognosis and treatment of myocarditis vary according to the cause, and clinical and hemodynamic data usually provide guidance to decide when to refer a patient to a specialist for endomyocardial biopsy. The aim of this review is to provide a practical and current approach to the evaluation and treatment of suspected myocarditis.

Cardiac cell-specific apoptotic and cytokine responses to reovirus infection: determinants of myocarditic phenotype

BACKGROUND

The pathophysiologic mechanisms underlying viral myocarditis are not well defined. As a result, effective treatments do not exist and viral myocarditis remains a potentially lethal infection of the heart.

METHODS AND RESULTS

We used cultured rat cardiac myocytes and fibroblasts to investigate apoptosis and cytokine production in response to infection by myocarditic vs. non-myocarditic strains of reovirus. Myocarditic reovirus strain 8B and non-myocarditic strain DB188 replicate comparably in each cardiac cell type. However, strain 8B and related myocarditic reoviruses preferentially increase apoptosis of myocytes relative to fibroblasts, whereas DB188 and nonmyocarditic strains preferentially increase fibroblast apoptosis. Infection of cardiac fibroblasts with the nonmyocarditic strain DB188 elicits substantial increases in a panel of cytokines compared to fibroblasts infected with strain 8B or mock-infected controls. Analysis of culture supernatants using cytometric bead arrays revealed that DB188 enhanced release of interleukin (IL)-1beta, IL-4, IL-6, IL-10, IL-12(p70), GRO-KC, tumor necrosis factor-alpha, and MCP-1 relative to 8B or mock-infected controls (all P < .05).

CONCLUSION

We hypothesize that differential cytokine production and cell-specific apoptosis are important determinants of myocarditic potential of reoviral strains. Therapies that target the beneficial effects of cytokines in limiting cytopathic damage may offer an effective and novel treatment approach to viral myocarditis.

Basal expression levels of IFNAR and Jak-STAT components are determinants of cell-type-specific differences in cardiac antiviral responses

Viral myocarditis is an important human disease, and reovirus-induced murine myocarditis provides an excellent model system for study. Cardiac myocytes, like neurons in the central nervous system, are not replenished, yet there is no cardiac protective equivalent to the blood-brain barrier. Thus, cardiac myocytes may have evolved a unique antiviral response relative to readily replenished cell types, such as cardiac fibroblasts. Our previous comparisons of these two cell types revealed a conundrum: reovirus T3D induces more beta-interferon (IFN-beta) mRNA in cardiac myocytes, yet there is a greater induction of IFN-stimulated genes (ISGs) in cardiac fibroblasts. Here, we investigated possible underlying molecular determinants. We found that greater basal expression of IFN-beta in cardiac myocytes results in greater basal activated nuclear STAT1 and STAT2 and greater basal ISG mRNA expression and provides greater basal antiviral protection relative to cardiac fibroblasts. Conversely, cardiac fibroblasts express greater basal IFN-alpha/beta receptor 1 (IFNAR1) and greater basal cytoplasmic Jak1, Tyk2, STAT2, and IRF9, leading to a greater increase in reovirus T3D- or IFN-induced nuclear activated STAT1 and STAT2 and greater induction of ISGs for a greater IFN-induced antiviral protection relative to cardiac myocytes. Our results suggest that high basal IFN-beta expression in cardiac myocytes prearms this vulnerable, nonreplenishable cell type, while high basal expression of IFNAR1 and latent Jak-STAT components in adjacent cardiac fibroblasts renders these cells more responsive to IFN and prevents them from inadvertently serving as a reservoir for viral replication and spread to cardiac myocytes. These studies provide the first indication of an integrated network of cell-type-specific innate immune components for organ protection.

Myocarditis

Myocarditis represents a heterogeneous final common pathway for myocardial inflammation of diverse etiologies and accounts for up to one-third of cases of dilated cardiomyopathy. The pathophysiology of viral myocarditis can be disaggregated into the effects of direct viral mediated injury, triggered acute and chronic autoimmune responses, and subsequent adverse remodeling. Recent research highlights the pathogenic role of persistent viral genome expression, Fas-ligand, tumor necrosis factor-alpha receptor 1, and antimyosin autoantibodies in the evolution of chronic systolic and diastolic heart failure. Recent refinements in endomyocardial biopsy evaluation, cardiac magnetic resonance imaging, and cytokine assays augment existing diagnostic modalities. Novel specific immunosuppressive targets aimed at interrupting myocyte injury and apoptosis, including interferon-beta seem promising to date in small clinical studies performed on selected patients.

Noninvasive imaging in myocarditis

Increased recognition of the role of inflammation in acute and chronic dilated cardiomyopathy has revived an interest in noninvasive imaging for detection of myocarditis. Diagnostic strategies that are based on molecular imaging promise to further advance our understanding and improve diagnostic precision. This article reviews the strengths and limitations of common clinical tests used for the diagnosis of myocarditis, with a focus on the emerging role of cardiovascular magnetic resonance imaging. Novel imaging modalities that are currently in preclinical development are discussed with recommendations for future clinical research.