Marco Anzini

Long-Term Evolution and Prognostic Stratification of Biopsy-Proven Active Myocarditis

Background— Active myocarditis is characterized by large heterogeneity of clinical presentation and evolution. This study describes the characteristics and the long-term evolution of a large sample of patients with biopsy-proven active myocarditis, looking for accessible and valid early predictors of long-term prognosis. Methods and Results— From 1981 to 2009, 82 patients with biopsy-proven active myocarditis were consecutively enrolled and followed-up for 147±107 months. All patients underwent clinical and echocardiographic evaluation at baseline and at 6 months. At this time, improvement/normality of left ventricular ejection fraction (LVEF), defined as a LVEF increase > 20 percentage points or presence of LVEF≥50%, was assessed. At baseline, left ventricular dysfunction (LVEF<50%) and left atrium enlargement were independently associated with long-term heart transplantation–free survival, regardless of the clinical pattern of disease onset. At 6 months, improvement/normality of LVEF was observed in 53% of patients. Persistence of New York Heart Association III to IV classes, left atrium enlargement, and improvement/normality of LVEF at 6 months emerged as independent predictors of long-term outcome. Notably, the short-term reevaluation showed a significant incremental prognostic value in comparison with the baseline evaluation (baseline model versus 6 months model: area under the curve 0.79 versus 0.90, P=0.03). Conclusions— Baseline left ventricular function is a marker for prognosis regardless of the clinical pattern of disease onset, and its reassessment at 6 months appears useful for assessing longer-term outcome.

Persistent Recovery of Normal Left Ventricular Function and Dimension in Idiopathic Dilated Cardiomyopathy During Long‐Term Follow‐up: Does Real Healing Exist?

Background An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long‐term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy . Methods and Results Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long‐term. Persistent apparent healing was defined as left ventricular ejection fraction ≥50% and indexed left ventricular end‐diastolic diameter ≤33 mm/m2 at both mid‐term (19±4 months) and long‐term (103±9 months) follow‐up. At mid‐term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9% of the whole population) showed persistent apparent healing at long‐term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant–free survival at very long‐term follow‐up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very long term, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation. Conclusions Persistent long‐term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial and individualized follow‐up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for long‐term apparent healing.

Formation of the inflammasome in acute myocarditis

Acutemyocarditisisanin flammatorydisorderoftheheartmuscleinwhichtheseverityofinjurydependsbothonthenatureoftheoffendingagent(i.e.virus)andontheensuinginflammatoryresponse.Thede fini-tion excludes, however, the response to ischemic or toxic injury. Theheart, however, like other organs, may provide a stereotyped responsetoinjury.Followingischemicinjury,theformationoftheinfl ammasomein the heart promotes heart failure [1].Theinflammasome is a macro-molecular structure activated during injury that amplifies the responseby processing Interleukin-1β (IL-1β) and IL-18, and promotion of celldeath [2]. Viral infections may lead to either death of the virus and thecell (pyroptosis), or survival of both cell and virus with persistence ofthe infection through inhibition of the inflammasome (evasion) [3].Therearenoreportsoftheinflammasomeinacutemyocarditis.Wehy-pothesize that the viral infection or the ensuing cellular destructionleads to the formation of the inflammasome, providing an opportunityto explore inflammasome-related markers for diagnostic or prognosticpurposes. Furthermore at present day, there are no specific treatmentsfor acute myocarditis, and thus inhibitors of the inflammasome couldrepresent a new therapeutic approach.We studied samples obtainedthrough endomyocardialbiopsy in11patients with acute lymphocytic myocarditis (b4 weeks of symptomsonset) in Trieste, Italy. The diagnosis was based upon pathology exam-ination and clinical scenario (Table 1). As a comparison group westudied autopsy samples of 11 patients with acute myocarditis diag-nosed post mortem, and 5 control subjects who had died withoutacute myocarditis or other acute cardiac conditions.Weemployedimmunofluorescencestainingtodetectin flammasomeaggregatesusingantibodiesraisedagainstthescaffoldprotein,ApoptosisSpeck-like protein containing a caspase-1 recruiting domain (ASC), and/or the effector protein, caspase-1, as previously described [1].Tocharac-terizethetypeofcell,weusedadoublestainingtechniquewithantibod-ies against cardiac actin to identify cardiomyocytes, S100A4 to identifyfibroblasts, andCD31 forendothelialcells. To overcomefor the auto fluo-rescence of sarcomeric proteins, we used a solution of 1% Sudan black in70% ethanol for 5 min. Images of samples were acquired with an IX70microscope and cellSens Dimension di gital imaging software (Olympus,Central Valley, PA) using a 40× objective (400× magnification). Filtersets for each separate fluorescence-conjugated antibody were layeredtorenderacompositeimage.Theinflammasome “specks” were countedby cell type (cardiomyocyte, leukocytes, fibroblasts and endothelialcells) per high power field of view (40×). Data are presented as medianand interquartile range and non-parametric Mann–Whitney test wasused.Intracellularaggregates of ASC and/ or caspase-1 indicative of the for-mation of the inflammasome were seen in leukocytes, cardiomyocytes,fibroblasts and endothelial cells in heart biopsy samples of all 11 cases(100%), and in heart samples of 10 of 11 post-mortem cases (91%), andin none of the controls (0%, P b 0.002)(Fig. 1). ASC aggregates co-localized with caspase-1 aggregates in virtually all cases. The numberof inflammasomes was variable across cases ranging between 3 and 14specks in biopsies, and between 0 and 45 specks per field in autopsies,without statistically significant differences (data not shown). Some

Myocarditis in Clinical Practice

Myocarditis is a polymorphic disease characterized by great variability in clinical presentation and evolution. Patients presenting with severe left ventricular dysfunction and life-threatening arrhythmias represent a demanding challenge for the clinician. Modern techniques of cardiovascular imaging and the exhaustive molecular evaluation of the myocardium with endomyocardial biopsy have provided valuable insight into the pathophysiology of this disease, and several clinical registries have unraveled the diseases long-term evolution and prognosis. However, uncertainties persist in crucial practical issues in the management of patients. This article critically reviews current information for evidence-based management, offering a rational and practical approach to patients with myocarditis. For this review, we searched the PubMed and MEDLINE databases for articles published from January 1, 1980, through December 31, 2015, using the following terms: myocarditis, inflammatory cardiomyopathy, and endomyocardial biopsy. Articles were selected for inclusion if they represented primary data or were review articles published in high-impact journals. In particular, a risk-oriented approach is proposed. The different patterns of presentation of myocarditis are classified as low-, intermediate-, and high-risk syndromes according to the most recent evidence on prognosis, clinical findings, and both invasive and noninvasive testing, and appropriate management strategies are proposed for each risk class.

Idiopathic dilated cardiomyopathy and persistent viral infection: Lack of association in a controlled study using a quantitative assay

BACKGROUND It remains unclear whether idiopathic dilated cardiomyopathy (DCM) might ensue as the consequence of viral myocarditis, due to viral persistence in cardiomyocytes. To address this issue, we quantified the levels of enterovirus, Epstein-Barr virus (EBV), Herpes Simplex Virus-1 (HSV-1), Herpes Simplex Virus-2 (HSV-2), adenovirus and parvovirus B19 genomes in endomyocardial biopsies (EMBs) from patients with DCM, active myocarditis and controls. METHODS Real-time polymerase chain reaction (PCR)-based methods using TaqMan probes were developed for the quantitative detection of viral genomes in EMBs from 35 patients with DCM and 17 with active myocarditis. A control group included 20 surgical patients with valve or coronary artery disease. RESULTS None of the 72 samples tested positive for enteroviruses, EBV, HSV-1 or -2. One DCM patient tested positive for adenovirus. Of notice, 20/52 (38%) of patients with cardiomyopathy and 8/20 (40%) of controls were positive for parvovirus B19; no significant differences in viral titre were detected between groups. CONCLUSIONS Our preliminary results disfavour the hypothesis that persistent myocardial viral infection might be a frequent cause of DCM. The detection of parvovirus B19 from both cardiomyopathy and non-cardiomyopathy patients supports the notion that this virus is widely spread in the population.

Paracrine effect of regulatory T cells promotes cardiomyocyte proliferation during pregnancy and after myocardial infarction

Cardiomyocyte proliferation stops at birth when the heart is no longer exposed to maternal blood and, likewise, to regulatory T cells (Tregs) that are expanded to promote maternal tolerance towards the fetus. Here, we report a role of Tregs in promoting cardiomyocyte proliferation. Treg-conditioned medium promotes cardiomyocyte proliferation, similar to the serum from pregnant animals. Proliferative cardiomyocytes are detected in the heart of pregnant mothers, and Treg depletion during pregnancy decreases both maternal and fetal cardiomyocyte proliferation. Treg depletion after myocardial infarction results in depressed cardiac function, massive inflammation, and scarce collagen deposition. In contrast, Treg injection reduces infarct size, preserves contractility, and increases the number of proliferating cardiomyocytes. The overexpression of six factors secreted by Tregs (Cst7, Tnfsf11, Il33, Fgl2, Matn2, and Igf2) reproduces the therapeutic effect. In conclusion, Tregs promote fetal and maternal cardiomyocyte proliferation in a paracrine manner and improve the outcome of myocardial infarction.Regulatory T cells (Tregs) expand during pregnancy to promote tolerance towards the fetus. Here the authors show that Tregs induce proliferation of fetal and maternal cardiomyocytes during pregnancy and enhance myocardial repair via proliferation-promoting paracrine actions.

[Controversial issues and working practice in myocarditis: from scientific data to clinical grounds].

Although the cause of myocarditis often remains unknown, a large variety of infections, systemic diseases, drugs and toxins have been associated with this disease. In most cases, myocarditis is induced by cardiotropic viruses and often evolves silently without discernible prognostic impact. However, in some patients, the lack of complete viral clearance and/or the association of a heart-specific inflammation can cause persistent myocyte damage, ultimately leading to progressive myocardial dilation and dysfunction or life-threatening arrhythmias. Spontaneous improvement of left ventricular function is described for 40-50% of patients. The diagnostic work-up and prognostic assessment of myocarditis should be multiparametric and all available resources should be employed, i.e. biomarkers of myocardial damage and ventricular dysfunction (troponin I, brain natriuretic peptide), advanced echocardiography, cardiac magnetic resonance and, in selected cases, endomyocardial biopsy (with histopathologic, immunohistochemical and virological analyses). These are the necessary prerequisites for an evidence-based and personalized management of myocarditis, which may require in some cases specific immunoactive treatments. However, controversial issues regarding diagnosis (such as role and timing of cardiac magnetic resonance imaging, role of endomyocardial biopsy) and therapy of myocarditis still remain unsolved. The purpose of this review is to analyze these crucial features in order to provide useful instructions for clinical practice.

Other Cardiomyopathies: Clinical Assessment and Imaging in Diagnosis and Patient Management

In this chapter describes clinical and imaging assessment in diagnosis and patient management of other cardiomyopathies (CMP) not included among the previously defined main groups of CMP. Most of these unclassified CMP are characterized by frequent reversibility of myocardial dysfunction after adequate treatment. The peculiar form called left ventricular noncompaction is also addressed.