Search

Background/Introduction With the growing prevalence of prediabetes in developed countries, complications of this predecessor of diabetes mellitus type 2 become increasingly important for medical research and practice. Prediabetes is defined as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and may also incorporate elevated hemoglobin A1. While overt type 2 diabetes is a well-established risk factor and can even be the cause of cardiac failure, this is not yet proven for prediabetes. Mitochondrial impairment is a key pathomechanism in heart failure, but it remains uncertain, whether prediabetes impairs myocardial energy metabolism in humans just as type 2 diabetes does. Purpose We aimed to scrutinize the impact of prediabetes on myocardial mitochondrial metabolism and cardiac function. Methods We included 50 heart transplant recipients with normal glucose tolerance (GT, n=25), prediabetes (n=8, 3 IFG and 5 IGT) or type 2 diabetes mellitus (T2DM, n=17), who had received a healthy donor heart from a non-diabetic donor. In this cohort, the impact of the recipients' metabolism should be displayed in the donor heart after transplantation. We performed oral glucose tolerance tests to assess the diabetes status, and cardiac magnetic resonance imaging to assess cardiac systolic and diastolic function, circulating biomarkers of oxidative stress in serum samples (thiobarbituric acid reactive substances (TBARS) and redox potential), as well as global T2 relaxation times as a marker of myocardial inflammation. In transcatheter endomyocardial biopsies, we assessed myocardial mitochondrial oxidative capacity using high-resolution respirometry and myocardial mRNA expression of nuclear factor kappa B p105 subunit (NFKB1). Results GT and IFG/IGT patients exhibited comparable demographic and clinical characteristics, whereas T2DM had higher BMI, glycemia, triglycerides and creatine kinase (all p Conclusion Our findings point towards mitochondrial impairment as a predecessor of overt heart failure in prediabetes and may represent an early footprint of prediabetic cardiomyopathy. Funding Acknowledgement Type of funding sources: None.

Background Mitochondrial dysfunction is a driving factor in the development of heart failure (HF) and relates to poor cardiac function. Through elevated oxidative stress it is linked to myocardial inflammation. Both mechanisms promote the development of cardiac fibrosis, a key contributor to adverse outcomes in ischaemic and non-ischaemic HF. Differences in myocardial mitochondrial function and inflammation between patients with ischaemic and non-ischaemic HF have been indicated. While immunosuppression in non-ischaemic HF with myocardial inflammation has improved long-term results, little is known about possible benefits in ischaemic HF. Purpose We hypothesised that: 1. Myocardial lymphocytic inflammation and fibrosis differ in patients with HF due to ischaemic cardiomyopathy (ICM) compared to patients with dilated cardiomyopathy (DCM). 2. Inflammation and fibrosis are associated with markers of mitochondrial dysfunction. Methods Myocardial tissue specimens were obtained from the left ventricular (LV) apex of 65 patients (n[ICM] = 33, n[DCM] = 32) with HF requiring an LV assist device or heart transplantation. We assessed oxidative phosphorylation capacity (OXPHOS) via high resolution respirometry in saponine-permeabilised myocardial fibres (OROBOROS Oxygraph-2k). Reactive oxygen species (ROS) production was measured fluoroscopically via the Amplex Red method. Immunohistochemistry staining for CD3 was performed on snap-frozen tissue and digitally analysed. Azan staining was used for quantification of fibrotic area. Statistical analysis was conducted with GraphPad Prism v9.0 and IBM SPSS v27.0. Results ICM and DCM patients did not differ significantly regarding age (60.9±5.4 vs. 55.8±12.4 years, p=0.11), sex (91% vs. 90% male, p=0.93), BMI (27.6±5.1 vs. 26.5±6.0 kg/m2, p=0.82), or diabetic status (31% vs. 20% Type 2 Diabetes mellitus, p=0.31). Tissue specimens of ICM patients displayed about three times larger fibrotic areas compared to DCM (20.9±21.2 vs. 7.2±5.6%, p=0.001). Cellular inflammation (>14 CD3+ cells/mm2) was significantly more common in ICM than DCM patients. (27 vs. 6%, p=0.024). Inflammation and fibrosis did not correlate significantly (r=0.09, p=0.46). Fibrosis was not associated with OXPHOS capacity (r=−0.129, p=0.33). In patients with inflammation, OXPHOS capacity was lower compared to patients without inflammation (92.3±40.1 vs. 131.6±55.6 pmol/(s*mg), p=0.031) and inflammation was associated with lower OXPHOS capacity (r=−0.296, p=0.019). There was a trend towards lower electron transfer capacity in patients with inflammation (98.6±43.1 vs. 129.7±48.3 pmol/(s*mg), p=0.053). ROS production was not significantly different between tissue specimens with or without inflammation (0.51±0.21 vs. 0.67±0.33 pmol/(s*ml), p=0.17). Conclusions Myocardial cellular inflammation is prominent in ICM patients and relates to impaired mitochondria. Future studies may evaluate possible benefits from immunosuppression in ICM patients. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Research Foundation (DFG)

Inflammatory cell infiltration is central to healing after acute myocardial infarction (AMI). The relation of regional inflammation to edema, infarct size (IS), microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional and global LV function is not clear. Here we noninvasively characterized regional inflammation and contractile function in reperfused AMI in pigs using fluorine (19F) cardiovascular magnetic resonance (CMR). Adult anesthetized pigs underwent left anterior descending coronary artery instrumentation with either 90 min occlusion (n = 17) or without occlusion (sham, n = 5). After 3 days, in surviving animals a perfluorooctyl bromide nanoemulsion was infused intravenously to label monocytes/macrophages. At day 6, in vivo 1H-CMR was performed with cine, T2 and T2* weighted imaging, T2 and T1 mapping, perfusion and late gadolinium enhancement followed by 19F-CMR. Pigs were sacrificed for subsequent ex vivo scans and histology. Edema extent was 35 ± 8% and IS was 22 ± 6% of LV mass. Six of ten surviving AMI animals displayed both MVO and IMH (3.3 ± 1.6% and 1.9 ± 0.8% of LV mass). The 19F signal, reflecting the presence and density of monocytes/macrophages, was consistently smaller than edema volume or IS and not apparent in remote areas. The 19F signal-to-noise ratio (SNR) > 8 in the infarct border zone was associated with impaired remote systolic wall thickening. A whole heart value of 19F integral (19F SNR × milliliter) > 200 was related to initial LV remodeling independently of edema, IS, MVO, and IMH. Thus, 19F-CMR quantitatively characterizes regional inflammation after AMI and its relation to edema, IS, MVO, IMH and regional and global LV function and remodeling., Basic Research in Cardiology, 117 (1), ISSN:0300-8428, ISSN:1435-1803

Background/Introduction Preclinical data indicate that plasminogen activator inhibitor-1 (PAI-1) is cardioprotective by repressing cardiac fibrosis through TGF-β and plasminogen mediated pathways. In addition it is linked to the recruitment and polarization of non-classical M2 macrophages in cancer. Purpose The role of cardiac PAI-1 in fibrogenesis and macrophage polarization is investigated in patients with dilated cardiomyopathy (DCM) and inflammatory dilated cardiomyopathy (DCMi). Methods We retrospectively analyzed endomyocardial biopsies (EMBs) of patients with DCM (n=27) and DCMi (n=149) for PAI-1 expression, number of activated myofibroblasts and M1/M2 macrophage polarization. Results Patients with high-grade DCMi (DCMi-high, CD3+ lymphocytes >30 cells/mm2) had significantly increased PAI-1 levels compared to DCM and low grade DCMi patients (DCMi-low, CD3+ lymphocytes = 14 - 30 cells/mm2) (15.5±0.4% vs. 1.0±0.1% and 4.0±0.1%, p≤0.001). Elevated PAI-1 expression in DCMi-high subjects was accompanied by a reduced number of alpha smooth muscle actin (α-SMA) positive myofibroblasts and an increased number of CD16+ CD68+ M2 macrophages, indicating anti-fibrogenic and M2 macrophage-favoring properties of PAI-1 in DCMi. Conclusion Our findings give evidence that elevated expression of PAI-1 suppresses cardiac fibrosis and promotes M2 macrophage polarization. Thus, PAI-1 could serve as a potential prognostic biomarker of cardiac fibrosis and inflammation, as well as possible therapeutic target in inflammatory cardiomyopathies. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ERA-Net on Cardiovascular Diseases (ERA-CVD) of the German Research Foundation (DFG)Transregional Collaborative Research Center “Inflammatory Cardiomyopathy-Molecular Pathogenesis and Therapy”

Background Human erythroparvovirus-1 (B19V) is the most frequently found virus in endomyocardial biopsies (EMBs). Recent studies have detected B19V genomes in various organs of symptomatic and asymptomatic individuals including endothelial cells of the heart muscle. Accordingly, B19V as a causative pathogen of myocardial damage has been questioned. To date, the majority of studies focused on the presence of viral DNA in the myocardium, but lack the analysis of viral RNAs as markers for viral activity. In contrast to latent infection, the expression of viral mRNAs is of clinical importance as we could demonstrate in previous studies. Only recently, novel antiviral treatment strategies have become available. A sensitive and specific method to identify and monitor patients that will profit from antiviral treatment is a prerequisite for successful therapy. During this study, we established a new PCR-based diagnostic method to characterize the expression of B19V RNAs coding for the non-structural (NS1) and capsid protein (VP1/2) in endomyocardial biopsies of patients with unexplained heart failure and demonstrated its feasibility in a clinical setting of molecular diagnostics. Methods To quantify B19V RNA expression, we developed real-time (reverse transcription) polymerase chain reactions (qPCRs) targeting the NS1 and VP1/2 regions of B19V genome. 576 randomly selected EMBs of patients with unexplained heart failure were tested for B19V genomes and transcription intermediates using qPCR and nested PCR. Results 403 of 576 (69.9%) EMBs were positive for B19V genomes (B19V DNA). Viral loads ranged from 15 to 51,118 genome equivalents/μg isolated DNA. Of the 403 B19V DNA-positive samples, B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 155/403 (38.4%) EMBs using the newly established B19V qPCRs. 89/403 samples were characterized by only NS1 mRNA detection while 24/403 revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 42/403 samples. Patients characterized by active B19V infection presented with a significantly reduced left ventricular ejection fraction (30.7±13.1%) in contrast to virus free patients (35.5±15.9%; p=0.025) or latently infected patients (34.7±15.7; p=0.043). Conclusion Our newly established molecular testing will improve detection and quantification of B19V. As we could demonstrate here, it is essential to screen for both viral transcription intermediates, the NS1 and VP1/2 viral mRNAs, in order to precisely differentiate between latent infection or a clinically relevant B19V-infection with transcriptional activity of the heart muscle. The results of our study revealed that a remarkable high proportion of 26.9% (155/576) of patients with unexplained heart failure is affected by transcriptional active B19V infection of the myocardium. Prospective studies must be conducted to evaluate our findings and furthermore, effective antiviral treatment strategies need to be adapted. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): IKDT GmbHn

Background Idiopathic giant cell myocarditis (IGCM) diagnostics is based on differential patterns of inflammatory cell infiltration, and multinucleated giant cells (GCs) in histological sections of endomyocardial biopsies (EMBs). However, the sampling error is high for the detection of focally GCs by histopathology. We report on a clinical evaluation of a recently published method for improved differential diagnosis of this frequently fatal disease by myocardial gene expression profiling. Objective This is to improve the diagnostics of IGCM by gene expression profiling, and to demonstrate the feasibility of this method in clinical practice in a large cohort of patients. Methods In this multicenter study, EMBs of n=427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age 47.03±15.69 years). In each patient, EMBs were analyzed by histology, immunohistology, molecular virology, and gene expression profiling. Results Out of the total of n=427 patient samples examined, GCs could be detected in 26 cases (6.0%) by histology. An established myocardial gene profile – consisting of 27 genes – was revealed resulting in a specified profile of 5 genes (chemokine receptor 5 (CCR5), chemokine receptor 6 (CCR6); carnitine palmitoyltransferase I (CPT1), toll-like receptor 8 (TLR8), and chemokine (C-C motif) ligand 20 (CCL20)) which identified histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Applying this newly established profiling on the remaining patient samples, additional n=31 (7.3%) patients were identified for IGCM without any histological proof of myocardial GCs. Conclusions Myocardial gene expression profiling is a reliable method in clinical practice to predict IGCM even without direct histological proof of GCs in EMB section. The gene profiling is of high clinical relevance to overcome the sampling error of purely histological examination, and to control the effectiveness of the therapy. The data clearly show the importance to take EMB in unexplained acute decompensation to get a diagnosis and improve the prognosis.

Background Plasminogen activator inhibitor type-1 (PAI-1) is an important inhibitor of the fibrinolytic pathway and an acute phase reactant in response to inflammatory cytokines, resulting in thrombosis, arteriosclerosis, and tissue fibrosis. It has been identified as a potential biomarker for coronary artery disease and metabolic syndrom. However, so far, nothing is known about its importance in nonischemic cardiomyopathy. Aims To analyzed PAI-1 expression in patients with different forms of cardiomyopathies and evaluate possible influence of PAI-1-dependent pathomechanisms in patients with intramyocardial inflammation. Methods and results In this study, endomyocardial biopsies (EMBs) from 309 patients (mean age 48.0±13.9 years) with different forms of cardiomyopathies were enrolled, including 123 patients with dilated cardiomyopathy (DCM) (mean LVEF 28.01±9.06%) and 186 patients with EMB-proven virus-negative inflammatory cardiomyopathy (DCMi) (mean LVEF 31.76±14.14%). 10 patients (mean LVEF 60.50±4.76%) without viral or inflammation in EMB served as controls. Hemodynamic parameters were measured by catheterization and echocardiography. EMBs were performed at first admission after exclusion of ischemic of valvular heart disease. In EMBs PAI-1 was assessed by immunohistology including digital imaging analysis. PAI-1 expression was significantly higher in patients with DCMi in contrast to DCM patients and controls (0.517±2.20 vs. 0.187±0.598 vs. 0.023±0.032% Area Fraction; p=0.0002). PAI-expression correlates significantly with lymphocytic infiltrates (for CD3 r=0.56, p Conclusion Myocardial inflammation is associated with a significant increase in PAI-1 expression in DCMi independently of the hemodynamic conditions. This new pathophysiological axis could be a potiential therapeutic target in future treatment stategies in DCMi.

Early treatment with ACE inhibitors of even moderate heart failure is clinically beneficial, even though haemodynamic measurements cannot adequately quantitate such improvement. Neurohumoral assessment is, however, supposed to be more accurate. In 55 patients with moderate heart failure (ejection fraction < or = 35%), we investigated the dose-dependent effects of ACE inhibition with quinapril taken orally (2.5, 5 or 10 mg b.i.d.) following a placebo-controlled, parallel design protocol over 12 weeks. Plasma components of the renin angiotensin system, catecholamines and ANF were measured together with haemodynamics both at rest and during exercise. Before ACE inhibitor treatment, median PRA, Ang I and II and catecholamines were normal, while ANF was increased. All these parameters, including ACE activity, rose during exercise. Chronic inhibition of ACE activity was dose-dependent and the maximal fall in Ang II occurred with quinapril 20 mg.day-1. Humoral changes appeared more assessible than haemodynamic alterations even though many of these changes were reasonably correlated. The effects of chronic ACE inhibition on circulating neurohumoral components in patients with moderate heart failure are small and dose-dependent. Since humoral changes are related to haemodynamics they should account for the clinical benefit. Appropriately high doses of ACE inhibitors should be chosen for treatment of heart failure.

Inflammatory cardiomyopathy is associated with a diffuse inflammation in the heart accompanied with cardiac fibrosis, cardiomyocyte apoptosis, and reduced capillary density. On the other hand, mesenchymal stromal cells (MSCs) have immunomodulatory, anti-fibrotic, anti-apoptotic, and pro-angiogenic features, making them attractive candidates for the treatment of inflammatory cardiomyopathy. The potential of MSC application for the treatment of myocarditis is supported by their beneficial effects in experimental models of acute and chronic inflammatory cardiomopathy. This review summarizes the cardioprotective features of MSCs and describes how MSCs are primed by the inflammatory environment to exert their protective effects. In view of clinical translation, searching for the optimal source of MSC and delivery route, allowing efficient and non-invasive cell application, the differences between MSCs of distinct origin and between diverse routes of application are outlined.

Cardiac inflammation is important for the prognosis of patients with inflammatory cardiomyopathy (CMi), but the mechanisms leading to it are not fully elucidated.To study the role of fractalkine (CX3CL1) in chemotactic and adhesive properties of peripheral blood mononuclear cells (PBMCs) in patients with CMi.Patients with enterovirus (EV)-positive CMi, patients with virus-negative CMi, patients with parvovirus B19 (B19) genomes with low intramyocardial inflammation and patients without cardiac inflammation and viral infection in the endomyocardial biopsy (EMB) were enrolled (n=10/group). The expression of CX3CL1 and monocyte chemoattractant protein (MCP-1) in EMBs was significantly increased in EV-positive and virus-negative patients with CMi in contrast to controls and B19-positive patients (EV+ vs controls: CX3CL1-area fraction (AF) % 0.078±0.012 vs 0.009±0.003 p0.05; MCP-1-AF % 0.093±0.023 vs 0.011±0.009). The receptor (CX3CR1)-mediated chemotaxis was increased twofold in PBMCs in comparison with those of controls. The MCP-1 secretion was 3.1-fold higher in PBMCs from EV-positive patients compared with controls, and this elevation was further increased by CX3CL1 in EV-positive patients. No significant CX3CL1-mediated MCP-1 increase was seen in PBMCs from healthy controls. Moreover, spontaneously beating neonatal rat cardiomyocytes exposed to CX3CL1 exhibited an attenuated positive chronotropic response to β-adrenergic stimulation with isoproterenol.The cardiac and plasma CX3CL1/CX3CR1 system is upregulated in CMi and this affects the functional potential of PBMCs. Moreover, a direct cardiodepressive effect of CX3CL1 in cardiac tissue was demonstrated since neonatal cardiomyocytes exhibited an attenuated positive chronotropic response to β-adrenergic stimulation.

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.

Five thousand consecutive percutaneous transluminal coronary angioplasties (PTCA) were electively performed between January 1988 and June 1993. They were analysed for the incidence of acute coronary occlusion, its acute treatment and subsequent course. In 133 patients (2.7%) the occlusion persisted. Recanalization by repeat PTCA was attempted in all of them, but succeeded in only 68 (51%). In 65 patients recanalization was impossible. In 25 of the latter--patients with a small infarct vessel and infarction having already occurred in the vessel's supply area while the haemodynamics remained stable--conservative treatment was practised. Acute surgical revascularization was undertaken in 30 patients (23%) with a large area and/or haemodynamic instability. In all, 14 patients died (overall death rate 0.28%, death rate of patients with occlusion 11%), ten of them before operative intervention was possible.--Not all coronary artery occlusions can be treated nonsurgically. Consequently, availability of surgical intervention at the place of elective PTCA is mandatory.

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 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.

Bei Patienten mit zentralvenosen Infusionskathetern oder implantierten Hickman-Kathetern bzw. Portsystemen kommt es durch Materialermudung oder Behandlungsfehler in 0,1–2,8% der Falle zu einer Katheterembolie. Bei einem 58-jahrigen gefaschirurgischen Patienten wurde postoperativ erfolgreich transfemoral das Fragment eines zentralvenosen Katheters aus der A. pulmonalis mit einem Schlingenkatheter geborgen. Anhand dieses Falls werden Inzidenz, Klinik, Diagnostik und interventionelle Therapie der Katheterembolie dargestellt.

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 use of restricted replication-competent adenoviruses (RRCAs) inducing tumor cell-specific lysis is a promising approach in cancer gene therapy. However, the use of RRCAs in humans carries considerable risk, since after injection into the patient, further regulation or inhibition of virus replication from the outside is impossible. Therefore, we have developed a novel system allowing external pharmacological control of RRCA replication. We show here that a tumor-selective E1B-deleted RRCA can be tightly regulated by use of doxycycline (dox)-controlled adenoviral E1A gene expression, which in turn determines vector replication. RRCA replication is switched on by addition and switched off by withdrawal of dox. The system results in efficient tumor cell killing after induction by dox, whereas cells are unaffected by the uninduced system. It was also employed for efficient external control of transgene expression from cotransfected replication-deficient adenovectors. Furthermore, the use of a liver cell-specific human alpha1-antitrypsin (hAAT)-promoter driving a tetracycline-controlled transcriptional silencer allowed specific protection of cells with hAAT-promoter activity in the absence of dox in vitro and in vivo, delineating a new principle of 'tissue protective' gene therapy. The concept of external control of RRCAs may help to improve the safety of cancer gene therapy.

Dilated cardiomyopathy (DCM) is aetiopathogenically linked to intra-myocardial inflammation, which is most often evoked by cardiotropic viral (coxsackieviral and adenoviral) infection. Diagnosis of inflammatory cardiomyopathy (InfCM) imposes sensitivity and specificity requirements that are not fulfilled by the histological Dallas criteria because of considerable interobserver variability and sampling error. Quantitative immunohistological evaluation of endo-myocardial biopsies consistently confirmed the presence of InfCM in approximately 50% of the DCM patients. In this context, T-lymphocytic infiltrates, macrophages and endothelial cellular adhesion molecule expression emerged as diagnostic hallmarks of InfCM. The close association between immunocompetent infiltrates and endothelial cellular adhesion molecule abundance confirmed the hypothesized inter-dependence of those factors. The homogenous cellular adhesion molecule expression pattern infers a negligible sampling error associated with immunohistological diagnosis of InfCM. Phenotypic characterization of infiltrates revealed that, in addition to the mean infiltration number of T lymphocytes (>7·0 cells .m m ‐2 ), activated and specifically cytotoxic lymphocytes, as well as macrophages, deserve attention in the diagnosis of InfCM. These insights were confirmed by automated digital image analysis, which enables a standardized quantification mode that is devoid of inter-observer variability. Several trials confirmed that, in contrast to the conventional Dallas criteria, the immunohistological InfCM criteria are valid for the selection of DCM patients who will benefit from immunosuppressive treatment. In the post-Dallas-criteria era, immunohistological evaluation of endo-myocardial biopsies may eventually guide immunomodulatory treatment of patients with InfCM. (Eur Heart J Supplements 2002; 4 (Suppl I): I54‐I62)

Extracellular matrix (ECM) homeostasis is an important factor for normal cardiac structure and function. Synthesis of collagens is regulated at the cellular level, whereas collagen deposition depends on a balance between matrix metalloproteinases and tissue inhibitors of metalloproteinases. Immune-mediated regulation of myocardial collagen synthesis and deposition during inflammation remains unclear. It appears possible that a paracrine/autocrine action of cytokines on inflammatory and myocardial cells may lead to altered interstitial metabolism resulting in left ventricular remodelling and dysfunction. Efforts to delineate the interaction between immune cells, myocardial cells and ECM are important because chronic myocardial inflammation is recognized in dilated cardiomyopathy.

Chronic viral induced inflammatory cardiomyopathy causes progression of left ventricular dysfunction and is an important cause of dilated cardiomyopathy. Despite of the progress made in heart failure therapy, mortality of dilated cardiomyopathy is still 10% per year. Current heart failure therapy is symptomatic and does not impact on the specific underlying pathogenic mechanisms. Thus, specific treatment strategies that are directed against the underlying pathogenetic causes are required if myocarditis and its sequela, namely inflammatory cardiomyopathy, are to be successfully treated. Because histological and, especially, clinical diagnosis is fraught with numerous problems, an aetiological classification based on histology, immunohistochemistry and molecular biology is favourable, particularly in view of the improvements in methods made in recent years. The combination of these diagnostic techni-ques allows a new classification of dilated cardiomyo-pathy by differentiating the disease entity in subgroups of virus positive and virus negative patients with or without cardiac inflammation. This may not only contribute toward improving our understanding of underlying pathological mechanisms, but ultimately may also assist in developing specific immunomodulatory treatments. Preliminary results from ongoing treatment trials suggest that specific antiviral or anti-inflammatory treatment strategies are successful in patients who have been carefully selected and characterized according to biopsy-based diagnostic criteria.

The molecular determinants of cardiac viral infections are currently under intense investigation because an understanding of these determinants may lead to an explanation for the highly variable clinical courses of viral heart diseases. Several articles in this volume deal with basic structures that are involved in virus entry and migration, switching between viral persistence and replication, and intracellular signals and immune reactions triggered by viruses. We focus upon the first area, in which recent studies have provided new insights of possible clinical and therapeutic relevance. Coxsackieviruses and adenoviruses are common agents in viral heart disease. In the majority of exposed individuals they do not cause myocardial disease, however. In 1997 a common receptor for the two viruses - the coxsackievirus-adenovirus-receptor (CAR) - was cloned which is a key determinant of cellular uptake of both viruses. We observed highly variable expression patterns for CAR in humans. Healthy donor hearts had low levels of CAR, whereas explanted hearts of patients with dilated cardiomyopathy (DCM) exhibited high CAR expression in their myocardium. Heart failure per se was not associated with CAR induction. Recombinant overexpression of human CAR in cardiomyocytes strongly increased their virus uptake rate, suggesting that CAR induction enhances cardiac vulnerability to viral heart diseases. Receptor induction may aggravate the clinical disease course, and therefore blockade of receptor expression or receptor-virus interactions offers new therapeutic perspectives. A broader analysis of the cardiovascular expression patterns of receptors for other viruses and virus-derived gene therapy vectors should lead to a better understanding of individual risk factors for viral heart diseases and their highly variable clinical courses, and lead to new therapeutic options, including advanced gene therapeutic strategies.

We report the case of a 45 year old man presenting to our emergency ward with acute onset of typical chest pain. The ECG showed ST-segment depression in the postero-lateral leads without elevation of any cardiac enzymes. The coronary angiogram showed a three-vessel disease with a subtotal, short stenosis of the right coronary artery and a severe ostial stenosis of the left main coronary artery. An operative revascularization with a venous graft to the right coronary artery and a angioplasty with an autologous vein patch of the left main coronary artery were performed. No peri- or postoperative complications occurred. Because of the importance of the left main coronary artery, the patient underwent an early post-operative coronary angiogram with intravascular ultrasound (IVUS) to confirm the patency of the patch angioplasty. We discuss the historical development, the indications and the main advantages of the patch angioplasty in comparison to conventional CABG procedures. The main issue of the presentation is the special value of IVUS in the pre- and postoperative assessment of the left main coronary artery. Within the last few years, IVUS has emerged from a pure research tool to the gold standard of coronary imaging. It is playing a more and more important role in the assessment of angiographically unclear lesions, mainly in the left main stem and its bifurcation. In addition, IVUS has a large influence in clinical decision making, e.g., reverral to CABG or PCI. It is also a powerful tool for optimizing the operative setting and provides the best possible postoperative control.

Ein 48-jahriger Patient mit dilatativer Kardiomyopathie bemerkte erstmals Ruhe- und Belastungsdyspnoe sowie eine Verschlechterung des Allgemeinzustandes. Bis auf ein leises Systolikum uber der Herzspitze war die klinische Untersuchung unauffallig. In der Echokardiographie stellte sich ein global schwer eingeschrankt kontrahierender und dilatierter linker Ventrikel ohne Ventrikelthromben dar. In der Herzkatheteruntersuchung wurden nach Ausschluss einer koronaren Herzerkrankung mehrere Endomyokardbiopsien entnommen. Die immunhistologische Auswertung der Biopsien zeigte als Ausdruck einer myokardialen Entzundungreaktion in das Myokardgewebe infiltrierende Lymphozyten sowie eine verstarkte interstitielle und endotheliale HLA-Expression. Als ein Mas der intravasalen Thrombozytenaktivierung wurden Thrombozytenoberflachenproteine am Durchflusszytometer quantitativ analysiert. Bei unserem Patienten zeigte sich eine signifikante Erhohung der Thrombozytenaktivierung sowohl im Vergleich zu einer gesunden Kontrollgruppe als auch zu 20 Patienten mit dilatativer Kardiomyopathie. Die Herzinsuffizienz des Patienten wurde medikamentos mit einem ACE-Hemmer, einem Schleifendiuretikum, einem Spironolacton sowie einem Digitalispraparat behandelt. Bei hochgradig eingeschrankter Pumpfunktion des linken Ventrikels erfolgte zeitgleich eine antikoagulatorische Therapie mit Phenprocoumon und mit Acetylsalicylsaure (ASS). Nach einem halben Jahr stellte sich in der erneut durchgefuhrten Echokardiographie bei weiterhin hochgradig eingeschrankter Kontraktilitat trotz adaquater Antikoagulation ein wandstandiger Ventrikelthrombus dar. Trotz antithrombotischer Therapie mit ASS und Phenprocoumon konnte die Entstehung eines Ventrikelthrombus nicht verhindert werden. Bei unserem Patienten mit dilatativer Kardiomyopathie lag eine erhohte Thrombozytenaktivierung (>4fache SD) vor. Es ist zu diskutieren, ob eine zusatzliche antiaggregatorische Therapie mit Clopidogrel bei Patienten mit dilatativer Kardiomyopathie und erhohter Plattchenaktivierung angezeigt ist. Thromboembolische Ereignisse sind bedeutende Komplikationen bei dilatativer Kardiomyopathie. Bei ca. 10–40% der Patienten treten im Verlauf der Erkrankung Embolien auf (5, 7). Oftmals kann dabei ein in der Echokardiographie sichtbarer Ventrikelthrombus nachgewiesen werden (6). Eine orale antikoagulatorische Therapie mit Marcumar wird deshalb bei Patienten mit dilatativer Kardiomyopathie empfohlen (9). Wir berichten uber einen Patienten mit inflammatorischer Kardiomyopathie und global hochgradig eingeschrankter Pumpfunktion, der in der durchflusszytometrischen Analyse von Thrombozytenoberflachenproteinen eine uberdurchschnittliche hohe Plattchenaktivierung zeigte und trotz adaquater Marcumarisierung und Therapie mit Acetylsalicylsaure innerhalb von einem halben Jahr einen Ventrikelthrombus entwickelte.

Human herpesvirus 6 (HHV-6) A and B are lymphotropic viruses with life-long persistence, primarily associated with non-cardiac diseases, and discussed as a possible etiologic factor of myocarditis and cardiomyopathy.To analyze the long-term spontaneous course of cardiac patients suffering from suspected inflammatory cardiomyopathy (CMi) with persisting HHV-6 A and B infections by follow-up biopsies.We prospectively evaluated patients (n=73) with biopsy-proven viral HHV-6 A and B infection in endomyocardial biopsies (EMBs), followed up by reanalysis of EMBs and left ventricular ejection fraction (LV-EF) measurements after a median period of 8.8 months (range 4-73 months). Beyond, we studied HHV-6 prevalence in isolated peripheral blood cells (PBCs) and HHV-6 species in EMBs. HHV-6 species-specific cellular infection sites within the myocardium were identified by immunohistochemistry (IHC).We identified 73 patients with cardiac HHV-6 A and B persistence or newly detected in follow-up EMB (95.0% B). Proof of HHV-6 in PBCs was primarily associated with A. Persistence of cardiac HHV-6 B genome was significantly associated with cardiac dysfunction at follow-up (LV-EF deteriorated from 58.2±16.0 to 51.8±17.2%, p0.001), and LV improvement was observed when HHV-6 B persistence resolved (LV-EF increased from 54.9±15.4 to 60.7±13.1%, p0.001).Persistence of cardiac HHV-6 B genomes was significantly associated with cardiac dysfunction, and hemodynamic parameters improved in association with HHV-6 B clearance.

C-type natriuretic peptide (CNP), a recent addition to the family of natriuretic peptides including atrial and brain natriuretic peptide (ANP, BNP), is believed to be an endothelium-derived vasodilator and to have an antimitotic effect. ANP and BNP concentrations are increased in conditions such as congestive heart failure, but cardiac CNP concentrations have not been investigated in this connection. Diabetes mellitus also involves myocardial dysfunctions without coronary artery disease or systemic hypertension. We therefore investigated the cardiac expression of CNP mRNA compared with that of BNP mRNA in streptozotocin (STZ)-diabetic rats. STZ- diabetic male Wistar rats (n=6) were studied in comparison with controls (n=6). The animals were characterised by their mean arterial blood pressure and plasma glucose concentrations. After extraction of total cardiac RNA, a specific cDNA probe of BNP was used for northern blot analysis, whereas myocardial CNP expression was analysed by an RNase-protection assay. Twelve weeks after diabetes was induced, the rats were normotensive (96.4+/-2.0 compared with 95.1+/-1.9 mmHg) and hyperglycaemic (615+/-61 compared with 165+/-21 mg/dl; P

Ein 49jahriger Patient erlitt nach laparoskopischer Leistenhernien-Operation einen Herzkreislaufstillstand. Das nach Einleitung der kardiopulmonalen Reanimation abgeleitete Elektrokardiogramm zeigte Kammerflimmern, nach Defibrillation eine Tachyarrhythmia absoluta mit neu aufgetretenem Rechtsschenkelblock sowie deutlichen ST-Hebungen im Bereich der Vorderwand. Nach einer Reanimationsdauer von ca. 20 min wurde unter Einsatz von Katecholaminen eine Kreislaufstabilisierung erreicht. Echokardiographisch kam ein Perikardergus von 7 mm mit geringer Imprimierung des leicht vergroserten rechten Ventrikels zur Darstellung. Unter dem Verdacht einer akuten Lungenarterienembolie (Differentialdiagnose: akuter Myokardinfarkt) wurde eine Katheteruntersuchung mit Darstellung der Lungenstrombahn und anschliesender Koronarangiographie durchgefuhrt. Die im Bereich des linken Pulmonalarterienhauptastes dokumentierten flottierenden Thromben konnten mit einem Pigtail-Katheter mechanisch fragmentiert werden. Koronarangiographisch fanden wir bei ansonsten unauffalligen Gefasen den Ramus interventricularis anterior (RIVA) proximal scharfkantig verschlossen. Die Anamnese, die Morphologie des RIVA-Verschlusses, der begleitende Perikardergus und die Rippen- und Sternumfrakturen liesen eine reanimationsbedingte Koronarperforation formal vom Typ III nach Sutton und Ellis wahrscheinlich erscheinen. Der RIVA wurde daraufhin rekanalisiert und bei fortbestehendem Kontrastmittelubertritt in den Perikardspalt zur Abdeckung der Perforation mit einem 19 mm langen Stent-Graft (Jostent®) versorgt. Diese Stents, die primar zur Behandlung von Koronaraneurysmata und rezidivierenden Instent-Restenosen entwickelt wurden, bestehen aus zwei coaxial ineinanderliegenden Edelstahl-Stents mit dazwischen eingebrachter Polytetrafluorethylen-Membran. In der abschliesenden Darstellung fand sich kein Kontrastmittelubertritt mehr.

The adenine nucleotide translocator (ANT) is an autoantigen in myocarditis and dilated cardiomyopathy. Carrier-specific antibodies impair myocardial energy metabolism and heart function. They cross-react with a myolemmal calcium channel and alter calcium fluxes in isolated myocytes. To test whether antibodies against the ANT can alter calcium homeostasis in intact hearts, guinea pigs were immunized with the carrier protein and their isolated hearts loaded with the intracellular calcium indicator INDO-1. The diastolic and systolic ratios of fluorescence signals at 410 nm and 510 nm (emission wavelengths of the calcium-bound and calcium-free indicator), 'd-s410/510', were measured by excitation at 364 nm. This index of the transient calcium concentration associated with the contraction cycle correlated with the external heart work (EHW) in non-immunized controls. EHW of immunized animals was lower (76 +/- 62 vs 153 +/- 47 mJ/g/min in controls, p < 0.005) and the amplitude of d-s410/510 was elevated (27.6 +/- 4.1% of the average ratio of the whole heart cycle vs 21.7 +/- 1.2% in controls, p < 0.005) and essentially independent of EHW. Isoproterenol stimulation increased EHW in all hearts but d-s410/510 was hightened in control hearts, only. Thus, a disorder between cytosolic calcium transients and work was recorded in hearts from guinea pigs immunized with the ANT. It may contribute to an immunopathic mechanism of heart failure subsequent to myocarditis.

Background —Previous studies dealing with the detection of enteroviral RNA in human endomyocardial biopsies have not differentiated between latent persistence of the enteroviral genome and active viral replication. Enteroviruses that are considered important factors for the development of myocarditis have a single-strand RNA genome of positive polarity that is transcribed by a virus-encoded RNA polymerase into a minus-strand mRNA during active viral replication. The synthesis of multiple copies of minus-strand enteroviral RNA therefore occurs only at sites of active viral replication but not in tissues with mere persistence of the viral genome. Methods and Results —We investigated enteroviral RNA replication versus enteroviral RNA persistence in endomyocardial biopsies of 45 patients with left ventricular dysfunction and clinically suspected myocarditis. Using reverse-transcriptase polymerase chain reaction in conjunction with Southern blot hybridization, we established a highly sensitive assay to specifically detect plus-strand versus minus-strand enteroviral RNA in the biopsies. Plus-strand enteroviral RNA was detected in endomyocardial biopsies of 18 (40%) of 45 patients, whereas minus-strand RNA as an indication of active enteroviral RNA replication was detected in only 10 (56%) of these 18 plus-strand–positive patients. Enteroviral RNA was not found in biopsies of the control group (n=26). Conclusions —These data demonstrate that a significant fraction of patients with left ventricular dysfunction and clinically suspected myocarditis had active enteroviral RNA replication in their myocardium (22%). Differentiation between patients with active viral replication and latent viral persistence should be particularly important in future studies evaluating different therapeutic strategies. In addition, molecular genetic detection of enteroviral genome and differentiation between replicating versus persistent viruses is possible in a single endomyocardial biopsy.

Two different isoforms of the adenine nucleotide translocase (ANT1 and ANT2) have been identified in the rat. In order to obtain enhanced knowledge of the ANT isoform expression, we analyzed the transcription pattern of both isoforms and their mRNA levels in various tissues of the rat using the PCR technique. A predominant ANT1 mRNA percentage was recorded in the skeletal muscle, heart and brain, ranging from 81 to 58%. In contrast to these tissues, the percentages of ANT2 were dominant with a range from 59 to 75% in the kidney, lung, spleen and liver. The level of total ANT mRNA varied markedly in the various organs. Tissues with a dominant ANT1 percentage simultaneously showed a high level of total ANT transcription (24–41 attomol/ng total RNA). In comparison to the latter, tissues with a prevalent ANT2 transcription were shown to have an even lower ANT transcription level (2–5 attomol/ng total RNA). The predominance of the ANT1 expression appeared to be restricted to tissues with an inability to regenerate by means of mitotic division, whereas a prevalent ANT2 transcription is found in cell types able to proliferate. The level of total ANT transcription but not the individual ANT isoform expression depends to a great extent on the energy requirements of the tissue.

Spontaneous coronary artery dissection is a rare cause of ischemic heart disease. Incidence, etiology and optimal treatment are ill-defined. Between July 1995 and December 1997, we prospectively identified 42 patients (36 men, six women, mean age 59 +/- 12 years) with spontaneous coronary artery dissection among 3803 consecutive angiographic examinations in which the diagnosis of coronary artery disease was established for the first time (incidence 1.1%). In comparison to the remaining study population with stable angina pectoris (8 cases of spontaneous coronary artery dissection among 2852 patients; incidence: 0.3%), the incidence of spontaneous coronary artery dissection was significantly higher in the patient subgroups with acute myocardial infarction (13/450; 2.9%) and with unstable angina pectoris or postinfarction angina (21/501; 4.2%). Dissection was most frequently located in the left anterior descending coronary artery (19 cases), followed by the right coronary artery (15 cases) and the left circumflex coronary artery (8 cases). Because of an ambiguous angiographic lesion appearance intravascular ultrasound imaging was performed in 13 patients to confirm the diagnosis. The presumed etiology of spontaneous coronary artery dissection was atherosclerotic plaque rupture in 35 cases, heavy physical exercise in four cases and hormonal influences related to pregnancy and contraception in one case. In two cases, no obvious risk factor could be identified. Therapy consisted of intracoronary stenting in 24 patients (including ten patients with acute myocardial infarction), coronary artery bypass grafting (CABG) in 8 patients and balloon angioplasty (PTCA) in seven patients. Three patients were treated conservatively. During a mean follow-up period of 13.5 +/- 9.9 months, two patients died and 31 patients remained entirely asymptomatic, including all patients who were treated with CABG. Restenosis developed in three patients after stent implantation (restenosis rate: 12.5%). Following primary PTCA, spontaneous coronary artery dissection recurred in two patients, one of whom subsequently died.

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 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 Kuhl 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 ( 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

Ein 47jahriger Patient wurde mit einem akuten Vorderwandinfarkt eingewiesen. Eine dringlich durchgefuhrte koronarangiographische Untersuchung zeigte einen proximalen Verschlus des Ramus interventricularis anterior (RIVA). Nach mechanischer Rekanalisation stellte sich eine Kaliberreduktion des Gefases an der Verschlusstelle dar; es wurde eine Ballondilatation (PTCA) mit konsekutiver Stent-Implantation aufgrund einer Dissektion durchgefuhrt. Danach verblieb bei normalem Koronarflus (TIMI 3) eine langstreckige Lumenreduktion des gesamten Gefassegments distal des Stents ohne erkennbare Stenose. Der RIVA wies am Beginn des mittleren Drittels eine Muskelbrucke auf, die auch einen abgehenden Diagonalast systolisch subtotal verschlos. Eine Dipyridamol-Thallium-Szintigraphie zeigte eine inkomplette anteroseptale Vernarbung und eine reversible anterolaterale Myokardischamie. Wir entschlossen uns daraufhin zur Implantation eines 3,0 mm-Stents im Bereich der Muskelbrucke. Die Wahl der Ballongrose wurde anhand der quantitativen koronarangiographischen Bestimmung des proximalen Referenzdurchmessers vorgenommen; es resultierte ein Misverhaltnis zwischen Gefas- und Ballondurchmesser im distalen Dilatationssegment mit konsekutiver Koronararterienperforation in den rechtsventrikularen Ausflustrakt. Der Patient blieb im Verlauf auch unter Ergometrie asymptomatisch und hamodynamisch stabil. In einer Kontroll-Koronarangiographie nach einer Woche war die Koronarfistel unverandert nachweisbar; der RIVA wurde rasch und vollstandig angefarbt (TIMI 3). Innerhalb von drei Monaten schlos sich die Fistel spontan.

Several findings pointed to an insufficient energy supply in heart muscle tissue of patients suffering from dilated cardiomyopathy (DCM). We found a lowered ANT transport capacity of the adenine nucleotide translocator (ANT), the only transport system for ATP and ADP in eucaryotic cells, in explanted hearts of DCM patients. The reduced ANT transport rate was accompanied by a marked elevation in total ANT protein caused by an increase in ANT 1 isoform protein. Simultaneously, a reduction in ANT 2 transcripts and an unchanged ANT 3 expression was observed. In contrast, patients with ischemic or valvular heart disease showed no alteration in ANT function or expression, which indicates the disease-specificity of these findings.

Autoimmune mechanisms are suspected to play an important role in the pathogenesis of human myocarditis. In order to evaluate the significance of autoimmune leukocytes for the development of human myocarditis (MC) and subsequent heart failure, we transferred 15 x 10(6) or 50 x 10(6) peripheral blood leukocytes (PBLs) from patients with immunohistologically proven MC and impaired left ventricular function into severe combined immune deficiency (SCID) mice that possess neither B nor T lymphocytes. PBLs from seven patients and five healthy controls were transferred into three SCID mice each by intraperitoneal injection. After 60 days human PBLs could be demonstrated in the peripheral blood of SCID mice, representing up to 10% of peripheral blood mononuclear cells. Likewise, human immunoglobulins were present in all transfused SCID mice (up to 3 mg.ml-1 IgG and IgM); however, autoantibodies against the adenine nucleotide translocator, a myocardial autoantigen, were only present in the mice receiving PBLs from patients with MC. Infiltrating human lymphocytes were also only found in the hearts of SCID mice having received PBLs from MC patients, but not in those receiving PBLs from normal controls. When we measured the slope of the left ventricular pressure pulse by direct puncture under ether anaesthesia, we found it to be decreased (dp/dt = 1750 +/- 194 mmHg.s-1 in mice receiving PBLs from MC patients, compared with mice receiving PBLs from controls (dp/dt = 2456 +/- 92 mmHg.s-1 or receiving no transfusion (dp/dt = 2576 +/- 142 mmHg.s-1. These results demonstrate that the impairment of the ventricular function seen in patients with MC can be transferred to SCID mice by transfer of PBLs. This proves the significance of autoimmune mechanisms for the pathogenesis of MC.