Endomyocardial biopsy: safety and prognostic utility in paediatric and adult myocarditis in the European Society of Cardiology EURObservational Research Programme Cardiomyopathy and Myocarditis Long-Term Registry.

BACKGROUND AND AIMS: Contemporary multicentre data on clinical and diagnostic spectrum and outcome in myocarditis are limited. Study aims were to describe baseline features, 1-year follow-up, and baseline predictors of outcome in clinically suspected or biopsy-proven myocarditis (2013 European Society of Cardiology criteria) in adult and paediatric patients from the EURObservational Research Programme Cardiomyopathy and Myocarditis Long-Term Registry. METHODS: Five hundred eighty-one (68.0% male) patients, 493 adults, median age 38 (27-52) years, and 88 children, aged 8 (3-13) years, were divided into 3 groups: Group 1 (n = 233), clinically suspected myocarditis with abnormal cardiac magnetic resonance; Group 2 (n = 222), biopsy-proven myocarditis; and Group 3 (n = 126) clinically suspected myocarditis with normal or inconclusive or no cardiac magnetic resonance. Baseline features were analysed overall, in adults vs. children, and among groups. One-year outcome events included death/heart transplantation, ventricular assist device (VAD) or implantable cardioverter defibrillator (ICD) implantation, and hospitalization for cardiac causes. RESULTS: Endomyocardial biopsy, mainly right ventricular, had a similarly low complication rate in children and adults (4.7% vs. 4.9%, P = NS), with no procedure-related death. A classical myocarditis pattern on cardiac magnetic resonance was found in 31.3% of children and in 57.9% of adults with biopsy-proven myocarditis (P < .001). At 1-year follow-up, 11/410 patients (2.7%) died, 7 (1.7%) received a heart transplant, 3 underwent VAD (0.7%), and 16 (3.9%) underwent ICD implantation. Independent predictors at diagnosis of death or heart transplantation or hospitalization or VAD implantation or ICD implantation at 1-year follow-up were lower left ventricular ejection fraction and the need for immunosuppressants for new myocarditis diagnosis refractory to non-aetiology-driven therapy. CONCLUSIONS: Endomyocardial biopsy was safe, and cardiac magnetic resonance using Lake Louise criteria was less sensitive, particularly in children. Virus-negative lymphocytic myocarditis was predominant both in children and adults, and use of immunosuppressive treatments was low. Lower left ventricular ejection fraction and the need for immunosuppressants at diagnosis were independent predictors of unfavourable outcome events at 1 year.

Prevalence, Characteristics, and Outcomes of COVID-19-Associated Acute Myocarditis.

BACKGROUND: Acute myocarditis (AM) is thought to be a rare cardiovascular complication of COVID-19, although minimal data are available beyond case reports. We aim to report the prevalence, baseline characteristics, in-hospital management, and outcomes for patients with COVID-19-associated AM on the basis of a retrospective cohort from 23 hospitals in the United States and Europe. METHODS: A total of 112 patients with suspected AM from 56 963 hospitalized patients with COVID-19 were evaluated between February 1, 2020, and April 30, 2021. Inclusion criteria were hospitalization for COVID-19 and a diagnosis of AM on the basis of endomyocardial biopsy or increased troponin level plus typical signs of AM on cardiac magnetic resonance imaging. We identified 97 patients with possible AM, and among them, 54 patients with definite/probable AM supported by endomyocardial biopsy in 17 (31.5%) patients or magnetic resonance imaging in 50 (92.6%). We analyzed patient characteristics, treatments, and outcomes among all COVID-19-associated AM. RESULTS: AM prevalence among hospitalized patients with COVID-19 was 2.4 per 1000 hospitalizations considering definite/probable and 4.1 per 1000 considering also possible AM. The median age of definite/probable cases was 38 years, and 38.9% were female. On admission, chest pain and dyspnea were the most frequent symptoms (55.5% and 53.7%, respectively). Thirty-one cases (57.4%) occurred in the absence of COVID-19-associated pneumonia. Twenty-one (38.9%) had a fulminant presentation requiring inotropic support or temporary mechanical circulatory support. The composite of in-hospital mortality or temporary mechanical circulatory support occurred in 20.4%. At 120 days, estimated mortality was 6.6%, 15.1% in patients with associated pneumonia versus 0% in patients without pneumonia (P=0.044). During hospitalization, left ventricular ejection fraction, assessed by echocardiography, improved from a median of 40% on admission to 55% at discharge (n=47; P<0.0001) similarly in patients with or without pneumonia. Corticosteroids were frequently administered (55.5%). CONCLUSIONS: AM occurrence is estimated between 2.4 and 4.1 out of 1000 patients hospitalized for COVID-19. The majority of AM occurs in the absence of pneumonia and is often complicated by hemodynamic instability. AM is a rare complication in patients hospitalized for COVID-19, with an outcome that differs on the basis of the presence of concomitant pneumonia.

Myocarditis in anti-synthetase syndrome: clinical features and diagnostic modalities.

OBJECTIVES: Myocarditis is an overlooked manifestation of anti-synthetase syndrome (ASS). Our study describes the clinical and instrumental features of ASS-myocarditis and evaluates the diagnostic performance of cardiac magnetic resonance (CMR) with mapping techniques. METHODS: Data from ASS-patients were retrospectively analyzed. CMR data of patients diagnosed with myocarditis, including late gadolinium enhancement (LGE), T2-ratio, T1-mapping, extra-cellular volume (ECV) and T2-mapping, were reviewed. Myocarditis was defined by the presence of symptoms of heart involvement with increased high-sensitive troponin T (hs-TnT) and/or NT-proBNP and at least an instrumental abnormality. Clinical features of ASS patients with and without myocarditis were compared. A p value<0.05 was considered. RESULTS: Among a cohort of 43 ASS-patients (median age 58[48.0-66.0] years; females 74.4%; anti-Jo1 53.5%), 13(30%) were diagnosed with myocarditis. In 54% of patients, myocarditis was diagnosed at clinical onset. All ASS-myocarditis patients had at least one CMR abnormality: increased ECV in all cases, presence of LGE, increased T1 and T2-mapping in 91%. The 2009-Lake Louis criteria (LLC) were satisfied by 6 patients, the 2018-LLC by 10. With the updated LLC, the sensitivity for myocarditis improved from 54.6% to 91.0%. ASS-patients with myocarditis were more frequently males(53% vs 13%;p=0.009) with fever(69% vs 17%;p=0.001), and had higher hs-TnT (88.0[23.55-311.5] vs 9.80[5.0-23.0]ng/L; p < 0.001), NT-proBNP(525.5[243.5-1575.25] vs 59.0[32.0-165.5;p=0.013]pg/ml;p=0.013) and C-reactive protein(CRP)(7.0[1.7-15.75] vs 1.85[0.5-2.86]mg/L;p=0.011) compared to those without myocarditis. CONCLUSION: In ASS, myocarditis is frequent, even at clinical onset. ASS-patients with myocarditis frequently presented with fever and increased CRP, suggesting the existence of an inflammatory phenotype. The use of novel CMR mapping techniques may increase the diagnostic sensitivity for myocarditis in ASS.

Electrocardiographic findings in patients with arrhythmogenic cardiomyopathy and right bundle branch block ventricular tachycardia.

AIMS: Little is known about patients with right bundle branch block (RBBB)-ventricular tachycardia (VT) and arrhythmogenic cardiomyopathy (ACM). Our aims were: (i) to describe electrocardiogram (ECG) characteristics of sinus rhythm (SR) and VT; (ii) to correlate SR with RBBB-VT ECGs; and (iii) to compare VT ECGs with electro-anatomic mapping (EAM) data. METHODS AND RESULTS: From the European Survey on ACM, 70 patients with spontaneous RBBB-VT were included. Putative left ventricular (LV) sites of origin (SOOs) were estimated with a VT-axis-derived methodology and confirmed by EAM data when available. Overall, 49 (70%) patients met definite Task Force Criteria. Low QRS voltage predominated in lateral leads (n = 37, 55%), but QRS fragmentation was more frequent in inferior leads (n = 15, 23%). T-wave inversion (TWI) was equally frequent in inferior (n = 28, 42%) and lateral (n = 27, 40%) leads. TWI in inferior leads was associated with reduced LV ejection fraction (LVEF; 46 ± 10 vs. 53 ± 8, P = 0.02). Regarding SOOs, the inferior wall harboured 31 (46%) SOOs, followed by the lateral wall (n = 17, 25%), the anterior wall (n = 15, 22%), and the septum (n = 4, 6%). EAM data were available for 16 patients and showed good concordance with the putative SOOs. In all patients with superior-axis RBBB-VT who underwent endo-epicardial VT activation mapping, VT originated from the LV. CONCLUSIONS: In patients with ACM and RBBB-VT, RBBB-VTs originated mainly from the inferior and lateral LV walls. SR depolarization and repolarization abnormalities were frequent and associated with underlying variants.

Functional Characterisation of the Rare SCN5A p.E1225K Variant, Segregating in a Brugada Syndrome Familial Case, in Human Cardiomyocytes from Pluripotent Stem Cells.

Brugada syndrome (BrS) is an inherited autosomal dominant cardiac channelopathy. Pathogenic rare mutations in the SCN5A gene, encoding the alpha-subunit of the voltage-dependent cardiac Na+ channel protein (Nav1.5), are identified in 20% of BrS patients, affecting the correct function of the channel. To date, even though hundreds of SCN5A variants have been associated with BrS, the underlying pathogenic mechanisms are still unclear in most cases. Therefore, the functional characterization of the SCN5A BrS rare variants still represents a major hurdle and is fundamental to confirming their pathogenic effect. Human cardiomyocytes (CMs) differentiated from pluripotent stem cells (PSCs) have been extensively demonstrated to be reliable platforms for investigating cardiac diseases, being able to recapitulate specific traits of disease, including arrhythmic events and conduction abnormalities. Based on this, in this study, we performed a functional analysis of the BrS familial rare variant NM_198056.2:c.3673G>A (NP_932173.1:p.Glu1225Lys), which has been never functionally characterized before in a cardiac-relevant context, as the human cardiomyocyte. Using a specific lentiviral vector encoding a GFP-tagged SCN5A gene carrying the specific c.3673G>A variant and CMs differentiated from control PSCs (PSC-CMs), we demonstrated an impairment of the mutated Nav1.5, thus suggesting the pathogenicity of the rare BrS detected variant. More broadly, our work supports the application of PSC-CMs for the assessment of the pathogenicity of gene variants, the identification of which is increasing exponentially due to the advances in next-generation sequencing methods and their massive use in genetic testing.

Myocardial Late Contrast Enhancement CT in Troponin-Positive Acute Chest Pain Syndrome.

Background Acute chest pain with mild troponin rise and inconclusive diagnosis after clinical evaluation represents a diagnostic challenge. Triple-rule-out (TRO) CT may exclude coronary artery disease (CAD), as well as acute aortic syndrome and pulmonary embolism, but cannot help identify other causes of myocardial injury. Purpose To investigate the diagnostic value of a comprehensive CT protocol including both an angiographic and a late contrast enhancement (LCE) scan in participants with troponin-positive acute chest pain. Materials and Methods In this prospective study, consecutive patients with troponin-positive acute chest pain or anginal equivalent and inconclusive diagnosis after clinical evaluation (symptoms, markers, electrocardiography, and echocardiography) who underwent TRO CT between June 2018 and September 2020 were enrolled. TRO CT was performed to evaluate the presence of obstructive CAD (stenosis ≥50%), acute aortic syndrome, and pulmonary embolism. If the findings on the TRO CT scan were negative, an LCE CT scan was acquired after 10 minutes to assess the presence and pattern of scar and quantify the myocardial extracellular volume fraction. CT-based diagnoses were compared with diagnoses obtained with reference standard methods, including invasive coronary angiography, cardiac MRI, and endomyocardial biopsy. Results Eighty-four patients (median age, 69 years [interquartile range, 50-77 years]; 45 men) were enrolled. TRO CT helped identify obstructive CAD in 35 participants (42%), acute aortic syndrome in one (1.2%), and pulmonary embolism in six (7.1%). LCE CT scans were acquired in the remaining 42 participants. The following diagnoses were reached with use of LCE CT: myocarditis (22 of 42 participants [52%]), takotsubo cardiomyopathy (four of 42 [10%]), amyloidosis (three of 42 [7.1%]), myocardial infarction with nonobstructed coronary arteries (three of 42 [7.1%]), dilated cardiomyopathy (two of 42 [4.8%]), and negative or inconclusive findings (eight of 42 [19%]). The addition of LCE CT improved the diagnostic rate of TRO CT from 42 of 84 participants (50% [95% CI: 38.9, 61.1]) to 76 of 84 (90% [95% CI: 82.1, 95.8]) (P < .001). Conclusion A CT protocol including triple-rule-out and late contrast enhancement CT scans improved diagnostic rate in participants presenting with acute chest pain syndrome. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Nagpal and Bluemke in this issue.

Dose-efficient multimodal microscopy of human tissue at a hard X-ray nanoprobe beamline.

X-ray fluorescence microscopy performed at nanofocusing synchrotron beamlines produces quantitative elemental distribution maps at unprecedented resolution (down to a few tens of nanometres), at the expense of relatively long measuring times and high absorbed doses. In this work, a method was implemented in which fast low-dose in-line holography was used to produce quantitative electron density maps at the mesoscale prior to nanoscale X-ray fluorescence acquisition. These maps ensure more efficient fluorescence scans and the reduction of the total absorbed dose, often relevant for radiation-sensitive (e.g. biological) samples. This multimodal microscopy approach was demonstrated on human sural nerve tissue. The two imaging modes provide complementary information at a comparable resolution, ultimately limited by the focal spot size. The experimental setup presented allows the user to swap between them in a flexible and reproducible fashion, as well as to easily adapt the scanning parameters during an experiment to fine-tune resolution and field of view.

Design and performance of a dedicated coherent X-ray scanning diffraction instrument at beamline NanoMAX of MAX IV.

The diffraction endstation of the NanoMAX beamline is designed to provide high-flux coherent X-ray nano-beams for experiments requiring many degrees of freedom for sample and detector. The endstation is equipped with high-efficiency Kirkpatrick-Baez mirror focusing optics and a two-circle goniometer supporting a positioning and scanning device, designed to carry a compact sample environment. A robot is used as a detector arm. The endstation, in continued development, has been in user operation since summer 2017.

Cardiac magnetic resonance in systemic sclerosis myocarditis: the value of T2 mapping to detect myocardial inflammation.

OBJECTIVES: Myocarditis in SSc is associated with a poor prognosis. Cardiac magnetic resonance (CMR) is the non-invasive diagnostic modality of choice for SSc myocarditis. Our study investigates the performance of the mapping techniques included in the revised Lake Louise criteria (LLC) for the identification of SSc myocarditis. METHODS: CMR data (right and left ventricular function and morphology, early and late gadolinium enhancement [LGE], T2 ratio, and T1 mapping, extracellular volume [ECV] and T2 mapping) of SSc patients diagnosed with myocarditis were reviewed. Myocarditis was defined by the presence of symptoms of SSc heart involvement with increased high-sensitive troponin T (hs-TnT) and/or NT-proBNP and at least an abnormality at 24 h ECG Holter and/or echocardiography and/or CMR. A P-value < 0.05 was considered as statistically significant. RESULTS: Nineteen patients (median age 54 [46-70] years; females 78.9%; diffuse SSc 52.6%; anti-Scl70+ 52.6%) were identified: 11 (57.9%) had echocardiographic, and 8 (42.8%) 24 h ECG Holter abnormalities. All patients had at least one CMR abnormality: LGE in 18 (94.7%), increased ECV in 10 (52.6%) and T2 mapping >50 ms in 15 (78.9%). Median T1 and T2 mapping were 1085 [1069-1110] ms and 53.1 [52-54] ms, respectively. T1 mapping directly correlated with NT-proBNP (r = 0.620; P = 0.005), ESR (r = 0.601; P = 0.008), CRP (r = 0.685; P = 0.001) and skin score (r = 0.507; P = 0.027); ECV correlated with NT-proBNP serum levels (r = 0.702; P = 0.001). No correlations emerged between T2 mapping and other parameters. Ten patients satisfied the 2009 LLC, 17 the 2018 LLC. With the new criteria including T2 mapping, the sensitivity improved from 52.6% to 89.5%. CONCLUSION: The CMR mapping techniques improve the sensitivity to detect myocardial inflammation in patients with SSc heart involvement. The evaluation of T2 mapping increases diagnostic accuracy for the recognition of myocardial inflammation in SSc.

The prevalence of left and right bundle branch block morphology ventricular tachycardia amongst patients with arrhythmogenic cardiomyopathy and sustained ventricular tachycardia: insights from the European Survey on Arrhythmogenic Cardiomyopathy.

AIMS: In arrhythmogenic cardiomyopathy (ACM), sustained ventricular tachycardia (VT) typically displays a left bundle branch block (LBBB) morphology while a right bundle branch block (RBBB) morphology is rare. The present study assesses the VT morphology in ACM patients with sustained VT and their clinical and genetic characteristics. METHODS AND RESULTS: Twenty-six centres from 11 European countries provided information on 954 ACM patients who had ≥1 episode of sustained VT spontaneously documented during patients' clinical course. Arrhythmogenic cardiomyopathy was defined according to the 2010 Task Force Criteria, and VT morphology according to the QRS pattern in V1. Overall, 882 (92.5%) patients displayed LBBB-VT alone and 72 (7.5%) RBBB-VT [alone in 42 (4.4%) or in combination with LBBB-VT in 30 (3.1%)]. Male sex prevalence was 79.3%, 88.1%, and 56.7% in the LBBB-VT, RBBB-VT, and LBBB + RBBB-VT groups, respectively (P = 0.007). First RBBB-VT occurred 5 years after the first LBBB-VT (46.5 ± 14.4 vs 41.1 ± 15.8 years, P = 0.011). An implanted cardioverter-defibrillator was more frequently implanted in the RBBB-VT (92.9%) and the LBBB + RBBB-VT groups (90%) than in the LBBB-VT group (68.1%) (P < 0.001). Mutations in PKP2 predominated in the LBBB-VT (65.2%) and the LBBB + RBBB-VT (41.7%) groups while DSP mutations predominated in the RBBB-VT group (45.5%). By multivariable analysis, female sex was associated with LBBB + RBBB-VT (P = 0.011) while DSP mutations were associated with RBBB-VT (P < 0.001). After a median follow-up of 103 (51-185) months, death occurred in 106 (11.1%) patients with no intergroup difference (P = 0.176). CONCLUSION: RBBB-VT accounts for a significant proportion of sustained VTs in ACM. Sex and type of pathogenic mutations were associated with VT type, female sex with LBBB + RBBB-VT, and DSP mutation with RBBB-VT.

Bi-atrial characterization of the electrical substrate in patients with atrial fibrillation.

BACKGROUND: Little is known regarding the characterization of electrical substrate in both atria in patients with atrial fibrillation (AF). METHODS: Eight consecutive patients undergoing AF ablation (five paroxysmal, three persistent) underwent electrical substrate characterization during sinus rhythm. Mapping of the left (LA) and right atrium (RA) was performed with the use of the HD Grid catheter (Abbott). Bipolar voltage maps were analyzed to search for low voltage areas (LVA), the following electrophysiological phenomena were assessed: (1) slow conduction corridors, and (2) lines of block. EGMs were characterized to search for fractionation. Electrical characteristics were compared between atria and between paroxysmal versus persistent AF patients. RESULTS: In the RA, LVAs were present in 60% of patients with paroxysmal AF and 100% of patients with persistent AF. In the LA, LVAs were present in 40% of patients with paroxysmal AF and 66% of patients with persistent AF. The areas of LVA in the RA and LA were 4.8±7.3 cm2 and 7.8±13.6 cm2 in patients with paroxysmal AF versus 11.7±3.0 cm2 and 2.1±1.8 cm2 in patients with persistent AF. In the RA, slow conduction corridors were present in 40.0% (paroxysmal AF) versus 66.7% (persistent AF) whereas in the LA, slow conduction corridors occurred in 20.0% versus 33.3% respectively (p = ns). EGM analysis showed more fractionation in persistent AF patients than paroxysmal (RA: persistent AF 10.8 vs. paroxysmal AF 4.7%, p = .036, LA: 10.3 vs. 4.1%, p = .108). CONCLUSION: Bi-atrial involvement is present in patients with paroxysmal and persistent AF. This is expressed by low voltage areas and slow conduction corridors whose extension progresses as the arrhythmia becomes persistent. This electrophysiological substrate demonstrates the important interplay with the pulmonary vein triggers to constitute the substrate for persistent arrhythmia.

Contrast - a lightweight Python framework for beamline orchestration and data acquisition.

The emergence of fourth-generation synchrotrons is prompting the development of new systems for experimental control and data acquisition. However, as general control systems are designed to cover a wide set of instruments and techniques, they tend to become large and complicated, at the cost of experimental flexibility. Here we present Contrast, a simple Python framework for interacting with beamline components, orchestrating experiments and managing data acquisition. The system is presented and demonstrated via its application at the NanoMAX beamline of the MAX IV Laboratory.

NanoMAX: the hard X-ray nanoprobe beamline at the MAX IV Laboratory.

NanoMAX is the first hard X-ray nanoprobe beamline at the MAX IV laboratory. It utilizes the unique properties of the world's first operational multi-bend achromat storage ring to provide an intense and coherent focused beam for experiments with several methods. In this paper we present the beamline optics design in detail, show the performance figures, and give an overview of the surrounding infrastructure and the operational diffraction endstation.

Etiology is a predictor of recurrence after catheter ablation of ventricular arrhythmias in pediatric patients.

BACKGROUND: Ventricular arrhythmias (VAs) are rare in pediatric patients, especially in absence of structural heart disease (SHD). Few data are available regarding the invasive VAs treatment with catheter ablation (CA) in pediatric patients and predictors of outcomes have not been fully investigated. OBJECTIVE: To describe the clinical presentation, procedural characteristics, and outcomes in pediatric patients undergoing CA for VAs. METHODS: Eighty-one consecutive pediatric patients (58 male [72%], 15.5 ± 2.2 years) treated by CA for ventricular tachycardia (VT) or premature ventricular beats (PVBs) were retrospectively evaluated. Study endpoints were VAs recurrence and mortality for any cause. RESULTS: Ninety-five procedures were performed in 81 patients, 52 (55%) PVBs and 43 (45%) VT ablations. During a follow-up of 35.0 months (interquartile range = 13.0-71.0), 14 patients (14.7%) had a VA recurrence: 11 (33.3%) patients treated with CA for VT and 3 (6.2%) patients treated for PVBs (p < .001). One patient (1%) died 26 months after the procedure during an electrical storm. Patients with SHD had higher VAs recurrence rate, as compared with idiopathic VAs (pairwise log-rank p < .001). Patients treated with CA for VT had higher VA recurrence rate, as compared with PVB patients (pairwise log-rank p = .002). At Cox multivariate analysis only SHD was an independent predictor of VAs recurrence (hazard ratio = 5.56, 95% confidence interval = 2.68-11.54, p < .001). CONCLUSION: CA of VAs is effective and safe in a pediatric population. CA of idiopathic and fascicular VAs are associated with lower recurrence rate, than VAs in the setting of SHD.

Immunosuppressive therapy in childhood-onset arrhythmogenic inflammatory cardiomyopathy.

We present, to our knowledge, the first case of immunosuppressive therapy (IST) application in a 12-year-old child with arrhythmogenic inflammatory cardiomyopathy resulting from the overlap between autoimmune myocarditis and primary arrhythmogenic cardiomyopathy. Indication to off-lable IST was compelling, because of recurrent drug-refractory ventricular arrhythmias (VAs). We show that IST was feasible, safe, and effective on multiple clinical endpoints, including symptoms, VA recurrences, and T-troponin release. Remarkably, all diagnostic and therapeutic strategies were worked out by a dedicated multidisciplinary team, including specialized pediatric immunologists.

Generation of a Triadin KnockOut Syndrome Zebrafish Model.

Different forms of sudden cardiac death have been described, including a recently identified form of genetic arrhythmogenic disorder, named "Triadin KnockOut Syndrome" (TKOS). TKOS is associated with recessive mutations in the TRDN gene, encoding for TRIADIN, but the pathogenic mechanism underlying the malignant phenotype has yet to be completely defined. Moreover, patients with TKOS are often refractory to conventional treatment, substantiating the need to identify new therapeutic strategies in order to prevent or treat cardiac events. The zebrafish (Danio rerio) heart is highly comparable to the human heart in terms of functions, signal pathways and ion channels, representing a good model to study cardiac disorders. In this work, we generated the first zebrafish model for trdn loss-of-function, by means of trdn morpholino injections, and characterized its phenotype. Although we did not observe any gross cardiac morphological defect between trdn loss-of-function embryos and controls, we found altered cardiac rhythm that was recovered by the administration of arrhythmic drugs. Our model will provide a suitable platform to study the effect of TRDN mutations and to perform drug screening to identify new pharmacological strategies for patients carrying TRDN mutations.

Early T1 Myocardial MRI Mapping: Value in Detecting Myocardial Hyperemia in Acute Myocarditis.

Background Hyperemia is a key component of acute myocarditis (AM). Early gadolinium uptake because of myocardial hyperemia may be quantified by using T1 mapping. Purpose To evaluate the value of early enhanced T1 shortening for the diagnosis of acute myocarditis. Materials and Methods Study participants suspected of having AM and healthy control (HC) participants were prospectively enrolled from September 2016 to May 2019. Participants underwent 1.5-T cardiac MRI including Lake Louise criteria, T2 mapping, native T1, and extracellular volume, with the addition of early enhanced T1 mapping (2 minutes after intravenous administration of 0.15 mmol/kg gadobutrol). Color-coded maps of the percentage of T1 shortening from precontrast to early postcontrast were generated. Optimal early T1 shortening cut-off value and its diagnostic performance in the identification of acute myocarditis were calculated. Results Forty-five study participants with AM (median age, 40 years; interquartile range [IQR], 20-46 years; 22 women) diagnosed according to multidisciplinary clinical evaluation, electrocardiography, laboratory test, echocardiography, cardiac MRI, and coronary CT and/or invasive angiography. Findings were confirmed by endomyocardial biopsy in 64% (29 of 45) of participants. MRI parameters were compared with 19 HC participants (median age, 39 years; IQR, 28-46 years; seven women). Median early T1 shortening was 75% (IQR, 72%-78%) in participants with AM versus 65% (IQR, 61%-66%) in HC participants (P < .001). Early T1 shortening showed high diagnostic performance (area under the receiver operating characteristic curve [AUC], 0.97; 95% confidence interval [CI]: 0.94, 1.00) and excellent interobserver reproducibility (intraclass correlation coefficient: 0.98; 95% CI: 0.96, 1.00). Early T1 shortening of 70% or greater identified acute myocarditis with 93% sensitivity, 100% specificity, and 95% diagnostic accuracy. Early T1 shortening had better diagnostic performance than late percentage T1 shortening (AUC, 0.97 vs 0.90, respectively; P = .03) and extracellular volume (AUC, 0.97 vs 0.88, respectively; P = .046), and similar to native T1 (AUC, 0.97 vs 0.93, respectively; P = .63) and T2 mapping (AUC, 0.97 vs 0.97, respectively; P > .99). Conclusion In this proof-of-concept study, percentage of T1 shortening at early enhanced T1 mapping showed high accuracy for the diagnosis of acute myocarditis. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by De Cecco and Monti in this issue.

Telemedicine in myocarditis: Evolution of a mutidisciplinary "disease unit" at the time of COVID-19 pandemic.

Myocarditis Disease Unit (MDU) is a functional multidisciplinary network designed to offer multidisciplinary assistance to patients with myocarditis. More than 300 patients coming from the whole Country are currently followed up at a specialized multidisciplinary outpatient clinic. Following the pandemic outbreak of the SARS-CoV-2 infection in Italy, we present how the MDU rapidly evolved to a "tele-MDU", via a dedicated multitasking digital health platform.

Efficacy and safety of mycophenolate mofetil in patients with virus-negative lymphocytic myocarditis: A prospective cohort study.

BACKGROUND: virus-negative lymphocytic myocarditis (VNLM) is a severe inflammatory heart disease with elusive therapies. We aimed to assess the efficacy of mycophenolate-mofetil (MMF) in patients with VNLM. METHODS: patients were enrolled in this prospective cohort study and were treated with MMF, as the initial treatment in case of concomitant systemic immune diseases (SIDs), or as rescue therapy in isolated myocarditis intolerant/resistant to azathioprine. All were initially evaluated for endomyocardial biopsy; ECG, 24-h Holter, echocardiography, troponin T and NT-proBNP were obtained in all patients at baseline and after 6 months. The primary end-point was the change in left-ventricular ejection-fraction (LVEF) on echocardiogram after 6 months. SECONDARY OUTCOMES: decrease in serum NT-proBNP and troponin-T levels, reduction of LV end-diastolic-volume (LVEDV), amelioration of regional wall motion abnormalities (RWMA), and modification of clinical status. RESULTS: 20 patients (10 females, median age at diagnosis 32 [41-59] years) were enrolled. Baseline echocardiography revealed a reduced LVEF (<55%) in 11 patients (55%) and a median LV-EF of 53.5 [44-60.5]%. Baseline median troponin T and NT-proBNP were 50.5 (14.4-288.5)ng/L and 257.0 (90.5-912.0)pg/ml, respectively. After 6 months, the median LVEF significantly improved (57 [50-61]%,p = 0.016), irrespective of concomitant steroid dose. Consistently, after 6 months LVEDV decreased from 135 ±â€¯50 ml to 114 ±â€¯38 ml (p < 0.001), and only 6 patients had RWMA, compared to 14 at baseline (p = 0.016). The amelioration of cardiac function was paralleled by a reduction of median troponin T (12.0 [10.0-24.0],p = 0.02) and NT-proBNP(79.5 [74.5-223-2],p = 0.007) and by a reduction in the number of patients with dyspnea NYHA class II-III(p = 0.02). None of the patients required drug discontinuation. CONCLUSIONS: MMF migh be a safe and effective therapeutic option in VNLM, both as first-line agent and as a rescue therapy.

Systemic sclerosis myocarditis has unique clinical, histological and prognostic features: a comparative histological analysis.

OBJECTIVE: To outline the clinical, histological and prognostic features of systemic sclerosis (SSc) endomyocardial biopsy-proven myocarditis with respect to those of diverse endomyocardial biopsy-proven virus-negative myocarditis (VNM). METHODS: We retrospectively analysed data from three cohorts of endomyocardial biopsy-proven myocarditis: SSc-related VNM (SSc-VNM); isolated VNM (i-VNM); and VNM related to other systemic autoimmune diseases (a-VNM). The degree of myocardial fibrosis was expressed as relative percentage and fibrotic score (0-3). Clinical data, cardiac enzymes, echocardiogram, 24 h ECG Holter and cardiac magnetic resonance were obtained at baseline and during follow-up. Non-parametric tests were used. RESULTS: We enrolled 12 SSc-VNM [11 females, mean age 49.3 (14.2) years; seven diffuse-SSc, five early-SSc], 12 i-VNM [12 females, mean age 47.7 (10.8) years] and 10 a-VNM [four females, mean age 48.4 (16.3) years] patients. SSc patients had higher degrees of myocardial fibrosis as assessed by both percentage [SSc-VNM: 44.8 (18.8)%; a-VNM: 28.6 (16.5)%; i-VNM: 24.9 (10.3)%; P = 0.019] and score [SSc-VNM: 2.3 (0.8); a-VNM: 1.4 (1.1); i-VNM: 1.2 (0.7); P = 0.002]. Myocardial fibrosis directly correlated with skin score (r = 0.625, P = 0.03) and number of ventricular ectopic beats on 24 h ECG Holter in SSc patients (r = 0.756, P = 0.01). Dyspnoea class was higher at presentation in SSc-VNM patients (P = 0.041) and we found heart failure only in SSc patients (25%) (P = 0.05). At cardiac magnetic resonance, myocardial oedema was nearly undetectable in SSc-VNM patients compared with others (P = 0.02). All patients received immunosuppressive treatment. The number of patients who died during follow-up due to cardiac complications was significantly higher in SSc-VNM patients (50%), as compared with a-VNM (0%) and i-VNM (8.3%) patients (P = 0.006). Patients who died during follow-up had higher degrees of myocardial fibrosis [52.2 (11.6)% vs 27.5 (12.9)%, P = 0.024; fibrotic score: 2.83 (0.41) vs 1.4 (0.9), P < 0.001]. CONCLUSION: SSc has unique clinical and histological features, as it tends to present more frequently with heart failure and a higher dyspnoea class and to show higher degrees of myocardial fibrosis. These specific features are paralleled by a worse cardiac prognosis.