Clinically Suspected and Biopsy-Proven Myocarditis Temporally Associated with SARS-CoV-2 Infection.

We review current data on clinically suspected [European Society of Cardiology (ESC) 2013 criteria] and biopsy-proven [ESC and World Health Organization (WHO) criteria] myocarditis that is temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. ESC/WHO etiological diagnosis of viral myocarditis is based on histological and immunohistological evidence of nonischemic myocyte necrosis and monolymphocytic infiltration, i.e., myocarditis, plus the identification of a specific cardiotropic virus by molecular techniques, in particular polymerase chain reaction (PCR)/in-situ hybridization, on endomyocardial biopsy (EMB)/autopsy tissue. There is not yet definitive EMB/autopsy proof that SARS-CoV-2 causes direct cardiomyocyte damage in association with histological myocarditis. Clinical epidemiology data suggest that myocarditis is uncommon for both SARS-CoV-2-positive and -negative PCR cases. We hypothesize that the rare virus-negative biopsy-proven cases may represent new-onset immune-mediated or latent pre-existing autoimmune forms,triggered or fostered by the hyperinflammatory state of severe COVID-19. We recommend the application of the ESC/WHO definitions and diagnostic criteria in future reports to avoid low-quality scientific information leading to an inaccurate estimate of myocarditis incidence based on misdiagnosis.

A Novel Circulating MicroRNA for the Detection of Acute Myocarditis.

BACKGROUND: The diagnosis of acute myocarditis typically requires either endomyocardial biopsy (which is invasive) or cardiovascular magnetic resonance imaging (which is not universally available). Additional approaches to diagnosis are desirable. We sought to identify a novel microRNA for the diagnosis of acute myocarditis. METHODS: To identify a microRNA specific for myocarditis, we performed microRNA microarray analyses and quantitative polymerase-chain-reaction (qPCR) assays in sorted CD4+ T cells and type 17 helper T (Th17) cells after inducing experimental autoimmune myocarditis or myocardial infarction in mice. We also performed qPCR in samples from coxsackievirus-induced myocarditis in mice. We then identified the human homologue for this microRNA and compared its expression in plasma obtained from patients with acute myocarditis with the expression in various controls. RESULTS: We confirmed that Th17 cells, which are characterized by the production of interleukin-17, are a characteristic feature of myocardial injury in the acute phase of myocarditis. The microRNA mmu-miR-721 was synthesized by Th17 cells and was present in the plasma of mice with acute autoimmune or viral myocarditis but not in those with acute myocardial infarction. The human homologue, designated hsa-miR-Chr8:96, was identified in four independent cohorts of patients with myocarditis. The area under the receiver-operating-characteristic curve for this novel microRNA for distinguishing patients with acute myocarditis from those with myocardial infarction was 0.927 (95% confidence interval, 0.879 to 0.975). The microRNA retained its diagnostic value in models after adjustment for age, sex, ejection fraction, and serum troponin level. CONCLUSIONS: After identifying a novel microRNA in mice and humans with myocarditis, we found that the human homologue (hsa-miR-Chr8:96) could be used to distinguish patients with myocarditis from those with myocardial infarction. (Funded by the Spanish Ministry of Science and Innovation and others.).

Clinical application of CMR in cardiomyopathies: evolving concepts and techniques : A position paper of myocardial and pericardial diseases and cardiac magnetic resonance working groups of Italian society of cardiology.

Cardiac magnetic resonance (CMR) has become an essential tool for the evaluation of patients affected or at risk of developing cardiomyopathies (CMPs). In fact, CMR not only provides precise data on cardiac volumes, wall thickness, mass and systolic function but it also a non-invasive characterization of myocardial tissue, thus helping the early diagnosis and the precise phenotyping of the different CMPs, which is essential for early and individualized treatment of patients. Furthermore, several CMR characteristics, such as the presence of extensive LGE or abnormal mapping values, are emerging as prognostic markers, therefore helping to define patients' risk. Lastly new experimental CMR techniques are under investigation and might contribute to widen our knowledge in the field of CMPs. In this perspective, CMR appears an essential tool to be systematically applied in the diagnostic and prognostic work-up of CMPs in clinical practice. This review provides a deep overview of clinical applicability of standard and emerging CMR techniques in the management of CMPs.

Society for Cardiovascular Magnetic Resonance 2021 cases of SCMR and COVID-19 case collection series.

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). "Cases of SCMR" is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. The COVID-19 Case Collection highlights the impact of coronavirus disease 2019 (COVID-19) on the heart as demonstrated on CMR. Each case in series consists of the clinical presentation and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2021 Cases of SCMR and the 2020 and 2021 COVID-19 Case Collection series of nine cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar literature search engine.

Clinically Suspected Myocarditis in the Course of Severe Acute Respiratory Syndrome Novel Coronavirus-2 Infection: Fact or Fiction?

Cardiac complications, including clinically suspected myocarditis, have been described in novel coronavirus disease 2019. Here, we review current data on suspected myocarditis in the course of severe acute respiratory syndrome novel coronavirus-2 (SARS-CoV-2) infection. Hypothetical mechanisms to explain the pathogenesis of troponin release in patients with novel coronavirus disease 2019 include direct virus-induced myocardial injury (ie, viral myocarditis), systemic hyperinflammatory response (ie, cytokine storm), hypoxemia, downregulation of angiotensin-converting enzyme 2, systemic virus-induced endothelialitis, and type 1 and type 2 myocardial infarction. To date, despite the fact that millions of SARS-CoV-2 infections have been diagnosed worldwide, there is no definitive proof that SARS-CoV-2 is a novel cardiotropic virus causing direct cardiomyocyte damage. Diagnosis of viral myocarditis should be based on the molecular assessment of endomyocardial biopsy or autopsy by polymerase chain reaction or in-situ hybridization. Blood, sputum, or nasal and throat swab virology testing are insufficient and do not correlate with the myocardial involvement of a given pathogen. Data from endomyocardial biopsies and autopsies in clinically suspected SARS-CoV-2 myocarditis are scarce. Overall, current clinical epidemiologic data do not support the hypothesis that viral myocarditis is caused by SARS-CoV-2, or that it is common. More endomyocardial biopsy and autopsy data are also needed for a better understanding of pathogenesis of clinically suspected myocarditis in the course of SARS-CoV-2 infection, which may include virus-negative immune-mediated or already established subclinical autoimmune forms, triggered or accelerated by the hyperinflammatory state of severe novel coronavirus disease 2019.

"Apical sparing" T-wave inversion in a case of mid-ventricular takotsubo syndrome.

Previous studies showed that myocardial edema correlates with dynamic T-wave inversion and QTc prolongation in a variety of acute cardiovascular diseases including takotsubo syndrome (TTS). We reported the case of a patient with "atypical" (mid-ventricular) TTS showing a unique pattern of diffuse T-wave inversion that spared only the apical precordial leads V3-V4. Cardiac magnetic resonance (CMR) showed myocardial edema involving all mid-ventricular segments but not the apex. Both ECG and CMR normalized at follow-up evaluation. This case further reinforces the theory of an association between presence and regional distribution of acute myocardial inflammation and dynamic repolarization changes.

Response to a massive SARS-CoV-2 infection in a nursing home transformed into a caring center.

BACKGROUND: The best policy to follow when nursing homes are massively hit by SARS-CoV2 is unclear. AIM: To describe COVID-19 containment in a nursing home transformed into a caring center. METHODS: Physicians and nurses were recruited. The facility was reorganized and connected with the laboratory of the reference hospital. Ultrasound was used to diagnose pneumonia. Patients needing intensive care were transferred to the reference hospital. Hydroxychloroquine/azithromycin/enoxaparin were used initially, while amiodarone/enoxaparin were used at a later phase. Under both regimens, methylprednisolone was added for severe cases. Prophylaxis was done with hydroxychloroquine initially and then with amiodarone. PERIOD COVERED: March 22-July 31, 2020. RESULTS: The facility was reorganized in two days. Ninety-two guests of the 121 (76%) and 25 personnel of 118 (21.1%) became swab test positive. Seven swab test negative patients who developed symptoms were considered to have COVID-19. Twenty-seven patients died, 23 swab test positive, 5 of whom after full recovery. Four patients needing intensive care were transferred (3 died). Mortality, peaking in April 2020, was correlated with symptoms, comorbidities, dyspnea, fatigue, stupor/coma, high neutrophil to lymphocyte ratio, C-reactive protein, interleukin-6, pro-calcitonin, and high oxygen need (p ≤ 0.001 for all). Among swab-positive staff, 3 had pneumonia and recovered. Although no comparison could be made between different treatment and prophylaxis strategies, potentially useful suggestions emerged. Mortality compared well with that of nursing homes of the same area not transformed into care centers. CONCLUSION: Nursing homes massively hit by SARS-CoV-2 can become caring centers for patients not needing intensive care.

Cardiovascular Magnetic Resonance of Myocardial Fibrosis, Edema, and Infiltrates in Heart Failure.

Cardiac magnetic resonance (CMR) imaging is a unique imaging modality, which provides accurate noninvasive tissue characterization. Various CMR sequences can be utilized to identify and quantify patterns of myocardial edema, fibrosis, and infiltrates, which are important determinants for diagnosis and prognostication of heart failure. This article describes available methods of tissue characterization imaging applied in CMR. The presence and patterns of abnormal tissue characterization are related to common etiologies of heart failure and the techniques employed to demonstrate this. CMR provides the opportunity to identify the etiology of heart failure based on the recognition of different patterns of myocardial abnormalities.

Performance of the Steno type 1 risk engine for cardiovascular disease prediction in Italian patients with type 1 diabetes.

BACKGROUND AND AIMS: Premature cardiovascular disease cause excess mortality in type 1 diabetes (T1D). The Steno T1D Risk Engine was developed and validated in northern European countries but its validity in other populations is unknown. We evaluated the performance of the Steno T1D Risk Engine in Italian patients with T1D. MATERIALS AND METHODS: We included patients with T1D with a baseline visit between July 2013 and April 2014, who were free of cardiovascular disease and had complete information to estimate risk. The estimated cardiovascular risk score was compared with the 5-year rate of cardiovascular events by means of logistic regression. RESULTS: Among 223 patients (mean age 43 ± 13 years, 34.5% male, mean duration of diabetes 22 ± 12 years) the mean estimated cardiovascular risk at 5 years was 5.9% (95% C.I. 5.2-6.5%). At baseline, high estimated risk discriminated the presence of asymptomatic atherosclerosis better than microangiopathy, and was not associated with markers of inflammation or endothelial activation. After a mean follow-up of 4.7 ± 0.5 years, only 3 cardiovascular events were observed and nonetheless the risk score was significantly associated with their incidence (OR 1.22; 95% C.I. 1.08-1.39, p = 0.001). However, the observed event rate was significantly lower than the estimated one (3 vs 13; 95% C.I. 12-14; p < 0.001). CONCLUSION: The Steno T1D Risk Score identified subjects with subclinical atherosclerosis and high cardiovascular risk in an Italian T1D population. However, the absolute risk was significantly overestimated. Further studies in larger population are needed to confirm these results.

Stricter criteria for left bundle branch block diagnosis do not improve response to CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) has proved to be effective in patients with heart failure and left bundle branch block (LBBB). Recently, new electrocardiography criteria have been proposed for the diagnosis of LBBB. These criteria are stricter than the current American Heart Association (AHA) criteria. We assessed the rate of echocardiographic response to CRT in patients with traditional LBBB versus patients who met the new criteria (strict LBBB). METHODS: Consecutive patients undergoing CRT were enrolled in the CRT MORE registry. Patients with no-LBBB QRS morphology according to AHA criteria, atrial fibrillation, right bundle branch block, and right ventricular pacing were excluded. Strict LBBB was defined as: QRS ≥ 140 ms for men and ≥130 ms for women, QS or rS in V1-V2, mid-QRS notching or slurring in ≥2 contiguous leads. Patients showing a relative decrease of ≥15% in left ventricular end-systolic volume (LVESV) at 12 months were defined as responders. RESULTS: Among 335 patients with LBBB, 131 (39%) had strict LBBB. Patients with and without strict LBBB showed comparable baseline characteristics, except for QRS duration (166 ± 20 ms vs 152 ± 25 ms, P < 0.001). On 12-month evaluation, 205 patients (61%) were responders; 85 of 131 (65%) had strict LBBB and 120 of 204 (59%) had traditional LBBB (P = 0.267). On multivariate analysis, a history of atrial fibrillation, larger LVESV, and the presence of mid-QRS notching in ≥1 lead (odds ratio 2.099; 95% confidence interval 1.061-4.152, P = 0.033) were independently associated with echocardiographic response. CONCLUSION: Stricter definition of LBBB did not improve response to CRT in comparison to the current AHA definition.

Extra-cardiac findings in cardiovascular magnetic resonance: what the imaging cardiologist needs to know.

Cardiovascular magnetic resonance (CMR) is an established non-invasive technique to comprehensively assess cardiovascular structure and function in a variety of acquired and inherited cardiac conditions. A significant amount of the neck, thorax and upper abdomen are imaged at the time of routine clinical CMR, particularly in the initial multi-slice axial and coronal images. The discovery of unsuspected disease at the time of imaging has ethical, financial and medico-legal implications. Extra-cardiac findings at the time of CMR are common, can be important and can change clinical management. Certain patient groups undergoing CMR are at particular risk of important extra-cardiac findings as several of the cardiovascular risk factors for atherosclerosis are also risk factors for malignancy. Furthermore, the presence of certain extra-cardiac findings may contribute to the interpretation of the primary cardiac pathology as some cardiac conditions have multi-systemic extra-cardiac involvement. The aim of this review is to give an overview of the type of extra-cardiac findings that may become apparent on CMR, subdivided by anatomical location. We focus on normal variant anatomy that may mimic disease, common incidental extra-cardiac findings and important imaging signs that help distinguish sinister pathology from benign disease. We also aim to provide a framework to the approach and potential further diagnostic work-up of incidental extra-cardiac findings discovered at the time of CMR. However, it is beyond the scope of this review to discuss and determine the clinical significance of extracardiac findings at CMR.

Cardiac MRI Anatomy and Function as a Substrate for Arrhythmias.

The use of cardiovascular magnetic resonance (CMR) has been implemented in the diagnostic work-up of patients with cardiomyopathies by providing an accurate assessment of biventricular volumes and function and a detailed myocardial tissue characterization in a one-stop-shop multi-parametric imaging technique. Its unique capability to perform an accurate tissue characterization of the myocardium, which is superior to other imaging modalities, has prompt its use in the analysis of myocardial arrhythmic substrates and in the prognostic risk stratification of patients. Although left ventricular ejection fraction (LVEF) has always been the best-known predictor of arrhythmic risk, the quantification of myocardial scar by CMR has been recognised as a powerful risk stratification tool, independent of LVEF. Moreover, due to its ability to identify myocardial arrhythmic substrate, both ventricular but more recently also atrial, CMR is increasingly offered as a guide to ablation procedures.

Relationship between T-wave inversion and transmural myocardial edema as evidenced by cardiac magnetic resonance in patients with clinically suspected acute myocarditis: clinical and prognostic implications.

BACKGROUND: The pathophysiologic mechanisms and the prognostic meaning of electrocardiographic (ECG) T-wave inversion (TWI) occurring in a subgroup of patients with clinically suspected acute myocarditis remain to be elucidated. Contrast-enhanced cardiac magnetic resonance (CMR) offers the potential to identify myocardial tissue changes such as edema and/or fibrosis which may underlie TWI. METHODS AND RESULTS: We studied 76 consecutive patients (median age 34years) with clinically suspected acute myocarditis, using a comprehensive CMR protocol which included T2 weighted sequences for myocardial edema. At the time of CMR, TWI was observed in 21 (27%) patients. There was a statistically significant association of TWI with the median number of left ventricular (LV) segments showing both any pattern of myocardial edema (transmural and non-transmural) [5 (3-7) vs. 3 (2-4); p=0.015] and myocardial late-gadolinium-enhancement [4 (3-7) vs. 3 (2-4); p=0.002]. Transmural myocardial edema involving ≥2 LV segments was found in 17/21 (81%) patients with TWI versus 13/55 (24%) patients without TWI (p<0.001) and remained the only independent predictor of TWI at multivariable analysis (OR=9.96; 95%CI=2.71-36.6; p=0.001). Overall, topographic concordance between the location of TWI across the ECG leads and the regional distribution of transmural myocardial edema was 88%. There was no association between acute TWI and reduced LV ejection fraction (<55%) at 6-months of follow-up. CONCLUSIONS: This is the first study to demonstrate an association between LV transmural myocardial edema as evidenced by CMR sequences and TWI in clinically suspected acute myocarditis. As an expression of reversible myocardial edema, development of TWI during the acute disease phase was not a predictor of LV systolic dysfunction at follow-up.

The Role of the Immune System in Pathobiology and Therapy of Myocarditis: A Review.

The role of the immune system in myocarditis onset and progression involves a range of complex cellular and molecular pathways. Both innate and adaptive immunity contribute to myocarditis pathogenesis, regardless of its infectious or non-infectious nature and across different histological and clinical subtypes. The heterogeneity of myocarditis etiologies and molecular effectors is one of the determinants of its clinical variability, manifesting as a spectrum of disease phenotype and progression. This spectrum ranges from a fulminant presentation with spontaneous recovery to a slowly progressing, refractory heart failure with ventricular dysfunction, to arrhythmic storm and sudden cardiac death. In this review, we first examine the updated definition and classification of myocarditis at clinical, biomolecular and histopathological levels. We then discuss recent insights on the role of specific immune cell populations in myocarditis pathogenesis, with particular emphasis on established or potential therapeutic applications. Besides the well-known immunosuppressive agents, whose efficacy has been already demonstrated in human clinical trials, we discuss the immunomodulatory effects of other drugs commonly used in clinical practice for myocarditis management. The immunological complexity of myocarditis, while presenting a challenge to simplistic understanding, also represents an opportunity for the development of different therapeutic approaches with promising results.

Long-term efficacy and safety of tailored immunosuppressive therapy in immune-mediated biopsy-proven myocarditis: A propensity-weighted study.

AIMS: Standardized immunosuppressive therapy (IS) had been previously investigated in biopsy-proven (BP) lymphocytic myocarditis with heart failure (HF). This study evaluated efficacy and safety of tailored IS in BP immune-mediated myocarditis, irrespective of histology and clinical presentation. METHODS AND RESULTS: Consecutive BP myocarditis patients treated with long-term tailored IS on top of optimal medical therapy (OMT), were compared with OMT non-IS controls using propensity-score weighting. The primary outcome was a composite of death or heart transplant, the secondary outcome was a composite of biventricular function, New York Heart Association (NYHA) class variation, and relapse. IS was managed by a multidisciplinary Cardioimmunology Team, involved a safety checklist and active patients' education. Ninety-one IS patients were compared with 267 non-IS patients. IS patients more frequently had systemic immune-mediated diseases (35% vs. 9.7%), lower baseline echocardiographic left ventricular ejection fraction (35% vs. 43%), lower right ventricular fractional area change (34% vs. 41%) and higher frequency of active lymphocytic, eosinophilic and giant cell myocarditis (71% vs. 58%, 12% vs. 1.1%, and 6.6% vs. 1.5%, respectively). At 5-year follow up, no difference was observed in the primary outcome (survival rate 93% in IS vs. 87% in non-IS), but IS patients had a higher relapse rate. Thus, IS patients, with a lower biventricular function and a higher risk profile at baseline, presented similar biventricular function and NYHA class to non-IS patients at follow-up. Minor adverse drug reactions occurred in 13% of patients, all resolved with therapy switch. CONCLUSIONS: Prolonged tailored IS is effective and safe in BP immune-mediated myocarditis irrespective of histology and clinical presentation.

CMR Predictors of Favorable Outcome in Myocarditis: A Single-Center Experience.

Background: Cardiovascular magnetic resonance (CMR) has emerged as the most accurate, non-invasive method to support the diagnosis of clinically suspected myocarditis and as a risk-stratification tool in patients with cardiomyopathies. We aim to assess the diagnostic and prognostic role of CMR at diagnosis in patients with myocarditis. Methods: We enrolled consecutive single-center patients with 2013 ESC consensus-based endomyocardial biopsy (EMB)-proven or clinically suspected myocarditis undergoing CMR at diagnosis. The pre-specified outcome was defined as NYHA class > I and echocardiographic left ventricular ejection fraction (LVEF) < 50% at follow-up. Results: We included 207 patients (74% male, median age 36 years; 25% EMB-proven). CMR showed the highest sensitivity in myocarditis with infarct-like presentation. Patients with EMB-proven myocarditis were more likely to have diffuse LGE and right ventricular LGE (p < 0.001), which was also more common among patients with arrhythmic presentation (p = 0.001). The outcome was met in 17 patients at any follow-up time point, more commonly in those with larger biventricular volumes (p < 0.001), CMR-based diagnosis of dilated cardiomyopathy (p < 0.001), and ischemic LGE (p = 0.005). Higher biventricular systolic function (p < 0.001) and greater LGE extent (p = 0.033) at diagnosis had a protective effect. Conclusions: In our single-center cohort of rigorously defined myocarditis patients, higher biventricular systolic function and greater LGE extent on CMR at diagnosis identified patients with better functional class and higher left ventricular ejection fraction at follow-up. Conversely, larger biventricular volumes, CMR-based DCM features, and the presence of an ischemic LGE pattern at diagnosis were predictors of worse functional class and LV systolic dysfunction at follow-up. Larger prospective studies are warranted to extend our findings to multi-center cohorts.

Multi-modality imaging to guide the implantation of cardiac electronic devices in heart failure: is the sum greater than the individual components?

Heart failure is a clinical syndrome with an increasing prevalence and incidence worldwide that impacts patients' quality of life, morbidity, and mortality. Implantable cardioverter-defibrillator and cardiac resynchronization therapy are pillars of managing patients with HF and reduced left ventricular ejection fraction. Despite the advances in cardiac imaging, the assessment of patients needing cardiac implantable electronic devices relies essentially on the measure of left ventricular ejection fraction. However, multi-modality imaging can provide important information concerning the aetiology of heart failure, the extent and localization of myocardial scar, and the pathophysiological mechanisms of left ventricular conduction delay. This paper aims to highlight the main novelties and progress in the field of multi-modality imaging to identify patients who will benefit from cardiac resynchronization therapy and/or implantable cardioverter-defibrillator. We also want to underscore the boundaries that prevent the application of imaging-derived parameters to patients who will benefit from cardiac implantable electronic devices and orient the choice of the device. Finally, we aim at providing some reflections for future research in this field.