Update on myocarditis in children

Features of Myocarditis: Morphological Differential Diagnosis in Post-COVID-19 Children

Myocarditis is characterized by dysfunction and destruction of cardiomyocytes, infiltrative inflammation, and development of fibrosis. Late diagnosis of myocarditis has been a serious global health problem, especially due to the spread of a new coronavirus infection. The aim of this review is to identify differences between myocarditis of viral etiology, including SARS-CoV-2 lesions, based on instrumental and pathomorphological findings.

MATERIAL AND METHODS

We analyzed publications covering the period from December 2019 to May 2023, published in publicly accessible international databases ("Medline", "PubMed", "Scopus"), with queries for the keywords "myocarditis", "children", "cardiovascular inflammation", "COVID-19", "SARS-CoV-2", "severe acute respiratory syndrome coronavirus 2", "differential diagnosis".

RESULTS

It was found that no unambiguous morphological criteria for the diagnosis of myocarditis coupled to SARS-CoV-2 lesions were identified. However, the detected histopathological changes such as virus-associated degeneration, apoptosis, cardiomyocyte necrosis, moderate interstitial hyperemia, myocardial tissue oedema, and capillary endothelial cell dysfunction were the major markers of SARS-CoV-2 infection.

CONCLUSION

It is necessary further reconsider morphological criteria to diagnose SARS-CoV-2-caused myocarditis, rather than solely relying on detecting viral RNA by PCR as the sole evidence-based criterion. Similar issues accompany diagnostics of myocardial lesions associated with other viral infections. Evidence for an etiological diagnosis of myocarditis can be provided by a comprehensive analysis of the diagnostic criteria obtained, confirming virus exposure, followed by development of distinct clinical symptoms, MRI and CT changes, and morphological criteria.

Leitlinie Myokarditis der Deutschen Gesellschaft für Pädiatrische Kardiologie

This consensus statement presents updated recommendations on diagnosis and treatment of myocarditis in childhood.

Clinical characteristics and outcome of biopsy-proven myocarditis in children - Results of the German prospective multicentre registry "MYKKE"

BACKGROUND

Heart failure (HF) due to myocarditis might not respond in the same way to standard therapy as HF due to other aetiologies. The aim of this study was to investigate the value of endomyocardial biopsies (EMB) for clinical decision-making and its relation to the outcome of paediatric patients with myocarditis.

METHODS

Clinical and EMB data of children with myocarditis collected for the MYKKE-registry between 2013 and 2020 from 23 centres were analysed. EMB studies included histology, immunohistology, and molecular pathology. The occurrence of major adverse cardiac events (MACE) including mechanical circulatory support (MCS), heart transplantation, and/or death was defined as a combined endpoint.

RESULTS

Myocarditis was diagnosed in 209/260 patients: 64% healing/chronic lymphocytic myocarditis, 23% acute lymphocytic myocarditis (AM), 14% healed myocarditis, no giant cell myocarditis. The median age was 12.8 (1.4-15.9) years. Time from symptom-onset to EMB was 11.0 (4.0-29.0) days. Children with AM and high amounts of mononuclear cell infiltrates were significantly younger with signs of HF compared to those with healing/chronic or healed myocarditis. Myocardial viral DNA/RNA detection had no significant effect on outcome. The worst event-free survival was seen in patients with healing/chronic myocarditis (24%), followed by acute (31%) and healed myocarditis (58%, p = 0.294). A weaning rate of 64% from MCS was found in AM.

CONCLUSIONS

EMB provides important information on the type and stage of myocardial inflammation and supports further decision-making. Children with fulminant clinical presentation, high amounts of mononuclear cell infiltrates or healing/chronic inflammation and young age have the highest risk for MACE.

Myocarditis Presenting as Sudden Death in Infants and Children: A Single Centre Analysis by ESGFOR Study Group

BACKGROUND

Acute myocarditis is an inflammatory disease of the heart mostly diagnosed in young people, which can present as sudden death. The etiology includes infectious agents (mostly viruses), systemic diseases and toxins. We aim to characterize infants and children with myocarditis at post-mortem presenting as sudden deaths.

METHODS

Retrospective evaluation of 813 post-mortems in infants and children dying suddenly and unexpectedly between 2009-2019. Data retrieved included histological features, microbiology and clinical history.

RESULTS

23 of 813 post-mortems reviewed corresponded to acute myocarditis and 1 to dilated cardiomyopathy related to remote Parvovirus infection. PCR identified enterovirus (7), parvovirus (7 cases, 2 also with HHV6 and 1 case with EVB), Influenza A (1), Parainfluenza type 3 (1). Two cases corresponded to hypersensitivity myocarditis, 1 was Group A Streptococcus and 5 idiopathic myocarditis. Enterovirus was frequent in infants (7/10), and in newborns was associated with meningoencephalitis or congenital myocarditis. More than 50% were less than 2 years of age and all remained clinically unsuspected.

CONCLUSION

Myocarditis represents almost 3% of all sudden pediatric deaths. Enterovirus and parvovirus were the most common viruses. This retrospective analysis showed that patients experienced viral symptoms but remained unsuspected, highlighting the need for more clinical awareness of myocarditis.

Prognostic Role of Left Ventricular Intramyocardial Fatty Metaplasia in Patients With Previous Myocarditis (MYOFAT Study)

Left ventricular intramyocardial fat (LV-IMF) is often found in patients with previous irreversible myocardial damage and may be detected by cardiac magnetic resonance (CMR). No data are currently available about the prevalence of LV-IMF in patients with previous myocarditis. Our aim was to assess the prevalence of LV-IMF in patients with previous myocarditis by repeating after >3 years a follow-up CMR examination and to evaluate its clinical and prognostic role. Patients with clinical suspected myocarditis who underwent CMR within the first week from the onset of their symptoms and underwent repeated CMR were enrolled. LV-IMF was detected as areas of left ventricular intramyocardial "India ink" black boundary with or without a hyperintense core. Overall, in 235 patients with a definitive diagnosis of acute myocarditis, CMR was repeated after a median of 4 (3 to 6) years from symptom onset. LV-IMF positive patients (n = 35, 15%) presented greater ventricular volumes and more frequently a mid-wall late gadolinium enhancement than those without LV-IMF (both p < 0.05). Patients presenting major cardiac events (sudden cardiac deaths, resuscitated cardiac arrest, and appropriate implantable cardioverter-defibrillator-firing) at follow-up had a greater prevalence of LV-IMF than those without (55% vs 11%, p < 0.001). Patients with LV-IMF had a higher incidence myocarditis relapse (27% vs 9%, p = 0.003) and a greater risk of major cardiac events (p < 0.0001) than those without. At logistic regression analysis, LV-IMF was an independent predictor of major cardiac events. In conclusion, LV-IMF is not an uncommon finding in patients with previous myocarditis and is associated with worse ventricular remodeling and prognosis.

Multiparametric cardiac magnetic resonance imaging in pediatric and adolescent patients with acute myocarditis

BACKGROUND

The diagnostic value of cardiac magnetic resonance imaging (MRI) employing the 2018 Lake Louise criteria in pediatric and adolescent patients with acute myocarditis is undefined.

OBJECTIVE

To evaluate the diagnostic value of the Lake Louise criteria in pediatric and adolescent patients with suspected acute myocarditis and to show the utility of cardiac MRI for follow-up in this patient cohort.

MATERIALS AND METHODS

Forty-three patients (age range: 8-21 years) with suspected acute myocarditis and 13 control patients who underwent cardiac MRI were retrospectively analyzed. T2-weighted and late gadolinium enhancement imaging were performed in all patients. T1 and T2 mapping were available in 26/43 patients (60%). The Lake Louise criteria were assessed. In 27/43 patients (63%), cardiac MRI follow-up was available. Receiver operating characteristic analysis, Pearson's correlation coefficient and paired Student's t-test were used for statistical analysis.

RESULTS

In the total cohort, the Lake Louise criteria achieved a sensitivity of 86% (95% confidence interval [CI]: 72-95%) and a specificity of 100% (95% CI: 79-100%) for the diagnosis of acute myocarditis. In the subgroup of patients with available mapping parameters, the diagnostic performance of the Lake Louise criteria was higher when mapping parameters were implemented into the score (area under the receiver operating characteristic curve: 0.944 vs. 0.870; P=0.033). T2 relaxation times were higher in patients with admission to the intermediate care unit and were associated with the length of intermediate care unit stay (r=0.879, P=0.049). Cardiac MRI markers of active inflammation decreased on follow-up examinations (e.g., T1 relaxation times: 1,032±39 ms vs. 975±33 ms, P<0.001; T2 relaxation times: 58±5 ms vs. 54±5 ms, P=0.003).

CONCLUSION

The Lake Louise criteria have a high diagnostic performance for the diagnosis of acute myocarditis and are a valuable tool for follow-up in pediatric and adolescent patients. The mapping techniques enhance the diagnostic performance of the 2018 Lake Louise criteria.

Evolution of acute myocarditis in a pediatric population: An MRI based study

BACKGROUND

Cardiac Magnetic Resonance (CMR) data regarding myocarditis presentation and disease course is still lacking in pediatric patients. We evaluate baseline CMR and evolution of functional and tissue abnormalities in children with acute myocarditis.

METHODS

CMR was performed in 125 patients with clinical diagnosis of acute myocarditis. Clinical follow-up was performed for a median of 498 (214-923) days.

RESULTS

LVEF was depressed (<55%) in 56 cases (45%) upon baseline CMR. LGE was found in 93 patients (77%) of cases. LGE was exclusively subepicardial in 29 patients (23%), while other LGE patterns (midwall/mixed) were present in 64 (51%). CMR was repeated in 92 (74%) patients. 67% presented recover of function at a median of 170 (70-746) days after onset of symptoms. Midwall/mixed LGE pattern had a statistically significant correlation with absent recover of function (OR 0.20 p 0.036). Thirteen patients (16%) had recovery from LV dysfunction but with persistence of LGE. Sub-epicardial pattern of LGE (OR 3.33, 95% CI 1.08-10.2, p = 0.036) and the presence of fever at admission (OR 4.67, 95% CI 1.16-18.7, p = 0.03) were associated with a significantly higher likelihood of complete normalization while midwall/mixed LGE pattern was associated with non-recovery.

CONCLUSIONS

In pediatric myocarditis, midwall/mixed LGE pattern is associated with absent recover of function. Patients with recover of function may still have persistence of LGE, while a complete recovery from functional and tissue abnormalities is found only in a third of patients. Midwall/mixed pattern of LGE at first MRI was associated to worse outcome.

Circular RNAs in childhood-related diseases and cancers: A review

Research into the diagnosis, treatment and prevention of childhood-related diseases is the key to reducing their morbidity and mortality. Circular RNAs (circRNAs) play critical roles, both in physiology and pathology, and there is ample evidence to show that they play varying roles in tissue development and gene regulation. Studies on circRNAs in different childhood-related diseases have confirmed their great potential for disease prevention and treatment. These breakthroughs highlight the pathological role of circRNAs in cancers, as well as cardiovascular and hereditary childhood illnesses. In this review, we summarize the role of circRNAs in childhood-related diseases and cancer, and provide an update of the possible diagnostic and therapeutic application of circRNAs.

Identifying myocardial injuries in "normal-appearing" myocardium in pediatric patients with clinically suspected myocarditis using mapping techniques

Background

Mapping techniques using cardiac magnetic resonance imaging have significantly improved the diagnostic accuracy for myocarditis with focal myocardial injuries. The aim of our study was to determine whether T1 and T2 mapping techniques could identify diffuse myocardial injuries in "normal-appearing" myocardium in pediatric patients with clinically suspected myocarditis and to evaluate the associations between diffuse myocardial injuries and cardiac function parameters.

Methods

Forty-six subjects were included in this study: 20 acute myocarditis patients, 11 subacute/chronic myocarditis patients and 15 control children. T2 values, native T1 values and the extracellular volume (ECV) of "normal-appearing" myocardium were compared among the three groups of patients. Associations between diffuse myocardial injuries and cardiac function parameters were also evaluated.

Results

The ECV of "normal-appearing" myocardium was significantly higher in the subacute/chronic myocarditis group than in the control group (30.1 ± 0.9 vs 27.0 ± 0.6, P =0.004). No significant differences in T1 and T2 values between the acute myocarditis and control groups were found. In the subacute/chronic myocarditis group, a significant association between ECV and left ventricle ejection fraction was found (P=0.03).

Conclusions

Diffuse myocardial injuries are likely to occur in subacute/chronic myocarditis patients with prolonged inflammatory responses. Mapping techniques have great value for the diagnosis and monitoring of myocarditis.

Use of the new Lake Louise Criteria improves CMR detection of atypical forms of acute myocarditis

The purpose of our study was to compare diagnostic performance of old and new Lake Louise Criteria (oLLC and nLLC) among different clinical presentations: infarct-like (IL), cardiomyopathic (CM) and arrhythmic (AR). 102 patients with clinical suspicion of acute myocarditis underwent cardiac magnetic resonance (CMR) on a 1.5 T scanner. Protocol included cine-SSFP, T2-weighted STIR, T2 mapping, early and late gadolinium enhancement and T1 mapping acquired before and after gadolinium administration. The degree of agreement has been calculated with Cohen's K test. 42 patients also underwent endomyocardial biopsy (EMB). IL onset was present in 54/102 patients, CM in 28/102 and AR in 20/102. nLLC were positive in 58.3% of the patients, while oLLC in 37.9%, k = 0.57 (IC: 0.428-0.713). The degree of agreement between nLLC and oLLC was 0.49 (IC: 0.111-0.876) for AR onset (nLLC positive in 35% vs oLLC in 15%), 0.25 (IC: 0.035-0.459) for CM pattern (nLLC positive in 60.7% vs oLLC 17.9%) and 0.73 (IC: 0.543-0.912) for IL presentation (nLLC positive in 66.7% vs oLLC in 57.4%). Diagnostic accuracy was 75% for both nLLC and oLLC among IL onset, and 41.6% for oLLC vs 66.7% for nLLC, as regards CM clinical presentation. nLLC have improved diagnostic performance of CMR for the diagnosis of acute myocarditis, in particular for atypical clinical presentation.

Predictors for In-hospital Mortality in Pediatric Patients with Acute Myocarditis – a Retrospective Study

Background: Acute myocarditis, a primary inflammatory cardiac disease commonly caused by viral infection, is an important cause of morbidity and mortality in children. Data obtained from forensic studies found an incidence of 15–33% for acute myocarditis in sudden deaths in the pediatric age group. Currently, there is a lack of data regarding the incidence and factors associated with short-term outcomes in pediatric patients admitted for acute myocarditis.

The aim of the study was to identify predictors for in-hospital mortality in a pediatric population admitted with acute myocarditis.

Material and methods: We conducted a retrospective observational cohort study that included 21 patients admitted for acute myocarditis. Clinical, laboratory, ECG, and imaging data acquired via 2D transthoracic echocardiography and cardiac magnetic resonance imaging were collected from the medical charts of each included patient. The primary end-point of the study was all-cause mortality occurring during hospitalization (period ranging from 10 to 14 days). The study population was divided into 2 groups according to the occurrence of the primary end-point.

Results: The mean age of the study population was 99.62 ± 77.25 months, and 61.90% (n = 13) of the patients were males. The in-hospital mortality rate was 23.9% (n = 5). Patients in the deceased group were significantly younger than the survivors (55.60 ± 56.18 months vs. 113.4 ± 78.50 months, p = 0.039). Patients that had deceased presented a significantly higher level of LDH (365 ± 21.38 U/L vs. 234.4 ± 63.30 U/L, p = 0.0002) and a significantly higher rate of ventricular extrasystolic dysrhythmias (60% vs. 6.25%, p = 0.02, OR: 22.5, 95% CI: 1.5–335) compared to survivors. The 2D echocardiography showed that patients that had deceased presented more frequently an impaired left ventricular ejection fraction (<30%) (p = 0.001) and a significantly higher rate of severe mitral regurgitation (p = 0.001) compared to survivors.

Conclusions: The most powerful predictors for in-hospital mortality in pediatric patients admitted for acute myocarditis were the presence of ventricular extrasystolic dysrhythmias on the 24h Holter ECG monitoring, impaired left ventricular systolic function (LVEF <30%), the presence of severe mitral regurgitation, and confirmed infection with Mycoplasma pneumoniae.

Myocarditis: somethings old and something new

"Since the pathological conditions take place at the cellular level, viral myocarditis and postinfectious autoimmunity can be suggested but not diagnosed clinically. All clinical methods including imaging techniques are misleading if infectious agents are involved. Accurate diagnosis demands simultaneous histologic, immunohistochemical, and molecular biological workup of the tissue. If the primary infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific antiviral treatment options in addition to basic symptomatic therapy are available under certain conditions. These may allow a tailored cause-specific treatment that improves symptoms and prognosis of patients with acute and chronic disease." Uwe Kühl; Heinz-Peter SchultheissViral myocarditis.Swiss Medical Weekly. 144():w14010, JAN 2014 DOI:10.4414/smw.2014.14010.

A paediatric influenza update 100 years after the Skyros island Spanish flu outbreak

This year marks the 100th anniversary of the 1918 Spanish flu outbreak on the Greek Aegean Sea island of Skyros, which devastated its population in less than 30 days. According to Constantinos Faltaits's annals published in 1919, the influenza attack on the island of Skyros commenced acutely ‘like a thunderbolt’ on the 27th of October, 1918 and was exceptionally severe and fatal. At that time, the viral cause of the influenza had not been detected, while the total number of victims of the Spanish flu outbreak has been estimated to have surpassed 50 million, worldwide. Almost one century after this Aegean Sea island's tragedy, the ‘4th Workshop on Paediatric Virology’, organised on the 22nd of September, 2018 in Athens, Greece, was dedicated to the 100 years of the ‘Spanish’ flu pandemic. This review article highlights the plenary and key lectures presented at the workshop on the recent advances on the epidemiology, clinical management and prevention of influenza in childhood.

Clinical presentation and early predictors for poor outcomes in pediatric myocarditis: A retrospective study

BACKGROUND

Myocarditis is an important cause of morbidity and mortality in children, leading to long-term sequelae including chronic congestive heart failure, dilated cardiomyopathy, heart transplantation, and death. The initial diagnosis of myocarditis is usually based on clinical presentation, but this widely ranges from the severe sudden onset of a cardiogenic shock to asymptomatic patients. Early recognition is essential in order to monitor and start supportive treatment prior to the development of severe adverse events. Of note, many cases of fulminant myocarditis are usually misdiagnosed as otherwise minor conditions during the weeks before the unexpected deterioration.

AIM

To provide diagnostic clues to make an early recognition of pediatric myocarditis. To investigate early predictors for poor outcomes.

METHODS

We conducted a retrospective cross-sectional single-center study from January 2008 to November 2017 at the Pediatric Department of our institution, including children < 18-years-old diagnosed with myocarditis. Poor outcome was defined as the occurrence of any of the following facts: death, heart transplant, persistent left ventricular systolic dysfunction or dilation at hospital discharge (early poor outcome), or after 1 year of follow-up (late poor outcome). We analyzed different clinical features and diagnostic test findings in order to provide diagnostic clues for myocarditis in children. Multivariable stepwise logistic regression analysis was performed using all variables that had been selected by univariate analysis to determine independent factors that predicted a poor early or late outcome in our study population.

RESULTS

A total of 42 patients [69% male; median age of 8 (1.5-12) years] met study inclusion criteria. Chest pain (40%) was the most common specific cardiac symptom. Respiratory tract symptoms (cough, apnea, rhinorrhea) (38%), shortness of breath (35%), gastrointestinal tract symptoms (vomiting, abdominal pain, diarrhea) (33%), and fever (31%) were the most common non-cardiac initial complaints. Tachycardia (57%) and tachypnea (52%) were the most common signs on the initial physical exam followed by nonspecific signs of respiratory tract infection (44%) and respiratory distress (35%). Specific abnormal signs of heart failure such as heart murmur (26%), systolic hypotension (24%), gallop rhythm (20%), or hepatomegaly (20%) were less prevalent. Up to 43% of patients presented an early poor outcome, and 16% presented a late poor outcome. In multivariate analysis, an initial left ventricular ejection fraction (LVEF) < 30% remained the only significant predictor for early [odds ratio (OR) (95%CI) = 21 (2-456), P = 0.027) and late [OR (95%CI) = 8 (0.56-135), P = 0.047) poor outcome in children with myocarditis. LVEF correlated well with age (r = 0.51, P = 0.005), days from the initiation of symptoms (r = -0.31, P = 0.045), and N-terminal pro-brain natriuretic peptide levels (r = 0.66, P < 0.001), but not with troponin T (r = -0.05, P = 0.730) or C-reactive protein levels (r = -0.13, P = 0.391). N-terminal pro-brain natriuretic peptide presented a high diagnostic accuracy for LVEF < 30% on echocardiography with an area under curve of 0.931 (95%CI: 0.858-0.995, P < 0.001). The best cut-off point was 2000 pg/mL with a sensitivity of 90%, specificity of 81%, positive predictive value of 60%, and negative predictive value of 96%.

CONCLUSION

The diagnosis of myocarditis in children is challenging due to the heterogeneous and unspecific clinical presentation. The presence of LVEF < 30% on echocardiography on admission was the major predictor for poor outcomes. Younger ages, a prolonged course of the disease, and N-terminal pro-brain natriuretic peptide levels could help to identify these high-risk patients.

What Raises Troponins in the Paediatric Population?

Troponin I is a cardiac enzyme that is released during myocardial injury. However, cardiac enzymes are non-specific and can occur in many cardiac and non-cardiac pathologies. We aim to (1) describe the range of acute conditions that were associated with raised troponins in the paediatric population in our institution and (2) quantify the extent of troponin elevation and correlate it with the underlying aetiology. We performed a retrospective observational study in a tertiary institution which included patients from 1 January 2009 to 31 December 2013. We identified patients with troponin I levels of more than 0.1 ng/ml who have not had cardiac surgery before. We recorded their final diagnoses, and then compared the peak troponin levels and the eventual final diagnoses. We identified 100 patients. The top few common diagnoses resulting in a raised troponin were sepsis (29%), cardiac pathologies (29%) such as tachyarrhythmias and cardiomyopathies and myocarditis (21%). Other pathologies included trauma and other causes of multiorgan dysfunction. The median peak troponin I was higher in cardiac as compared to non-cardiac pathologies: 2.15 (0.52-15.0) and 0.44 (0.21-1.68), respectively. There was no statistically significant difference in the peak troponin I values in the presence of hypotension or renal impairment. We described the range of conditions that may result in raised troponin I levels. The extent of raised troponin I levels may potentially be useful in differentiating between cardiac and non-cardiac pathologies. However, further studies on a larger scale are required to establish whether extent of troponin I elevation has a diagnostic role for cardiac pathologies.

Histopathologic Analysis in Sudden Infant and Child Deaths: A Practical Approach

The forensic pathologist responsible for sudden unexpected death (SUD) investigation in the pediatric setting faces many challenges. It usually takes many years to obtain reasonable experience and exposure to the wide variety of diseases that may present as SUD in a pediatric context, and to appreciate the differences in the etiology and clinical context between the pediatric and adult SUD setting. In pediatric SUD, it is necessary to conduct a systematic, pediatric-focused autopsy investigation including extensive histopathological assessment and ancillary testing. Postmortem histologic findings in the context of SUD in the pediatric population are often subtle and distinctly different from those seen in the adult population. The pathologist must have an understanding of both developmental and pathological processes in order to correctly interpret the findings during a pediatric autopsy. A system-based, histopathology-focused review of common entities, normal variants, and incidental findings that can prove challenging will be discussed. For the forensic pathologist tasked with pediatric SUD autopsies, development of a strong collaborative relationship with a pediatric pathologist and/or neuropathologist to assist with histopathological analysis is strongly endorsed.

Identification of targeting peptides for the diagnosis of myocarditis

Aim: Current diagnostic tests for myocarditis are invasive and have low diagnostic value. Our aim was to identify potential targeting peptides to detect early myocarditis following intravenous delivery. Materials & methods: We used an animal model of experimental autoimmune myocarditis and a phage display library to identify potential targeting peptides. After several steps, we selected two peptides, MyH-PhD-05 and MyH-PhD-120, for in vivo screening using fluorescent imaging. Immunofluorescence and proteonomic analysis was used to identify potential cellular and molecular targets of MyH-PhD-05. Echocardiography was used to assess functional changes. Results: Peptide MyH-PhD-05 was able to detect animals with severe myocarditis even in the absence of functional changes. Immunofluorescence demonstrated that MyH-PhD-05 colocalizes with CD4+ T cells and monocytes (CD11b+) in cardiac infiltrates. Conclusion: We identified potential targeting peptides for the diagnosis of myocarditis. Future studies will focus on better identification of potential targets and translating this technology to clinically relevant imaging modalities.

Utility of cardiac MRI in paediatric myocarditis

BACKGROUND

The diagnostic role of cardiac MRI in myocarditis is evolving, however with extremely limited data in paediatrics. The goal of this study was to assess the utility of cardiac MRI in paediatric myocarditis and present a new prognostic score for risk stratification.

METHOD

The present study is a retrospective investigation of children with a clinical diagnosis of myocarditis, including analysis of demographics, clinical presentation, diagnostic studies, including cardiac MRI, and outcomes.

RESULTS

A total of 44 patients met the inclusion criteria, of whom 20 had undergone cardiac MRI. Patients who underwent cardiac MRI were older (median 15.6 versus 11.1 years, p=0.004), had a shorter length of hospital stay (median 4.0 versus 12.5 days, p=0.004), had overall less-severe illness at presentation as evidenced by a higher left-ventricular ejection fraction on echocardiography, had lower peak brain-type natriuretic peptide, were less likely to require advanced mechanical support, and were less likely to experience cardiac death or transplant. In patients who had undergone cardiac MRI, the most common findings were increased early gadolinium enhancement (n=9) or late gadolinium enhancement (n=9). Cardiac MRI findings did not predict a worse outcome. Independent predictors of the need for heart-failure medications at 1-year follow-up included inotrope requirement, extracorporeal membrane oxygenator requirement, and antiarrhythmic requirement at presentation (p<0.05).

CONCLUSION

In paediatric myocarditis, cardiac MRI is not used uniformly, has a low yield, and does not predict worse outcomes. Future research should evaluate clinical decision-making and the cost-benefit analysis of cardiac MRI in the diagnosis of paediatric myocarditis.

Case Report: III° atrioventricular block due to fulminant myocarditis managed with non-invasive transcutaneous pacing

Fulminant myocarditis is a life-threatening clinical condition. It is the inflammation of myocardium leading to acute heart failure, cardiogenic shock and cardiac arrhythmias. Incidence of fulminant myocarditis is low and mortality is high. Most grievous complications of fulminant myocarditis is mainly cardiac arrhythmias; if there is delay on active management of the patient, it may be fatal. Here, we describe a case of III° atrioventricular block due to fulminant myocarditis that was managed with non-invasive transcutaneous cardiac pacing in the absence of ECMO. The non-invasive transcutaneous pacemaker is a safe, effective and convenient device to revert arrhythmias.

Cardiovascular pre-participation screening in young athletes: Recommendations of the Association of European Paediatric Cardiology

Sudden death in young competitive athletes can be avoided by implementation of pre-participation screening programmes. A screening programme should be performed only by trained physicians and should include the athlete's personal and family history, physical examination results, and the readings from a 12-lead-electrocardiogram. The athlete should undergo this screening programme every second year to detect progressive diseases. In addition, the programme should include detailed instructions to the athletes to pause training during infections in order to prevent sudden death due to myocarditis.

Autosomal Recessive Cardiomyopathy Presenting as Acute Myocarditis

BACKGROUND

Myocarditis is inflammation of the heart muscle that can follow various viral infections. Why children only rarely develop life-threatening acute viral myocarditis (AVM), given that the causal viral infections are common, is unknown. Genetic lesions might underlie such susceptibilities. Mouse genetic studies demonstrated that interferon (IFN)-α/β immunity defects increased susceptibility to virus-induced myocarditis. Moreover, variations in human TLR3, a potent inducer of IFNs, were proposed to underlie AVM.

OBJECTIVES

This study sought to evaluate the hypothesis that human genetic factors may underlie AVM in previously healthy children.

METHODS

We tested the role of TLR3-IFN immunity using human induced pluripotent stem cell-derived cardiomyocytes. We then performed whole-exome sequencing of 42 unrelated children with acute myocarditis (AM), some with proven viral causes.

RESULTS

We found that TLR3- and STAT1-deficient cardiomyocytes were not more susceptible to Coxsackie virus B3 (CVB3) infection than control cells. Moreover, CVB3 did not induce IFN-α/β and IFN-α/β-stimulated genes in control cardiomyocytes. Finally, exogenous IFN-α did not substantially protect cardiomyocytes against CVB3. We did not observe a significant enrichment of rare variations in TLR3- or IFN-α/β-related genes. Surprisingly, we found that homozygous but not heterozygous rare variants in genes associated with inherited cardiomyopathies were significantly enriched in AM-AVM patients compared with healthy individuals (p = 2.22E-03) or patients with other diseases (p = 1.08E-04). Seven of 42 patients (16.7%) carried rare biallelic (homozygous or compound heterozygous) nonsynonymous or splice-site variations in 6 cardiomyopathy-associated genes (BAG3, DSP, PKP2, RYR2, SCN5A, or TNNI3).

CONCLUSIONS

Previously silent recessive defects of the myocardium may predispose to acute heart failure presenting as AM, notably after common viral infections in children.

Toward evidence-based diagnosis of myocarditis in children and adolescents: Rationale, design, and first baseline data of MYKKE, a multicenter registry and study platform

The aim of this registry is to provide data on age-related clinical features of suspected myocarditis and to create a study platform allowing for deriving diagnostic criteria and, at a later stage, testing therapeutic interventions in patients with myocarditis.

STUDY DESIGN AND RESULTS

After an initial 6-month pilot phase, MYKKE was opened in June 2014 as a prospective multicenter registry for patients from pediatric heart centers, university hospitals, and community hospitals with pediatric cardiology wards in Germany. Inclusion criteria consisted of age<18 years and hospitalization for suspected myocarditis as leading diagnosis at the discretion of the treating physician. By December 31, 2015, fifteen centers across Germany were actively participating and had enrolled 149 patients. Baseline data reveal 2 age peaks (<2 years, >12 years), show higher proportions of males, and document a high prevalence of severe disease courses in pediatric patients with suspected myocarditis. Severe clinical courses and early adverse events were more prevalent in younger patients and were related to severely impaired leftventricular ejection fraction at initial presentation.

SUMMARY

MYKKE represents a multicenter registry and research platform for children and adolescents with suspected myocarditis that achieve steady recruitment and generate a wide range of real-world data on clinical course, diagnostic workup, and treatment of this group of patients. The baseline data reveal the presence of 2 age peaks and provide important insights into the severity of disease in children with suspected myocarditis. In the future, MYKKE might facilitate interventional substudies by providing an established collaborating network using common diagnostic approaches.

Myocarditis in Paediatric Patients: Unveiling the Progression to Dilated Cardiomyopathy and Heart Failure

Myocarditis is a challenging and potentially life-threatening disease associated with high morbidity in some paediatric patients, due to its ability to present as an acute and fulminant disease and to ultimately progress to dilated cardiomyopathy. It has been described as an inflammatory disease of the myocardium caused by diverse aetiologies. Viral infection is the most frequent cause of myocarditis in developed countries, but bacterial and protozoal infections or drug hypersensitivity may also be causative agents. The prompt diagnosis in paediatric patients is difficult, as the spectrum of clinical manifestation can range from no myocardial dysfunction to sudden cardiac death. Recent studies on myocarditis pathogenesis have revealed a triphasic nature of this disease, which influences the diagnostic and therapeutic strategies to adopt in each patient. Endomyocardial biopsy remains the gold standard for diagnosing myocarditis, and several non-invasive diagnostic tools can be used to support the diagnosis. Intravenous immunoglobulin has become part of routine practice in the treatment of myocarditis in paediatric patients at many centres, but its true effect on the cardiac function has been the target of many studies. The aim of this review is to approach the recently discovered facets of paediatric myocarditis regarding its progression to dilated cardiomyopathy.

Lyme Myocarditis Presenting as Chest Pain in an Adolescent Girl

A previously healthy adolescent girl presented to the emergency department with new onset chest and right upper quadrant abdominal pain. Laboratory studies and imaging were consistent with myocarditis. She developed heart block after admission and required stabilization in the cardiac intensive care unit. Lyme serology returned positive, and her condition was diagnosed as Lyme disease-associated myocarditis.

Exercise-Triggered Chest Pain as an Isolated Symptom of Myocarditis in Children

In childhood, chest pain occurring at exercise is a common complaint. A cardiac etiology for it is exceptionally found, explaining that most children do not undergo systematic cardiological investigation. However, chest pain at exercise may manifest as the unique symptom of a viral myocarditis. Recognizing this form of myocardial injury, however, might help to avoid clinical deterioration by providing adequate care. In this paper, we report on two children presenting with the unique clinical symptom of chest pain related to physical activity and in whom laboratory and cardiac investigations suggested transient myocardial damage related to myocarditis.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Immune Therapy

OBJECTIVE

In this Consensus Statement, we review the etiology and pathophysiology of inflammatory processes seen in critically ill children with cardiac disease. Immunomodulatory therapies aimed at improving outcomes in patients with myocarditis, heart failure, and transplantation are extensively reviewed.

DATA SOURCES

The author team experience and along with an extensive review of the medical literature were used as data sources.

DATA SYNTHESIS

The authors synthesized the data in the literature to present current immumodulatory therapies. For each drug, the physiologic rationale, mechanism of action, and pharmacokinetics are synthesized, and the evidence in the literature to support the therapy is discussed.

CONCLUSIONS

Immunomodulation has a crucial role in the treatment of certain pediatric cardiac diseases. Immunomodulatory treatments that have been used to treat myocarditis include corticosteroids, IV immunoglobulin, cyclosporine, and azathioprine. Contemporary outcomes of pediatric transplant recipients have improved over the past few decades, partly related to improvements in immunomodulatory therapy to prevent rejection of the donor heart. Immunosuppression therapy is commonly divided into induction, maintenance, and acute rejection therapy. Common induction medications include antithymocyte globulin, muromonab-CD3, and basiliximab. Maintenance therapy includes chronic medications that are used daily to prevent rejection episodes. Examples of maintenance medications are corticosteroids, cyclosporine, tacrolimus, sirolimus, everolimus, azathioprine, and mycophenolate mofetil. Rejection of the donor heart is diagnosed either by clinically or by biopsy and is treated with intensification of immunosuppression.

Analysis of clinical parameters and cardiac magnetic resonance imaging as predictors of outcome in pediatric myocarditis

Myocarditis causes significant morbidity and mortality in pediatric patients, with potential adverse outcomes including heart failure, transplantation requirement, and/or death. The objective of this study was to determine predictors of early and late poor outcomes, defined as requirement for extracorporeal membrane oxygenation, ventricular assist device, transplantation, or death in pediatric myocarditis patients. A retrospective cohort study was conducted to evaluate pediatric myocarditis presenting over a 5-year period at a pediatric institution. Patients were identified using an institutional heart failure database and International Classification of Diseases, Ninth Revision, discharge diagnosis codes for myocarditis and confirmed by review of medical records. Data extraction included epidemiologic factors, the presenting ejection fraction (EF), initial and peak troponin levels, brain natriuretic peptide (BNP) level, pathogen identification, cardiac magnetic resonance imaging (MRI), and outcomes. Univariate and multivariate regression was performed to identify variables predictive of outcomes. Because published pediatric cardiac MRI data are sparse, whether late enhancement was associated with specific clinical variables or predictive of outcomes was also evaluated. Fifty-eight patients were identified. The mean age was 10.5 years, 64% were male, 62% were Caucasian, 15% were African-American, and 23% were Hispanic or Asian. Eighty-one percent presented at the institution <1 week after symptom onset. Presenting EFs were normal (>50%) or mildly decreased (40% to 50%) in 48%, moderately decreased (30% to 40%) in 9%, and severely decreased (<30%) in 42%. Thirty patients (52%) underwent viral studies; 17 of these (56%) had acute viral origins of myocarditis identified, including 8 with parvovirus (2 with influenza coinfection), 7 with enterovirus, 1 with Epstein-Barr virus, and 1 with cytomegalovirus. Twenty-eight percent had poor outcomes. Univariate analysis identified Hispanic or Asian race (odds ratio [OR] 4.5, p = 0.05), a severely decreased EF (OR 13, p = 0.002), initial BNP >10,000 pg/ml (OR 5.6, p = 0.01), and peak BNP >10,000 pg/ml (OR 13.65, p = 0.001) as risk factors for poor outcomes; initial and peak troponin >1 ng/ml were correlated significantly with good outcomes (OR 0.22, p = 0.04, and OR 0.26, p = 0.05, respectively). Multivariate analysis adjusting for severe EF, troponin, BNP, and cardiac MRI revealed peak BNP >10,000 ng/L (OR 27.71, p = 0.04), a severely decreased EF (OR 12.8, p = 0.03), and late enhancement on cardiac MRI (OR 24.51, p = 0.04) as risk factors for poor outcomes. Thirty-four patients underwent cardiac MRI (50% with abnormal and 50% with normal results). No significant differences were found between these groups with respect to gender, race, symptom duration, the EF, BNP, troponin, inflammation on cardiac biopsy, or pathogen identification. In conclusion, this study provides data from a large cohort of pediatric myocarditis patients. A presenting EF <30%, peak BNP >10,000 ng/L, and cardiac MRI late enhancement were identified as predictors of poor outcomes.

Prevalence of myocarditis in pediatric intensive care unit cases presenting with other system involvement

OBJECTIVE

To assess children with myocarditis, the frequency of various presenting symptoms, and the accuracy of different investigations in the diagnosis.

METHODS

This was an observational study of 63 patients admitted to PICU with non-cardiac diagnosis. Cardiac enzymes, chest-X ray, echocardiography, and electrocardiogram were performed to diagnose myocarditis among those patients.

RESULTS

There were 16 cases of definite myocarditis. The age distribution was non-normal, with median of 5.5 months (3.25-21). Of the 16 patients who were diagnosed with myocarditis, 62.5% were originally diagnosed as having respiratory problems, and there were more females than males. Among the present cases, the accuracy of cardiac enzymes (cardiac troponin T [cTn] and creatine phosphokinase MB [CKMB]) in the diagnosis of myocarditis was only 63.5%, while the accuracy of low fractional shortening and of chest-X ray cardiomegaly was 85.7 and 80.9%; respectively. Cardiac troponin folds 2.02 had positive predictive value of 100%, negative predictive value of 88.7%, specificity of 100%, sensitivity of 62.5%, and accuracy of 90.5%.

CONCLUSIONS

Children with myocarditis present with symptoms that can be mistaken for other types of illnesses. When clinical suspicion of myocarditis exists, chest-X ray and echocardiography are sufficient as screening tests. Cardiac troponins confirm the diagnosis in screened cases, with specificity of 100%.

Targeting matrix metalloproteinase activity and expression for the treatment of viral myocarditis

Infectious agents including viruses can infect the heart muscle, resulting in the development of heart inflammation called myocarditis. Chronic myocarditis can lead to dilated cardiomyopathy (DCM). DCM develops from the extensive extracellular matrix (ECM) remodeling caused by myocarditis and may result in heart failure. Epidemiological data for viral myocarditis has long suggested a worse pathology in males, with more recent data demonstrating sex-dependent pathogenesis in DCM as well. Matrix metalloproteinases (MMPs), long known modulators of the extracellular matrix, have important roles in mediating heart inflammation and remodeling during disease and in convalescence. This ability of MMPs to control both the inflammatory response and ECM remodeling during myocarditis makes them potential drug targets. In this review, we analyze the role of MMPs in mediating myocarditis/DCM disease progression, their sex-dependent expression, and their potential as drug targets during viral myocarditis and DCM.

Prevalence and spectrum diseases predisposing to sudden cardiac death: are they the same for both the athlete and the nonathlete?

Sudden cardiac death (SCD) is a rare but devastating event among young people. The precise scale of the event remains undefined. This uncommon but catastrophic event usually is proved to be the consequence of varied unsuspected congenital or acquired cardiovascular diseases. Hypertrophic cardiomyopathy and coronary artery anomalies are the two most frequent causes of SCD. Most commonly, SCD resulting from these diseases occurs during or immediately after exercise. This report highlights the prevalence and spectrum of SCD-predisposing diseases and how they are affected by athletic participation. In addition, disease-specific guidelines for sports participation are addressed.