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Cardiac toxicity is an adverse event of several classes of anti-cancer drugs. Herein, we present the case of a 52-year-old woman with metastatic renal cell carcinoma (RCC), previously treated with debulking surgery, pembrolizumab (immune checkpoint inhibitor) in combination with axitinib (tyrosine kinase inhibitor (TKI)), followed by lenvatinib (TKI) and belzutifan (HIF-2α inhibitor), who developed myocarditis proven by cardiac magnetic resonance and endomyocardial biopsy. The case was notable for reporting a not-yet described adverse event during treatment with belzutifan plus lenvatinib, the etiology of which was of unobvious determination given the pre-exposure to pembrolizumab, a known cause of drug-related myocarditis. We surmise that myocarditis was a delayed adverse event related to pembrolizumab (8 months after treatment interruption), although we emphasize that only attentive monitoring of cardiac adverse events of patients exposed to belzutifan and lenvatinib in the context of large clinical trials may rule out any causal implication of these drugs., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

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 performance of cardiac MRI (CMRI) with mapping techniques in assisting diagnosis of ASS myocarditis., Methods: Data from patients with ASS were retrospectively analysed. CMRI data for patients diagnosed with myocarditis, including late gadolinium enhancement (LGE), T2 ratio, T1 mapping, extracellular volume (ECV) and T2 mapping, were reviewed. Myocarditis was defined by the presence of symptoms and/or signs suggestive for heart involvement, including increased high-sensitive troponin T (hs-TnT) and/or N-terminal pro-brain natriuretic peptide (NT-proBNP), and at least an instrumental abnormality. The clinical features of patients with ASS with and without myocarditis were compared. A P-value of <0.05 was considered statistically significant., Results: Among a cohort of 43 patients with ASS [median age 58 (48.0-66.0) years; females 74.4%; anti-Jo1 53.5%], 13 (30%) were diagnosed with myocarditis. In 54% of those 13 patients, myocarditis was diagnosed at clinical onset. All patients with ASS with myocarditis had at least one CMRI abnormality: increased ECV in all cases, presence of LGE in 91%, and increased T1 and T2 mapping in 91%. The 2009 Lake Louise criteria (LLC) were satisfied by 6 patients, and the 2018 LLC by 10 patients. With the updated LLC, the sensitivity for myocarditis improved from 54.6% to 91.0%. Patients with ASS 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 CRP [7.0 (1.7-15.75) vs 1.85 (0.5-2.86) mg/l; P = 0.011] compared with those without myocarditis., Conclusion: In ASS, myocarditis is frequent, even at clinical onset. Patients with ASS with myocarditis frequently presented with fever and increased CRP, suggesting the existence of an inflammatory phenotype. The use of novel CMRI mapping techniques may increase diagnostic sensitivity for myocarditis in ASS., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Background: mRNA COVID-19 vaccines have been associated with myocarditis in the general population. However, application of gold standard techniques is often missing, and data about patients with history of myocarditis have not been reported yet., Methods: We evaluated 21 patients (median age 27, 86% males) for suspected myocarditis after receiving mRNA COVID-19 vaccine. We divided cases with previous diagnosis of myocarditis (PM, N.=7), from naïve controls (NM, N.=14). All patients were investigated thoroughly by cardiac magnetic resonance (100%) with or without endomyocardial biopsy (14%)., Results: Overall, 57% of patients met updated Lake Louise criteria and none fulfilled Dallas criteria, with no remarkable differences between groups. Acute coronary syndrome-like presentation was more frequent in NM with earlier normalization of troponin than PM. NM and PM already healed from myocarditis were clinically comparable, whereas PM with active inflammation had subtle presentation and were evaluated for immunosuppressive therapy modulation. None had fulminant myocarditis and/or malignant ventricular arrhythmia at presentation. No major cardiac events occurred by 3 months., Conclusions: In this study, the suspicion of mRNA COVID-19 vaccine-associated myocarditis was inconstantly confirmed by gold standard diagnostics. Myocarditis was uncomplicated in both PM and NM patients. Larger studies with longer follow-up are needed to validate COVID-19 vaccination in this population.

Introduction: Cardiac injury is commonly reported in COVID-19 patients, resulting associated to pre-existing cardiovascular disease, disease severity, and unfavorable outcome. Aim is to report cardiac magnetic resonance (CMR) findings in patients with myocarditis-like syndrome during the acute phase of SARS-CoV-2 infection (AMCovS) and post-acute phase (cPACS)., Methods: Between September 2020 and January 2022, 39 consecutive patients (24 males, 58%) were referred to our department to perform a CMR for the suspicion of myocarditis related to AMCovS (n = 17) and cPACS (n = 22) at multimodality evaluation (clinical, laboratory, ECG, and echocardiography). CMR was performed for the assessment of volume, function, edema and fibrosis with standard sequences and mapping techniques. CMR diagnosis and the extension and amount of CMR alterations were recorded., Results: Patients with suspected myocarditis in acute and post-COVID settings were mainly men (10 (59%) and 12 (54.5%), respectively) with older age in AMCovS (58 [48-64]) compared to cPACS (38 [26-53]). Myocarditis was confirmed by CMR in most of cases: 53% of AMCovS and 50% of cPACS with negligible LGE burden (3 [IQR, 1-5] % and 2 [IQR, 1-4] %, respectively). Myocardial infarction was identified in 4/17 (24%) patients with AMCovS. Cardiomyopathies were identified in 12% (3/17) and 27% (6/22) of patients with AMCovS and cPACS, including DCM, HCM and mitral valve prolapse., Conclusions: In patients with acute and post-acute COVID-19 related suspected myocarditis, CMR improves diagnostic accuracy characterizing ischemic and non-ischemic injury and unraveling subclinical cardiomyopathies., (© 2022 The Authors. Journal of Clinical Ultrasound published by Wiley Periodicals LLC.)

Over recent years, preclinical and clinical evidence has implicated myocardial inflammation (M-Infl) in the pathophysiology and phenotypes of traditionally genetic cardiomyopathies. M-Infl resembling myocarditis on imaging and histology occurs frequently as a clinical manifestation of classically genetic cardiac diseases, including dilated and arrhythmogenic cardiomyopathy. The emerging role of M-Infl in disease pathophysiology is leading to the identification of druggable targets for molecular treatment of the inflammatory process and a new paradigm in the field of cardiomyopathies. Cardiomyopathies constitute a leading cause of heart failure and arrhythmic sudden death in the young population. The aim of this review is to present, from bedside to bench, the current state of the art about the genetic basis of M-Infl in nonischemic cardiomyopathies of the dilated and arrhythmogenic spectrum in order to prompt future research towards the identification of novel mechanisms and treatment targets, with the ultimate goal of lowering disease morbidity and mortality.

Introduction: Inflammatory bowel disease (IBD) may be associated with several extraintestinal comorbidities, including cardiovascular disease (CVD). Chronic inflammation is recognized as an important factor in atherogenesis, thrombosis, and myocarditis., Areas Covered: IBD patients may be at increased risk for developing early atherosclerosis, cardiovascular events, peripheral artery disease, venous thromboembolism, myocarditis, and arrhythmias. Anti-tumor necrosis factor agents and thiopurines have been shown to have a protective effect against acute arterial events, but more research is needed. However, an increased risk of venous thromboembolism and major cardiovascular events has been described with the use of Janus kinase inhibitors., Expert Opinion: CVD risk is slightly increased in patients with IBD, especially during flares. Thromboprophylaxis is strongly recommended in hospitalized patients with active disease as the benefit of anticoagulation outweighs the risk of bleeding. The pathogenetic relationship between CVD and IBD and the impact of IBD drugs on CVD outcomes are not fully elucidated. CVD risk doesn't have the strength to drive a specific IBD treatment. However, proper CVD risk profiling should always be done and the best strategy to manage CVD risk in IBD patients is to combine appropriate thromboprophylaxis with early and durable remission of the underlying IBD.

Background: Previous studies suggest low diagnostic sensitivity of cardiac magnetic resonance (CMR) imaging based on Lake Louise criteria (LLC) to identify patients with complicated presentations of acute myocarditis (AM). We evaluated classic and updated LLC in patients with AM proven by right ventricular septal endomyocardial biopsy (RVS-EMB)., Methods: From an initial population of 499 patients with clinically suspected AM from a multicenter retrospective cohort, we included 74 patients with histologically proven myocarditis on RVS-EMB and available CMR within 30 days since admission. The prevalence of total and septal CMR abnormalities [namely, T2-weighted images (T2W), late gadolinium enhancement (LGE), T2 and T1 mapping, and extracellular volume (ECV)] were assessed in patients with complicated vs. uncomplicated AM., Results: Among 74 patients [mean age 38 ± 15 years, 65% males, left ventricular ejection fraction (LVEF) 40 ± 18%] with RVS-EMB-proven AM, 53 (72%) had a complicated presentation. The classic LLC were positive in 56/74 patients (76%), whereas the updated ones were positive in 41/41 of cases (100%). Septal involvement, documented in 48/74 patients (65%) by conventional T2W/LGE and in 39/41 cases (95%) by mapping techniques (p < 0.001), was more common in patients with complicated AM. In the 41 patients undergoing both evaluations, CMR sensitivity for myocarditis was 85% for the classic LLC vs. 100% for the updated LLC (p = 0.006)., Conclusion: In patients with myocarditis on RVS-EMB, CMR using updated LLC has high sensitivity in the detection of AM when performed within 30 days. Septal abnormalities are more common in patients with complicated AM., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Purpose: Immune checkpoint blocker (ICB) associated myocarditis (ICB-myocarditis) may present similarly and/or overlap with other cardiac pathology including acute coronary syndrome presenting a challenge for prompt clinical diagnosis., Methods: An international registry was used to retrospectively identify cases of ICB-myocarditis. Presence of coronary artery disease (CAD) was defined as coronary artery stenosis >70% in patients undergoing coronary angiogram., Results: Among 261 patients with clinically suspected ICB-myocarditis who underwent a coronary angiography, CAD was present in 59/261 patients (22.6%). Coronary revascularization was performed during the index hospitalisation in 19/59 (32.2%) patients. Patients undergoing coronary revascularization less frequently received steroids administration within 24 h of admission compared to the other groups (p = 0.029). Myocarditis-related 90-day mortality was 9/17 (52.7%) in the revascularised cohort, compared to 5/31 (16.1%) in those not revascularized and 25/156 (16.0%) in those without CAD (p = 0.001). Immune-related adverse event-related 90-day mortality was 9/17 (52.7%) in the revascularized cohort, compared to 6/31 (19.4%) in those not revascularized and 31/156 (19.9%) in no CAD groups (p = 0.007). All-cause 90-day mortality was 11/17 (64.7%) in the revascularized cohort, compared to 13/31 (41.9%) in no revascularization and 60/158 (38.0%) in no CAD groups (p = 0.10). After adjustment of age and sex, coronary revascularization remained associated with ICB-myocarditis-related death at 90 days (hazard ratio [HR] = 4.03, 95% confidence interval [CI] 1.84-8.84, p < 0.001) and was marginally associated with all-cause death (HR = 1.88, 95% CI, 0.98-3.61, p = 0.057)., Conclusion: CAD may exist concomitantly with ICB-myocarditis and may portend a poorer outcome when revascularization is performed. This is potentially mediated through delayed diagnosis and treatment or more severe presentation of ICB-myocarditis., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: LL has served on the advisory board for Daiichi Sankyio, Senaca, Astra Zeneca and Servier, as an external expert for Astra Zeneca and received speakers' honoraria from Novartis and MSD. LL is receiving grants from the German Center for Cardiovascular Research (DZHK), German Reuter Foundation (DFG) LE3570/2-1; 3570/3-1 and grant 01KC2006B from the Federal Ministry for Education and Research (BMBF). DA received speakers’ honoraria from BMS, Ipsen and participated to ad-boards from Sanofi and AstraZeneca. KT has received honoraria from Bristol Myers Squibb, Pfizer, Ono Pharmaceutical, Merck BioPharma, Bayer, and grants from Otsuka, Daiichi, Sankyo and Takeda. JM has served on advisory boards for Bristol Myers Squibb, Takeda, Regeneron, Audentes, Deciphera, Ipsen, Janssen, ImmunoCore, Boston Biomedical, Amgen, Myovant, Triple Gene/Precigen, Cytokinetics and AstraZeneca and supported by NIH grants (R01HL141466, R01HL155990, R01HL156021). JES have received consultancy fees from BMS, BeiGene, AstraZeneca, Novartis, and grants from BMS, Novartis, French Agence Nationale de la Recherche, Fondation Coeur et Recherche, Fédération Française de Cardiologie. All other authors have nothing to declare., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

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 &lt; 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 &gt;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 Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) scan has no recognized role in diagnosis, prognosis, and disease monitoring in patients with arrhythmic myocarditis., Objectives: The purpose of this study was to investigate the value of FDG-PET scan in arrhythmic myocarditis., Methods: The authors enrolled 75 consecutive patients (age 47 ± 14 years, 65% men) undergoing FDG-PET scan for arrhythmic myocarditis. Myocarditis was diagnosed by endomyocardial biopsy (EMB) and, whenever applicable, cardiac magnetic resonance (CMR)., Results: Indications for FDG-PET scan included either contraindication to CMR (n = 50) or mismatch between CMR and EMB (n = 25). Overall, 50 patients (67%) had positive FDG-PET. Sensitivity was 75% referring to EMB, and 73% to CMR. Specificity was 67% referring to EMB, and 59% to CMR. FDG-PET accuracy was lower in the presence of borderline myocarditis, and either late (>30 days) or on-immunosuppression FDG-PET scanning. Anteroseptal distribution pattern, found in 12 of 50 (24%) patients including 7 of 7 cardiac sarcoidosis cases, was associated with greater occurrence of ventricular arrhythmias and atrioventricular blocks in 4.2 ± 1.7 years of follow-up (10 of 12 vs 7 of 38, and 7 of 12 vs 0 of 38, respectively; both P < 0.001). In 39 patients (52%), FDG-PET was repeated by 13 ± 2 months, allowing immunosuppression withdrawal after FDG uptake normalization either by first (76%) or second reassessment (24%)., Conclusions: FDG-PET scan may be a clinically useful diagnostic technique in arrhythmic myocarditis, in particular when CMR is unsuitable because of irregular heartbeat or implantable cardioverter-defibrillator-related artifacts. Anteroseptal FDG distribution is associated with a worse arrhythmic outcome and should raise the suspicion of cardiac sarcoidosis. During follow-up, repeated FDG-PET allows myocarditis monitoring to guide immunosuppression withdrawal., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The risk of adverse cardiovascular events in patients with acute myocarditis (AM) and desmosomal gene variants (DGV) remains unknown., Objectives: The purpose of this study was to ascertain the risk of death, ventricular arrhythmias, recurrent myocarditis, and heart failure (main endpoint) in patients with AM and pathogenic or likely pathogenetic DGV., Methods: In a retrospective international study from 23 hospitals, 97 patients were included: 36 with AM and DGV (DGV[+]), 25 with AM and negative gene testing (DGV[-]), and 36 with AM without genetics testing. All patients had troponin elevation plus findings consistent with AM on histology or at cardiac magnetic resonance (CMR). In 86 patients, CMR changes in function and structure were re-assessed at follow-up., Results: In the DGV(+) AM group (88.9% DSP variants), median age was 24 years, 91.7% presented with chest pain, and median left ventricular ejection fraction (LVEF) was 56% on CMR (P = NS vs the other 2 groups). Kaplan-Meier curves demonstrated a higher risk of the main endpoint in DGV(+) AM compared with DGV(-) and without genetics testing patients (62.3% vs 17.5% vs 5.3% at 5 years, respectively; P &lt; 0.0001), driven by myocarditis recurrence and ventricular arrhythmias. At follow-up CMR, a higher number of late gadolinium enhanced segments was found in DGV(+) AM., Conclusions: Patients with AM and evidence of DGV have a higher incidence of adverse cardiovascular events compared with patients with AM without DGV. Further prospective studies are needed to ascertain if genetic testing might improve risk stratification of patients with AM who are considered at low risk., Competing Interests: Funding Support and Author Disclosures Dr Ammirati has received a grant from the Italian Ministry of Health (GR-2019-12368506) and is a consultant for Kiniksa and Cytokinetics. Dr Adler is a consultant for Abbott, Abiomed, AstraZeneca, Endotronix, Ionis, Medtronic, and Novartis; is on the board of directors of Genstem Therapeutics; and is a shareholder of Rocket Pharmaceuticals. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Cardiovascular involvement is a common complication of COVID-19 infection and is associated to increased risk of unfavorable outcome. Advanced imaging modalities (coronary CT angiography and Cardiac Magnetic Resonance) play a crucial role in the diagnosis, follow-up and risk stratification of patients affected by COVID-19 pneumonia with suspected cardiovascular involvement. In the present manuscript we firstly review current knowledge on the mechanisms by which SARS-CoV-2 can trigger endothelial and myocardial damage. Secondly, the implications of the cardiovascular damage on patient's prognosis are presented. Finally, we provide an overview of the main findings at advanced cardiac imaging characterizing COVID-19 in the acute setting, in the post-acute syndrome, and after vaccination, emphasizing the potentiality of CT and CMR, the indication and their clinical implications., (Copyright © 2022 Elsevier Inc. All rights reserved.)

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.

Aims: The outcomes of patients presenting with acute myocarditis and life-threatening ventricular arrhythmias (LT-VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population., Methods and Results: We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT-VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter-defibrillator therapy or synchronized external cardioversion. Median follow-up was 23 months [first to third quartile (Q1-Q3) 7-60]. Fifty-eight (37.2%) patients experienced MAEs after discharge, at a median of 8 months (Q1-Q3 2.5-24.0 months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38-6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39-8.53), and absence of positive short-tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40-4.79) at first CMR., Conclusions: Among patients discharged with a diagnosis of myocarditis and LT-VA, 37.2% had recurrences of MAEs during follow-up. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence., (© 2021 European Society of Cardiology.)

Competing Interests: Conflicts of interest and sources of funding: CC received speaking fees from Pfizer, Roche, and Novartis. GDL received speaking fees from Pfizer and received consultation honoraria from Novartis, SOBI, and Celgene. GC received speaking fees and consultation honoraria from Pfizer, Novartis, and SOBI. LD received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Sanofi-Genzyme, and SOBI. AT, SilS, GP, SimS, AP and AE declare no conflicts of interest. The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unrestricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Merck Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi Genzyme, and SOBI.

Aims: The aim of this study was to evaluate the sensitivity of right ventricular endomyocardial biopsy (EMB) in myocarditis patients with cardiac magnetic resonance (CMR) and electroanatomical mapping (EAM) showing left ventricular abnormalities., Methods: We performed right ventricular EMB in 144 consecutive patients (66% men, age 43 ± 15 years) with acute symptoms and CMR-proved diagnosis of left ventricular myocarditis. Right ventricular EMB sensitivity has been evaluated in patients with different localization and extension of abnormal substrate at both CMR and -- when performed -- EAM. Abnormal substrate was defined, respectively, by late gadolinium enhancement (LGE) and low-voltage areas (LVAs)., Results: Globally, right ventricular EMB sensitivity was 87.5%. EMB-negative cases had significantly smaller fragment sizes (cumulative area 2.8 ± 1.7 vs. 3.8 ± 1.8 mm2, P = 0.023), and lower LGE surface extension (24.7 ± 14.2 vs. 38.5 ± 20.2%, P = 0.006) and transmurality (32.0 ± 26.1 vs. 49.3 ± 22.6, P = 0.003). Right ventricular EMB sensitivity in patients with LGE involving both right ventricular and interventricular septum (IVS), isolated right ventricular or IVS, and remote left ventricular areas (n = 10, 49 and 67 cases) was 83.3, 84.4 and 90.5%, respectively (P = 0.522). Overall, 34 patients (23.6%) underwent EAM. On the basis of EAM, right ventricular EMB sensitivity was 85.3%: in detail, it was 50.0, 88.2 and 86.7% in patients with both right ventricular and IVS, isolated right ventricular/IVS and distant left ventricular involvement (n = 2, 17 and 15, respectively, P > 0.05). Sample size area was the only factor associated with right ventricular EMB sensitivity (hazard ratio = 1.6/mm2, 95% confidence interval 1.1-2.4, P = 0.013)., Conclusion: Right ventricular EMB is still an accurate technique to confirm diagnosis in patients with CMR-proved left ventricular myocarditis. In particular, provided there is an adequate sample size, its sensitivity is comparable among patients with heterogeneous LGE or LVA localization., (Copyright © 2021 Italian Federation of Cardiology - I.F.C. All rights reserved.)

Competing Interests: Author Disclosures All authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Background: Little is known about the risk stratification of patients with myocarditis undergoing ventricular tachycardia (VT) ablation., Objectives: This study sought to describe VT ablation results and identify factors associated with arrhythmia recurrences in a cohort of patients with myocarditis., Methods: The authors enrolled 125 consecutive patients with myocarditis, undergoing VT ablation. Before ablation, disease stage was evaluated, to identify active (AM) versus previous myocarditis (PM). The primary study endpoint was assessment of VT recurrences by 12-month follow-up. Predictors of VT recurrences were retrospectively identified., Results: All patients (age 51 ± 14 years, 91% men, left ventricular ejection fraction 52% ± 9%) had history of myocarditis diagnosed by endomyocardial biopsy (59%) and/or cardiac magnetic resonance (90%). Furthermore, all had multiple episodes of drug-refractory VTs. Multimodal pre-procedural staging identified 47 patients with AM (38%) and 78 patients with PM (62%). All patients showed low-voltage areas (LVA) at electroanatomical map (97% epicardial or endoepicardial); of them, 25 (20%) had wide borderzone (WBZ, constituting >50% of the whole LVA). VT recurrences were documented in 25 patients (20%) by 12 months, and in 43 (34%) by last follow-up (median 63 months; interquartile range: 39 to 87). At multivariable analysis, AM stage was the only predictor of VT recurrences by 12 months (hazard ratio: 9.5; 95% confidence interval: 2.6 to 35.3; p < 0.001), whereas both AM stage and WBZ were associated with arrhythmia recurrences anytime during follow-up. No VT episodes were found after redo ablation was performed in 23 patients during PM stage., Conclusion: Our findings suggest that VT ablation should be avoided during AM, but is often of benefit for recurrent VT after the acute phase of myocarditis., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to investigate the effects of immunosuppression on arrhythmic myocarditis., Background: The effects of immunosuppressive therapy (IST) on ventricular arrhythmia (VA) have not been reported in patients with immune-mediated biopsy-proven myocarditis. Furthermore, myocarditis arrhythmic risk is still unpredictable., Methods: We enrolled 255 patients with biopsy-proven virus-negative myocarditis and VA (major: ventricular fibrillation, ventricular tachycardia; minor: nonsustained ventricular tachycardia, Lown grade ≥2 premature ventral complexes) at presentation. Serum cardiac autoantibodies (antiheart antibodies, anti-intercalated disk autoantibodies [AIDA]) were detected by a standardized indirect immunofluorescence technique. Whenever accepted and noncontraindicated, IST was started. Control individuals (IST - ) were chosen after 1:1 matching to IST + patients by age, sex, ethnicity, left ventricular ejection fraction, VA type, and treatment., Results: A total of 58 matched patient couples (age 42 ± 13 years; 67% male) were analyzed in the main study cohort. IST duration was 12 ± 1 months. By the 24-month prospective follow-up, major VA occurred in 6 IST + versus 10 IST - patients (p = 0.42), with no episodes following IST termination. As compared to IST - patients, IST + patients showed a significant reduction in minor VA burden, as well as improvement in clinical, laboratory, and imaging findings (all p < 0.05). Major VA onset and positive AIDA status were independently associated with major VA at follow-up (hazard ratio [HR]: 14.2; 95% confidence interval [CI]: 2.9 to 68.7 and HR: 8.0; 95% CI: 2.6 to 25.2, respectively; both p < 0.001). Furthermore, in the whole study population (N = 255), IST was independently associated with protection from major VA (HR: 0.3; 95% CI: 0.2 to 0.7; p = 0.01) at 38 ± 21 months of follow-up., Conclusions: In patients with immune-mediated virus-negative myocarditis presenting with VA, IST is associated with positive effects on minor VA and nonarrhythmic endpoints. Short-term effects are limited on major VA, which were independently associated with major VA onset and positive AIDA., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

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., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Virus-negative or autoimmune myocarditis(VNM) is an inflammatory disease affecting the myocardium that may occur as a distinct disease with exclusive cardiac involvement, or in the context of systemic autoimmune or inflammatory disorders. The pathogenesis of VNM involves both innate and acquired immunity and is not completely elucidated: an early immune-mediated pathogenic process lead to subacute and chronic stages and eventually results in tissue remodeling, fibrosis, contractile dysfunction, dilated cardiomyopathy and arrhythmic burden, accounting for a dismal prognosis. Treatment interventions effectively curbing the acute inflammatory process at an early stage can prevent late cardiac remodeling and improve patient's outcome. The mainstay of treatment of VNM remains symptomatic therapy of heart failure and arrhythmia, while the use of immunosuppressive treatments has long been considered controversial until recently, and strategies effectively targeting the inflammatory and immune-mediated substrate of the disease remain elusive. Only steroids and azathioprine have been tested in clinical trials, and nowadays represent the therapy of choice. A substantial proportion of patients are resistant to first line strategies, suggesting that some critical inflammatory mechanisms are not responsive to conventional immunosuppression with steroids and azathioprine, or experience drug-related adverse events. Thus, second-line targeted therapeutic strategies to treat VNM are eagerly awaited. Recent data on the pathogenic mechanisms underlying myocardial inflammation are paving the way to novel, promising treatment strategies for myocarditis, which could reformulate future treatment strategies for VNM. In this review, we summarize the current therapeutic opportunities, beyond corticosteroids, to treat VNM, including conventional and biologic immunosuppressive drugs and cytokine blocking agents., Competing Interests: Declaration of Competing Interest Prof Dagna received consultation honoraria from Novartis, Roche, Sanofi-Genzyme, and SOBI. Drs. De Luca and Campochiaro received consultation honoraria from SOBI. The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Roche, Sanofi-Genzyme, and SOBI., (Copyright © 2020 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.)

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.

Background: Ventricular arrhythmias (VAs) have never been systematically investigated in patients with myocarditis at different stages., Objectives: The purpose of this study was to compare baseline and follow-up characteristics of VAs in patients with active myocarditis (AM) versus previous myocarditis (PM)., Methods: A total of 185 consecutive patients (69% males, age 44 ± 15 years, left ventricular ejection fraction 49 ± 14%) with myocarditis and VA at index hospitalization, including ventricular fibrillation, ventricular tachycardia (VT), nonsustained ventricular tachycardia (NSVT), and Lown's grade ≥2 premature ventricular complexes, were enrolled. AM and PM groups were defined based on endomyocardial biopsy and cardiac magnetic resonance findings. A subset of patients (n = 46, 25%) also underwent electroanatomic mapping and VA transcatheter ablation., Results: At presentation, AM patients (n = 123, 66%) more commonly had ventricular fibrillation (8 cases vs. 0 cases; p = 0.053), and both irregular (61% vs. 11%; p < 0.001) and polymorphic VA (NSVT and VT: 19% vs. 2%; p = 0.002; premature ventricular complexes: 63% vs. 16%; p < 0.001). Only in PM patients with NSVT or VT, the dominant morphology (right-bundle branch block with superior axis) was 100% predictive of abnormal LV inferoposterior substrate at both cardiac magnetic resonance and electroanatomic mapping. At 27 ± 7 months prospective follow-up, 55 patients (30%) experienced malignant VA (AM vs. PM, p = 0.385). Although a prevalence of polymorphic and irregular VA was confirmed in AM patients with persistent inflammation in follow-up (58%), a predominance of monomorphic and regular VA was found in AM patients after myocarditis healing (42%), as well as in PM patients (all p < 0.001)., Conclusions: In myocarditis patients, polymorphic and irregular VA are more common during the active inflammatory phase, whereas monomorphic and regular VA are associated with healed myocarditis., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Myocarditis is a complex inflammatory disease of the myocardium, occurring secondary to viral infections or autoimmune mechanisms in most cases. Among its multiple clinical manifestations, arrhythmias are often underdiagnosed, in spite of their important prognostic value. In particular, ventricular arrhythmias complicating either active or previous myocarditis, are a significant cause of sudden cardiac death, especially in young people. Because of the absence of clinical trials specifically addressing this topic, nowadays updated international guidelines report extremely generic recommendations about optimal clinical management of patients with arrhythmic myocarditis. This review aims at both (i) showing the state of the art about patients with myocarditis and arrhythmias (ventricular arrhythmias in particular); and (ii) suggesting optimal diagnostic and therapeutic strategies for these patients, based on the experience of a high-volume referral center for arrhythmic myocarditis and ventricular arrhythmia management.

Introduction: No studies so far addressed the role of invasive programmed ventricular stimulation (PVS) in myocarditis patient's arrhythmic risk stratification., Methods and Results: We present a single-center prospective study on 96 consecutive adult patients (44 ± 13 years, 70.1% males) with myocarditis and ventricular arrhythmias (VA) at index hospitalization. Depending on baseline endomyocardial biopsy (EMB) and cardiac magnetic resonance, patients were divided into two groups: active (A) vs nonactive (NA) myocarditis. All of the patients underwent PVS at index hospitalization. Medical treatment and implantable cardioverter-defibrillator (ICD) implantation were clinically-driven. Malignant VA episodes (MVA = ventricular tachycardias [VT], ventricular fibrillation [VF], appropriate ICD therapy) were evaluated at 54 ± 18 months follow-up (FU). Patients who underwent VT ablation or with myocarditis recurrence (n = 9) were excluded. Of 87 patients, 41 (47.2%) were in group A. PVS was positive in 32 cases (36.8%), 16 A vs 16 NA (P = NS), with no associations with VA type at presentation. Before discharge, 55 patients (63.2%) underwent ICD implant. In FU, MVA occurred in 27 patients (31.0%), 13 A vs 14 NA (P = NS), 18 PVS+ vs 9 PVS- (P < .001). The association between PVS result and FU MVA was maximal in group NA (high rule-out performance with negative predictive value = 90.0%, P < .001) and minimal in group A (low rule-in performance with PPV = 43.8%, P = .302). In the whole population, three independent factors for major VA were identified: major arrhythmic onset by sustained VT or VF (HR 2.8, 95% CI, 1.0-7.4, P = .042), presence of fibrosis at EMB (HR 5.8, 95% CI, 1.1-30.0, P = .038), and PVS positivity (HR 4.2, 95% CI, 1.7-10.7, P = .003)., Conclusion: In myocarditis patients presenting with VA, PVS is associated with FU MVA in NA patients, but not in A ones. Overall, risk stratification of arrhythmic myocardits is still complex and multifactorial., (© 2020 Wiley Periodicals, Inc.)

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 ± 50 ml to 114 ± 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., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

To explore the potential role of two- (2D) and three-dimensional (3D) cardiac magnetic resonance (CMR) feature tracking (FT) myocardial strain analysis in identifying sub-clinical myocardial systolic and diastolic dysfunction in acute myocarditis patients with preserved ejection fraction (EF). Prospective two centre study-control study. Thirty patients (9 female, 37.2 ± 11.8 years.) with a CMR diagnosis of acute myocarditis according to the Lake Louise Criteria and preserved EF (≥ 55%) were included in the analysis. CMR data from 24 healthy volunteers (11 female, 36.2 ± 12.5 years.) served as control. 2D and 3D LV tissue tracking analysis were performed in a random fashion by two double-blinded operators. Variables were checked for normality and analysed with parametric test. The baseline characteristics of myocarditis patients with preserved EF and the healthy volunteers were perfectly comparable, except for the LV mass index and T1 and T2 mapping values (p < 0.001). The results of the interobserver variability in the 2D and 3D LV CMR FT myocardial strain analysis were p > 0.42, ICC > 0.80 and η 2  > 0.98. There was no statistical difference in 2D and 3D global radial, circumferential and longitudinal strain peak (%) and both systolic and diastolic strain rate (1/s) between acute myocarditis with preserved EF and healthy volunteers (all p = ns). There were no difference in 2D and 3D global radial, circumferential and longitudinal strain peak and both systolic and diastolic strain rate of the LV between acute myocarditis patients with preserved ejection fraction and healthy volunteers.

Many kinds of arrhythmias may occur in patients with myocarditis at any stage of the disease. However, compared to the other clinical presentations, arrhythmic myocarditis has been poorly described in the literature. Arrhythmias occurring in either ongoing or previous myocardial inflammation are complex and heterogeneous, and the disease itself is often underdiagnosed, thus limiting data collection and interpretation. However, different from the other clinical presentations, arrhythmic myocarditis requires specific diagnostic, prognostic, and therapeutic considerations. The aim of this review is to critically summarize the state of the art on myocarditis presenting with arrhythmias in terms of epidemiology, etiology, diagnosis, prognosis, and treatment., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: Myocarditis has been described in association with many systemic immune-mediated diseases (SIDs). However, the role of SIDs in influencing clinical presentation and outcome of patients with a new diagnosis of biopsy-proved myocarditis, has never been investigated so far., Methods: We enrolled 25 consecutive cases with biopsy-proved myocarditis in the context of SIDs, and controls with isolated myocarditis, matched 1:1 by age, gender, ethnicity and clinical presentation. All of the patients presented with acute symptoms, normal coronary arteries, and no previous history of myocarditis. Detailed diagnostic workup, including blood exams, echocardiogram, arrhythmia monitoring and cardiac magnetic resonance (CMR) were obtained at baseline and at defined time points, up to 12-month follow-up (FU)., Results: At presentation, patients with SIDs had more commonly inflammatory biomarkers elevation, signs of associated pericarditis, and replacement fibrosis at histology, as compared to controls (18 vs. 6, 20 vs. 12, and 21 vs. 11, respectively; all p < 0.05). The Lake Louise criteria at CMR were negative in 19 vs. 10 patients with and without underlying SIDs, respectively (p = 0.021). Baseline ECG, in-hospital arrhythmia telemonitoring and echocardiographic findings were not significantly different between groups (all p = n.s.). At 12-month FU, the composite major endpoint of cardiac death, end-stage heart failure or malignant ventricular arrhythmias was significantly more common in cases than in controls (7 vs. 1, respectively, p = 0.049)., Conclusion: In patients with a new diagnosis of myocarditis, the presence of underlying SIDs is associated with distinct baseline clinical features and a significantly worse 1-year outcome., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals., Methods: A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance., Results: At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). β-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation., Conclusions: In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.