Fulminant and acute lymphocytic myocarditis: the prognostic value of clinicopathological classification

Role of Toll-Like Receptors and Th Responses in Viral Myocarditis

Myocarditis is the common cause of sudden cardiac death, dilated cardiomyopathy (DCM) and heart failure (HF) in young adults. The most common type of myocarditis is viral myocarditis (VMC). Toll-like receptors (TLRs) are vital to identify pathogens in vivo. TLRs promote the differentiation of naive CD4⁺T cells to T helper (Th) cells, activate the immune response, and participate in the pathogenesis of autoimmune and allergic diseases. Although the pathogenesis of VMC is unclear, autoimmune responses have been confirmed to play a significant role; hence, it could be inferred that VMC is closely related to TLRs and Th responses. Some drugs have been found to improve the prognosis of VMC by regulating the immune response through activated TLRs. In this review, we discuss the role of TLRs and Th responses in VMC.

Intracellular virus sensor MDA5 mutation develops autoimmune myocarditis and nephritis

Mutations in IFIH1 gene encoding viral RNA sensor MDA5 have been reported responsible for many interferonopathies, including Aicardi-Goutières syndrome (AGS) and monogenic lupus, however, the pathological link between IFIH1 mutations and various autoimmune symptoms remains unclear. Here, we generated transgenic mice expressing human MDA5 R779H mutant (R779H Tg), reported in AGS and monogenic lupus patient. Mice spontaneously developed myocarditis and nephritis with upregulation of type I IFNs in the major organs. R779H Tg Mavs-/- and R779H Tg Ifnar-/- showed no phenotypes, indicating direct MDA5-signaling pathway involvement. Rag-2 deficiency and bone marrow cells transfer from wild type to adult mice did not prevent myocarditis development, while mice with cardiomyocyte-specific expression of hMDA5 R779H showed cardiomegaly and high expression of inflammatory cytokines. Taken together, our study clarifies that type I IFNs production and chemokines from cardiomyocytes starts in neonatal period and is critical for the development of myocarditis. Activated lymphocytes and auto-antibodies exacerbate the pathogenesis but are dispensable for the onset.

Right ventricular dominant myocarditis requiring cardiac resynchronization therapy-defibrillator: a case report

Fulminant myocarditis is an inflammatory disease of the cardiac muscle that severely deteriorates cardiac function and often causes haemodynamic collapse in a manner similar to acute coronary syndrome. In rare cases, the myocardium of the right ventricle is dominantly damaged. In cases of lymphocytic myocarditis, a common type of fulminant myocarditis, cardiac function is often recovered after peak myocardial inflammation subsides; however, some cases show irreversible myocardial damage. Herein, we report the case of a 43-year-old woman with irreversible, right-side dominant ventricular myocardial damage; she presented with various cardiopulmonary conditions including complete atrioventricular block, ventricular tachycardia, right heart failure, right ventricular thrombosis, and pulmonary embolism. The patient was successfully treated with medications and a cardiac resynchronization therapy-defibrillator device.

Diagnosis and Management of Myocarditis: An Evidence-Based Review for the Emergency Medicine Clinician

BACKGROUND

Myocarditis is a potentially fatal condition that can be misdiagnosed in the emergency department (ED) setting.

OBJECTIVE

The purpose of this narrative review article is to provide a summary of the background, pathophysiology, diagnosis, and management of myocarditis, with a focus on emergency clinicians.

DISCUSSION

Myocarditis occurs when inflammation of the heart musculature causes cardiac dysfunction. Symptoms may range from mild to severe and are often preceded by a viral prodrome. Laboratory assessment and an electrocardiogram can be helpful for the diagnosis, but echocardiography is the ideal test in the ED setting. Some patients may also require advanced imaging, though this will often occur during hospitalization or follow-up. Treatment is primarily focused on respiratory and hemodynamic support. Initial hemodynamic management includes vasopressors and inotropes, whereas more severe cases may require an intra-aortic balloon pump, extracorporeal membrane oxygenation, or a ventricular assist device. Nonsteroidal anti-inflammatory drugs should be avoided while intravenous immunoglobulin is controversial.

CONCLUSION

Myocarditis is a serious condition with the potential for significant morbidity and mortality. It is important for clinicians to be aware of the current evidence regarding the diagnosis, management, and disposition of these patients.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

This is an update of a previous review. Case reports and case series have described dramatic responses to intravenous immunoglobulin (IVIG) in people with presumed viral myocarditis, and its administration has become commonplace.

OBJECTIVES

The primary objective of this review was to compare event-free (death, requirement for a cardiac transplant, or placement of a left ventricular assist device) or overall (death) survival of adults and children with presumed viral myocarditis treated with IVIG versus those who did not receive IVIG. A secondary objective was to determine if a group of patients with presumed viral myocarditis could be identified (on the basis of age, duration of symptoms, acuity of onset of symptoms, cardiac function at presentation, virological results, or the presence or absence of histological evidence of acute myocarditis on cardiac biopsy in patients in whom a biopsy was performed) who would be the most likely to benefit from IVIG.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, DARE, CINAHL, Web of Science Core Collection, and LILACS in July 2019, and two trial registries in November 2019. We contacted authors of trials and checked reference lists of relevant papers. We applied no language restrictions.

SELECTION CRITERIA

We included studies if (1) participants had a clinical diagnosis of acute myocarditis with a left ventricular ejection fraction (LVEF) ≤ 0.45, left ventricular end-diastolic diameter (LVEDD) > 2 standard deviations (SDs) above the norm, or a left ventricular shortening fraction (LVSF) > 2 SDs below the mean, with duration of cardiac symptoms < 6 months; (2) participants had no evidence of non-infectious or bacterial cardiac disease; and (3) participants were randomly assigned to receive at least 1 g/kg of IVIG versus no IVIG or placebo. We excluded studies if (1) participants had received immunosuppression before outcome assessment; or (2) onset of myocarditis was reported to have occurred < 6 months postpartum.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results and extracted data. We assessed risk of bias with the Cochrane 'Risk of bias' tool. We conducted meta-analysis for two outcomes (overall survival and improvement in LVEF) with two adult trials. Other meta-analyses were not possible because only three relevant trials were included, and researchers analysed markedly different populations and used different outcome measures.

MAIN RESULTS

In this update we added two trials to the two previously included trials. A quasi-randomised trial was previously included due to a paucity of evidence from randomised trials; however, with the addition of two new randomised trials, it was removed from this update. For two adult trials, the overall risk of bias was unclear with very low-certainty evidence for all outcomes. The first trial studied 62 adults with recent-onset dilated cardiomyopathy randomly assigned to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The effect on event-free survival between groups was uncertain (risk ratio (RR) of any event 1.76, 95% confidence interval (CI) 0.48 to 6.40). The second trial studied 41 adults with acute myocarditis randomised to either high-dose IVIG (1 to 2 g/kg over two days) or no treatment. The IVIG group reported greater survival time after 60 days (no raw data, P < 0.01), but the evidence is uncertain. We pooled the reported number of deaths in both trials, with no evidence of a difference between groups (RR 0.91, 95% CI 0.23 to 3.62, I² = 31%, very low-certainty evidence). The evidence on the effect of IVIG treatment on LVEF (pooled mean difference (MD) -0.01, 95% CI -0.06 to 0.05) after 12 months and an unknown time frame is uncertain. The results for functional capacity, assessed by peak oxygen consumption at 12 months, were uncertain (MD -0.80, 95% CI -4.57 to 2.97). The results for infusion-related side effects were also uncertain due to a very large CI (RR 20.29, 95% CI 1.25 to 329.93). Lastly, there was uncertain evidence addressing failure to attain complete recovery (RR 0.46, 95% CI 0.19 to 1.14).  Evidence for improvement in LVEDD, left ventricular shortening fraction, and hospitalisation status in adults was not reported.  In the single included paediatric trial, the overall risk of bias was low with very low-certainty evidence for all outcomes. The trial included 86 children in Egypt presenting with acute myocarditis. Children were randomly assigned to 1 g/kg IVIG daily for two consecutive days or placebo followed by echocardiography one and six months post randomisation for recording of LVEDD and LVSF. The evidence for overall survival after six months was uncertain (risk of death RR 0.48, 95% CI 0.20 to 1.15). The evidence was also uncertain for improvement in LVEDD and LVSF after six months (LVEDD MD -4.00, 95% CI -9.52 to 1.52; LVSF no raw data).  Evidence for improvement in LVEF, functional capacity, side effects, complete recovery, and hospitalisation status in children was not reported.  AUTHORS' CONCLUSIONS: Evidence from two trials of very low certainty and with unclear risk of bias provides contradictory evidence on the use of IVIG in the treatment of adults with presumed viral myocarditis. One trial reported that use of IVIG results in longer survival time after 60 days, whilst the other trial found that IVIG does not provide an appreciable benefit. The evidence of a difference in event-free or overall survival, LVEDD, or LVSF is of very low certainty in a single paediatric trial with a low risk of bias. Until higher-quality studies with low risk of bias and larger sample sizes have demonstrated benefit in a particular group of patients, the evidence for treatment with IVIG for presumed viral myocarditis is uncertain. Further studies of the pathophysiology of myocarditis would lead to improved diagnostic criteria, which would facilitate future research.

Fulminant Myocarditis: Epidemiology, Pathogenesis, Diagnosis, and Management

Fulminant myocarditis (FM) is a rare, distinct form of myocarditis that has been difficult to classify. Since 1991, the definition of FM has evolved, and it is currently considered an acute illness with hemodynamic derangement and arrhythmias due to a severe inflammatory process requiring support of cardiac pump function and/or urgent management of serious arrhythmias. Diagnosis is aided through use of biomarkers and cardiac imaging, but endocardial biopsy remains the gold standard. Recent evidence has revealed that patients with FM are significantly more likely to die or require heart transplantation than those with the nonfulminant form, refuting previous studies proposing a paradoxically low mortality in patients with FM. Acute hemodynamic derangement is managed by intensive contemporary pharmacologic and interventional approaches, whereas the role of immunosuppressive therapy has not been clarified. Early recognition and aggressive management are essential for favorable outcomes. In conclusion, FM is an inflammatory process requiring intensive support, and it causes a higher morbidity and mortality than acute nonfulminant myocarditis.

Diagnostic Dilemmas and Management of Fulminant Myocarditis

Myocarditis is commonly a diagnosis of exclusion. We report a case of fulminant myocarditis in a patient with cardiogenic shock in whom the initial diagnosis was unclear. Early supportive care including extracorporeal membrane oxygenation and intraaortic balloon pump were instituted. Complete recovery of cardiac function was achieved. This case highlights the difficulty in diagnosing myocarditis and the benefits of early intensive support.

Fulminant Myocarditis: A Review of the Current Literature

Myocarditis is an inflammatory disease of the myocardium with a wide spectrum of symptoms and severity. Fulminant myocarditis is a small cohort of this disease that tends to present with sudden onset acute heart failure, cardiogenic shock, or life-threatening arrhythmias. The most common type, and the one with the best likelihood for recovery, is lymphocytic myocarditis. More rare, and often more fatal, forms are eosinophilic myocarditis and giant cell myocarditis. Delayed recognition and lack of standardized therapy guidelines continue to challenge clinicians treating these critically ill patients. This article will review the most up-to-date literature regarding recognition and recommended treatment for fulminant myocarditis as it pertains to clinical practice.

Left ventricular end-diastolic dimension as a predictive factor of outcomes in children with acute myocarditis

In this study, we sought predictors of mortality in children with acute myocarditis and of incomplete recovery in the survivor group. We classified our patients into three groups according to their outcomes at last follow-up: full recovery was classified as group I, incomplete recovery was classified as group II, and death was classified as group III. In total, 55 patients were enrolled in the study: 33 patients in group I, 11 patients in group II, and 11 patients in group III. The initial left ventricular fractional shortening - left ventricular fractional shortening - was significantly lower in group III (p=0.001), and the left ventricular end-diastolic dimension z score was higher in groups II and III compared with group I (p=0.000). A multivariate analysis showed that the left ventricular end-diastolic dimension z score (odds ratio (OR), 1.251; 95% confidence interval (CI), 1.004-1.559), extracorporeal membrane oxygenation (OR, 9.842; 95% CI, 1.044-92.764), and epinephrine infusion (OR, 18.552; 95% CI, 1.759-195.705) were significant predictors of mortality. The left ventricular end-diastolic dimension z score was the only factor that predicted incomplete recovery in the survivor group (OR, 1.360; 95% CI, 1.066-1.734; p=0.013). The receiver operating characteristic curve of the left ventricular end-diastolic dimension z score at admission showed a cut-off level of 3.01 for predicting mortality (95% CI, 0.714-0.948). In conclusion, a high left ventricular end-diastolic dimension z score on admission was a significant predictor of worse outcomes, both regarding mortality and incomplete recovery.

Factors and values at admission that predict a fulminant course of acute myocarditis: data from Tokyo CCU network database

Prognosis of acute myocarditis is generally benign, but fulminant cases exist which require advanced life support devices, such as percutaneous cardio-pulmonary support (PCPS) and ventricular assist devices (VAD), and lead to fatal outcomes. The purpose of this study was to identify predictors and their values at admission which might foreshadow a fulminant course of myocarditis. Data from 138 patients (mean age 42.0 years, 79 males) with a diagnosis of acute myocarditis in the Tokyo CCU Network database from 2007 to 2009 were analyzed retrospectively. Patients were divided into fulminant (in-hospital death, or PCPS or VAD requirement, N = 42) and non-fulminant groups (N = 96). Clinical data at admission were compared between them. Overall in-hospital mortality was 14.5%. On multivariate analysis, low systolic blood pressure (BPsys, odds ratio (OR)/mmHg 0.97; 95% confidence interval (CI) 0.93-1.00, p = 0.032) and electrocardiographic QRS complex prolongation (OR/10 ms 1.28; 95% CI 1.10-1.59, p = 0.0034) at admission were independent factors associated with a fulminant course. By receiver operator characteristic curve analysis, the area under the curve predicting a fulminant course was 0.769 for low BPsys and 0.821 for prolongation of QRS duration. The optimal cut-off value was 101 mmHg for BPsys (sensitivity 79.5%, specificity 68.0%), and 120 ms for QRS duration (sensitivity 72.2%, specificity 88.0%). Systolic hypotension and prolonged QRS on admission are predictors of a fulminant course of myocarditis.

Fulminant lymphocytic myocarditis associated with orbital myositis and diaphragmatic paralysis

Although the clinical presentation of myocarditis is very diverse, ranging from mild dyspnea to hemodynamic collapse, myocarditis accompanied with extracardiac myositis is extremely rare. We report a single case of fulminant myocarditis associated with orbital myositis and diaphragmatic paralysis in a 40-year-old man, which was successfully managed by immunosuppressive therapy with steroid.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

This is an update of a previous review. Case reports and case series have described dramatic responses to intravenous immunoglobulin (IVIG) in people with presumed viral myocarditis, and its administration has become commonplace.

OBJECTIVES

The primary objective of this review was to compare transplant-free survival of adults and children with presumed viral myocarditis treated with IVIG versus those who did not receive IVIG. A secondary objective was to determine if a group of patients with presumed viral myocarditis could be identified (on the basis of age, duration of symptoms, acuity of onset of symptoms, cardiac function at presentation, virological results or the presence or absence of histological evidence of acute myocarditis on cardiac biopsy in patients in whom a biopsy was performed) who would be the most likely to benefit from IVIG.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 12 of 12), the Database of Abstracts of Reviews of Effects (DARE) (2013, Issue 4 of 4), MEDLINE (Ovid, 1946 to January Week 3 2014), EMBASE (Ovid, 1980 to Week 4 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) EBSCO, Web of Science (Thomson Reuters, 1970 to 24 January 2014), the Latin American and Caribbean Health Science Information Database (LILACS) (1982 to 30 January 2014), trials registries and conference proceedings. We contacted authors of trials and checked reference lists of relevant papers. We applied no language restrictions.

SELECTION CRITERIA

We included studies if (1) participants had a clinical diagnosis of acute myocarditis with a left ventricular ejection fraction (LVEF) ≤ 0.45, left ventricular end-diastolic diameter (LVEDD) > 2 standard deviations (SDs) above the norm or a shortening fraction (SF) > 2 SDs below the mean with duration of cardiac symptoms < 6 months; (2) participants had no evidence of non-infectious or bacterial cardiac disease; and (3) participants were randomly assigned to receive at least 1 g/kg of IVIG versus no IVIG or placebo. We excluded studies if (1) participants had received immunosuppression before outcome assessment; or (2) onset of myocarditis was reported to occur < 6 months post partum.

DATA COLLECTION AND ANALYSIS

Two review authors screened searches and extracted data independently. We assessed quality using the 'Risk of bias' tool. Meta-analysis was not possible because only two relevant studies were found, and researchers analysed markedly different populations.

MAIN RESULTS

In this update, review authors added one study to the study from the original review. The first relevant study involved 62 adults with recent-onset dilated cardiomyopathy randomly assigned to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The overall risk of bias was unclear. The incidence of death or the requirement for cardiac transplant or placement of a left ventricular assist device was low in both groups (odds ratio (OR) for event-free survival 0.52, 95% confidence interval (CI) 0.12 to 2.30). Follow-up at six months and at 12 months showed equivalent improvement in LVEF (mean difference (MD) 0.00, 95% CI -0.07 to 0.07 at six months; MD 0.01, 95% CI -0.06 to 0.08 at 12 months). Functional capacity as assessed by peak oxygen consumption was equivalent in the two groups at 12 months (MD -0.80, 95% CI -4.57 to 2.97). Infusion-related side effects were more common in the treated group, but all were reported to be mild (OR 30.16, 95% CI 1.69 to 539.42).The second study added at this update included 83 children in India with suspected viral encephalitis and myocarditis. The overall risk of bias was high. The odds ratio for event-free survival was 7.39 (95% CI 0.91 to 59.86). Follow-up occurred only until hospital discharge, and LVEF was 49.5% in the treated group versus 35.9% in the placebo group (risk difference 13.6%, 95% CI 5.1 to 22.1%; P value = 0.001).

AUTHORS' CONCLUSIONS

Evidence from one trial does not support the use of IVIG for the treatment of adults with presumed viral myocarditis. The only paediatric trial had high risk of bias but suggested that benefit may be seen in the select group of children beyond the neonatal period who have viral encephalitis with myocarditis. Until higher-quality studies have demonstrated benefit in a particular group of patients, IVIG for presumed viral myocarditis should not be provided as routine practice in any situation. Further studies of the pathophysiology of myocarditis would lead to improved diagnostic criteria, which would facilitate future research.

Management of fulminant myocarditis: a diagnosis in search of its etiology but with therapeutic options

Fulminant myocarditis is a clinical syndrome with signs of acute heart failure, cardiogenic shock, or life-threating rhythm disturbances in the context of suspected myocarditis. It is not an etiological diagnosis, but may have different underlying causes and pathogenetic processes - viral, bacterial, toxic, and autoreactive. Clinical management of the disease entity at the acute stage involves hemodynamic monitoring in an intensive care unit or similar setting. Rapid routine work-up is mandatory with serial EKGs, echocardiography, cardiac MRI, heart catheterization with endomyocardial biopsy for histology, immunohistology, and molecular analysis for the underlying infection and pathogenesis. Heart failure therapy is warranted in all cases according to current guidelines. For fulminant autoreactive myocarditis, immunosuppressive treatment is beneficial; for viral myocarditis, IVIg can resolve the inflammation, reduce the viral load, and even eradicate the microbial agent. ECMO, IABP, ventricular assist devices, LifeVest, or ICD implantation can bridge to recovery or to heart transplantation.

A case of reversible very low voltage electrocardiogram in fulminant myocarditis

Clinical features of acute myocarditis range from a subclinical state to a fulminant state. Fulminant myocarditis with ventricular arrhythmia or atrioventricular block is associated with a high mortality rate. In cases in which aggressive medical therapy for fulminant myocarditis is not likely to be successful, intensive and emergency mechanical circulatory support, such as extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pump, should be considered. We report life salvage of acute fulminant myocarditis in a 53-year-old woman presented with malignant arrhythmia and cardiogenic shock supported by ECMO.

Fulminant myocarditis associated with novel H1N1 influenza A

Myocarditis secondary to H1N1 influenza has been described in children, but only very rarely in adults. We describe a 36-year-old man with no significant medical history who presented with flu-like symptoms of 3-week duration. When he sought medical attention, he was already manifesting heart failure secondary to fulminant myocarditis, along with multiorgan failure. Despite aggressive management, including circulatory support with a catheter-based mechanical cardiac assist device (Impella 2.5 Cardiac Assist Device, Abiomed, Danvers, MA) as a bridge to cardiac transplant, and aggressive antiviral and antibacterial therapy, the patient died of cardiac arrest. An H1N1 polymerase chain reaction postmortem assay produced positive results, and a diagnosis of fulminant viral myocarditis and multiorgan system failure was established.

Imaging spectrum of sudden athlete cardiac death

Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

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.

Survival in biopsy-proven myocarditis: a long-term retrospective analysis of the histopathologic, clinical, and hemodynamic predictors

OBJECTIVE

We hypothesized that histopathology predicts survival without cardiac transplantation in patients with biopsy-proven myocarditis.

BACKGROUND

The role of endomyocardial biopsy in diagnosing myocarditis remains controversial. Histopathology has been integrated with clinical and hemodynamic features to predict prognosis. However, the influence of histopathology on survival > 5 years has not been explored.

METHODS

We retrospectively identified 112 consecutive patients with histopathologic confirmation of myocarditis. We examined these patients' clinical presentation, hemodynamic assessment, hospital course, and treatment. We selected 14 variables that might influence survival without cardiac transplantation.

RESULTS

A total of 62 (55%) of 112 patients had lymphocytic myocarditis; 88 (79%) and 63 (56%) were alive without cardiac transplantation at 1 and 5 years, respectively. Median follow-up was a mean 95.5 months and median 74.5 months. Among the 55 with complete data of the 14 candidate predictor variables, age, sex, and clinical presentation with congestive heart failure and ventricular (ventricular tachycardia or fibrillation) or atrial arrhythmias (atrial fibrillation or flutter) did not predict the study end point of death or need for transplantation. In univariate analysis, pulmonary capillary wedge pressure > or = 15 mm Hg significantly predicted the study end point. In multivariate analysis, pulmonary capillary wedge pressure > or = 15 mm Hg and histopathology of lymphocytic, granulomatous, or giant cell myocarditis each significantly predicted mortality or transplant (P = .047, P = .013, and P = .054, respectively) on cumulative survival without cardiac transplantation.

CONCLUSIONS

Histopathology predicts long-term survival in patients with myocarditis. Clinical presentation, including presentation with congestive heart failure, ventricular tachycardia/ventricular fibrillation, or atrial fibrillation/atrial flutter, does not predict survival without transplantation. Endomyocardial biopsy can play a role in predicting transplant-free survival in patients with myocarditis.

Acute myocarditis mimicking acute myocardial infarction: a clinical nightmare with forensic implications

Authors present the case of the sudden death of a 30-year-old man, 3 h since his hospitalization by the onset of aspecific chest pain. ECG findings revealed the presence of localized ST segment elevation in precordial leads (V1-V4) and DII-DII, and aVF mimicking acute antero-inferior myocardial infarction. A diagnosis of acute antero-inferior myocardial infarction was advanced and the patient introduced to thrombolytic therapy. Suddenly, on ECG monitor, conduction abnormalities were early recorded (ventricular extrasystole) followed by ventricular tachycardia degenerating in fatal ventricular fibrillation. An alleged medical malpractice was sued against the cardiologist. A complete immunohistochemical study was performed. Histologically, the heart presented massive interstitial lymphocytic infiltrate and focal myocytes necrosis. The diagnosis of acute lymphocytic myocarditis was established as the cause of death.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

Case reports and case series have described dramatic responses to IVIG in adults and children with presumed viral myocarditis. Administration of IVIG has become commonplace in the management of this condition.

OBJECTIVES

To compare the outcome of patients with presumed viral myocarditis treated with IVIG to patients who did not receive IVIG.

SEARCH STRATEGY

We searched CENTRAL (Issue 2, 2003), MEDLINE/PubMed (1966-2003), EMBASE (1988-2003), CINAHL (1982-2003), Web of Science (1975-2003), trials registries and conference proceedings. We contacted authors of trials and checked reference lists of relevant papers.

SELECTION CRITERIA

Studies were included if: (1) patients had a clinical diagnosis of acute myocarditis with either a left ventricular ejection fraction (LVEF) <= 0.45, LVEDD of >2 SDs above the norm, or a shortening fraction (SF) >2 SDs below the mean and the duration of cardiac symptoms was less than six months; (2) patients had no evidence of non-infectious or bacterial cardiac disease; and, (3) patients were randomised to receive at least 1 gm/kg of IVIG versus no IVIG or placebo. Studies were excluded if: (1) patients had received immunosuppression prior to outcome assessment; or, (2) onset of myocarditis was less than six months postpartum.

DATA COLLECTION AND ANALYSIS

Searches were screened and inclusion criteria applied independently by two reviewers. Quality was assessed by two reviewers using the Jadad scale and allocation concealment. Data were extracted independently by two reviewers. Meta-analysis was not possible because only one relevant study was found.

MAIN RESULTS

The relevant study involved 62 adults with acute myocarditis randomized to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The incidence of death or requirement for cardiac transplant or placement of a left ventricular assist device was low in both groups (OR for event-free survival was 0.52 ,95% CI 0.12 to 2.30). Follow-up at six and 12 months showed equivalent improvement in LVEF (mean difference 0.00, 95% CI -0.07 to 0.07 at six months, mean difference 0.01, 95% CI -0.06 to 0.08 at 12 months). Functional capacity as assessed by peak oxygen consumption was equivalent in the two groups at 12 months (mean difference -0.80, 95% CI -4.57 to 2.97). Infusion-related side effects were more common in the treated group, but all appeared to be mild (OR 30.16, 95% CI 1.69 to 539.42).

AUTHORS' CONCLUSIONS

Evidence from one trial does not support the use of IVIG for the management of adults with presumed viral myocarditis. There are no randomized paediatric trials. Further studies of the pathophysiology of this entity would lead to improved diagnostic criteria which would facilitate future research.