In this position statement of the ESC Working Group on Myocardial and Pericardial Diseases an expert consensus group reviews the current knowledge on clinical presentation, diagnosis and treatment of myocarditis, and proposes new diagnostic criteria for clinically suspected myocarditis and its distinct biopsy-proven pathogenetic forms. The aims are to bridge the gap between clinical and tissue-based diagnosis, to improve management and provide a common reference point for future registries and multicentre randomised controlled trials of aetiology-driven treatment in inflammatory heart muscle disease.

Background-Inflammatory mechanisms have been proposed to be important in heart failure (HF), and cytokines have been implicated to add to the progression of HF. However, it is unclear whether such mechanisms are already activated when hypertrophied hearts still appear well-compensated and whether such early mechanisms contribute to the development of HF. Methods and Results-In a comprehensive microarray study, galectin-3 emerged as the most robustly overexpressed gene in failing versus functionally compensated hearts from homozygous transgenic TGRmRen2-27 (Ren-2) rats. Myocardial biopsies obtained at an early stage of hypertrophy before apparent HF showed that expression of galectin-3 was increased specifically in the rats that later rapidly developed HF. Galectin-3 colocalized with activated myocardial macrophages. We found galectin-3-binding sites in rat cardiac fibroblasts and the extracellular matrix. Recombinant galectin-3 induced cardiac fibroblast proliferation, collagen production, and cyclin D1 expression. A 4-week continuous infusion of low-dose galectin-3 into the pericardial sac of healthy Sprague-Dawley rats led to left ventricular dysfunction, with a 3-fold differential increase of collagen I over collagen III. Myocardial galectin-3 expression was increased in aortic stenosis patients with depressed ejection fraction. Conclusions-This study shows that an early increase in galectin-3 expression identifies failure-prone hypertrophied hearts. Galectin-3, a macrophage-derived mediator, induces cardiac fibroblast proliferation, collagen deposition, and ventricular dysfunction. This implies that HF therapy aimed at inflammatory responses may need to be targeted at the early stages of HF and probably needs to antagonize multiple inflammatory mediators, including galectin-3.

In this paper the Working Group on Myocardial and Pericardial Disease proposes a revised definition of dilated cardiomyopathy (DCM) in an attempt to bridge the gap between our recent understanding of the disease spectrum and its clinical presentation in relatives, which is key for early diagnosis and the institution of potential preventative measures. We also provide practical hints to identify subsets of the DCM syndrome where aetiology directed management has great clinical relevance.

In this multi-centre, international study, NT-proBNP testing was valuable for diagnostic evaluation and short-term prognosis estimation in dyspnoeic subjects with suspected or confirmed acute HF and should establish broader standards for use of the NT-proBNP in dyspnoeic patients.

Abstract:In the past few years, the crucial role of different micro-RNAs (miRNAs) in the cardiovascular system has been widely recognized. Recently, it was discovered that extracellular miRNAs circulate in the bloodstream and that such circulating miRNAs are remarkably stable. This has raised the possibility that miRNAs may be probed in the circulation and can serve as novel diagnostic markers. Although the precise cellular release mechanisms of miRNAs remain largely unknown, the first studies revealed that these circulating miRNAs may be delivered to recipient cells, where they can regulate translation of target genes. In this review, we will discuss the nature of the stability of miRNAs that circulate in the bloodstream and discuss the available evidence regarding the possible function of these circulating miRNAs in distant cell-to-cell communication. Furthermore, we summarize and discuss the usefulness of circulating miRNAs as biomarkers for a wide range of cardiovascular diseases such as myocardial infarction, heart failure, atherosclerosis, hypertension, and type 2 diabetes mellitus. One of the major challenges in cardiovascular research is the identification of reliable biomarkers that can be measured routinely in easily accessible samples, such as plasma. Because of their stability in the circulation, miRNAs are currently being explored for their potential as biomarkers for cardiovascular disease. Thus far, distinctive patterns of circulating miRNAs have been found for myocardial infarction, 11 heart failure (HF), 12 atherosclerotic disease, 13 type 2 diabetes mellitus (DM), 14 and hypertension. 15 In the present review, we will discuss the available evidence of the cellular release mechanisms and the nature of the stability of miRNAs in the bloodstream (eg, microparticles, RNA-binding proteins, and HDL). Next, we will discuss the available evidence for a possible function of miRNAs in cell-to-cell communication. Finally, we will review the current knowledge about circulating miRNAs as putative biomarkers in cardiovascular disease. Cellular Release and Stability of Extracellular miRNAsAs early as 1972, it was reported that intact extracellular RNA could be detected in plasma despite the presence of ribonucleases that were expected to destroy any freely circulating RNA. 16 It has therefore been suggested that this extracellular RNA, including miRNAs, is somehow shielded to prevent its degradation. As discussed in the sections below, evidence is now accumulating that miRNAs are protected against degradation by being packaged in lipid vesicles or by being associated with protein or lipoprotein complexes (Figure). Plasma miRNAs in MicroparticlesEl-Hefnawy et al 17 were among the first to show that plasma RNA is protected from degradation by its inclusion in protein or lipid vesicles. Depending on their size and mode of release from cells, these particles are known as exosomes, microvesicles (MVs), or apoptotic bodies. 18 Exosomes are small vesicles (50 -100 nm) that originate from the endosome and are release...

Rationale: Aberrant expression profiles of circulating microRNAs (miRNAs) have been described in various diseases and provide high sensitivity and specificity. We explored circulating miRNAs as potential biomarkers in patients with heart failure (HF). Objective: The goal of this study was to determine whether miRNAs allow to distinguish clinical HF not only from healthy controls but also from non-HF forms of dyspnea. Methods and Results: A miRNA array was performed on plasma of 12 healthy controls and 12 HF patients. From this array, we selected 16 miRNAs for a second clinical study in 39 healthy controls and in 50 cases with reports of dyspnea, of whom 30 were diagnosed with HF and 20 were diagnosed with dyspnea attributable to non-HF-related causes. This revealed that miR423-5p was specifically enriched in blood of HF cases and receiver-operator-characteristics (ROC) curve analysis showed miR423-5p to be a diagnostic predictor of HF, with an area under the curve of 0.91 (P<0.001). Five other miRNAs were elevated in HF cases but also slightly increased in non-HF dyspnea cases. Conclusion: We identify 6 miRNAs that are elevated in patients with HF, among which miR423-5p is most strongly related to the clinical diagnosis of HF. Recent studies have unveiled powerful and unexpected roles for microRNAs (miRNAs) in cardiovascular diseases, including HF. There are estimated to be more than 1000 different miRNAs, many of which are expressed in a tissue and cell-specific manner. 3 It was discovered only recently that miRNAs are also abundantly present in blood, where they can be detected in plasma, platelets, and erythrocytes, as well as in nucleated blood cells. 4 Aberrant expression profiles of miRNAs have been identified in blood of subjects with sickle cell anemia, prostate cancer, lung cancer and myocardial injury. 4 -6 This led us to hypothesize that miRNA profiling can also be used for diagnostic approaches in HF.Here we explored whether circulating miRNAs can be used as biomarkers in patients with HF. We first performed miRNA arrays on RNA isolated from plasma and selected 16 miRNAs expressed differentially in HF patients. Next, we evaluated these miRNAs in a second group of patients, consisting of 50 cases with reports of dyspnea, of whom 30 were diagnosed with HF (HF cases) and 20 were diagnosed to have dyspnea attributable to non-HF causes (non-HF cases). One circulating miRNA in particular, miR423-5p, was able to distinguish HF cases from non-HF cases.In conclusion, we demonstrate a number of miRNAs as putative biomarkers for HF, in particular miR423-5p. MethodsHuman plasma samples were obtained with informed consent under a general waiver by the Academic Medical Center institutional review board for the proper secondary use of human material. For the dyspnea registry, plasma samples were obtained as part of a multicenter effort involving 3 centers in The Netherlands. Experiments described were performed on samples obtained at the Academic Medical Center. For a detailed description of the dyspnea registry,...

Our data show potential utility of galectin-3 as a useful marker for evaluation of patients with suspected or proven acute HF, whereas apelin measurement was not useful for these indications. Moreover, the combination of galectin-3 with NT-proBNP was the best predictor for prognosis in subjects with acute HF.

Abstract-The myocardium of the failing heart undergoes a number of structural alterations, most notably hypertrophy of cardiac myocytes and an increase in extracellular matrix proteins, often seen as primary fibrosis. Connective tissue growth factor (CTGF) is a key molecule in the process of fibrosis and therefore seems an attractive therapeutic target. Regulation of CTGF expression at the promoter level has been studied extensively, but it is unknown how CTGF transcripts are regulated at the posttranscriptional level. Here we provide several lines of evidence to show that CTGF is importantly regulated by 2 major cardiac microRNAs (miRNAs), miR-133 and miR-30. First, the expression of both miRNAs was inversely related to the amount of CTGF in 2 rodent models of heart disease and in human pathological left ventricular hypertrophy. Second, in cultured cardiomyocytes and fibroblasts, knockdown of these miRNAs increased CTGF levels. Third, overexpression of miR-133 or miR-30c decreased CTGF levels, which was accompanied by decreased production of collagens. Fourth, we show that CTGF is a direct target of these miRNAs, because they directly interact with the 3Ј untranslated region of CTGF. Taken together, our results indicate that miR-133 and miR-30 importantly limit the production of CTGF. We also provide evidence that the decrease of these 2 miRNAs in pathological left ventricular hypertrophy allows CTGF levels to increase, which contributes to collagen synthesis. In conclusion, our results show that both miR-133 and miR-30 directly downregulate CTGF, a key profibrotic protein, and thereby establish an important role for these miRNAs in the control of structural changes in the extracellular matrix of the myocardium.