[Quality analysis for treatment of heart muscle diseases]

Distinct examinations and resulting therapies are depending on the cardiomyopathy phenotype and the severity of the myocardial compromise. Specific treatment modalities for distinct cardiomyopathies, demand detailed diagnostic procedures in addition to the routine diagnostic workup. Quality analyses for causal treatment strategies of different cardiomyopathies are missing. Most diagnostic procedures are unable to detect the relevant pathophysiological changes that generally occur at the cellular and molecular level of myocardial tissue or individual cells. Therefore, often only additional biopsy-based tissue analyses can provide the necessary basis for causal treatment options.

[State of diagnostics and therapy of inflammatory cardiomyopathie]

Myocardial inflammation of cardiac muscle is caused by intramyocardial infiltration of immunological competent cells. Etiologically, the relevant factors are the direct or indirect influence of infectious pathogens, toxic, chemical or physical agents, allergic-hyperergic reactions and myocardial inflammatory events in the context of systemic diseases. Clinically significant infections include cardiotropic viruses, which are capable of causing acute or chronic damage to the myocardium under certain conditions. The wide variety of etiologies in inflammatory cardiomyopathy and its heterogeneous clinical presentations have impeded patients identification and consensus on the most appropriate diagnostic criteria and specific therapeutic strategies. Although the Dallas criteria have standardized the histological definition of active myocarditis, the recognition of true etiologies of acute and chronic stages of inflammatory cardiomyopathies require additional and more sensitive markers of tissue inflammation and molecular biological identification of responsible infectious agents. Actually, only biopsy-based diagnosis and characterization of patients allow identification of patients who may get benefit from specific immunosuppressive or anti-viral treatment strategies.

[Myocarditis]

Myocarditis is an inflammatory disease of the cardiac muscle caused by intramyocardial infiltration of immunocompetent cells following any kind of cardiac injury. Classic myocarditis mainly occurs by the host's immune response against organisms that cause common infectious illnesses, as a manifestation of hypersensitivity or as toxic reaction to drug administration. Chronic inflammatory events may survive successful clearance of initial cardiotoxic agents, be triggered or amplified by autoimmunologic processes, or develop in the context of systemic diseases. In many cases, however, the cause of inflammatory changes, which may spread from a focus or be diffused throughout the cardiac muscle, remains unclear. Since clinical and histologic classification criteria of myocarditis alone are unsuitable for a clinically useful classification of inflammatory cardiac muscle disease, only the combination of clinical and histologic methods with immunohistochemical characterization of the inflammatory process and molecular biology virus detection ensure a reliable diagnosis and subsequent indication of specific treatment options.

Prevalence of erythrovirus genotypes in the myocardium of patients with dilated cardiomyopathy

Parvovirus B19 (PVB19) is a member of the human erythrovirus family detected frequently in endomyocardial biopsies from patients with dilated cardiomyopathy. Human erythroviruses cluster into three genotypes 1-3 which share a high degree of homology between major structural proteins and may cause indistinguishable infections clinically and serologically. In human cardiac tissue erythrovirus genotypes other than PVB19 have not yet been reported. Three hundred seventeen consecutive patients with symptomatic dilated cardiomyopathy (median left ventricular ejection fraction: 28.6%, range 5-45%) who underwent endomyocardial biopsy for the elucidation of the etiology, were analyzed using a new consensus PCR assay designed for the detection of the three erythrovirus genotype sequences. Endomyocardial biopsies of 151 (47.6%) patients were erythrovirus-positive. Genotype 1 specific sequences were detected in 43/151 (28.5%) of positive biopsy samples, whereas genotype 2-specific sequences so far considered rare in human disease and not yet been described in human heart tissue was identified in 108/151 (71.5%) of virus-positive endomyocardial biopsies with a preference in patients above 50 years of age. In spite of younger age, systolic left ventricular dysfunction of genotype 1-positive patients was significantly reduced as compared to genotype 2-positive patients (24.4+/-10.4% vs. 31.0+/-9.5%, P=0.0001) at the initial presentation. The data show that two genetically distinct erythrovirus variants with a different age distribution are detectable in endomyocardial biopsies of patients with dilated cardiomyopathy. The erythrovirus genotype 2, not described previously in human heart tissue, is highly prevalent in the heart but the less prevalent genotype 1 is associated with more severe disturbed cardiac function.

Genomic expression profiling of human inflammatory cardiomyopathy (DCMi) suggests novel therapeutic targets

The clinical phenotype of human dilated cardiomyopathy (DCM) encompasses a broad spectrum of etiologically distinct disorders. As targeting of etiology-related pathogenic pathways may be more efficient than current standard heart failure treatment, we obtained the genomic expression profile of a DCM subtype characterized by cardiac inflammation to identify possible new therapeutic targets in humans. In this inflammatory cardiomyopathy (DCMi), a distinctive cardiac expression pattern not described in any previous study of cardiac disorders was observed. Two significantly altered gene networks of particular interest and possible interdependence centered around the cysteine-rich angiogenic inducer 61 (CYR61) and adiponectin (APN) gene. CYR61 overexpression, as in human DCMi hearts in situ, was similarly induced by inflammatory cytokines in vascular endothelial cells in vitro. APN was strongly downregulated in DCMi hearts and completely abolished cytokine-dependent CYR61 induction in vitro. Dysbalance between the CYR61 and APN networks may play a pathogenic role in DCMi and contain novel therapeutic targets. Multiple immune cell-associated genes were also deregulated (e.g., chemokine ligand 14, interleukin-17D, nuclear factors of activated T cells). In contrast to previous investigations in patients with advanced or end-stage DCM where etiology-related pathomechanisms are overwhelmed by unspecific processes, the deregulations detected in this study occurred at a far less severe and most probably fully reversible disease stage.

Overview on chronic viral cardiomyopathy/chronic myocarditis

Myocarditis is most often induced by cardiotropic viruses and often resolves with minimal cardiac remodelling and without discernable prognostic impact. Acute myocarditis has a highly diverse clinical presentation (asymptomatic, infarct-like presentation, atrioventricular (AV)-block, atrial fibrillation, sudden death due to ventricular tachycardia, fulminant myocarditis with severely depressed contractility). Progression of myocarditis to its sequela, dilated cardiomyopathy (DCM), has been documented in 20% of cases and is pathogenically linked to chronic inflammation and viral persistence. Persistence of cardiotropic viruses (enterovirus, adenovirus) constitutes one of the predominant aetiological factors in DCM. Additionally, circulating autoantibodies to distinct cardiac autoantigens have been described in patients with DCM, providing evidence for autoimmune involvement. Since clinical complaints of myocarditis and DCM are unspecific, a positive effect of any specific therapy depends on an accurate biopsy-based diagnosis and characterization of the patients with histological, immunohistological and molecular biological methods (PCR), which have developed into sensitive tools for the detection of different viruses, active viral replication, and myocardial inflammation. The immunohistochemical characterization of infiltrates has supported a new era in the diagnosis of myocardial inflammation compared with the Dallas criteria, which has led to a new entity of secondary cardiomyopathies acknowledged by the WHO, the inflammatory cardiomyopathies (DCMi). Immunohistochemically quantified lymphocytes significantly better reflect troponin levels and correlate with findings by anti-myosin scintigraphy compared with the histological analysis. Furthermore, the orchestrated induction of endothelial cell adhesion molecules (CAMs) in 65% of DCM patients has confirmed that CAM induction is a prerequisite for lymphocytic infiltration in DCMi. The combination of these immunohistological with molecular biological diagnostic techniques of virus analysis allows a further classification of dilated cardiomyopathy by differentiating the disease entity in subgroups of virus-positive and virus-negative patients with or without cardiac inflammation. Further analysis of the predominant Th1-/Th2-immune response may provide additional prognostic information on the natural course of the disease. This differential analysis improves the clinical management of patients and is an indispensable prerequisite for the development of specific antiviral or immunomodulatory treatment strategies.

Anti-viral treatment in patients with virus-induced cardiomyopathy

Ongoing viral persistence in the myocardium is associated with an adverse prognosis of cardiomyopathy eventually resulting in a reduced capacity for work and thus it is associated with enormous social costs. Experimental and clinical data highlight that an imbalance of the cytokine network and a defect in the cytokine-induced immune response may constitute major causes leading to the development of virus persistence and progression of myocardial dysfunction. Reversibility of cardiac impairment during the early stages of the disease and the arising chance of specific treatment options demand early diagnosis and treatment of the disease. Our pilot data on anti-viral treatment using INF-beta showed beneficial clinical effects and suggest that some of the ventricular dysfunction and wall motion abnormalities resolved after elimination of the responsible agents. The data also suggest that elimination of cardiotropic viruses and associated clinical effects may occur even in DCM patients presenting with a long history.

[Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy]

Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

[Cardiomyopathies II. Hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy]

This review focuses on hypertrophic (HCM), restrictive (RCM) and arrhythmogenic right ventricular cardiomyopathies (ARVC). The clinical phenotype of HCM depends not only on the gene mutations involved, but also on "modifier genes". It is characterized by an asymmetrical hypertrophy. Investigations of endomyocardial biopsies (EMBs) typically reveal a disarray of the hypertrophied cardiomyocytes. Percutaneous septum ablation has gained relevance as the treatment of choice in hypertrophic obstructive cardiomyopathy. Myocardial and endomyocardial RCM-forms can be differentiated. Enlargement of the atria in concert with normal dimensions of the ventricles and almost normal systolic contractility as well as the dip-plateau phenomenon are characteristic findings in RCM. EMB diagnostics are pivotal to identify the causes underlying secondary RCM types. Treatment is directed at heart failure and specifically at the underlying disease. With ARVC, apoptosis, viral infection/inflammation and genetic dystrophy result in fibrofatty degeneration primarily of the right, and with further progression also of the left ventricle. The primary treatment goal in ARVC is prevention of sudden cardiac death. As for other cardiomyopathies, there is increasing evidence for the superiority of ICD compared with pharmacological approaches.

Genome-environment interactions in the molecular pathogenesis of dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a heart muscle disease characterized by impaired contractility and dilation of the ventricles. In a subset of DCM patients, classical inheritance patterns occur (familial DCM), which have led to the identification of specific genomic loci and gene defects causing monogenic DCM subtypes. In the majority of DCM patients, however, there is no evidence for a monogenic etiology of the disorder (sporadic DCM), and in the absence of other recognizable etiological factors, these cases were classified as "idiopathic". Recent research suggests that cardiotropic viruses are important environmental factors in the pathogenesis of "idiopathic" cases and that DCM commonly results from interactions between genetic and environmental factors, whereas "pure" genetic forms are rather rare. Regarding genetics, the clinical cardiomyopathic phenotype associated with single gene defects may be highly variable for unknown reasons. Furthermore, a novel class of genetic defects was identified recently which provide a molecular basis for abnormal reactions of cardiomyocytes to environmental stress. These defects are paradigms of specific molecular links between genome and environment during the pathogenesis of DCM. Regarding environmental factors, a recent molecular virological study based on myocardial biopsies in a large series of sporadic DCM patients has detected cardiac viral infections in the majority of patients, with a broad spectrum of virus species being involved. Apparently, DCM does not only occur as a late sequela of acute viral myocarditis, but also in patients without clinical history of cardiac viral disease. Cardiotropic viruses thus emerge as prevalent environmental factors which may cause or influence the course of DCM in a large fraction of cases. Synopsis of current data suggests that a comprehensive picture of DCM pathogenesis can only be drawn if both genetic and environmental pathogenetic factors are considered. The course of cardiac viral infections depends strongly on genetic host factors and may range from rapid and complete virus elimination or silencing without clinical symptoms, to rapidly progressive or fatal disease. Viruses interact not only with genetically heterogenous host systems of virus uptake, migration, and antiviral immunity, but, due to their prevalence in DCM hearts, are also likely to encounter multiple structural proteins of cardiac cells known to be defective in familial DCM. The combined knowledge on DCM-associated gene defects and viruses therefore suggests in-depth studies on genome-environment interactions in DCM pathogenesis which may underlie the high clinical variability observed both in monogenic and virus-associated DCM and have implications for the clinical management of DCM patients.

High prevalence of cardiac parvovirus B19 infection in patients with isolated left ventricular diastolic dysfunction

BACKGROUND

The etiology of left ventricular (LV) isolated diastolic dysfunction often remains unclear. In the present study, we report a strong association between parvovirus B19 (PVB19) genomes and isolated LV diastolic dysfunction.

METHODS AND RESULTS

In 70 patients (mean+/-SD age, 43+/-11 years) admitted with exertional dyspnea and/or reduced exercise tolerance despite preserved LV systolic contractility (ejection fraction=68%), isolated diastolic dysfunction was clinically suspected. Patients with classic risk factors for diastolic dysfunction such as hypertension, coronary heart disease, diabetes mellitus, or pulmonary disease had been excluded. Diastolic function was assessed by echocardiography and LV and RV catheterization. Endomyocardial biopsies (EMBs) were analyzed for the presence of storage or infiltrative diseases or myocarditis, including molecular screening for cardiotropic virus genomes. In a substudy of 24 patients who reported atypical angina, coronary endothelial function was additionally investigated with a coronary Doppler flow-wire technique. In 37 of 70 patients (53%), isolated diastolic dysfunction was confirmed as the cause of their clinical symptoms. No evidence for cardiac storage or infiltrative diseases was found in these cases, but in 35 of 37 of these patients (95%), cardiotropic virus genomes were detected in EMBs (P<0.001). PVB19 was the most frequent pathogen in 31 of 37 patients (84%). In a subgroup of 10 patients with diastolic dysfunction and coexisting endothelial dysfunction, all 10 (100%) were PVB19 positive.

CONCLUSIONS

PVB19 genomes were predominant in patients with unexplained, isolated diastolic dysfunction. A strong association with the incidence of endothelial dysfunction was obvious, consistent with the hypothesis that PVB19-induced endothelial dysfunction may be a possible pathomechanism underlying diastolic dysfunction.

Nucleic acid-based modulation of cardiac gene expression for the treatment of cardiac diseases. Approaches and perspectives

During the past few years major conceptual and technical advances have been made towards the therapeutic modulation of cardiac gene expression for the treatment of cardiac diseases. Among these are 1) the identification of new molecular therapy targets in cardiac disorders, often derived from genetic animal models. 2) A better understanding of the molecular and cellular determinants of cardiac gene transfer in vivo, in animal models and in first clinical trials. 3) The development of novel regulatable and long-term stable vector systems. This review is focused on nucleic acid-based modulation of cardiac calcium homeostasis as a paradigm for the new gene therapeutic approaches, since recent landmark papers have suggested this to be a molecular target of key importance in heart failure. In particular, the development of severe heart failure in the genetic MLP(-/-) animal model could be completely abolished by the targeted ablation of phospholamban (PL), a key regulator of cardiac calcium homeostasis. This impressive effect of permanent germline PL ablation provides-in conjunction with former important work on disturbed calcium handling in the failing human heart-a rationale for the gene therapeutic approach of ad hoc suppression of PL by antisense strategies (antisense RNAs, ribozymes, RNA interference) or PL variants. Based on the broad spectrum of methods employed to characterize this general strategy, PL-targeted approaches may be considered as a paradigm of future genetic treatments of cardiac disorders, although the differences between animal models and humans must be kept in mind. High safety of any such therapy will be a prerequisite for any possible clinical application and therefore novel methods to improve control are being devised: 1) The regulation of gene therapy vectors by biochemical abnormalities associated with the target disease itself (" Induction-by-Disease" gene therapy). 2) External control of vector activity by the employment of drug-sensitive promotors. In addition, the important goal of cardiac long-term stability of the therapeutic vectors has recently been achieved in animal models using vectors derived from adeno-associated viruses (AAVs).

[The Lyme carditis as a rare differential diagnosis to an anterior myocardial infarction]

An acute Lyme carditis affects about 0.3-4% of patients with Lyme borreliosis. The acute period of the disease may be associated with critical atrioventricular conduction abnormalities (complete heart block), supraventricular and ventricular arrhythmias as well a left ventricular failure. Normally, Lyme carditis is completely reversible. Therefore the prognosis largely depends on the management of the acute complications and early antibiotic therapy. Even if the symptoms are spontaneously reversible, antibiotic therapy should be applied to prevent a chronic cardiomyopathy and other manifestations of Lyme borreliosis. We report on a 47-year old patient with acute ECG changes initially suggesting an acute coronary syndrome. However, case history and the erythema migrans indicated an acute Lyme carditis which was confirmed serologically and by myocardial biopsy later.

[Increased thrombocyte activation in dilated cardiomyopathy: a risk factor for development of ventricular thrombosis despite anticoagulant therapy?]

HISTORY AND CLINICAL FINDINGS

A 48-year-old patient with dilated cardiomyopathy complained of dyspnea at rest, severe sleeplessness and a slight pain in the stomach. The clinical examination was normal except for a murmur at the apex of the heart. There was no evidence of edema or congestion of the jugular veins.

INVESTIGATION

The echocardiography demonstrated a dilated left ventricle with severely compromised function. No ventricular thrombi were present at this time. Coronary artery disease was excluded by coronary angiography. Endomyocardial biopsies were obtained from the right ventricular septum. The immunohistological analysis of the endomyocardial biopsy specimens revealed pathologically increased lymphocytic infiltrates and increased expression of interstitial and endothelial MHC I and II antigens. Flow cytometric analysis of platelets surface antigens (P-selectin, GP53, thrombospondin) was performed as a measure for intravasal platelet activation. Our patient compared to a healthy control group (> 4 SD) and to other patients with dilated cardiomyopathy (> 2 SD). A high grade increase of platelet activation was found.

TREATMENT AND COURSE

ACE inhibitor, diuretics, spironolactone and digitalis were used to treat the heart insufficiency. Due to the severe left ventricular dysfunction phenprocoumone and aspirin were also prescribed. A follow-up echocardiography was performed 6 months later. Comparable to the first examination left ventricular contractility was found to be severely reduced. In addition, a marginal thrombus was now present in the left ventricle despite antithrombotic therapy.

DISCUSSION

An increased platelet activation was found in the peripheral circulation of our patient with dilated cardiomyopathy. After 6 months, ventricular thrombi were found in the dilated ventricle, although aspirin and phenprocoumone had been administred. We speculate that an additional thrombotic treatment with clopidogrel is necessary in patients with dilated cardiomyopathy and increased platelet activation.

[Myocarditis and dilated cardiomyopathy. New methods in diagnosis and therapy]

In 20% of cases, acute myocarditis can progress to dilated cardiomyopathy as a result of persistence of intramyocardial inflammation or of a virus genome. Both acute myocarditis (10-year survival rate 45%) and dilated cardiomyopathy (leading indication for cardiac transplantation) have a grave prognosis. Etiopathogenic differentiation of dilated cardiomyopathy was made possible for the first time by the use of immunohistochemical and molecular-biological diagnostic procedures applied to endomyocardial biopsy material. In addition to conventional treatment of heart failure, initial randomized studies have shown immunosuppression and antiviral immunomodulation to be effective measures and harbingers of a new era of rational therapeutic concepts in the treatment of dilated cardiomyopathy.

Co-occurrence of spondyloarthropathy and connective tissue disease: development of Sjögren's syndrome and mixed connective tissue disease (MCTD) in a patient with ankylosing spondylitis

Spondylarthropathies (SpA) and connective tissue diseases (CTD) are clinically distinct entities which, at first glance, seem to have little in common. However, a link between SpA and CTD has recently been suggested by a study in which a higher prevalence of Sjögren's syndrome (SS) and sicca symptoms was reported in patients with ankylosing spondylitis (AS) and undifferentiated SpA (1). Another link between SpA and CTD is a possible side effect of a DMARD widely used to treat SpA: sulfasalazine (SAS). SAS was reported to induce antinuclear antibodies (ANA) and systemic lupus erythematosus (SLE)-like syndromes such as drug-induced lupus. This report describes a 54-year-old white male, HLA B27-positive AS patient with some syndesmophytes who, after 15 years of disease, developed SS with salivary gland involvement, Raynaud's syndrome and anti-Ro antibodies. Then, 20 years after the onset of AS, he became acutely ill, suffering severe myositis and myocarditis along with swollen hands and highly elevated autoantibody titers recognizing UIRNP; his condition was interpreted as mixed connective tissue disease (MCTD). The patient had been treated with SAS and azathioprine (AZA) alone several times during the last years because he had not tolerated other DMARDs. A combination of both drugs had been prescribed 3 weeks before a severe flair because of progredient high disease activity with painful peripheral arthritis of the MCP and PIP joints which, however, had not shown radiographic erosions. We describe the rare development of MCTD in an AS patient and report, for the first time, the onset of MCTD potentially triggered by sulfasalazine.

The possible role of myocardial biopsy in systemic sclerosis

The histopathological features of heart involvement in systemic sclerosis (SSc) are not widely known. In internal and transplantation medicine, myocardial biopsies are increasingly used to diagnose cardiomyopathies including myocarditis. In two SSc patients presenting with dyspnoea with no evidence of pulmonary involvement, the cause of the compromised heart function was sought by myocardial biopsy. Immunohistological analysis revealed an increased number of CD3+ + T cells indicating myocarditis in one, and increased amounts of fibroblasts in both SSc patients. The authors think that myocardial involvement in SSc should be differentially evaluated and they propose the use of myocardial biopsies as a tool to distinguish between inflammatory and fibrotic forms of heart involvement in SSc patients.

The shift in the myocardial adenine nucleotide translocator isoform expression pattern is associated with an enteroviral infection in the absence of an active T-cell dependent immune response in human inflammatory heart disease

OBJECTIVES

This study evaluates the relevance of an enteroviral infection and the intramyocardial T-cell immune response for the alteration in the adenine nucleotide translocator isoform transcription pattern (ANTitp) in patients suspected of having myocardial inflammation.

BACKGROUND

The ANT, the only mitochondrial carrier for ADP and ATP, plays a significant role in the energy metabolism and is involved in the apoptosis process. Its function and expression were found to be altered in the myocardium of patients with dilated cardiomyopathy and myocarditis.

METHODS

The ANTitp was analyzed in endomyocardial biopsies from 53 patients with clinically suspected inflammatory heart disease (csIHD). Enteroviral RNA was detected in the biopsies using the reverse transcripted polymerase chain reaction technique. The activation of the cellular immune system was assessed by the quantification of T-lymphocytes employing immunohistochemistry.

RESULTS

The ANTitp was found to be altered in 21 csIHD patients. Enteroviral genome was found in the heart of 71.4% of these patients, but only 37.5% of the patients with a normal ANTitp were virus-positive (p < 0.02). The infiltration with CD3+, CD45R0+ and CD8+ T-cells was substantially lower in myocardial specimens with an altered ANTitp than in biopsies with a normal ANTitp. Combining the data, an altered ANTitp was primarily found in virus-positive heart tissue, which was less infiltrated with lymphocytes or not at all.

CONCLUSIONS

An enteroviral infection is linked to changes in the ANT isoform expression in human heart tissue, which shows little or no evidence of an active T-cell dependent immune response. These results make a contribution to a better understanding of the pathophysiology of enterovirus-induced human inflammatory heart disease.

Antimyosin autoantibodies are associated with deterioration of systolic and diastolic left ventricular function in patients with chronic myocarditis

OBJECTIVES

The study evaluates the clinical course and the development of systolic and diastolic left ventricular function in patients with chronic myocarditis with or without autoantibodies against cardiac myosin.

BACKGROUND

Patients with myocarditis often show autoantibodies against cardiac myosin. The clinical and pathophysiologic significance of these antimyosin autoantibodies (AMAAB) is yet unknown. The results from studies comparing the clinical course and the development of left ventricular function in patients with chronic myocarditis with or without AMAAB are not yet available.

METHODS

Thirty-three patients with biopsy proven chronic myocarditis underwent analysis of AMAAB, right and left heart catheterization and left ventriculography at baseline and after six months. Left ventricular volumes and ejection fraction as well as the time constant of left ventricular relaxation "tau" and the constant of myocardial stiffness "b" were determined at baseline and at follow-up.

RESULTS

In 17 (52%) patients, AMAAB could be detected at baseline. After six months, AMAAB were still found in 13 (76%) initially antibody-positive patients. No initially antibody-negative (n = 16) patient developed AMAAB during follow-up. Clinical symptoms improved slightly in antibody-negative patients and remained stable in antibody-positive patients. Left ventricular ejection fraction developed significantly better in antibody-negative patients (+8.9 +/- 10.1%) compared with antibody-positive patients (-0.1 +/- 9.4%) (p < 0.012). Stroke volume (SV) and stroke volume index (SVI) also improved in antibody-negative patients (SV: +20 +/- 31 ml; SVI: +10 +/- 17 ml) compared with antibody-positive patients (SV: -14 +/- 43 ml; SVI: -8 +/- 22 ml) (SV: p < 0.015; SVI: p < 0.016). Left ventricular end-diastolic and end-systolic volumes and the time constant of left ventricular relaxation "tau" did not change significantly different in antibody-positive and antibody-negative patients. The constant of myocardial stiffness "b" improved significantly in antibody-negative patients (-6.1 +/- 10.8) compared with antibody-positive patients (+7.3 +/- 22.6) (p < 0.040). Analyzing only the persistently antibody-positive patients yielded essentially the same results.

CONCLUSIONS

Antimyosin autoantibodies are associated with worse development of left ventricular systolic function and diastolic stiffness in patients with chronic myocarditis.

Dilated cardiomyopathy is associated with significant changes in collagen type I/III ratio

BACKGROUND

It is controversial whether myocardial fibrosis in end-stage dilated cardiomyopathy (DCM) is associated with altered collagen type I/type III (Col I/Col III) ratio.

METHODS AND RESULTS

Patients with DCM (ejection fraction [EF] <50%, n=12) and with mild global left ventricular dysfunction (EF >50%, n=18) were examined. Col I, Col III, and transforming growth factors-beta1 (TGF-beta1) and -beta2 (TGF-beta2) gene expression in endomyocardial biopsies was evaluated by quantitative competitive reverse transcriptase-polymerase chain reaction (qRT-PCR). Collagen content was quantified after picrosirius red and immunohistological staining and by hydroxyproline assay. In patients with EF <50%, there was a pronounced 2- to 6-fold increase of myocardial Col I mRNA abundance (P<0.01), with a corresponding 1.6-fold increase at the protein level versus that found in patients with EF >50%. The Col III mRNA abundance showed a 2.0-fold increase (P<0.04). There was a relevant shift in the Col I/Col III mRNA ratio for DCM patients (Col I/Col III, 8.2) compared with patients with an EF >50% (Col I/Col III, 6. 4). In addition, total collagen content was increased in patients with EF <50% (n=3) (4.3+/-0.1%) compared with patients with EF >50% (n=8) (2.7+/-0.9%) (P<0.004). The biochemically determined ratio of hydroxyproline/total protein (n=12) was correlated to the Col I mRNA abundance (P<0.05, r=0.77). TGF-beta1 and TGF-beta2 showed elevated myocardial mRNA abundances (1- to 7-fold and 4- to 5-fold, respectively) in DCM patients.

CONCLUSIONS

Differential increase of Col I and Col III leads to an increased Col I/Col III ratio in DCM myocardium. Because Col I provides substantial tensile strength and stiffness, this may contribute to systolic and in particular diastolic dysfunction in DCM.

Expression of cell adhesion molecules in dilated cardiomyopathy: evidence for endothelial activation in inflammatory cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is pathogenically linked to inflammatory cardiomyopathy (InfCM), which is characterized by intramyocardial infiltration. The transendothelial migration of immunocompetent cells is mediated by cell adhesion molecules (CAMs).

METHODS AND RESULTS

We investigated the expression pattern of CAMs (immunoglobulin superfamily, 32 selectins, and beta1- and beta2-integrins) in endomyocardial biopsies from DCM patients (n=152; left ventricular ejection fraction <40%) using immunohistochemistry. Whereas few specimens obtained at autopsy (controls; n=14) presented enhanced expression regarding single endothelial CAMs (human leukocyte antigen [HLA] class I, 7%; HLA-DR, 14%; CD29, 14%), none demonstrated concurrent abundance of >3 CAMs (inflammatory endothelial activation), nor did any control tissue prove positive for InfCM (>7.0 CD3+ lymphocytes per 1 mm2). In comparison, 64% (n=97) of the DCM biopsies were evaluated positive for InfCM and 67% (n=101) for inflammatory endothelial activation, respectively. Whereas expression of HLA class I, HLA-DR, intercellular cell adhesion molecule-1, and CD29 was distributed homogeneously within a patient's serial sections, immunoreactivity of vascular cell adhesion molecule-1, lymphocyte function antigen-3, and the selectins was accentuated on single vascular endothelia. Sixty-six percent of the DCM biopsies presented CD29 abundance also within the extracellular matrix and the sarcolemma. CD62P and CD62E were present in 16% and 40% of the DCM patients, respectively. Endothelial CAM representatives correlated with one another (P<0.05), except for CD62P with HLA. Endothelial CAM expression correlated with intramyocardial infiltrates phenotyped by the corresponding counterreceptors.

CONCLUSIONS

Inflammatory endothelial activation is present in 67% of DCM patients. Because CAM expression correlates with the immunohistological diagnosis of InfCM and counterreceptor-bearing intramyocardial infiltrates, evaluation of endothelial CAMs might be of diagnostic significance in InfCM.

Detection of adenoviral genome in the myocardium of adult patients with idiopathic left ventricular dysfunction

BACKGROUND

The use of molecular biological techniques has demonstrated the importance of enteroviral infection of the myocardium in the pathogenesis of myocarditis and dilated cardiomyopathy in adults and adenovirus and enterovirus infection in children. The aim of this study was to determine the frequency of adenoviral infection of the myocardium of adults with impaired left ventricular function of unknown origin.

METHODS AND RESULTS

Nested polymerase chain reaction (nPCR) was used to determine the frequency of detection of adenoviral DNA and enteroviral RNA in myocardial tissue samples from 94 adult patients with idiopathic left ventricular dysfunction and 14 control patients. Histological and immunohistological analyses were performed to detect myocardial inflammation. Adenoviral genomic DNA was detected by nPCR in 12 of the 94 patients with left ventricular dysfunction (in each case, adenovirus type 2), whereas enteroviral RNA was detected in another 12 patients. All control samples were negative for both viruses. In all patients, active myocarditis was excluded according to the Dallas criteria. However, there was significantly decreased CD2, CD3, and CD45RO T lymphocyte counts in the adenovirus-positive group compared with the adenovirus-negative group (P<0.05), whereas no differences were associated with enterovirus infection.

CONCLUSIONS

Although enteroviruses are an important causative agent in the pathogenesis of myocarditis and dilated cardiomyopathy, this study shows that adenovirus infection is also important in the pathogenesis of left ventricular failure in adults. However, the pathogenetic basis of disease associated with adenovirus infection may be different than that after infection with other agents, particularly with respect to activation of the host immune response.

[Syncope in 3rd degree atrioventricular block. Detection of virus genome in the myocardium]

HISTORY AND CLINICAL FINDINGS

A 28-year-old woman was admitted after syncope which had been preceded by several flulike episodes. There was no history of any other serious disease. Physical examination was unremarkable. Heart sounds were regular and normal, there were no murmurs.

INVESTIGATIONS

White cell count was 9400/microliter, with a normal differential count. Erythrocyte sedimentation rate and C-reactive protein were also normal. Virus serology revealed no abnormality. The electrocardiogram (ECG) showed complete (third degree) atrioventricular (AV) block with an idioventricular rhythm of 38 beats/min and right bundle branch block pattern.

TREATMENT AND COURSE

A temporary transvenous pacemaker was inserted on the first hospital day. As myocarditis was suspected a right ventricular endomyocardial biopsy was obtained. Histological and immunohistological examinations demonstrated no unequivocal findings. But molecular-biological tests revealed. Coxsackie-B3 virus genome. The pacemaker was removed on the 6th day, when the ECG had shown intermittent second degree AV block. Regular sinus rhythm with a PR interval of 0.18 s was recorded on day 12, and 24-hour ECG monitoring for several days until her discharge on the 18th day confirmed this rhythm throughout.

CONCLUSION

In aetiologically undetermined disease molecular-biological techniques can be indispensable for the exact diagnosis and may be decisive for administering specific treatment.

Antimyosin scintigraphy and immunohistologic analysis of endomyocardial biopsy in patients with clinically suspected myocarditis--evidence of myocardial cell damage and inflammation in the absence of histologic signs of myocarditis

OBJECTIVES

This study compares the results of antimyosin scintigraphy in patients with clinically suspected myocarditis with histologic and immunohistologic findings in the endomyocardial biopsy.

BACKGROUND

In patients with clinically suspected myocarditis, antimyosin scintigraphy often demonstrates myocardial cell damage but histologic evaluation of the endomyocardial biopsy often fails to show evidence of myocarditis. Recently developed immunohistologic techniques appear to be more sensitive for the detection of myocardial inflammation than histologic analysis alone. Studies comparing antimyosin scintigraphy and immunohistologic analysis of the endomyocardial biopsy in patients with clinically suspected myocarditis are not yet available.

METHODS

Sixty-five patients with clinically suspected myocarditis underwent antimyosin scintigraphy. Antimyosin antibody uptake was correlated with histologic and immunohistologic findings in the endomyocardial biopsy.

RESULTS

Antimyosin scintigraphy showed evidence of myocardial cell damage in 36 (55%) of the 65 patients and was negative in 29 (45%) patients. Histologic analysis of the endomyocardial biopsy revealed myocarditis in nine patients: six had a positive and three had a negative antimyosin scan, respectively. Thirty (83%) of 36 patients with evidence of myocardial cell damage on antimyosin scintigraphy were histologically negative for myocarditis. Immunohistologic analysis showed evidence of myocarditis in 31 (86%) of 36 patients with a positive antimyosin scan and also in 17 (59%) of 29 patients with a normal scan (p < 0.047).

CONCLUSIONS

Antimyosin scintigraphy often shows myocyte injury in patients with clinically suspected myocarditis. Histologic analysis of the endomyocardial biopsy alone is often negative, but additional immunohistologic analysis of the endomyocardial biopsy frequently provides evidence of myocardial inflammation in these patients. With immunohistologic analysis as the reference method, antimyosin scintigraphy has a high specificity but a lower sensitivity for the detection of myocarditis.

[Antimyosin scintigraphy for diagnosis and follow-up of patients with clinically suspected myocarditis]

Antimyosin-scintigraphy is believed to have a high specificity but a low sensitivity for the diagnosis of myocarditis when histological analysis of endomyocardial biopsy is used as the reference method. However, the histological evaluation itself seems to have a low sensitivity for the diagnosis of myocarditis. Therefore, immunohistological techniques have been developed for the detection of lymphocytic infiltrates and increased expression of HLA antigens in the myocardium. The present study compares the results of antimyosin-scintigraphy with histological and immunohistological analysis of the endomyocardial biopsy. 65 patients with clinically suspected myocarditis underwent antimyosin-scintigraphy and histological and immunohistological analysis of the endomyocardial biopsy. Myocarditis could be diagnosed histologically in only 9/36 (25%) patients with a positive antimyosin scan but additional immunohistological analysis revealed lymphocytic infiltrates in 31 (86%) of these patients. In 29 patients with a normal antimyosin scan, histological analysis showed evidence of myocarditis in 3 (10%) patients; additional immunohistological evaluation disclosed lymphocytic infiltrates in 17 (59%) patients. With immunohistological analysis of the endomyocardial biopsy as the reference method, antimyosin-scintigraphy has a high sensitivity but a lower specificity for the diagnosis of myocarditis. Detection of autoantibodies against human cardiac myosin in patients with myocarditis is associated with a significantly lower incidence of positive antimyosin scans in these patients. Antimyosin-scintigraphy was repeated after six months in 14 patients with myocarditis. Histological and immunohistological evaluation of the endomyocardial biopsy now showed persistent myocarditis in 3/8 patients with a positive antimyosin scan and in 5/6 patients with a normal antimyosin scan.

[Detection of enteroviral RNA in endomyocardial biopsies in inflammatory cardiomyopathy and idiopathic dilated cardiomyopathy]

The role of enteroviral myocardial infection in the development of dilated cardiomyopathy could only be substantiated after the introduction of molecular biological techniques (polymerase chain reaction, in-situ hybridization) in virological diagnostics of dilated cardiomyopathy. By using histological and especially immunohistological techniques for the detection of myocardial inflammation in patients with the tentative clinical diagnosis of dilated cardiomyopathy, a differentiation between inflammatory cardiomyopathy and idiopathic dilated cardiomyopathy on the basis of the WHO classification 1995 (31) was made. Inflammatory cardiomyopathy is defined by myocarditis in association with cardiac dysfunction and is diagnosed by established histological and especially immunohistological techniques. The combination of histological, immunohistological, and molecularbiological techniques enabled a subgroup analysis of the incidence of enteroviral myocardial RNA in patients with inflammatory cardiomyopathy in comparison to patients with idiopathic dilated cardiomyopathy. The study involved a total of 75 patients with impaired left ventricular function (EF < 50%) and the tentative clinical diagnosis of dilated cardiomyopathy. Right ventricular endomyocardial biopsies were obtained from all patients for further clarification of the cause of left ventricular functional disorder. All biopsies were analyzed for the presence of acute and chronic inflammatory myocardial alterations by histological ("Dallas" criteria) and immunohistological techniques (lymphocytic infiltrates, MHC antigen expression). Furthermore, each biopsy was examined by reverse transcriptase polymerase chain reaction (RT-PCR) in combination with Southern blot hybridization for the presence of enteroviral RNA. Active myocarditis was excluded in all patients by histological examination according to the "Dallas" criteria. Using immunohistological techniques, 26/75 patients (35%) had evidence for chronic inflammatory myocardial alterations in the sense of lymphocytic infiltrates (> or = 2,0 CD3 T-lymphocytes/ visual field at 400 magnification (HPF); > or = 7 CD3 T-lymphocytes/mm2). These patients were diagnosed as having inflammatory cardiomyopathy. To differentiate between patients with and without myocardial inflammation, cases with focal cellular infiltration and an average cell number between 2.5 and 2.0 CD3 T-lymphocytes/HPF and an increased expression of additional immune markers, i.e., MHC antigens, were not addressed in the group of patients with inflammatory cardiomyopathy. This is in contrast to Kühl et al (19). Consequently these patients were classified as patients with idiopathic dilated cardiomyopathy. These criteria of diagnosing myocardial inflammation were based on published results (20, 23, 26, 27, 49) and on our own control group (n = 85) (19) in which mean CD3 T-lymphocyte count/HPF in normal myocardial tissue were 0.7 (range 0.0-1.4). In addition, a subgroup analysis was performed of patients with a CD3 T-lymphocyte count > or = 3 CD3 T-lymphocytes/HPF (> or + 11 CD3 T-lymphocytes/mm2). The other 49/75 patients without myocardial inflammation (< 2.0 CD3 T-lymphocytes /HPF) were diagnosed as having idiopathic dilated cardiomyopathy. In 27/75 patients (36%), RT-PCR in combination with Southern blot hybridization revealed enteroviral RNA in the endomyocardial biopsies. The detection rate of enteroviral RNA did not differ between inflammatory cardiomyopathy (8/26 (31%)) and idiopathic dilated cardiomyopathy (19/49 39%)). In the subgroups of patients with a CD3 T-lymphocyte cell count > or = 3 CD3 T-lymphocytes/HPF (> or = 11 CD3 T-lymphocytes/mm2) (mean 4.4 +/-2.1 CD3 T-lymphocytes/HPF), three of the ten patients were enteroviral RNA positive (30%). In summary, the introduction of histological and immunohistological techniques in the extended diagnostics of dilated cardiomyopathy enables a subgroup analysis of the incidence of enteroviral myocardial RNA in

[Pathogenesis of inflammatory cardiomyopathies]

The development of dilated cardiomyopathy from chronic myocarditis is caused by the persistence of enteroviral infections and chronic myocardial inflammation. New molecularbiological and immunohistochemical techniques improve diagnosis and allow predictions of the development of the disease. This facilitates the decision for a specific immunomodulatory therapy.

[Cardiac troponin T in the diagnosis and follow up of suspected myocarditis]

BACKGROUND AND OBJECTIVE

Results of routine laboratory tests for demonstrating myocardial damage in patients suspected of having myocarditis are often negative. This study was undertaken to ascertain (1) whether measuring Tropinin T (cTnT) in these patients can sensitively determine myocardial cell death, (2) to what extent this correlates with the findings of endomyocardial biopsy, and (3) whether measurement of cTnT can provide noninvasive assessment of the course of myocarditis.

PATIENTS AND METHODS

80 consecutive patients (52 men, 28 women) with clinically suspected myocarditis were investigated. The main clinical symptoms were heart failure (n = 45), angina pectoris (n = 25) or cardiac arrhythmias (n = 10). In most patients the symptoms had developed in temporal relation to a viral infection. Coronary heart disease was excluded in all by coronary angiography. Interventricular septal endomyocardial biopsies were examined histologically and immunohistologically. cTnT was measured with a highly sensitive sandwich-immunoassay.

RESULTS

An increased level of cTnT (> 0.1 ng/ml) was demonstrated in 28 of the 80 patients (35%). Myocarditis was diagnosed histologically in only 5 patients, but immunohistologically in 26 of 28 (93%) with a raised cTnT level and in 23 of 52 (44%) with a normal cTnT level. The cTnT level was more frequently elevated in patients with a brief rather than a long history of myocarditis. After 6 months the cTnT level was elevated in only 4 of 28 patients with myocarditis, but the myocardial biopsy showed persisting myocarditis in 14 patients.

CONCLUSION

Measurement of cTnT is a very sensitive way of demonstrating myocardial cell damage in patients clinically suspected of having myocarditis. Immunohistological analysis can often provide positive results even if the histological findings are unremarkable. The sensitivity in diagnosing of cTnT is greatest when the patient is tested shortly after the onset of symptoms.

[Biphasic course of left ventricular dysfunction in a 22-year-old female with acute myocarditis]

HISTORY AND CLINICAL FINDINGS

Two days before admission a 22-year-old woman developed general fatigue, nausea, headache and retrosternal pain. Physical examination was unremarkable.

INVESTIGATIONS

Erythrocyte sedimentation rate was increased to 20/48, C-reactive protein to 3.3 mg/dl, and there was evidence of myocardial damage (creatine kinase 609 U/l, creatine kinase-MB 42 U/l, troponine T 8.39 ng/ml); ST-segment elevations in I, II, III, aVF and V-V6 of the ECG. Echocardiography revealed clearly thickened myocardium, moderate but haemodynamically not significant pericardial effusion, as well as impaired left ventricular function. Antimyosin scintigraphy was very abnormal. Cardiac catheterization confirmed the left ventricular dysfunction, rise of left ventricular enddiastolic pressure to 17 mm Hg, and a markedly reduced cardiac output of 2.4 l/min. Myocardial biopsy showed severe myocarditis with marked myocytolysis and considerable lymphocytic infiltrations. Enteroviral RNA was demonstrated in the myocardium by polymerase chain reaction.

TREATMENT AND COURSE

The haemodynamics became normal within only 3 days. Myocardial biopsy after 6 months was unremarkable histologically and immunohistologically, and left ventricular function was also normal. However, while after a further 12 months myocardial biopsy remained normal and no virus was demonstrated, there was definite, though moderate, impairment in left ventricular function, indicating a dilated cardiomyopathy.

INTERPRETATION

Even when histological and immunohistological evidence of healing of an acute viral myocarditis has been achieved, with complete normalization of left ventricular function, a dilated cardiomyopathy may subsequently develop. The pathophysiological mechanism of this occurrence remains unknown.

Differential myocardial abundance of collagen type I and type III mRNA in dilated cardiomyopathy: effects of myocardial inflammation

OBJECTIVE

The collagen subtypes I (Col I) and III (Col III) are essential components of the cardiac extracellular matrix (ECM) maintaining the functional integrity of the heart. Histological, immunohistological, and biochemical studies, however, demonstrate characteristical changes of the ECM in dilated cardiomyopathy, myocarditis, ischemic cardiomyopathy, and hypertensive heart disease.

METHODS

In order to investigate possible effects of inflammatory processes on mRNA abundance of Col I and Col III, we examined 24 patients with the presumptive clinical diagnosis of dilated cardiomyopathy (EF = 30 +/- 11%). 12 Patients were classified as idiopathic dilated cardiomyopathy without any evidence of myocardial inflammation; the remaining 12 patients were classified as inflammatory cardiomyopathy due to the immunohistologically documented inflammatory myocardial process.

RESULTS

Quantification of reverse transcription polymerase chain reaction (RT-PCR) products revealed significant differences as to the mRNA abundance ratio Col III/Col I between subgroups of patients with inflammatory cardiomyopathy (1.16 +/- 0.18) and idiopathic dilated cardiomyopathy (2.77 +/- 0.65) regardless of left ventricular dysfunction (p < or = 0.05).

CONCLUSION

It is not yet known, whether different Col III/Col I ratios differentially influence diastolic compliance. Our data suggest that inflammatory mechanisms seen in inflammatory cardiomyopathy influence the mRNA abundance of collagen subtypes I and III.

Cardiac troponin T in patients with clinically suspected myocarditis

OBJECTIVES

The present study investigated whether myocyte injury can be assessed sensitively by measurement of serum levels of cardiac troponin T (cTnT) in patients with clinically suspected myocarditis and whether cTnT levels may predict the results of histologic and immunohistologic analysis of endomyocardial biopsy specimens.

BACKGROUND

Conventionally used laboratory variables often fail to show myocyte injury in patients with clinically suspected myocarditis, possibly because of a low extent of myocardial injury in these patients. Sensitive variables for myocyte injury have not yet been investigated.

METHODS

Eighty patients with clinically suspected myocarditis were screened for creatine kinase (CK) activity, MB isoform of CK (CK-MB) activity and cTnT. Endomyocardial biopsy specimens were examined histologically and immunohistologically.

RESULTS

cTnT was elevated in 28 of 80 patients with clinically suspected myocarditis, CK in 4 and CK-MB in 1. Histologic analysis alone of the endomyocardial biopsy specimen revealed evidence of myocarditis in only five patients, all with elevated cTnT levels. Twenty-three of 28 patients with elevated cTnT levels had histologically negative findings for myocarditis. Additional immunohistologic analysis revealed evidence of myocarditis in 26 (93%) of 28 patients with elevated cTnT levels and in 23 (44%) of 52 patients with normal cTnT levels. Mean cTnT levels were higher in patients with myocarditis proved histologically or immunohistologically, or both, than in patients without myocarditis (0.59 +/- 1.68 vs. 0.04 +/- 0.05, p < 0.001).

CONCLUSIONS

Measurement of serum levels of cTnT provides evidence of myocyte injury in patients with clinically suspected myocarditis more sensitively than does conventional determination of cardiac enzyme levels. Myocardial cell damage may be present even in the absence of histologic signs of myocarditis. Additional immunohistologic analysis often shows lymphocytic infiltrates in these patients. Elevated levels of cTnT are highly predictive for myocarditis in this group.

[Immunosuppressive therapy for effective suppression of life threatening ventricular tachyarrhythmias in chronic myocarditis]

Chronic myocarditis predisposes to the occurrence of spontaneous ventricular arrhythmias. It is not known if an immunosuppressive treatment-as a casual therapy-leads to arrhythmia suppression. In the present study, 12 patients (four female, eight male, mean age 53 +/- 15 years) with a mean left-ventricular ejection fraction of 52 +/- 19% were included. After exclusion of coronary macroangiopathy, the presence of chronic myocarditis was demonstrated by immunohistological evaluation of right-ventricular biopsies taking the number of specific lymphocytes (CD 2-8), of activated macrophages and the degree of HLA-expression on interstitial and endothelial cells as a basis. Seven patients had a successful resuscitation due to ventricular fibrillation in their case history, three patients presented sustained monomorphic ventricular tachycardia and two syncopes with inducible tachyarrhythmias. As a "conventional" therapy ten patients received antiarrhythmic drugs and four patients an implantable cardioverter/defibrillator. After confirmation of the diagnosis by a second biopsy after 3 months, all patients underwent an immunosuppressive therapy with methylprednisolone. The initial dose of 1 mg/kg body weight was reduced by 20 mg each every 2 weeks, until a maintenance dosage of 8-12 mg/day was achieved. If the control study after 6 months still gave a positive result, a combined therapy with azathioprine, 100-150 mg/day, was carried out for a further 6 months. In nine patients (75%), the control biopsy became negative, in three patients (25%), the biopsy remained to be positive. In the group presenting negative biopsies, no tachyarrhythmia relapse occurred within a follow-up period of 49 +/- 13 months, while in the group with positive biopsies, relapses occurred in two of three patients. Complete suppression during EPS after therapy was achieved in 50% of the patients who were inducible before therapy. In addition to lymphocyte infiltration, particularly HLA expression on endothelial and interstitial cells was significantly reduced; left-ventricular ejection fraction was improved only in tendency, while left-ventricular filling pressure decreased significantly. In summary, in patients with chronic myocarditis and malignant ventricular arrhythmias, a high-dose immunosuppressive long-term therapy results in the significant reduction of inflammatory infiltrations in about 75% of the cases and, at the same time, in the effective suppression of arrhythmias.

Cell-mediated cytotoxicity in hearts with dilated cardiomyopathy: correlation with interstitial fibrosis and foci of activated T lymphocytes

OBJECTIVES

The purpose of this study was to investigate the expression of perforin and T-cell intracellular antigen-1, two crucial components of lymphocyte-mediated cytotoxicity, in endomyocardial biopsies from patients with idiopathic dilated cardiomyopathy.

BACKGROUND

Previous reports have demonstrated the presence of myocardial interstitial fibrosis and increased infiltrating lymphocytes in patients with dilated cardiomyopathy. However, the pathogenic significance of these lymphocytic infiltrates remains unclear.

METHODS

Endomyocardial biopsies from 134 patients with idiopathic dilated cardiomyopathy were histologically and immunohistologically analyzed. Monoclonal antibodies against diverse T-lymphocyte antigens, perforin and T-cell intracellular antigen-1 were used with the highly sensitive avidin-biotin complex technique. Positive cells were counted in at least 10 high power field.

RESULTS

Perforin and T-cell intracellular antigen-1 were immunohistologically detected in all biopsies. Immunoreactivity was restricted to the cytoplasm and was granular in nature, indicating specific staining of cytoplasmic granules. Correlations were established between the expression of perforin and T-cell intracellular antigen-1 and the abundance of foci of various T-lymphocyte subpopulations and, most importantly, the degree of interstitial fibrosis on routine histologic examination (p = 0.015).

CONCLUSIONS

Cytotoxic activity is clearly present in endomyocardial biopsies from patients with idiopathic dilated cardiomyopathy. Local activation-that is, focal accumulation of T lymphocytes-seems to be important for the generation of lymphocyte-mediated cytotoxicity. The interstitial fibrosis commonly seen in dilated cardiomyopathy may be caused by cytotoxic T-lymphocyte damage to the myocardium.

[Cardiac sarcoidosis: diagnostic validation by endomyocardial biopsy and therapy with corticosteroids]

A 66-year-old woman with pulmonary sarcoidosis had a 1.5-year history of congestive heart failure presenting as dilated cardiomyopathy. Transvenous endomyocardial biopsy specimens initially revealed lymphocytic myocarditis but subsequently showed a non-cesating giant-cell granuloma typical of Boeck's sarcoid. In addition to standard therapy the patient was given corticosteroids. This case illustrates the difficulties and importance of diagnosing cardiac sarcoidosis as a potentially treatable form of dilated cardiomyopathy.

Complete AV-block in two children with immunohistochemical proven myocarditis

We report two children with acquired third degree AV-block caused by acute myocarditis. The diagnosis was proven by endomyocardial biopsy. Severe lymphocytic myocardial infiltration was shown using immunohistological methods. One of the children was treated with prednisone During therapy conduction disturbance nearly disappeared and infiltration was markedly reduced in a subsequent biopsy. In the other patient the parents refused immunosuppressive treatment and a permanent pacemaker was necessary for persistent bradycardia.

CONCLUSION

Immunohistological staining of an endomyocardial biopsy can be used to establish the diagnosis of myocarditis in patients with atypical clinical manifestation, such as complete AV-block, and can support the decision for therapy. In one patient improvement was documented by the disappearance of inflammatory activity in a repeated biopsy.

Immunohistological evidence for a chronic intramyocardial inflammatory process in dilated cardiomyopathy

OBJECTIVE

To determine whether immunohistochemical analysis of cardiac biopsies from patients presenting clinically as dilated cardiomyopathy (DCM) show a chronic inflammatory process.

DESIGN

Comparative case control study.

SETTING

Tertiary referral centre.

PATIENTS

Biopsies from 170 patients with DCM and 85 control patients with other cardiac diseases.

RESULTS

Nine patients had sufficient interstitial inflammatory cells to be called borderline myocarditis on conventional histology, leaving 161 patients with DCM. In 78 patients with DCM (48%) there were T lymphocytes in the myocardium. In 48 (62%) of these 78 T lymphocyte densities were in the range 2-14 per high power field (HPF), equivalent to 7-50 per mm2 of tissue. In 43 (89%) interstitial and endothelial immune activation was demonstrated by MHC expression. In 30 patients with T cell counts in the range 1.5-2.0 per HPF, 80% also showed endothelial activation. Lymphocyte density correlated with increased expression of MHC class I and II antigens and the adhesion molecules ICAM, VCAM, ELAM, LFA-3, and GMP140. In all control biopsies the T lymphocyte density was less than 1.0 per HPF (less than 2-5 per mm2 of tissue).

CONCLUSIONS

Nearly half the patients with DCM had increased T lymphocyte density and immune activation of endothelial and interstitial cells in their cardiac biopsies. A chronic autoimmune process is still active within the myocardium in a significant percentage of patients with DCM. Immunohistochemical analysis of cardiac biopsies will enhance the sensitivity of cardiac biopsy and is essential for the diagnosis of myocarditis.