Suspected chronic myocarditis at cardiac MR: diagnostic accuracy and association with immunohistologically detected inflammation and viral persistence

Results From the Big Ten COVID-19 Cardiac Registry: Impact of SARS-COV-2 on Myocardial Involvement

OBJECTIVE

COVID-19 has been associated with myocardial involvement in collegiate athletes. The first report from the Big Ten COVID-19 Cardiac Registry (Registry) was an ecological study that reported myocarditis in 37 of 1597 athletes (2.3%) based on local clinical diagnosis. Our objective was to assess the relationship between athlete and clinical characteristics and myocardial involvement.

DESIGN

Cross-sectional study.

SETTING

We analyzed data from 1218 COVID-19 positive Big Ten collegiate athletes who provided informed consent to participate in the Registry.

PARTICIPANTS

1218 athletes with a COVID-19-positive PCR test before June 1, 2021.

ASSESSMENT OF INDEPENDENT VARIABLES

Demographic and clinical characteristics of athletes were obtained from the medical record.

MAIN OUTCOME MEASURES

Myocardial involvement was diagnosed based on local clinical, cardiac magnetic resonance (CMR), electrocardiography, troponin assay, and echocardiography. We assessed the association of clinical factors with myocardial involvement using logistic regression and estimated the area under the receiver operating characteristic (ROC) curve.

RESULTS

25 of 1218 (2.0%) athletes met criteria for myocardial involvement. The logistic regression model used to predict myocardial involvement contained indicator variables for chest pain, new exercise intolerance, abnormal echocardiogram (echo), and abnormal troponin. The area under the ROC curve for these indicators was 0.714. The presence of any of these 4 factors in a collegiate athlete who tested positive for COVID-19 would capture 55.6% of cases. Among noncases without missing data, 86.9% would not be flagged for possible myocardial involvement.

CONCLUSION

Myocardial involvement was infrequent. We predicted case status with good specificity but deficient sensitivity. A diagnostic approach for myocardial involvement based exclusively on symptoms would be less sensitive than one based on symptoms, echo, and troponin level evaluations. Abnormality of any of these evaluations would be an indication for CMR.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

Differentiation of acute non-ST elevation myocardial infarction and acute infarct-like myocarditis by visual pattern analysis: a head-to-head comparison of different cardiac MR techniques

OBJECTIVES

Parametric cardiac magnetic resonance (CMR) techniques have improved the diagnosis of pathologies. However, the primary tool for differentiating non-ST elevation myocardial infarction (NSTEMI) from myocarditis is still a visual assessment of conventional signal-intensity-based images. This study aimed at analyzing the ability of parametric compared to conventional techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns.

METHODS

Twenty NSTEMI patients, twenty infarct-like myocarditis patients, and twenty controls were examined using cine, T2-weighted CMR (T2w) and late gadolinium enhancement (LGE) imaging and T1/T2 mapping on a 1.5 T scanner. CMR images were presented in random order to two experienced fully blinded observers, who had to assign them to three categories by a visual analysis: NSTEMI, myocarditis, or healthy.

RESULTS

The conventional approach (cine, T2w and LGE combined) had the best diagnostic accuracy with 92% (95%CI: 81-97) for NSTEMI and 86% (95%CI: 71-94) for myocarditis. The diagnostic accuracies using T1 maps were 88% (95%CI: 74-95) and 80% (95%CI: 62-91), 84% (95%CI: 67-93) and 74% (95%CI: 54-87) for LGE, and 83% (95%CI: 66-92) and 73% (95%CI: 53-87) for T2w. The accuracies for cine (72% (95%CI: 52-86) and 60% (95%CI: 38-78)) and T2 maps (62% (95%CI: 40-79) and 47% (95%CI: 28-68)) were significantly lower compared to the conventional approach (p < 0.001 and p < 0.0001).

CONCLUSIONS

The conventional approach provided a reliable visual discrimination between NSTEMI, myocarditis, and controls. The diagnostic accuracy of a visual pattern analysis of T1 maps was not significantly inferior, whereas the diagnostic accuracy of T2 maps was not sufficient in this context.

CLINICAL RELEVANCE STATEMENT

The ability of parametric compared to conventional CMR techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns can avoid potentially unnecessary invasive coronary angiography and help to shorten CMR protocols and to reduce the need of gadolinium contrast agents.

KEY POINTS

• A visual differentiation of ischemic from non-ischemic patterns of myocardial injury is reliably achieved by a combination of conventional CMR techniques (cine, T2-weighted and LGE imaging). • There is no significant difference in accuracies between visual pattern analysis on native T1 maps without providing quantitative values and a conventional combined approach for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls. • T2 maps do not provide a sufficient diagnostic accuracy for visual pattern analysis for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.

SARS-CoV-2-Induced Myocarditis: A State-of-the-Art Review

In this review, we investigated whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can directly cause myocarditis with severe myocardial damage induced by viral particles. A review of the major data published from 2020 to 2022 was performed by consulting the major databases alongside first-hand experiences that emerged from the cardiac biopsies and autopsy examinations of patients who died of SARS-CoV-2 infections. From this study, a significantly large amount of data suggests that the Dallas criteria were met in a residual percentage of patients, demonstrating that SARS-CoV-2 myocarditis was a rare clinical and pathological entity that occurred in a small percentage of subjects. All cases described here were highly selected and subjected to autopsies or endomyocardial biopsies (EMBs). The most important discovery, through the detection of the SARS-CoV-2 genome using the polymerase chain reaction, consisted in the presence of the viral genome in the lung tissue of most of the patients who died from COVID-19. However, the discovery of the SARS-CoV-2 viral genome was a rare event in cardiac tissue from autopsy findings of patients who died of myocarditis It is important to emphasize that myocardial inflammation alone, as promoted by macrophages and T cell infiltrations, can be observed in noninfectious deaths and COVID-19 cases, but the extent of each cause is varied, and in neither case have such findings been reported to support clinically relevant myocarditis. Therefore, in the different infected vs. non-infected samples examined, none of our findings provide a definitive histochemical assessment for the diagnosis of myocarditis in the majority of cases evaluated. We report evidence suggesting an extremely low frequency of viral myocarditis that has also been associated with unclear therapeutic implications. These two key factors strongly point towards the use of an endomyocardial biopsy to irrefutably reach a diagnosis of viral myocarditis in the context of COVID-19.

COVID-19: The Many Ways to Hurt Your Heart

Coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has become a global pandemic, affecting the lives of billions of individuals [...].

Clinical Utilization of Multimodality Imaging for Myocarditis and Cardiac Sarcoidosis

Myocarditis is defined as inflammation of the myocardium according to clinical, histological, biochemical, immunohistochemical, or imaging findings. Inflammation can be categorized histologically by cell type or pattern, and many causes have been implicated, including infectious, most commonly viral, systemic autoimmune diseases, vaccine-associated processes, environmental factors, toxins, and hypersensitivity to drugs. Sarcoid myocarditis is increasingly recognized as an important cause of cardiomyopathy and has important diagnostic, prognostic, and therapeutic implications in patients with systemic sarcoidosis. The clinical presentation of myocarditis may include an asymptomatic, subacute, acute, fulminant, or chronic course and may have focal or diffuse involvement of the myocardium depending on the cause and time point of the disease. For most causes of myocarditis except sarcoidosis, myocardial biopsy is the gold standard but is limited due to risk, cost, availability, and variable sensitivity. Diagnostic criteria have been established for both myocarditis and cardiac sarcoidosis and include clinical and imaging findings particularly the use of cardiac magnetic resonance and positron emission tomography. Beyond diagnosis, imaging findings may also provide prognostic value. This case-based review focuses on the current state of multimodality imaging for the diagnosis and management of myocarditis and cardiac sarcoidosis, highlighting multimodality imaging approaches with practical clinical vignettes, with a discussion of knowledge gaps and future directions.

Comparing the findings and diagnostic sensitivity of cardiovascular magnetic resonance in biopsy confirmed acute myocarditis with infarct-like vs. heart failure presentation

BACKGROUND

Cardiovascular magnetic resonance (CMR) is considered the reference imaging modality in providing a non-invasive diagnosis of acute myocarditis (AM), as it allows for the detection of myocardial injury associated with AM. However, the diagnostic sensitivity and pattern of CMR findings appear to differ according to clinical presentation.

METHODS

This is a retrospective cross-sectional study. Consecutive adult patients presenting to a single tertiary centre in South Africa between August 2017 and January 2022 with AM confirmed on endomyocardial biopsy (EMB) were enrolled. Patients with infarct-like symptoms, defined as those presenting primarily with chest pain syndrome with associated ST-T wave changes on electrocardiogram, or heart failure (HF) symptoms, defined as clinical signs and symptoms of HF without significant chest discomfort, were compared using contrasted CMR and parametric techniques with EMB confirmation of AM as diagnostic gold standard.

RESULTS

Forty-one patients were identified including 23 (56%) with infarct-like symptoms and 18 (44%) with HF symptoms. On CMR, the infarct-like group had significantly higher ejection fractions of both ventricles (LVEF 55.3 ± 15.3% vs. 34.4 ± 13.5%, p < 0.001; RVEF 57.3 ± 10.9% vs. 42.9 ± 18.2%, p = 0.008), without significant differences in end diastolic volumes (LVEDVI 82.7 ± 30.3 ml/m2 vs. 103.4 ± 35.9 ml/m2, p = 0.06; RVEDVI 73.7 ± 22.1 ml/m2 vs. 83.9 ± 29.9 ml/m2, p = 0.25). Myocardial oedema was detected more frequently on T2-weighted imaging (91.3% vs. 61.1%, p = 0.03) and in more myocardial segments [3.0 (IQR 2.0-4.0) vs. 1.0 (IQR 0-1.0), p = 0.003] in the infarct-like group. Despite the absence of a significant statistical difference in the prevalence of late gadolinium enhancement (LGE) between the two groups (95.7% vs. 72.2%, p = 0.07), the infarct-like group had LGE detectable in significantly more ventricular segments [4.5 (IQR 2.3-6.0) vs. 2.0 (IQR 0-3.3), p = 0.02] and in a different distribution. The sensitivity of the original Lake Louise Criteria (LLC) was 91.3% in infarct-like patients and 55.6% in HF patients. When the updated LLC, which included the use of parametric myocardial mapping techniques, were applied, the sensitivity improved to 95.7% and 72.2% respectively.

CONCLUSION

The pattern of CMR findings and its diagnostic sensitivity appears to differ in AM patients presenting with infarct-like and HF symptoms. Although the sensitivity of the LLC improved with the addition of parametric mapping in the HF group, it remained lower than that of the infarct-like group, and suggests that EMB should be considered earlier in the course of patients with clinically suspected AM presenting with HF.

[Diagnostic and prognostic utility of cardiac magnetic resonance imaging in myocarditis]

Cardiac magnetic resonance imaging (CMR) became over the last 30 years an essential tool in the management of patients with myocarditis. Noninvasive diagnosis of acute myocarditis relies on a clinical picture compatible with myocarditis and fulfilling of the updated 2018 Lake Louise criteria. These criteria include highlights of myocardial edema by conventional T2-weighted sequences or by T2 mapping in one hand and evidence of myocardial injury using late gadolinium enhancement sequences, T1 mapping or extra-cellular volume measurement in the other hand. It is recommended to perform basal examination in the 2 or 3 weeks following acute episode and to repeat CMR during follow-up. The literature reports excellent diagnostic accuracy, between 80% and 90%, making CMR a robust and reliable noninvasive alternative to endomyocardial biopsy. Besides, beyond its diagnostic performance, CMR can also help to identify patients with unfavourable long-term outcome. For instance, medio-ventricular and septal location of late gadolinium enhancement, degree of late gadolinium enhancement extent or high T2 mapping values are independent predictive factors of major cardio-vascular events.

Patterns of cardiovascular magnetic resonance inflammation in acute myocarditis from South Asia and Middle East

Background

Cardiovascular magnetic resonance (CMR) is the test of choice for diagnosis and risk stratification of myocardial inflammation in acute viral myocarditis. The objective of this study was to assess patterns of CMR inflammation in a cohort of acute myocarditis patients from Northern Africa, Asia, and the Middle East using unsupervised machine learning.

Methods

A total of 169 racially and ethnically diverse adults (≥18 years of age) with CMR confirmed acute myocarditis were studied. The primary outcome was a combined clinical endpoint of cardiac death, arrhythmia, and dilated cardiomyopathy. Machine learning was used for exploratory analysis to identify patterns of CMR inflammation.

Results

Our cohort was diverse with 25% from Northern Africa, 33% from Southern Asia, and 28% from Western Asia/the Middle East. Twelve patients met the combined clinical endpoint – 3 had arrythmia, 8 had dilated cardiomyopathy, and 1 died. Patients who met the combined endpoint had increased anterior (p = 0.034) and septal (p = 0.042) late gadolinium enhancement (LGE). Multivariable logistic regression, adjusted for age, gender, and BMI, found that patients from Southern Asia (p = 0.041) and the Middle East (p = 0.043) were independently associated with lateral LGE. Unsupervised machine learning and factor analysis identified two distinct CMR patterns of inflammation, one with increased LGE and the other with increased myocardial T1/T2.

Conclusions

We found that anteroseptal inflammation is associated with worsened outcomes. Using machine learning, we identified two patterns of myocardial inflammation in acute myocarditis from CMR in a racially and ethnically diverse group of patients from Southern Asia, Northern Africa, and the Middle East.

Cardiac Involvement in Human Immunodeficiency Virus Infected Patients: An Observational Cardiac Magnetic Resonance Study

Objectives: To investigate the subclinical imaging changes in terms of myocardial inflammation and fibrosis and to explore the risk factors associated with myocardial fibrosis by cardiac magnetic resonance (CMR) approach in a Chinese HIV/AIDS cohort.

Methods: We evaluated myocardial function (cine), myocardial inflammation (T1, T2), and myocardial fibrosis (through extracellular volume fraction [ECV] and late gadolinium enhancement [LGE]) by a multiparametric CMR scan protocol in a total of 68 participants, including 47 HIV-infected individuals, who were divided into two groups: asymptomatic HIV (HIV+) (n = 30), and acquired immunodeficiency syndrome (AIDS) (n = 17), and 21 healthy controls.

Results: HIV-infected patients had lower left (55.3 ± 6.5 vs. 63.0 ± 7.9%, P < 0.001) and right ventricular systolic function (35.9 ± 15.7 vs. 50.8 ± 9.3%, P < 0.001). Radial systolic strain (30.7 ± 9.3 vs. 39.3 ± 9.4%, P = 0.001), circumferential systolic strain (−17.5 ± 2.6 vs. −19.4 ± 2.7%, P = 0.008), and longitudinal systolic strain (−9.4 ± 5.7 vs. −12.8 ± 3.1%, P = 0.012) were also decreased in HIV. Native T1 relaxation time (1,337.2 ± 70.2 vs. 1,249.5 ± 47.0 ms, P < 0.001), ECV value (33.5 ± 6.2 vs. 28.5 ± 2.9 ms, P = 0.026), and T2 relaxation time (45.2 ± 3.5 vs. 42.0 ± 2.6 ms, P = 0.001) were higher in HIV-infected patients compared with controls. Myocardial fibrosis, predominantly in the mid-inferior wall, was detected in 24.4% of the HIV-infected patients. HIV+ had a significantly lower value of ECV [29.1 (26.1, 31.8) vs. 35.2 (31.8, 41.9) %, P < 0.001] and frequency of LGE [3/25 (8%) vs. 7/16 (43.8%), P = 0.014)] compared with AIDS. AIDS was associated with myocardial fibrosis.

Conclusions: HIV-infected patients were associated with changes in myocardial function and higher rates of subclinical myocardial inflammation and fibrosis, which were more abnormal with greater severity of the disease. AIDS was associated with myocardial fibrosis, where the observations supported earlier initiation of antiretroviral therapy in the Chinese HIV/AIDS cohort.

Evaluating the relationship between myocarditis and mRNA vaccination

Introduction

Inflammatory conditions affecting the heart and surrounding tissues have been recently reported following mRNA vaccination. Evaluating trends in the epidemiology of these events and possible mechanisms related to vaccination will enhance vaccine safety surveillance and inform best practices for future vaccine campaigns.

Areas covered

Epidemiology of the burden of vaccine-associated myocarditis are reviewed. Key summaries of available data from public health advisory bodies and vaccine safety surveillance databases are critically reviewed. The possible biological pathways for vaccine-associated heart inflammations are introduced. A critical synthesis of available information to inform vaccine recommendations and best practices is provided. The citations were selected by the authors based on PubMed searches of the literature, national vaccine safety surveillance databases and summaries from national public health bodies.

Expert opinion

Myocarditis may be associated with vaccination, through several biological mechanisms. Studies have shown that live viral vaccinations can act as a trigger for hypersensitivity inflammatory reactions, but further work is required to examine how the mRNA formulation may induce these autoimmune responses. Given that the risk of these adverse events is low, and the benefit of protection against disease is so great, the receipt of mRNA vaccines is recommended.

Viral Myocarditis-From Pathophysiology to Treatment

The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.

Subendocardial Involvement as an Underrecognized Cardiac MRI Phenotype in Myocarditis

Background Subendocardial late gadolinium enhancement (LGE) detected with cardiac MRI in myocarditis represents a diagnostic dilemma, since it may resemble myocardial ischemia. Purpose To explore and compare the histopathologic characteristics and clinical features and outcomes in patients with myocarditis with and without subendocardial involvement at cardiac MRI. Materials and Methods This retrospective study evaluated 39 patients with myocarditis pathologically proven by means of either endomyocardial biopsy or explant pathologic findings between 2015 and 2020. Patients were divided into two groups according to cardiac MRI phenotype: 18 with subendocardial involvement (mean age ± standard deviation, 40 years ± 17; 10 women) and 21 with no subendocardial involvement (mean age, 35 years ± 11; six women). The median follow-up period was 784 days (interquartile range [IQR], 90-1123 days). The Student t test, Mann-Whitney U test, and univariable Cox regression were used for statistical analyses. Results In the 18 patients with subendocardial involvement, 12 (67%) had lymphocytic myocarditis and six (33%) had giant cell myocarditis. Patients with subendocardial involvement compared with those without subendocardial involvement had lower left ventricular ejection fraction (mean ± standard deviation, 27% ± 11 vs 41% ± 19; P = .004), larger LGE extent (median, 13% [IQR, 10%-22%] vs 5% [IQR, 2%-17%]; P < .001), higher rates of cardiac death or transplant (eight of 18 patients [44%] vs one of 21 patients [4.8%]; P = .006), higher probability of giant cell myocarditis (six of 18 [33%] vs one of 21 [4.8%]; P = .02), and more major adverse cardiovascular events (MACE) (15 of 18 [83%] vs seven of 21 [33%]; P = .002). In a subgroup of patients with comparable LGE extent (median, 15% vs 16%; P = .40) and left ventricular ejection fraction (median, 27% vs 31%; P = .26), the prognostic difference in terms of MACE remained (15 of 17 patients [88%] vs five of 10 [50%]; P = .02). Conclusion Subendocardial involvement detected with cardiac MRI in myocarditis indicated more severe clinical features, including a higher frequency of severe lymphocytic myocarditis or giant cell myocarditis and worse prognosis. © RSNA, 2021 See also the editorial by de Roos in this issue.

Cardiovascular consequences of viral infections: from COVID to other viral diseases

Infection of the heart muscle with cardiotropic viruses is one of the major aetiologies of myocarditis and acute and chronic inflammatory cardiomyopathy (DCMi). However, viral myocarditis and subsequent dilated cardiomyopathy is still a challenging disease to diagnose and to treat and is therefore a significant public health issue globally. Advances in clinical examination and thorough molecular genetic analysis of intramyocardial viruses and their activation status have incrementally improved our understanding of molecular pathogenesis and pathophysiology of viral infections of the heart muscle. To date, several cardiotropic viruses have been implicated as causes of myocarditis and DCMi. These include, among others, classical cardiotropic enteroviruses (Coxsackieviruses B), the most commonly detected parvovirus B19, and human herpes virus 6. A newcomer is the respiratory virus that has triggered the worst pandemic in a century, SARS-CoV-2, whose involvement and impact in viral cardiovascular disease is under scrutiny. Despite extensive research into the pathomechanisms of viral infections of the cardiovascular system, our knowledge regarding their treatment and management is still incomplete. Accordingly, in this review, we aim to explore and summarize the current knowledge and available evidence on viral infections of the heart. We focus on diagnostics, clinical relevance and cardiovascular consequences, pathophysiology, and current and novel treatment strategies.

Acute Myocarditis in Children: An Overview of Treatment and Recent Patents

BACKGROUND

Pediatric myocarditis is rare but challenging. This overview summarized the current knowledge and recent patents on childhood myocarditis.

METHODS

Clinical queries and keywords of "myocarditis" and "childhood" were used as search engine.

RESULTS

Viral infections are the most common causes of acute myocarditis. Affected children often have a prodrome of fever, malaise, and myalgia. Clinical manifestations of acute myocarditis in children can be nonspecific. Some children may present with easy fatigability, poor appetite, vomiting, abdominal pain, exercise intolerance, respiratory distress/tachypnea, dyspnea at rest, orthopnea, chronic cough with wheezing, chest pain, unexplained tachycardia, hypotension, syncope, and hepatomegaly. Supraventricular arrhythmias, ventricular arrhythmias, and heart block may be present. A subset of patients have fulminant myocarditis and present with cardiovascular collapse, which may progress to severe cardiogenic shock, and even death. A high index of suspicion is crucial to its diagnosis and timely management. Cardiac magnetic resonance imaging is important in aiding clinical diagnosis while, endomyocardial biopsy remains the gold standard. The treatment consists of supportive therapy, ranging from supplemental oxygen and fluid restriction to mechanical circulatory support. Angiotensinconverting enzyme inhibitors, angio-tensin II receptor blockers, β-blockers, and aldosterone antagonists might be used for the treatment of heart failure while, immunosuppression treatments remain controversial. There are a few recent patents targeting prevention or treatment of viral myocarditis, including an immunogenic composition comprising a PCV-2 antigen, glutathione-S-transferase P1, neuregulins, NF-[kappa] B inhibitor, a pharmaceutical composition which contains 2-amino-2- (2- (4-octyl phenyl) - ethyl) propane 1,3-diol, a composition containing pycnojenol, Chinese herbal concoctions, and a Korean oral rapamycin. Evidence of their efficacy is still lacking.

CONCLUSION

This article reviews the current literature regarding etiology, clinical manifestations, diagnosis, and management of acute myocarditis in children.

Cardiac Magnetic Resonance Imaging Findings in 2954 COVID-19 Adult Survivors: A Comprehensive Systematic Review

Background

Recent studies have utilized MRI to determine the extent to which COVID‐19 survivors may experience cardiac sequels after recovery.

Purpose

To systematically review the main cardiac MRI findings in COVID‐19 adult survivors.

Study type

Systematic review.

Subjects

A total of 2954 COVID‐19 adult survivors from 16 studies.

Field Strength/sequence

Late gadolinium enhancement (LGE), parametric mapping (T1‐native, T2, T1‐post (extracellular volume fraction [ECV]), T2‐weighted sequences (myocardium/pericardium), at 1.5 T and 3  T.

Assessment

A systematic search was performed on PubMed, Embase, and Google scholar databases using Boolean operators and the relevant key terms covering COVID‐19, cardiac injury, CMR, and follow‐up. MRI data, including (if available) T1, T2, extra cellular volume, presence of myocardial or pericardial late gadolinium enhancement (LGE) and left and right ventricular ejection fraction were extracted.

Statistical Tests

The main results of the included studies are summarized. No additional statistical analysis was performed.

Results

Of 1601 articles retrieved from the initial search, 12 cohorts and 10 case series met our eligibility criteria. The rate of raised T1 in COVID‐19 adult survivors varied across studies from 0% to 73%. Raised T2 was detected in none of patients in 4 out of 15 studies, and in the remaining studies, its rate ranged from 2% to 60%. In most studies, LGE (myocardial or pericardial) was observed in COVID‐19 survivors, the rate ranging from 4% to 100%. Myocardial LGE mainly had nonischemic patterns. None of the cohort studies observed myocardial LGE in “healthy” controls. Most studies found that patients who recovered from COVID‐19 had a significantly greater T1 and T2 compared to participants in the corresponding control group.

Data Conclusion

Findings of MRI studies suggest the presence of myocardial and pericardial involvement in a notable number of patients recovered from COVID‐19.

Level of Evidence

3

Technical Efficacy Stage

3

The potential role of plasma miR-155 and miR-206 as circulatory biomarkers in inflammatory cardiomyopathy

AIMS

Establishing a diagnosis of inflammatory cardiomyopathy (iCMP) by non-invasive means remains challenging despite advances in cardiac magnetic resonance imaging. Previous studies suggested the involvement of microRNAs in the pathogenesis of iCMP. We examined the association of a predefined set of circulatory microRNAs with clinical characteristics of iCMP and evaluated their diagnostic performance in suspected iCMP.

METHODS AND RESULTS

Eighty-nine patients with clinical suspicion of iCMP were included in the analysis. All patients underwent cardiac catheterization with left ventricular endomyocardial biopsy, echocardiography, and cardiac magnetic resonance imaging applying the Lake Louise criteria (LLC). Plasma levels of miR-21, miR-126, miR-133a, miR-146b, miR-155, and miR-206 were determined using real-time polymerase chain reaction. Based on immunohistological findings on endomyocardial biopsy, iCMP was diagnosed in 67% of study participants (n = 60). Plasma levels of miR-155 and miR-206 were significantly increased in patients with iCMP as compared with patients with dilated cardiomyopathy (P = 0.008 and P = 0.009, respectively). In receiver operating characteristic curve analysis, miR-155 and miR-206 demonstrated superior diagnostic performance for iCMP (0.68 and 0.67, respectively) compared with LLC [area under the curve (AUC) 0.60], Troponin T (AUC 0.51), and N-terminal pro-brain natriuretic peptide (AUC 0.51). While baseline miR-155 and miR-206 plasma levels were predictive for biopsy-proven iCMP (odds ratio = 2.61, 95% confidence interval = 1.28-5.31, P = 0.008 and odds ratio = 2.65, 95% confidence interval = 1.27-5.52, P = 0.009) on univariate logistic regression analysis, the presence of positive LLC, high baseline C-reactive protein, or presence of clinical symptoms and signs of viral infection failed to predict iCMP (P > 0.05, respectively).

CONCLUSIONS

The present data suggest that plasma levels of miR-206 and miR-155 are potential novel biomarkers for confirming the diagnosis of iCMP.

COVID-19 myocarditis and prospective heart failure burden

Introduction: COVID-19 is causing considerable morbidity and mortality worldwide. Serious respiratory complications aside, the heart is also frequently involved. The mechanisms and the extent of the myocardial injury, along with the short and long-term cardiovascular (CV) outcomes in COVID-19 survivors remain unclear. Areas covered: myocardial injury has been found in a considerable proportion of hospitalized COVID-19 patients and is associated with a worse prognosis. The late onset of CV complications with myocarditis-like changes revealed by CMR has been reported in COVID-19 survivors. Previous observational studies on viral myocarditis provide evidence of a significant incomplete recovery with residual dysfunction and remodeling of left ventricle. Incomplete recovery is thought to be the result of persistent myocardial inflammation due to a post-viral autoimmune response. Considering the significant inflammatory nature of COVID-19, COVID-19 survivors may be at risk of developing persistent residual myocardial injury, the sequelae of which are unclear. Expert commentary: COVID-19 is an emerging threat for the heart. The extent of CV injury, along with the short and long-term sequelae, requires further investigation. The early detection of residual myocardial changes in COVID-19 survivors is of utmost importance in order to identify those patients at risk of CV complication development.

Diagnostic value of 3.0 T cardiac MRI in children with suspected myocarditis: multi-parameter analysis for the evaluation of acute and chronic myocarditis

BACKGROUND

Cardiac magnetic resonance (CMR) is an established tool for detection of myocarditis. However, no comprehensive data for CMR based on the "Lake Louise" criteria in pediatric myocarditis exists to date.

PURPOSE

To evaluate the value of multi-parameter CMR in children with suspected acute (AMC) and chronic myocarditis (CMC).

MATERIAL AND METHODS

We examined 73 pediatric patients with clinically suspected AMC (n = 25) and CMC (n = 48). We compared them to 17 controls. All individuals underwent CMR, including function analyses, T2 ratio, early gadolinium enhancement ratio (EGEr), and late gadolinium enhancement (LGE).

RESULTS

In AMC, 19 (76%) patients were abnormal in any two of three parameters (T2 ratio, EGEr, and LGE). There was a significant difference between AMC and controls in LVEF (51.2% vs. 61.3%), mass (130.2 ± 14.0 vs. 120.5 ± 13.9 g), T2 ratio (1.96 ± 0.2 vs. 1.69 ± 0.13), and EGEr (4.1 ± 0.27 vs. 3.4 ± 0.39) (P < 0.05). In CMC, 26 (54.1%) patients were abnormal in any two of three parameters. There was no significant difference between CMC and controls in LVEF and mass, but there was a statistical difference in T2 ratio (1.88 ± 0.18 vs. 1.69 ± 0.13) and in EGEr (3.93 ± 0.22 vs. 3.4 ± 0.39) (P < 0.05). There was an increase in LVEF while both T2 ratio and EGEr significantly decreased (P < 0.05) during follow-up of acute fulminant myocarditis.

CONCLUSION

Comprehensive CMR may serve as a powerful tool in children with suspected AMC. CMR in assessment of CMC may be valuable, but it is not satisfactory.

Recent Advances in T1 and T2 Mapping in the Assessment of Fulminant Myocarditis by Cardiac Magnetic Resonance

PURPOSE OF REVIEW

This review was undertaken to summarise recent data relating to T1 and T2 relaxation times in the assessment of myocarditis using cardiac MRI, and the effect new studies have had on the established diagnostic criteria, leading to recently proposed revised criteria for the cardiac MRI assessment of myocarditis.

RECENT FINDINGS

In 2018, updates to the 2009 Lake Louise Criteria (LLC) were proposed, based on studies showing improved accuracy of T1 mapping techniques over T1 signal intensity ratio-based imaging, although for the detection of myocardial oedema either T2-weighted images or increased T2 relaxation times can be used. Non-ischaemic distribution of scar on late gadolinium-enhanced (LGE) T1-weighted imaging remains in the newly revised criteria, which, although can have low sensitivity due to fibrosis presenting diffusely or due to CMR being performed early in the disease process before scar formation, remains in the LLC due to its high specificity. Early gadolinium enhancement has been removed from the LLC, as T1 quantification has higher diagnostic accuracy for the detection of myocardial injury. In the CMR assessment of myocarditis, T1 and T2 quantifications are now recommended over T1- and T2-weighted imaging. Late gadolinium enhancement in a non-ischaemic pattern remains in the updated criteria, whereas early gadolinium enhancement has been superseded by T1 quantification.

Cardiovascular Magnetic Resonance in Nonischemic Myocardial Inflammation: Expert Recommendations

This JACC Scientific Expert Panel provides consensus recommendations for an update of the cardiovascular magnetic resonance (CMR) diagnostic criteria for myocardial inflammation in patients with suspected acute or active myocardial inflammation (Lake Louise Criteria) that include options to use parametric mapping techniques. While each parameter may indicate myocardial inflammation, the authors propose that CMR provides strong evidence for myocardial inflammation, with increasing specificity, if the CMR scan demonstrates the combination of myocardial edema with other CMR markers of inflammatory myocardial injury. This is based on at least one T2-based criterion (global or regional increase of myocardial T2 relaxation time or an increased signal intensity in T2-weighted CMR images), with at least one T1-based criterion (increased myocardial T1, extracellular volume, or late gadolinium enhancement). While having both a positive T2-based marker and a T1-based marker will increase specificity for diagnosing acute myocardial inflammation, having only one (i.e., T2-based OR T1-based) marker may still support a diagnosis of acute myocardial inflammation in an appropriate clinical scenario, albeit with less specificity. The update is expected to improve the diagnostic accuracy of CMR further in detecting myocardial inflammation.

Cardiac MRI and Texture Analysis of Myocardial T1 and T2 Maps in Myocarditis with Acute versus Chronic Symptoms of Heart Failure

BackgroundThe establishment of a timely and correct diagnosis in heart failure-like myocarditis remains one of the most challenging in clinical cardiology.PurposeTo assess the diagnostic potential of texture analysis in heart failure-like myocarditis with comparison to endomyocardial biopsy (EMB) as the reference standard.Materials and MethodsSeventy-one study participants from the Magnetic Resonance Imaging in Myocarditis (MyoRacer) trial (ClinicalTrials.gov registration no. NCT02177630) with clinical suspicion for myocarditis and symptoms of heart failure were prospectively included (from August 2012 to May 2015) in the study. Participants underwent biventricular EMB and cardiac MRI at 1.5 T, including native T1 and T2 mapping and standard Lake Louise criteria. Texture analysis was applied on T1 and T2 maps by using an open-source software. Stepwise dimension reduction was performed for selecting features enabling the diagnosis of myocarditis. Diagnostic performance was assessed from the area under the curve (AUC) from receiver operating characteristic analyses with 10-fold cross validation.ResultsIn participants with acute heart failure-like myocarditis (n = 31; mean age, 47 years ± 17; 10 women), the texture feature GrayLevelNonUniformity from T2 maps (T2_GLNU) showed diagnostic performance similar to that of mean myocardial T2 time (AUC, 0.69 for both). The combination of mean T2 time and T2_GLNU had the highest AUC (0.76; 95% confidence interval [CI]: 0.43, 0.95), with sensitivity of 81% (25 of 31) and specificity of 71% (22 of 31). In patients with chronic heart failure-like myocarditis (n = 40; mean age, 48 years ± 13; 12 women), the histogram feature T2_kurtosis demonstrated superior diagnostic performance compared to that of all other single parameters (AUC, 0.81; 95% CI: 0.66, 0.96). The combination of the two texture features, T2_kurtosis and the GrayLevelNonUniformity from T1, had the highest diagnostic performance (AUC, 0.85; 95% CI: 0.57, 0.90; sensitivity, 90% [36 of 40]; and specificity, 72% [29 of 40]).ConclusionIn this proof-of-concept study, texture analysis applied on cardiac MRI T1 and T2 mapping delivers quantitative imaging parameters for the diagnosis of acute or chronic heart failure-like myocarditis and might be superior to Lake Louise criteria or averaged myocardial T1 or T2 values.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by de Roos in this issue.

Systematic Review of PCR Proof of Parvovirus B19 Genomes in Endomyocardial Biopsies of Patients Presenting with Myocarditis or Dilated Cardiomyopathy

Background: Diverse viral infections have been associated with myocarditis (MC) and dilated cardiomyopathy (DCM). In this meta-analysis, we summarize the published results on the association of parvovirus B19 (B19V) genomes with human MC/DCM versus controls. Methods: n = 197 publications referring to B19V and MC or DCM were retrieved using multiple PubMed search modes. Out of these, n = 29 publications met the inclusion criteria with data from prospective analyses on >10 unselected patients presenting with MC or DCM (dataset: MA01). Data retrieved simultaneously from both controls and MC/DCM patients were available from n = 8 from these publications (dataset: MA02). Results: In the dataset MA01 B19V genomes were detected in 42.6% of the endomyocardial biopsies (EMB) in this cohort by PCR. In the dataset MA02 comprising n = 638 subjects, there was no statistically significant different rate of B19V positivity in myocardial tissues comparing controls (mean: 38.8 + 24.1%) versus the MC/DCM-patients (45.5 + 24.3%; p = 0.58). There was also no statistical difference between the positivity rate of B19V genomes in myocardial tissues of MA01 (46.0 + 19.5%) and the two patient groups of MA02 (p > 0.05). Conclusions: This systematic review reveals that the mean rate of PCR detected B19V genomes in patients presenting with MC/DCM does not differ significantly from the findings in control myocardial tissues. These data imply pathogenetically insignificant latency of B19V genomes in a proportion of myocardial tissues, both in MC-/DCM-patients and in controls. More information (i.e., replicative status, viral protein expression) is pertinent to achieve a comprehensive workup of myocardial B19V infection.

Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods

BACKGROUND

To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM).

METHODS

A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit.

RESULTS

In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P < .001). There were no significant differences among LLC, T2-weighted short inversion time inversion recovery (STIR) sequences, early (EGE), and late (LGE) gadolinium-enhancement sequences for diagnosis of AM. The AUC for qualitative (T2-weighted STIR 0.92, EGE 0.87 and LGE 0.88) and quantitative (ER 0.89 and global RE 0.80) analyses were also similar.

CONCLUSIONS

Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

Subclinical left ventricular dysfunction and correlation with regional strain analysis in myocarditis with normal ejection fraction. A new diagnostic criterion

BACKGROUND

The diagnosis of myocarditis is challenging, especially in case of normal left ventricular systolic function. The aim of this study is to test the hypothesis that 2D speckle tracking echocardiography (2DSTE) can detect subclinical left ventricular (LV) dysfunction in patients with myocarditis and preserved LV function without regional wall motion abnormalities and that regional strain analysis can correlate with cardiac magnetic resonance (CMR) findings.

METHODS

Study population consisted of 25 consecutive patients with myocarditis and 19 controls. All patients underwent a full echocardiographic study at the first day of their admission and in addition to conventional echocardiographic measurements, global longitudinal and circumferential strain of the left ventricle (LVGLS, LVCS accordingly), as well as regional strains of the lateral wall, were estimated. Moreover, all patients underwent a CMR scan during the first week from their admission.

RESULTS

Although there was no statistical difference between the two groups of patients in systolic function, myocarditis patients demonstrated significantly impaired LVGLS (-16.5 ± 2.2 vs -20.5 ± 1.3%, p < 0.0001) and LVCS (-16.4 ± 3.7 vs -20.9 ± 2%, p = 0.002), as well as segmental longitudinal strains of the lateral wall. CMR in all myocarditis patients revealed late gadolinium enhancement in the lateral left ventricle free wall.

CONCLUSIONS

In patients with acute myocarditis with preserved ejection fraction, 2DSTE evaluation appears to be a promising, useful noninvasive and inexpensive tool in addition to existing methods used for the diagnosis of acute myocarditis, since it seems to be able to identify myocardial fibrosis early in the setting of the disease.

Hybrid cardiac imaging using PET/MRI: a joint position statement by the European Society of Cardiovascular Radiology (ESCR) and the European Association of Nuclear Medicine (EANM)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) have both been used for decades in cardiovascular imaging. Since 2010, hybrid PET/MRI using sequential and integrated scanner platforms has been available, with hybrid cardiac PET/MR imaging protocols increasingly incorporated into clinical workflows. Given the range of complementary information provided by each method, the use of hybrid PET/MRI may be justified and beneficial in particular clinical settings for the evaluation of different disease entities. In the present joint position statement, we critically review the role and value of integrated PET/MRI in cardiovascular imaging, provide a technical overview of cardiac PET/MRI and practical advice related to the cardiac PET/MRI workflow, identify cardiovascular applications that can potentially benefit from hybrid PET/MRI, and describe the needs for future development and research. In order to encourage its wide dissemination, this article is freely accessible on the European Radiology and European Journal of Hybrid Imaging web sites.

KEY POINTS

• Studies and case-reports indicate that PET/MRI is a feasible and robust technology. • Promising fields of application include a variety of cardiac conditions. • Larger studies are required to demonstrate its incremental and cost-effective value. • The translation of novel radiopharmaceuticals and MR-sequences will provide exciting new opportunities.

Cardiac MRI Texture Analysis of T1 and T2 Maps in Patients with Infarctlike Acute Myocarditis

Purpose To assess the diagnostic potential of texture analysis applied to T1 and T2 maps obtained with cardiac MRI for the diagnosis of acute infarctlike myocarditis. Materials and Methods This prospective study from August 2012 to May 2015 included 39 participants (overall mean age ± standard deviation, 34.7 years ± 12.2 [range, 18-63 years]; mean age of women, 46.1 years ± 10.8 [range, 24-63 years]; mean age of men, 29.8 years ± 9.2 [range, 18-56 years]) from the Magnetic Resonance Imaging in Myocarditis (MyoRacer) trial with clinical suspicion of acute myocarditis and infarctlike presentation. Participants underwent biventricular endomyocardial biopsy, cardiac catheterization, and cardiac MRI at 1.5 T, in which native T1 and T2 mapping as well as Lake Louise criteria (LLC) were assessed. Texture analysis was applied on T1 and T2 maps by using a freely available software package. Stepwise dimension reduction and texture feature selection was performed for selecting features enabling the diagnosis of myocarditis by using endomyocardial biopsy as the reference standard. Results Endomyocardial biopsy confirmed the diagnosis of acute myocarditis in 26 patients, whereas 13 participants had no signs of acute inflammation. Mean T1 and T2 values and LLC showed a low diagnostic performance, with area under the curve in receiver operating curve analyses as follows: 0.65 (95% confidence interval [CI]: 0.45, 0.85) for T1, 0.67 (95% CI: 0.49, 0.85) for T2, and 0.62 (95% CI: 0.42, 0.79) for LLC. Combining the texture features T2 run-length nonuniformity and gray-level nonuniformity resulted in higher diagnostic performance with an area under the curve of 0.88 (95% CI: 0.73, 1.00) (P < .001) and a sensitivity and specificity of 89% [95% CI: 81%, 93%] and 92% [95% CI: 77%, 93%], respectively. Conclusion Texture analysis of T2 maps shows high sensitivity and specificity for the diagnosis of acute infarctlike myocarditis. © RSNA, 2018 Online supplemental material is available for this article.

Staphylococcus aureus Myocarditis with Associated Left Ventricular Apical Thrombus

Staphylococcus aureus myocarditis is a rare diagnosis with a high mortality rate, usually seen in people who are immunocompromised. Here, we report a case of a 44-year-old man on methotrexate for rheumatoid arthritis who presented in septic shock and was diagnosed with staphylococcus aureus myocarditis. The myocarditis was associated with a left ventricular apical thrombus, with normal systolic function. The myocarditis and associated thrombus were characterised on transthoracic echocardiogram and subsequently on cardiac magnetic resonance imaging. Cardiac magnetic resonance (CMR) imaging showed oedema in the endomyocardium, consistent with acute myocarditis, associated with an apical mural thrombus. Repeat CMR 3 weeks following discharge from hospital showed marked improvement in endomyocardial oedema and complete resolution of the apical mural thrombus. He was treated with a 12-week course of antibiotics and anticoagulated with apixaban. The patient was successfully managed with intravenous antibiotics and anticoagulation with complete recovery.

Feasibility of FDG-PET in myocarditis: Comparison to CMR using integrated PET/MRI

OBJECTIVE

Besides cardiac sarcoidosis, FDG-PET is rarely used in the diagnosis of myocardial inflammation, while cardiac MRI (CMR) is the actual imaging reference for the workup of myocarditis. Using integrated PET/MRI in patients with suspected myocarditis, we prospectively compared FDG-PET to CMR and the feasibility of integrated FDG-PET/MRI in myocarditis.

METHODS

A total of 65 consecutive patients with suspected myocarditis were prospectively assessed using integrated cardiac FDG-PET/MRI. Studies comprised T2-weighted imaging, late gadolinium enhancement (LGE), and simultaneous PET acquisition. Physiological glucose uptake in the myocardium was suppressed using dietary preparation.

RESULTS

FDG-PET/MRI was successful in 55 of 65 enrolled patients: two patients were excluded due to claustrophobia and eight patients due to failed inhibition of myocardial glucose uptake. Compared with CMR (LGE and/or T2), sensitivity and specificity of PET was 74% and 97%. Overall spatial agreement between PET and CMR was κ = 0.73. Spatial agreement between PET and T2 (κ = 0.75) was higher than agreement between PET and LGE (κ = 0.64) as well as between LGE and T2 (κ = 0.56).

CONCLUSION

In patients with suspected myocarditis, FDG-PET is in good agreement with CMR findings.

Incremental value of cardiovascular magnetic resonance feature tracking derived atrial and ventricular strain parameters in a comprehensive approach for the diagnosis of acute myocarditis

PURPOSE/INTRODUCTION

This study aims to evaluate the incremental diagnostic value of cardiac magnetic resonance (CMR) feature tracking (FT) derived atrial and ventricular strain-analysis in patients with acute myocarditis (myocarditis) as an additional tool to established Lake-Louise criteria (LLC).

MATERIAL AND METHODS

A total of 86 patients with clinically proven myocarditis and 30 healthy controls underwent a comprehensive CMR protocol. In addition to established LLC, FT derived strain parameters from the left (LA) and right atrium (RA) as well as the left (LV) and right ventricle (RV) were assessed. Receiver operating characteristics analysis was performed to compare diagnostic performance.

RESULTS

Patients with myocarditis showed significantly reduced LA passive strain (LA ε_e: 26.3 ± 14.5 vs. 33.5 ± 10.1%, p = .007), LA peak early negative strain rate (LA SRe: -1.94 ± 0.59 1/s vs. -1.46 ± 0.62 1/s, p < .001), LV global longitudinal strain (LV GLS: -17.2 ± 4.9% vs. -13.3 ± 6.2%, p < .001), LV midventricular circumferential strain (LV mid CS: -25.9 ± 4.7% vs. -22.0 ± 6.5%, p < .001), and an increased RV basal circumferential SR (RV basal CSR: -0.70 ± 028 vs. -0.58 ± 0.34 1/s, p = .096) compared to healthy controls. In a subgroup analysis of patients with myocarditis and preserved LV function, RV basal CSR was also significantly increased compared to healthy controls (-0.74 ± 0.27 vs. -0.57 ± 0.26 1/s; p = .035) whereas LA SRe (-1.49 ± 0.59 vs. -1.32 ± 0.74%; p = .005) was significantly reduced. In multinominal logistic regression analysis, LA SRe and RV basal CSR proved to be the best independent predictors of myocarditis with preserved LV function. Combined with LLC, strain parameters enhanced the diagnostic performance in such patients (Areas under the curve (AUC): LLC: 0.78, LLC + LV GLS + LA SRe: 0.86), whereas LA SRe was the best performing single parameter (AUC: 0.72).

CONCLUSION

Combining quantitative CMR derived atrial and ventricular strain parameters with established LLC parameters can improve the diagnostic performance in patients with suspected myocarditis, including those with preserved LV function. Further investigations should focus on LA function, which appears to be more sensitive to early functional changes than LV function.

Clinical use of cardiac PET/MRI: current state-of-the-art and potential future applications

Combined PET/MRI is a novel imaging method integrating the advances of functional and morphological MR imaging with PET applications that include assessment of myocardial viability, perfusion, metabolism of inflammatory tissue and tumors, as well as amyloid deposition imaging. As such, PET/MRI is a promising tool to detect and characterize ischemic and non-ischemic cardiomyopathies. To date, the greatest benefit may be expected for diagnostic evaluation of systemic diseases and cardiac masses that remain unclear in cardiac MRI, as well as for clinical and scientific studies in the setting of ischemic cardiomyopathies. Diagnosis and therapeutic monitoring of cardiac sarcoidosis has the potential of a possible 'killer-application' for combined cardiac PET/MRI. In this article, we review the current evidence and discuss current and potential future applications of cardiac PET/MRI.

Cardiac Findings in Amyotrophic Lateral Sclerosis: A Magnetic Resonance Imaging Study

The objective of this study was to investigate the potential involvement of cardiac structure and function by cardiac magnetic resonance (CMR) imaging in amyotrophic lateral sclerosis (ALS) patients. Our study included 35 patients with ALS without a history of cardiac disease and an age- and gender-matched healthy control group (n = 34). All subjects received a CMR in a 1.5-T whole-body scanner. Patients were also screened with Holter monitoring, echocardiography, and a blood test of cardiac markers. Myocardial mass in ALS hearts was reduced compared to the control group, and ejection volumes in the left and right heart were severely decreased in ALS patients, as shown by echocardiography and CMR. The myocardium showed increased T1 enhancement in 77% of the patients compared to 27% of controls (p = 0.0001). A trend toward late gadolinium enhancement patterns consistent with myocardial fibrosis was observed in 23.5% of the patients (9.1% of controls). Holter monitoring was normal in all patients as well as troponin T. Cardiac involvement seems to be present in ALS patients without clinical cardiac symptoms and with a normal cardiac routine assessment. Structural myocardial defects in CMR may be due to sympathetic dysfunction and may account for reported cardiac deaths in late-stage ALS patients.

Performance of Cardiac Magnetic Resonance Imaging for Diagnosis of Myocarditis Compared with Endomyocardial Biopsy: A Meta-Analysis

Background

Cardiac magnetic resonance imaging (CMRI) is considered to be useful for the diagnosis of myocarditis, and the Lake Louise Criteria (LLC) has been proved to be of significance as the standard of diagnosis. However, the diagnostic performance of LLC-based CMRI for myocarditis compared with endomyocardial biopsy (EMB) has not been quantitatively evaluated in a meta-analysis.

Material/Methods

The databases PubMed, Cochrane’s Library, and EMBASE were searched to identify studies on LLC and its individual components for the diagnosis of myocarditis. EMB was the control reference. The sensitivity, specificity, and positive and negative diagnostic likelihood ratios were calculated with a random-effects model. The area under the receiver operating characteristic curve (AUC) was estimated to show overall effectiveness.

Results

We included 9 cohorts (614 patients) of patients with suspected MC. The combined sensitivities, specificities, and AUCs for T1-weighed global relative enhancement were 0.66, 0.73, and 0.71; for T2-weighed edema ratio they were 0.52, 0.73, and 0.72; for the late gadolinium enhancement, they were 0.70, 0.57, and 0.67; and for LLC-based CMRI they were 0.70, 0.56, and 0.70, respectively. Subgroup analysis indicated that the sensitivities, specificities, and diagnostic accuracies of LLC and its individual component-based CMRI seemed to be similar in patients with acute or chronic myocarditis. Results of the Deeks’ funnel plot asymmetry test showed no significant publication bias among the studies.

Conclusions

CMRI based on LLC or its individual components seems to have moderate accuracy in diagnosis of acute or chronic myocarditis.

Early myocardial gadolinium enhancement in patients with myocarditis: Validation of "Lake Louise consensus" criteria using a single bolus of 0.1mmol/Kg of a high relaxivity gadolinium-based contrast agent

OBJECTIVES

Global early gadolinium enhancement (EGE) is an accepted cardiac magnetic resonance (CMR) criterion for diagnosis of myocarditis. However, recommended enhancement thresholds are based specifically on standard-relaxivity Gd-chelates. We evaluated the performance of a high relaxivity MR contrast agent for detection of myocardial hyperemia in patients referred for endomyocardial biopsy (EMB).

METHODS

We retrospectively enrolled 54 patients (mean age: 44.1 years [range=18-77years]; 72% men) with suspected myocarditis who underwent CMR and EMB within four weeks of clinical onset. CMR imaging protocol included T2-weighted short tau inversion-recovery sequence, EGE and late gadolinium enhanced (LGE) imaging. For EGE imaging, free-breathing ECG-gated turbo spin echo T1-weighted (TSE T1w) sequences were acquired before and within the first three minutes after gadobenate dimeglumine (0.1mmol/Kg) administration. The ratio (EGEr) between myocardial and musculoskeletal early enhancement was calculated. Myocardial edema, EGE and late gadolinium enhancement (LGE) were correlated with EMB results. Receiver operating characteristic (ROC) curve analysis of EGE values was applied on the overall population.

RESULTS

EMB revealed myocarditis in 34/54 patients. Sensitivity, specificity and accuracy values of 0.61, 0.85 and 0.70, respectively, were obtained for a standard EGE threshold (EGEr>4.0). ROC analysis revealed an area under the curve of 0.701 for EGEr (IC95%:0.556-0.846, p=0.014) and 0.706 for absolute enhancement (IC95%:0.563-0.849, p=0.012). Sensitivity, specificity and accuracy values were 0.67, 0.80 and 0.72, respectively, for myocardial edema and 0.76, 0.75 and 0.76, respectively, for LGE.

CONCLUSIONS

High relaxivity contrast agents provide comparable results to standard-relaxivity chelates for EGE assessment in diagnosing myocarditis.

Cardiac profile of asymptomatic children with Becker and Duchenne muscular dystrophy under treatment with steroids and with/without perindopril

BACKGROUND

To evaluate cardiovascular function in boys with Duchenne (DMD) and Becker (BMD) muscular dystrophy, using cardiac magnetic resonance (CMR).

METHODS

This is a single point cross sectional study of twenty-four boys with genetically ascertained DMD, and 10 with BMD, aged 10.5 ± 1.5 years (range 9-13), were prospectively evaluated by a 1.5 T system and compared with those of age-sex matched controls. The DMD patients were divided in 2 groups. Group A (N = 12) were under treatment with both deflazacort and perindopril, while Group B (n = 12) were under treatment with deflazacort, only. BMD patients did not take any medication. Biventricular function was assessed using a standard SSFP sequence. Late gadolinium enhancement (LGE) was assessed from T1 images taken 15 min after injection of 0.2 mg/Kg gadolinium DTPA using a 3D-T1-TFE sequence.

RESULTS

Group A and BMDs were asymptomatic with normal ECG, 24 h ECG recording and echocardiogram. Group B were asymptomatic but 6/12 had abnormal ECG and mildly impaired LVEF. Their 24 h ECG recording revealed supraventricular and ventricular extrasystoles (all at 12-13 yrs). LV indices in Group A and BMD did not differ from those of controls. However, LV indices in Group B were significantly impaired compared with controls, Group A and BMDs (p < 0.001). An epicardial LGE area = 3 ± 0.5% of LV mass was identified in the posterolateral wall of LV only in 6/12 patients of Group B, but in not in any BMD or Group A.

CONCLUSION

Children with either BMD or DMD under treatment with both deflazacort and perindopril present preserved LV function and lack of LGE. However, further large scale multicenter studies are warranted to confirm these data, including further CMR mapping approaches.

Update on the Role of Cardiac Magnetic Resonance in Acquired Nonischemic Cardiomyopathies

Cardiomyopathies refer to a variety of myocardial disorders without underlying coronary artery disease, valvular heart disease, hypertension, or congenital heart disease. Several imaging modalities are available, but cardiac magnetic resonance (CMR) has now established itself as a crucial imaging technique in the evaluation of several cardiomyopathies. It not only provides comprehensive information on structure and function, but also can perform tissue characterization, which helps in establishing the etiology of cardiomyopathy. CMR is also useful in establishing the diagnosis, providing guidance for endomyocardial biopsy, accurate quantification of function, volumes, and fibrosis, prognostic determination, risk stratification, and monitoring response to therapy. In this article, we review the current role of CMR in the evaluation of several acquired nonischemic cardiomyopathies, particularly focusing on recent advances in knowledge. We also discuss in detail a select group of common acquired nonischemic cardiomyopathies.

Multimodality imaging approach in the diagnosis of chronic myocarditis with preserved left ventricular ejection fraction (MCpEF): The role of 2D speckle-tracking echocardiography

BACKGROUND

Up to one third of patients with chronic myocarditis (MC) have preserved left ventricular (LV) ejection fraction (MCpEF). The purpose of this study was to evaluate the role of adding 2D speckle-tracking echocardiography (STE) to cardiac magnetic resonance imaging (cMRI) in the diagnosis of patients with MCpEF.

METHODS AND RESULTS

We analyzed 67 patients with suspected MCpEF who underwent endomyocardial biopsy (EMB). Thirty-two patients with confirmed chronic myocardial inflammation by EMB served as study group (MCpEF) and the remaining patients (n=35) served as control group. In all patients, 2D STE and cMRI were performed within 48h before EMB. Patients with MCpEF had significantly lower LV global longitudinal systolic strain (GLS) than controls (GLS: -17.01±2.42% vs. -19.39±3.81%, p<0.001; respectively). In line, an abnormal GLS had adequate diagnostic performance to detect MCpEF (sensitivity, specificity, and accuracy of 82%, 70%, and 76%, respectively), which was superior to cMRI based on the Lake-Louise criteria (sensitivity, specificity, and accuracy 54%, 71%, and 67%, respectively). In addition, adding GLS to the Lake-Louise criteria improved significantly the diagnostic performance of cMRI to detect MCpEF (sensitivity, specificity, and accuracy 96%, 55%, and 75%, respectively).

CONCLUSION

The findings of this study suggest that GLS using 2D STE could play an important role in the diagnostic evaluation of patients with suspected chronic myocarditis with preserved LV ejection fraction (MCpEF).

A cohort study reveals myocarditis to be a rare and life-threatening presentation of large vessel vasculitis

BACKGROUND

The predominant forms of adult large vessel vasculitis (LVV) are giant cell arteritis (GCA) and Takayasu arteritis (TA). Cardiac involvement in LVV is a cause of morbidity and mortality, particularly in TA. Cardiac failure is most commonly secondary to uncontrolled arterial hypertension or myocardial ischaemia. Pulmonary hypertension and aortic valve incompetence following ascending aortic dilatation represent other serious cardiovascular complications. However, cardiac failure as a consequence of myocarditis is rarely reported, principally in single case reports or in autopsy studies.

METHODS

The Imperial College LVV database was, retrospectively, reviewed to identify patients with cardiac involvement at presentation. Patients with evidence for myocarditis were identified. The cardiac presentation, imaging studies and subsequent medical and surgical management were reviewed in detail.

RESULTS

The cohort included 139 patients with TA and 24 with GCA. Sixteen presented with cardiac failure without a history of ischaemic coronary heart disease, 14 (10%) with TA and 2 (8.3%) with GCA. Cardiovascular disease identified at presentation included aortic regurgitation (n = 11), myocarditis (n = 4) and hypertensive cardiomyopathy secondary to renal artery stenosis (n = 1). Those patients with evidence of myocarditis at presentation (2.8%) underwent transthoracic echocardiography and cardiac magnetic resonance imaging (CMR). These non-invasive techniques were sufficient for diagnosis of clinically significant myocarditis. Furthermore, they were subsequently used to monitor response to treatment, with serial improvement in left ventricular ejection fraction (LVEF) observed in all 4 patients (p < 0.05). Prednisolone plus cyclophosphamide (CyC) therapy was associated with significant improvement in heart failure symptoms and LVEF in 3 cases. In one case where CyC was contraindicated, tocilizumab treatment led to marked improvement in cardiac symptoms.

CONCLUSION

Clinically significant myocarditis in LVV remains a rare but serious presentation. Non-invasive imaging techniques offer an alternative to the gold-standard myocardial biopsy. Initial aggressive immunosuppressive therapy is recommended and led to significant improvements in LVEF and cardiac status.