Biventricular assist device placement and immunosuppression as therapy for necrotizing eosinophilic myocarditis

Mechanical Circulatory Support Systems in Fulminant Myocarditis: Recent Advances and Outlook

Background: Fulminant myocarditis (FM) constitutes a severe and life-threatening form of acute cardiac injury associated with cardiogenic shock. The condition is characterised by rapidly progressing myocardial inflammation, leading to significant impairment of cardiac function. Due to the acute and severe nature of the disease, affected patients require urgent medical attention to mitigate adverse outcomes. Besides symptom-oriented treatment in specialised intensive care units (ICUs), the necessity for temporary mechanical cardiac support (MCS) may arise. Numerous patients depend on these treatment methods as a bridge to recovery or heart transplantation, while, in certain situations, permanent MCS systems can also be utilised as a long-term treatment option. Methods: This review consolidates the existing evidence concerning the currently available MCS options. Notably, data on venoarterial extracorporeal membrane oxygenation (VA-ECMO), microaxial flow pump, and ventricular assist device (VAD) implantation are highlighted within the landscape of FM. Results: Indications for the use of MCS, strategies for ventricular unloading, and suggested weaning approaches are assessed and systematically reviewed. Conclusions: Besides general recommendations, emphasis is put on the differences in underlying pathomechanisms in FM. Focusing on specific aetiologies, such as lymphocytic-, giant cell-, eosinophilic-, and COVID-19-associated myocarditis, this review delineates the indications and efficacy of MCS strategies in this context.

Comparative Efficacy and Safety of Mycophenolate Mofetil and Azathioprine in Combination with Corticosteroids in the Treatment of Lymphocytic Myocarditis

AIMS

This paper aimed to study the efficacy and safety of mycophenolate mofetil (MM) in combination with corticosteroids in the treatment of lymphocytic myocarditis (LM) when compared to the standard combination of corticosteroids and azathioprine.

METHODS

The study included 50 adult patients (47.8 ± 10.8 y.o.) in a NYHA III functional class due to LM who were verified using endomyocardial biopsy. The main group included 29 patients who received MM at 2 g/day. The comparison group comprised 21 patients who received azathioprine at 150 [50; 150] mg/day. Both groups were administered with methylprednisolone. The average follow-up period was 30 [22; 35] months, but no less than 6 months.

RESULTS

The groups were comparable in the baseline parameters and standard drug therapy. In both groups, there was a comparable significant increase in the ejection fraction (from 30.6 ± 7.7% to 44.0 ± 9.4% vs. 29.2 ± 7.7% to 46.2 ± 11.8%, p < 0.001), and a decrease in systolic pressure in the pulmonary artery and the dimensions of the left ventricle and atrium. The frequency of death was two (6.9%) and two (9.5%), transplantation was one (3.4%) and one (4.8%) patient and the "death + transplantation" endpoint was three (10.3%) and three (14.3%) without differences between the groups. The presence of the parvovirus B19 in the myocardium in 6/5 patients did not affect the results. The incidence of infectious complications was comparable. The most severe infectious complications were pneumonia and fatal purulent encephalitis (both cases in the azathioprine group), leptospirosis meningitis (in the mycophenolate mofetil group).

CONCLUSIONS

In the patients with LM, the combination of corticosteroids with MM at a dose of 2 g/day was at least no less effective than with azathioprine. There was a tendency toward a better tolerance using MM.

Fulminant myocarditis in adults: a narrative review

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe hemodynamic compromise secondary to acute myocardial inflammation, often presenting as profound cardiogenic shock, life-threatening ventricular arrhythmias and/or electrical storm. FM may be refractory to conventional therapies and require mechanical circulatory support (MCS). The immune system has been recognized as playing a pivotal role in the pathophysiology of myocarditis, leading to an increased focus on immunosuppressive treatment strategies. Recent data have highlighted not only the fact that FM has significantly worse outcomes than non-FM, but that prognosis and management strategies of FM are heavily dependent on histological subtype, placing greater emphasis on the role of endomyocardial biopsy in diagnosis. The impact of subtype on severity and prognosis will likewise influence how aggressively the myocarditis is managed, including whether MCS is warranted. Many patients with refractory cardiogenic shock secondary to FM end up requiring MCS, with venoarterial extracorporeal membrane oxygenation demonstrating favorable survival rates, particularly when initiated prior to the development of multiorgan failure. Among the challenges facing the field are the need to more precisely identify immunopathophysiological pathways in order to develop targeted therapies, and the need to better optimize the timing and management of MCS to minimize complications and maximize outcomes.

Diagnosis and treatment of eosinophilic myocarditis

Eosinophilic myocarditis is a type of inflammatory cardiomyopathy characterized by eosinophilic infiltration into myocardial tissue. The accurate myocarditis incidence rate is difficult to determine because of the clinical limitations of an endomyocardial biopsy. The primary pathogenesis of eosinophilic myocarditis is the release of related substances by eosinophils, leading to cell membrane damage and cell destruction. However, evidence suggests that specific genes play a role in myocarditis development.As CMR imaging availability increases, the diagnosis rate of eosinophilic myocarditis will increase. The diagnosis of myocarditis mainly depends on an endocardial biopsy. Glucocorticoids can relieve patients' symptoms, but the early use of steroids may prevent intermediate disease stage development (i.e., thrombonecrosis and fibrosis with wall thrombosis). Anticoagulant therapy may also affect disease development. In addition to routine follow-up, a regular myocardial biopsy should be considered for discharged patients, if possible.

Hypereosinophilic syndrome: considerations for the cardiologist

Eosinophil-mediated endomyocardial damage is a well-known complication in patients with hypereosinophilic syndromes (HES). Although management and survival have improved significantly, some patients continue to develop severe cardiomyopathy as a direct consequence of uncontrolled hypereosinophilia. Cardiologists play a key role in early detection and treatment. At the early generally asymptomatic stage, related to subendocardial eosinophilic infiltrates, elevation of the biomarker of cardiac damage (serum troponin) and cardiac MRI are the best tools for diagnosis. As disease progresses, patients typically develop intracardiac mural thrombi and may experience variable degrees of heart failure due to valve damage and/or subendocardial fibrosis, all of which are more readily detectable with traditional echocardiographic investigation. New imaging modalities such as strain imaging and specific sequences in MRI offer the perspective of detecting subtle perturbations and distinguishing inflammatory versus fibrotic stages. Endomyocardial biopsy may help in difficult settings, namely, when blood eosinophilia is not prominent, but may be non-contributive due to sampling issues or eosinophil degranulation or replacement by fibrosis, and must always be performed after careful consideration of the risk:benefit ratio. Although treatment of the HES itself should be managed by clinicians with expertise in this rare disorder with the aim of lowering eosinophil counts to prevent and treat eosinophil-mediated organ damage and dysfunction, cardiologists play a key role in managing the associated cardiopathy. There are no consensual disease-specific guidelines for treating eosinophil-mediated thrombotic complications and cardiopathy, which should be managed according to classical international recommendations.

Fast spontaneous recovery from acute necrotizing eosinophilic myopericarditis without need for immunosuppressive therapy: a case report of a 27-year-old male

Background

Eosinophilic myocarditis (EM) is rare but accounts for 12-22% of histologically proven acute myocarditis cases. Acute necrotizing EM is considered an aggressive, life-threatening disease which is usually treated by high-dose corticosteroid therapy.

Case summary

We report the case of a 27-year-old man with acute severe pericarditic chest pain, moderately reduced left ventricular (LV) ejection fraction, and a small pericardial effusion. Troponin I level was highly elevated in the absence of coronary artery disease, leading to the diagnosis of acute myopericarditis. In the absence of blood eosinophilia and despite a negative cardiac magnetic resonance study, LV endomyocardial biopsy revealed an acute necrotizing EM. With conventional antiphlogistic and heart failure therapy, the patient became symptom-free and inflammatory and cardiac necrosis markers as well as LV ejection fraction normalized within days. Thus, in the absence of a systemic hypereosinophilic disorder, there was no need for steroid therapy. Long-term follow-up over 12 months showed sustained normalization of cardiac structure and function.

Discussion

Acute necrotizing eosinophilic myopericarditis is not always a dreadful cardiac disease. There are idiopathic cases which may quickly resolve without immunosuppression. There seems to be a publication bias towards critical cases.

Severe Eosinophilic Myocarditis in the Portion of Left Ventricular Wall Excised to Insert a Left Ventricular Assist Device for Severe Heart Failure

Described herein are 3 adults in whom histologic study of the left ventricular myocardium excised ("LV core") to insert a left ventricular assist device (LVAD) disclosed severe acute myocarditis and the inflammatory cells included numerous eosinophils (eosinophilic myocarditis). Examination of the clinical records disclosed elevated absolute eosinophil counts at the time of insertion of the LVAD and the counts rapidly (<30 days) returned to normal after the operation. Because of the numerous medications that each patient was taking at the time of LVAD insertion, identification of a specific initiating medication as its cause was not possible. Of the 3 patients, 2 had idiopathic-dilated cardiomyopathy and 1 had ischemic cardiomyopathy and each had had heart failure for years. The eosinophilic myocarditis in these 3 patients appears to have been transient and superimposed on the earlier cardiomyopathy.

Recognition and Initial Management of Fulminant Myocarditis: A Scientific Statement From the American Heart Association

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe diffuse cardiac inflammation often leading to death resulting from cardiogenic shock, ventricular arrhythmias, or multiorgan system failure. Historically, FM was almost exclusively diagnosed at autopsy. By definition, all patients with FM will need some form of inotropic or mechanical circulatory support to maintain end-organ perfusion until transplantation or recovery. Specific subtypes of FM may respond to immunomodulatory therapy in addition to guideline-directed medical care. Despite the increasing availability of circulatory support, orthotopic heart transplantation, and disease-specific treatments, patients with FM experience significant morbidity and mortality as a result of a delay in diagnosis and initiation of circulatory support and lack of appropriately trained specialists to manage the condition. This scientific statement outlines the resources necessary to manage the spectrum of FM, including extracorporeal life support, percutaneous and durable ventricular assist devices, transplantation capabilities, and specialists in advanced heart failure, cardiothoracic surgery, cardiac pathology, immunology, and infectious disease. Education of frontline providers who are most likely to encounter FM first is essential to increase timely access to appropriately resourced facilities, to prevent multiorgan system failure, and to tailor disease-specific therapy as early as possible in the disease process.

Idiopathic hypereosinophilic syndrome presenting with multiple organ damage: A case report

RATIONALE

Idiopathic hypereosinophilic syndrome (IHES) is a rare disease in which patients which present with eosinophilia-associated damage. Previous studies focused on organ damage from increased eosinophilic granulocytosis. We report IHES in a patient who presented with multiple organ damage (MOD).

PATIENT CONCERNS

A 52-year-old male presented with MOD, including myocardial damage suggestive of myocardial infarction, cardiac tamponade, respiratory failure, skin damage, and gastrointestinal damage.

DIAGNOSES

The absolute eosinophil count was 12,920/mm, much higher than occurs in other diseases associated with eosinophilia (1500/mm), and suggesting a diagnosis of IHES.

INTERVENTIONS

Prednisone combined with hydroxyurea.

OUTCOMES

At 6 months after completion of drug treatment, the patient had no chest pain or dyspnea, and the results of a blood panel, chest computed tomography, and gastroscopy were normal.

LESSONS

MOD is very rare in patients with IHES. Patients receiving prompt diagnosis and treatment have very good prognoses.

The Clinicopathological Profile of Eosinophilic Myocarditis

Eosinophilic myocarditis (EM) is a rare form of myocarditis. As there is extreme diversity in its manifestations, the true incidence is difficult to assess and no proper epidemiological criteria are present. It generally presents with a wide array of clinical manifestations. Clinical presentation tends to differ in cases and not all the patients show the same signs and symptoms. The etiology of EM often remains obscure but potential causes have been identified which may include hypersensitivity to drugs, exposure to certain viruses and parasites, and hyper-eosinophilic syndromes. Endomyocardial biopsy is considered to be a gold standard for the diagnosis of EM. Echocardiography, cardiac magnetic resonance, and bio markers particularly serum eosinophilic cationic protein concentrations are also known to aid in diagnosis. EM may lead to progressive, irreversible, and fatal myocardial damage if prompt diagnosis is not made and therapy is not initiated. The current treatment regimens include corticosteroids, cytotoxic agents, and immunosuppressive therapy. However, a proper treatment criterion is yet to be established.

Significance of troponin I level as a marker of disease activity in the management of acute necrotizing eosinophilic myocarditis with normal peripheral eosinophil count: a case report

Background

Eosinophilic myocarditis is characterized by myocardial eosinophilic infiltration and is largely associated with hypereosinophilia. However, eosinophilic myocarditis with a normal peripheral eosinophilic count has been previously reported. Since the absence of eosinophilia poses a challenge for therapeutic management, we evaluated whether troponin I (TnI) levels can be used in the management of eosinophilic myocarditis where peripheral eosinophilia is absent.

Case summary

We report the case of a 77-year-old woman who developed cardiogenic shock due to acute necrotizing eosinophilic myocarditis, which required mechanical circulatory support. She did not have hypereosinophilia, but endomyocardial biopsy confirmed massive infiltration of eosinophils into the myocardium. We administered high-dose corticosteroids for 3 days and she dramatically improved. Along with this, the TnI level, which was elevated at the time of patient presentation, also decreased after steroid therapy. Troponin I level did not increase again without taking any oral prednisolone, and the follow-up biopsy after 6 months showed complete recovery of eosinophilic myocarditis.

Discussion

Troponin I-guided treatment is a useful tool in the management of eosinophilic myocarditis because it helps with therapeutic decisions, especially in the absence of eosinophilia.

Fatal acute necrotizing eosinophilic myocarditis temporally related to use of adalimumab in a patient with relapsing polychondritis

Tumor necrosis factor α (TNF-α) antagonists are being increasingly used as maintenance therapies for rheumatic diseases, and therefore knowledge of their adverse effects is important. We report a case of fatal acute necrotizing eosinophilic myocarditis temporally related to use of a second course of the TNF-α antagonist, adalimumab. A 51-year-old woman with relapsing polychondritis took adalimumab 2 weeks before presenting with acute myocarditis. Within hours of presentation to the emergency department, she had cardiac arrest due to fulminant heart failure. Autopsy demonstrated necrotizing eosinophilic myocarditis. This is a rare cause of fulminant heart failure. This is the first report of a TNF-α antagonist potentially associated with acute necrotizing eosinophilic myocarditis.

Eosinophilic myocarditis: two case reports and review of the literature

Background

Eosinophilic myocarditis is a rare and often under-diagnosed subtype of myocarditis with only around 30 cases published in the medical literature. In this article we present two patients with eosinophilic myocarditis with the aim to demonstrate the often elusive nature of the disease and present the current scientific literature on this topic.

Case presentation

A 76 years old Caucasian gentleman and a 36 years old Aboriginal gentleman both presenting with heart failure symptoms were eventually diagnosed with eosinophilic myocarditis after extensive evaluation. Their presentation, assessment, and medical management is explored in this article.

Conclusions

Eosinophilic myocarditis remains a rare and likely under-diagnosed subtype of myocarditis. The key features of this disease include myocardial injury in the setting of non-contributory coronary artery disease. Endomyocardial biopsy remains the definitive gold standard for diagnosis of noninfectious eosinophilic myocarditis. Non-invasive cardiac imaging in the setting of peripheral eosinophilia can be strongly suggestive of eosinophilic myocarditis with potential for earlier diagnosis. Failure to diagnose eosinophilic myocarditis and the delay of therapy may lead to irreversible myocardial injury. Therapies for this disease have yet to be validated in large prospective studies.

Fatal eosinophilic myocarditis develops in the absence of IFN-γ and IL-17A

CD4(+) T cells play a central role in inflammatory heart disease, implicating a cytokine product associated with Th cell effector function as a necessary mediator of this pathophysiology. IFN-γ-deficient mice developed severe experimental autoimmune myocarditis (EAM), in which mice are immunized with cardiac myosin peptide, whereas IL-17A-deficient mice were protected from progression to dilated cardiomyopathy. We generated IFN-γ(-/-)IL-17A(-/-) mice to assess whether IL-17 signaling was responsible for the severe EAM of IFN-γ(-/-) mice. Surprisingly, IFN-γ(-/-)IL-17A(-/-) mice developed a rapidly fatal EAM. Eosinophils constituted a third of infiltrating leukocytes, qualifying this disease as eosinophilic myocarditis. We found increased cardiac production of CCL11/eotaxin, as well as Th2 deviation, among heart-infiltrating CD4(+) cells. Ablation of eosinophil development improved survival of IFN-γ(-/-)IL-17A(-/-) mice, demonstrating the necessity of eosinophils in fatal heart failure. The severe and rapidly fatal autoimmune inflammation that developed in the combined absence of IFN-γ and IL-17A constitutes a novel model of eosinophilic heart disease in humans. This is also, to our knowledge, the first demonstration that eosinophils have the capacity to act as necessary mediators of morbidity in an autoimmune process.

Heart failure mimicking prior myocardial infarction in a patient with idiopathic hypereosinophilic syndrome

Idiopathic hypereosinophilic syndrome (IHES) is characterized by sustained, nonreactive hypereosinophilia with eosinophilia-associated organ damage. Cardiac involvement occurs in about 60% of patients with HES and it is the major cause of mortality in these patients. Cardiac dysfunction is reversible only after early corticosteroid (CS) initiation.Herein we report a 33-year old male who was referred to our Cardiology Department with electrocardiographic and echocardiographic abnormalities suggesting myocardial infarction. At presentation he complained of dyspnea, cough and persistent fever. His white blood cell (WBC) count was elevated, with eosinophil predominance in the differential. After cardiological and haematological work-up, the final diagnosis of HES-associated cardiac involvement was established. Early treatment with CS led to eosinophil count normalization with only moderate cardiac function improvement. Currently, the patient is in good condition overall and is in NYHA class II while still on prednisone.

A review of DRESS-associated myocarditis

DRESS (drug rash with eosinophilia and systemic symptoms), also known as drug-induced hypersensitivity syndrome, is a severe, systemic drug reaction most commonly associated with aromatic anticonvulsants and sulfonamides. Patients typically present with fever, facial edema, cervical lymphadenopathy and a morbilliform eruption, which may progress to erythroderma. Hematologic abnormalities are a hallmark of the condition, including eosinophilia and atypical lymphocytosis. Visceral organ involvement typically manifests as hepatic dysfunction but may include lymphadenopathy, nephritis, interstitial pneumonitis, and myocarditis. Five to ten percent of patients with DRESS die from systemic complications, making timely recognition and treatment essential to prevent life-threatening manifestations. Myocarditis is a fatal and under-recognized manifestation of DRESS, which may occur long after the initial diagnosis. We review the literature of previously reported cases of DRESS and myocardial involvement, highlighting the presenting symptoms associated with cardiac involvement, treatments used, and the outcome for each patient. In addition, we offer an algorithm for early diagnosis, treatment, and subsequent monitoring of these patients.

Myocarditis

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

Clozapine-induced cardiotoxicity: a clinical update

Clozapine is a valuable drug for patients with treatment-resistant schizophrenia. Myocarditis is the most publicised cardiac complication of clozapine treatment, but cardiomyopathy and pericarditis have also been reported. Myocarditis has heterogeneous and non-specific presenting features, making it difficult to identify patients with clozapine-related myocarditis clinically. A high index of suspicion is required. The gold standard for diagnosis of myocarditis is an endomyocardial biopsy, but this is not a practical initial approach. Transthoracic echocardiography is a valuable, reproducible and widely available tool to assist in diagnosis of clozapine-induced cardiotoxicity. The level of B-type natriuretic peptide, a hormone secreted in response to ventricular wall stress, may be useful for evaluating patients with clozapine-induced cardiac dysfunction and may in the future be useful for screening asymptomatic patients. The mainstay of treatment of clozapine-induced cardiotoxicity is cessation of clozapine and provision of supportive care.

Fulminant eosinophilic myocarditis associated with visceral larva migrans caused by Toxocara canis infection

A 19-year-old man was transferred to hospital because of myocarditis with cardiogenic shock. Echocardiography showed a left ventricular ejection fraction of 23.8% and an intermediate amount of pericardial effusion. The patient immediately received an intra-aortic balloon pump and percutaneous cardiopulmonary support. Right ventricular endomyocardial biopsy was performed in the acute phase and showed extensive eosinophilic inflammatory cell infiltration, severe interstitial edema and moderate myocardial necrosis. High-dose corticosteroids were administered. Because the patient's antibody titer against Toxocara canis was high and his symptoms had appeared after eating raw deer meat, the diagnosis was fulminant eosinophilic myocarditis caused by a hypersensitivity reaction to visceral larval migrans. After starting high-dose corticosteroids, the ejection fraction dramatically improved, the eosinophilia decreased and the patient made a full recovery.

Fulminant myocarditis

Fulminant myocarditis is an inflammatory process that occurs in the myocardium and causes acute-onset heart failure. If patients with fulminant myocarditis are aggressively supported in a timely manner, nearly all can have an excellent recovery. In this Review, we discuss the clinical and histological distinguishing features of fulminant myocarditis and contrast this disease entity with nonfulminant myocarditis. The epidemiology, pathophysiology, clinical presentation, methods of diagnosis, management options and prognosis of fulminant myocarditis are reviewed in detail.

Cardiovascular manifestations of hypereosinophilic syndromes

The hypereosinophilic syndromes (HESs) are characterized by persistent marked eosinophilia (>1500 eosinophils/mm(3)), the absence of a primary cause of eosinophilia (such as parasitic or allergic disease), and evidence of eosinophil-mediated end organ damage. Cardiovascular complications of HES are a major source of morbidity and mortality in these disorders. The most characteristic cardiovascular abnormality in HES is endomyocardial fibrosis. Patients who have an HES also may develop thrombosis, particularly in the cardiac ventricles, but also occasionally in deep veins. Because of the rarity of these disorders, specific guidelines for the management of the cardiac and thrombotic complications of HES are lacking. This article reviews the diagnosis and management of the cardiovascular manifestations of HES.

Spontaneous myocarditis mimicking human disease occurs in the presence of an appropriate MHC and non-MHC background in transgenic mice

Most individuals have viral infections at some point in their life, however, only few develop autoreactivity to cardiac myosin following infection resulting in myocarditis suggesting a genetic predisposition. Most mouse models of myocarditis are induced by viral infection or by immunization with cardiac myosin. We generated HLA-DR3.Abetao and HLA-DQ8.Abetao transgenic mice in NOD and HLA-DQ8.Abetao in B10 background to study spontaneous autoimmunity. A high mortality was observed in NOD.DQ8 female mice 16 weeks or older. Echocardiography showed marked systolic dysfunction. Histopathology of various organs revealed an enlarged heart with mononuclear infiltrate consisting of CD4 and Mac-1+ cells and myocyte necrosis. The autoimmunity was associated with the presence of spontaneous autoreactive T cells and antibodies to cardiac myosin. Serologically, mice were negative for all known mouse viruses. NOD.DR3.Abetao, the transgene negative littermates, NOD, and B10.DQ8 Abetao mice had no gross or microscopic cardiac pathology. Spontaneous cellular and humoral response to cardiac myosin suggests that NOD.DQ8 may harbor autoreactive cells that can lead to spontaneous myocarditis and dilated cardiomyopathy. HLA-DQ8 is required for the predisposition to the spontaneous autoreactivity while NOD background influences onset and progression of disease. This model of myocarditis occurs predominantly in female mice and may provide insight into the pathogenesis of heart disease in women.

National Institutes of Health-sponsored workshop on inflammation and immunity in dilated cardiomyopathy

Nonischemic dilated cardiomyopathy (DCM) is an uncommon cause of heart failure but has widespread importance because it is the cause of 45% of heart transplantations. Multiple experimental and clinical lines of evidence have implicated altered immunity in the pathogenesis of DCM. However, advances in the understanding of the mechanisms of altered immunity have not affected the diagnosis or treatment of DCM. In recognition of this problem, the National Institutes of Health sponsored an expert workshop with 2 aims: to review the current understanding of inflammation and immunity as they relate to DCM and to identify the most promising areas for future clinical research efforts in the field. This report summarizes the scientific opportunities, perceived needs and barriers, and workshop recommendations on research directions in DCM. The major recommendations from the members of the workshop are organized according to the following themes: cardiotropic viruses, innate and acquired immune responses, environmental factors, novel diagnostics, and novel therapeutics.