Clinical Presentation and Outcome in a Contemporary Cohort of Patients With Acute Myocarditis: Multicenter Lombardy Registry

Re-evaluation of intravenous steroid therapy for histologically confirmed fulminant myocarditis

BACKGROUND

The efficacy of intravenous steroids (IS) for fulminant myocarditis (FMP) remains controversial. We aimed to compare outcomes in FMP patients who received IS [IS(+)] and those who did not [IS(-)].

METHODS AND RESULTS

Data from 344 patients with histologically confirmed FMP requiring catecholamines or mechanical support were extracted from the Japanese Registry of Fulminant Myocarditis. The primary outcome was a composite of 90-day mortality and heart transplantation. Among the patients (median age 54, 40 % female), 195 received IS, 98 died within 90 days, and 16 died or underwent transplantation after 90 days. The IS(+) group had lower left ventricular ejection fraction and lower ratio of lymphocytic myocarditis, higher use of intra-aortic balloon pumping, Venoarterial extracorporeal membrane oxygenation (VA-ECMO), and intravenous immunoglobulin. Crude analysis showed worse 90-day outcomes in the IS(+) group (36.3 % vs. 19.2 %, P = 0.0021); however, after propensity score matching (PSM), outcomes were similar (26.2 % vs. 24.2 %; P = 0.95). Unadjusted Cox regression indicated worse outcomes with IS (HR 1.95, 95 % CI 1.26-3.04; P = 0.0026), but this was not significant after PSM (HR 1.02, 95 % CI 0.56-1.87; P = 0.95). Among low-risk patients, the IS(-) group showed better outcomes than the IS(+) group post-PSM (P = 0.0031). In the patients with VA-ECMO or ventricular assist devices, early IS (within 2 days of admission) showed comparable prognosis to delayed/no IS, with a trend toward better outcomes post-PSM.

CONCLUSIONS

IS effectiveness in FMP patients may vary, showing limited prognostic benefit overall. Careful consideration is warranted in its use for this population.

Clinical Considerations for Competitive Sports Participation for Athletes With Cardiovascular Abnormalities: A Scientific Statement From the American Heart Association and American College of Cardiology

COLLABORATORS

Larry A. Allen, MD, MHS, FAHA, FACC; Mats Börjesson, MD, PhD, FACC; Alan C. Braverman, MD, FACC; Julie A. Brothers, MD; Silvia Castelletti, MD, MSc, FESC; Eugene H. Chung, MD, MPH, FHRS, FAHA, FACC; Timothy W. Churchill, MD, FACC; Guido Claessen, MD, PhD; Flavio D'Ascenzi, MD, PhD; Douglas Darden, MD; Peter N. Dean, MD, FACC; Neal W. Dickert, MD, PhD, FACC; Jonathan A. Drezner, MD; Katherine E. Economy, MD, MPH; Thijs M.H. Eijsvogels, PhD; Michael S. Emery, MD, MS, FACC; Susan P. Etheridge, MD, FHRS, FAHA, FACC; Sabiha Gati, BSc (Hons), MBBS, PhD, MRCP, FESC; Belinda Gray, BSc (Med), MBBS, PhD; Martin Halle, MD; Kimberly G. Harmon, MD; Jeffrey J. Hsu, MD, PhD, FAHA, FACC; Richard J. Kovacs, MD, FAHA, MACC; Sheela Krishnan, MD, FACC; Mark S. Link, MD, FHRS, FAHA, FACC; Martin Maron, MD; Silvana Molossi, MD, PhD, FACC; Antonio Pelliccia, MD; Jack C. Salerno, MD, FACC, FHRS; Ankit B. Shah, MD, MPH, FACC; Sanjay Sharma, BSc (Hons), MBChB, MRCP (UK), MD; Tamanna K. Singh, MD, FACC; Katie M. Stewart, NP, MS; Paul D. Thompson, MD, FAHA, FACC; Meagan M. Wasfy, MD, MPH, FACC; Matthias Wilhelm, MD.

This American Heart Association/American College of Cardiology scientific statement on clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities or diseases is organized into 11 distinct sections focused on sports-specific topics or disease processes that are relevant when considering the potential risks of adverse cardiovascular events, including sudden cardiac arrest, during competitive sports participation. Task forces comprising international experts in sports cardiology and the respective topics covered were assigned to each section and prepared specific clinical considerations tables for practitioners to reference. Comprehensive literature review and an emphasis on shared decision-making were integral in the writing of all clinical considerations presented.

Clinical Considerations for Competitive Sports Participation for Athletes With Cardiovascular Abnormalities: A Scientific Statement From the American Heart Association and American College of Cardiology

This American Heart Association/American College of Cardiology scientific statement on clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities or diseases is organized into 11 distinct sections focused on sports-specific topics or disease processes that are relevant when considering the potential risks of adverse cardiovascular events, including sudden cardiac arrest, during competitive sports participation. Task forces comprising international experts in sports cardiology and the respective topics covered were assigned to each section and prepared specific clinical considerations tables for practitioners to reference. Comprehensive literature review and an emphasis on shared decision-making were integral in the writing of all clinical considerations presented.

Assessing customized multivalent chemokine-binding peptide treatment in a murine model of coxsackievirus B3 myocarditis

Myocarditis, an inflammatory disease of the heart muscle, is often triggered by viral infections. This inflammation, which can lead to severe cardiac dysfunction and adverse outcomes, is mediated by various CC and CXC chemokines that interact with receptors in a "one-to-many" fashion. Ticks have evolved chemokine-binding salivary proteins known as Evasins, which efficiently suppress inflammation. This study explores a tailored Evasin-derived CC chemokine-targeting strategy using a 17-mer synthetic dimeric peptide, BK1.3. This peptide inhibits the inflammatory chemokines CCL2, CCL3, CCL7, and CCL8 in murine Coxsackievirus B3 (CVB3) infection, a viral trigger of myocarditis. Administered at a dose of 5 mg/kg twice daily, BK1.3 effectively maintains virus control without exacerbating CVB3-induced morbidity markers, such as hemodynamic compromise, multiorgan failure with hepatitis and pancreatitis, hypothermia, hypoglycemia, and weight loss. Metabolic profiling combined with proteomics reveals preserved reprogramming of lipid storage and gluconeogenesis capacity in the liver, alongside sustained energy production in the injured heart muscle. In survivors of acute CVB3 infection exhibiting manifestations of the subacute phase, BK1.3 enhances virus control, reduces myeloid cell infiltration in the heart and liver, improves markers of liver injury, and alleviates cardiac dysfunction, as evidenced by echocardiographic global longitudinal strain analysis. These findings affirm the safety profile of BK1.3 peptide therapeutics in a preclinical mouse model of acute CVB3 infection and emphasize its potential for therapeutic advancement in addressing virus-induced inflammation in the heart.

Salmonellosis-Induced Pericarditis and Pericardial Effusion: A Case Report and Literature Review

While salmonellosis is commonly thought to predominantly impact the gastrointestinal system, bacteremia and localized extraintestinal infections such as meningitis, empyema, and pericarditis can develop, particularly in immunocompromised individuals. Here, we present a case of a 69-year-old with multiple comorbidities, who presented to the emergency department with dyspnea and hemodynamics instability in the form of hypoxia and hypotension and was found to have moderate pericardial effusion without echocardiographic signs of tamponade. The ischemic workup was unrevealing, and further infectious workups, including pericardial tissue biopsy and pericardial fluid culture, showed growth in Salmonella groups C and D. Subsequently, the patient was diagnosed with Salmonella-induced pericarditis and pericardial effusion and discharged home on oral antibiotics following pericardiocentesis and hemodynamics stabilization. Invasive infections caused by non-typhoidal Salmonella are becoming more prevalent in immunocompromised individuals. Acute bacterial myopericarditis is uncommon in advanced nations, yet it can be life-threatening if not treated promptly. Therefore, a high index of suspicion, early detection, and aggressive invasive and non-invasive therapies would strongly be considered to achieve a desirable outcome and good prognosis.

Acute myocarditis: 2024 state of the art

Acute myocarditis (AM) is an inflammatory injury of the myocardium secondary to infections, systemic autoimmune disorders, medications, or toxic agents. The patient's genetic underground is a likely concurrent aetiology/contributory mechanism recently implicated in a proportion of AM. This review focuses on some critical new concepts of AM, updated indications for endomyocardial biopsy when cardiac magnetic resonance imaging is not sufficient or feasible, and estimation of long-term events after discharge. Furthermore, studies exploring AM as the cause of sudden cardiac death will be examined to assess the characteristics of patients who die due to AM before hospital admission. Managing the most severe clinical presentation, termed fulminant myocarditis (FM) characterized by haemodynamic instability due to ventricular arrhythmias or severe acute pump failure, will be summarized. Specific issues aimed to reduce the high mortality rate of FM, like early recognition, referring these patients from spoke centres to a hub centre, timely temporary mechanical circulatory support when indicated, early endomyocardial biopsy, and eventually immunosuppression, will be briefly discussed. Immune checkpoint inhibitors and desmosomal gene variant-associated AM will be highlighted as paradigmatic new forms of myocarditis.

Cardiovascular magnetic resonance parametric mapping in the risk stratification of patients affected by chronic myocarditis

OBJECTIVES

Chronic myocardial inflammation is the substrate for arrhythmias and dilated cardiomyopathy onset, causing morbidity and mortality. Cardiovascular magnetic resonance (CMR) is the noninvasive gold standard for myocardial inflammation detection, due to the high sensitivity of the parametric mapping techniques. However, the potential prognostic capabilities of CMR mapping have not been studied in the setting of chronic myocarditis.

METHODS

This is a retrospective study on consecutive patients undergoing CMR with suspicion of chronic myocarditis from September 2017 to November 2021. CMR was acquired according to 2018 Lake Louise Criteria recommendations. The outcome (chronic heart failure, recurrent chronic myocarditic chest pain, ICD/PM implantation, arrhythmias [Lown class ≥ 2]) was collected at follow-up. The extent and degree of native T1, T2, and extracellular volume fraction alterations were used to create multivariate binary logistic regression models for outcome prediction, with or without left ventricle ejection fraction; their AUCs were compared with DeLong test. Differences between other parameters were assessed using Chi-square test, Fisher's exact test, or Mann-Whitney U-test.

RESULTS

The population included 88 patients (age 43 [32-52] yo), mostly male (53/88, 60%). After a median follow-up of 21 (17-34) months, 31/88 (35%) patients experienced the outcome. The model based on the extension of mapping alterations and LV dysfunction reached a good predictability (AUC 0.71). The model based on the intensity of mapping alterations and LV dysfunction had a very good performance (AUC 0.80).

CONCLUSION

The quantitative analysis of CMR mapping parameters indicative of myocardial damage severity may improve risk stratification in patients with chronic myocarditis.

CLINICAL RELEVANCE STATEMENT

The intensity of myocardial damage, assessed as the degree of native T1, T2, and ECV alteration, together with left ventricle dysfunction, improved patient risk stratification. Further prospective studies will be necessary for validation before clinical application.

KEY POINTS

Risk stratification of patients affected by chronic myocarditis is an unmet clinical need. Cardiovascular MRI (CMR) can role in risk stratification thanks to its multiparametric capabilities of tissue characterization. A model based on CMR parametric mapping and left ventricle ejection fraction can predict arrhythmia, heart failure, and recurrent symptoms.

Assessing the causal effect of inflammation-related genes on myocarditis: A Mendelian randomization study

AIMS

Prior evidence has shown a significant link between inflammation and the development of myocarditis. This study aimed to investigate the causal relationship between inflammation-related genes (IRGs) and myocarditis.

METHODS AND RESULTS

In this study, the causal relationship between 167 IRGs and myocarditis were investigated using datasets from the Gene Set Enrichment Analysis and Integrative Epidemiology Unit open genome-wide association study (IEU OpenGWAS) databases. The GWAS data (finn-b-I9 MYOCARD) contained single nucleotide polymorphisms (SNPs) data from 117 755 myocarditis samples (16 379 455 SNPs, 829 cases vs. 116 926 controls). Five algorithms [MR-Egger, weighted median, inverse variance weighted (IVW), simple mode, and weighted mode regression] were employed for the MR analysis, with IVW as the primary method, and sensitivity analysis was conducted. Subcellular localization and protein-protein interaction (PPI) network analyses were performed for selected biomarkers. Results were verified in ebi-a-GCST90018882 (24 180 570 SNPs, 633 cases vs. 427 278 controls) and finn-b-I9 MYOCARD EXNONE (16 380 466 SNPs, 829 cases vs. 217 963 controls) to enhance reliability.

RESULTS

IRF7 and ADORA2B were shown to be two exposure factors after screening. Univariable MR (UVMR) analysis revealed that IRF7 was a risk factor for myocarditis [IVW: odd ratio (OR) = 1.041, 95% confidence interval (CI) = 1.018-1.955, P = 0.039], while ADORA2B was a protective factors for myocarditis (IVW: OR = 0.799, 95% CI = 0.640-0.997, P = 0.047). Sensitivity analysis confirmed the robustness of these findings. Multivariable MR (MVMR) analysis further demonstrated a direct causal role of ADORA2B in preventing myocarditis. Subcellular localization analysis indicated predominant cytoplasmic expression and limited mitochondrial expression for both genes. The results of PPI analysis showed that 20 genes were predicted to be associated with IRF7 function, such as response to type I interferon, pattern recognition receptor signalling pathway, and toll-like receptor signalling pathway. The results in finn-b-I9 MYOCARD EXNONE were consistent with MR analysis.

CONCLUSIONS

The findings indicated there was a causal connection between IRGs (IRF7 and ADORA2B) and myocarditis, which offered a crucial point of reference and guidance for future studies and myocarditis treatment.

Acute Myocarditis and Inflammatory Cardiomyopathies: Insights From Cardiac Magnetic Resonance Findings

Myocardial inflammation encompasses a broad spectrum of conditions, including acute myocarditis, chronic inflammatory cardiomyopathy, and several overlapping entities that differ in clinical presentation, pathophysiology, and progression. These conditions range from self-limiting acute inflammation to chronic myocardial injury and dysfunction. The etiologic classification of myocardial inflammation highlights the complexity of its pathogenesis, involving direct tissue damage, immune-mediated mechanisms, and environmental triggers. Cardiac magnetic resonance (CMR) imaging has become a central diagnostic tool in the assessment of myocardial inflammation, providing precise characterization of myocardial tissue, assessing cardiac function, and stratifying prognosis. Advanced techniques such as T1 and T2 mapping and extracellular volume quantification have further expanded its diagnostic capabilities. This review highlights the essential role of CMR in diagnosing myocardial inflammation, recognizing various imaging findings associated with different underlying causes, and informing clinical management. The standardization of CMR protocols, along with advancements in imaging techniques and strengthened interdisciplinary collaboration, represents a fundamental step toward improving diagnostic accuracy, patient outcomes, and the understanding of the broad spectrum of myocardial inflammatory diseases.

Prognostic Value of Myocardial Parametric Mapping in Patients with Acute Myocarditis: A Retrospective Study

Purpose To investigate the prognostic value of T1 mapping, extracellular volume fraction (ECV), and T2 mapping in a large cohort of patients with acute myocarditis. Materials and Methods This retrospective study included patients with acute myocarditis who underwent cardiac MRI (3.0 T) between March 2016 and October 2022. Diagnosis was confirmed by diagnostic cardiac MRI criteria or endomyocardial biopsy. The primary end point was major adverse cardiovascular events (MACEs), defined as the composite of cardiac death, heart failure hospitalization, heart transplantation, sustained ventricular arrhythmia, and recurrent myocarditis. Univariable and multivariable Cox regression analyses were performed to assess the association of clinical and cardiac MRI variables with the primary end point. The prognostic value of each model was assessed using the Harrell C index. Results A total of 235 patients (mean age, 32 years ± 13 [SD]; 150 [63.8%] men) were included. During a mean follow-up of 1637 days (IQR: 1441-1833 days), MACEs occurred in 45 (19%) patients. Patients with MACEs had higher global native T1, ECV, and T2 values (1342 msec ± 64 vs 1263 msec ± 48; P < .001; 39.1% ± 8.7 vs 32.7% ± 5.7; P < .001; 61.1 msec ± 10.0 vs 55.3 msec ± 9.4; P = .03, respectively). In a series of multivariable Cox regression models, native T1 (per 10-msec increase: hazard ratio, 1.61; 95% CI: 1.31, 1.98; P < .001) and ECV (per 5% increase: hazard ratio, 1.70; 95% CI: 1.38, 2.08; P < .001) independently predicted MACE occurrence, and the addition of native T1 (Harrell C index = 0.76) or ECV (Harrell C index = 0.79) to the model including only clinical variables, left ventricular ejection fraction, and septal late gadolinium enhancement (Harrell C index = 0.72) improved discrimination for the primary end point. Conclusion Cardiac MRI-derived native T1 and ECV were independent predictors of MACEs in patients with acute myocarditis and provided incremental prognostic value when combined with conventional parameters. Keywords: MRI, Cardiac, Heart, Inflammation Supplemental material is available for this article. © RSNA, 2025.

Risk stratification and exercise recommendations in cardiomyopathies and channelopathies: a practical guide for the multidisciplinary team

Exercise offers a plethora of health benefits. However, certain genetic and acquired diseases such as cardiomyopathies and channelopathies are associated with sudden cardiac death during exercise. Several factors complicate exercise prescription in individuals living with these conditions. The lack of high-quality evidence supporting exercise recommendations, variation in the clinical phenotypes within the same condition and sparse physician education around exercise prescription all leads to a reluctance to provide specific guidance on how to engage in physical activity.This article aims to summarise the latest evidence underpinning risk stratification and current guideline recommendations for physical activity in individuals with cardiomyopathies and channelopathies wishing to engage in exercise. It also aims to provide a basic practical approach to exercise prescription for health professionals involved in the care of these patients. This approach may then serve as a foundation that can be easily personalised. Since risk can never be completely eliminated, all decisions regarding exercise participation should be taken following shared dialogue between the physician, patient and wider stake holders where appropriate.

Elevated Neutrophil-to-Lymphocyte Ratio Predicts Prognosis in Acute Myocarditis

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) is an easy-to-use inflammatory biomarker. Baseline NLR is independently associated with incident cardiovascular events and all-cause mortality. However, whether this applies to acute myocarditis (AM) has not been evaluated.

OBJECTIVES

The present study aimed to investigate the prognostic value of NLR in patients with AM.

METHODS

A total of 1,150 consecutive patients with a diagnosis of AM admitted to 10 international tertiary referral cardiac centers were included in the study. The diagnosis was confirmed using cardiac magnetic resonance or endomyocardial biopsy. The primary outcome measure was a composite of all-cause mortality or heart transplantation. Patients were divided into 2 groups according to an NLR cutoff of 4 derived from spline regression analysis and 70:30 train-test split algorithm.

RESULTS

Patients with an NLR <4 were younger and more likely to present with chest pain, and those with an NLR ≥4 were more likely to present with breathlessness and have other comorbidities. Over a median follow-up of 228 weeks, a NLR ≥4 was associated with a worse prognosis (P < 0.0001). After adjustment for prognostic variables, NLR emerged as an independent predictor of outcome (HR: 3.03 [95% CI: 1.30-7.04]; P = 0.010). Elevated NLR remained associated with worse outcomes among patients with preserved ejection fraction at baseline, who are conventionally considered to be at lower risk of adverse events (P < 0.0001).

CONCLUSIONS

In patients with AM, elevated NLR is associated with worse prognosis and may be valuable for stratifying patients, even those conventionally considered at low risk.

Sports behaviour and adherence to sports and exercise recommendations in patients with myocarditis

Aim

In the clinical setting of acute myocarditis, existing guidelines recommend refraining from moderate-intensity to high-intensity sports for 3-6 months, yet the extent to which these recommendations are implemented by clinicians and followed by patients remains unclear.

Methods

From January 2020 to December 2023, consecutive patients with myocarditis according to European Society of Cardiology criteria were prospectively enrolled. Myocarditis was categorised into acute, subacute and non-acute myocarditis. Patients completed a sports questionnaire and sports behaviour was categorised into no sports (NSP), recreational (REC) or competitive sports (COMP).

Results

A total of 165 patients with myocarditis (mean age 50±17 years, 35% women) completed the questionnaire. Overall 73 (44%) patients received sports counselling. A total of 44 (72%) patients engaged in sports (REC+COMP) with acute or subacute myocarditis, received sports counselling with 38 (87%) adhering. Overall COMP patients (all male) received more counselling (11/11; 100%) compared with REC (53/105; 50%) and NSP (9/49; 18%). Of 39 women in the REC group, 14 (36%) received recommendations, whereas of 66 men 39 (59%) received recommendations (p<0.001). Of all patients engaged in sports, 55% received recommendations. Self-reported adherence to recommendations was significantly lower in COMP (73%) compared with REC (92%, p<0.001).

Conclusion

Although only half of the myocarditis patients received counselling regarding sports activity, adherence to these recommendations was generally high but varied by activity level. Women received fewer recommendations overall compared with men. While competitive athletes were counselled more frequently than recreational athletes, they were less likely to adhere to the recommendations.

Ring-like late gadolinium enhancement: differential diagnosis and mimics

Advances in cardiac magnetic resonance have promoted tissue characterization with high spatial and contrast resolution, and late gadolinium enhancement (LGE) sequences have improved the detection of myocardial fibrosis. The distribution pattern of LGE facilitates differentiation between ischemic and nonischemic etiologies and aids in refining diagnoses within nonischemic cardiomyopathies, suggesting specific etiological factors. A distinctive nonischemic LGE pattern that has recently gained prominence is the ring-like pattern, defined as a subepicardial or mid-wall circumferential or semi-circumferential enhancement, which involves at least three contiguous segments within the same short-axis slice. Initially identified as a diagnostic marker for desmoplakin and filamin C-related cardiomyopathies, the pattern has been reported in nongenetic conditions; nevertheless, it remains an uncommon finding in these diseases. In this article, we aim to present the differential diagnoses of ring-like LGE and its mimics. The combination of epidemiological, clinical, electrocardiographic, and additional features enables a focused refinement of the differential diagnosis associated with ring-like LGE.

Management of acute myocarditis: a systematic review of clinical practice guidelines and recommendations

The management of acute myocarditis (AM) is addressed in multiple clinical guidelines. We systematically reviewed current guidelines developed by national and international medical organizations on the management of AM to aid clinical practice. Publications in MEDLINE, EMBASE and Cochrane were identified between 1 January 2013 and 12 April 2024. Additionally, the websites of relevant organizations and the Guidelines International Network, Guideline Central, and NHS knowledge and library hub were reviewed. Two reviewers independently screened titles and abstracts, two reviewers assessed the rigour of guideline development, and one reviewer extracted the recommendations. Two of the three guidelines identified showed good rigour of development. Those rigorously developed agreed on the definition of AM, sampling serum troponin as part of the workflow for AM, testing for B-type natriuretic peptides in heart failure, key diagnostic imaging in the form of cardiovascular magnetic resonance, coronary angiography to exclude significant coronary disease, indications for endomyocardial biopsy (EMB), and indications for immunosuppression and advanced treatment options. Discrepancies exist in sampling creatine kinase-myocardial bound as a marker of myocardial injury, indications for EMB, and indications for immunosuppression and treatment of uncomplicated AM. Evidence is lacking for the use of 18F-Fluorodeoxyglucose Positron Emission Tomography for myocardial imaging, exercise restriction, follow-up measures, and genetic testing, and there are few high-quality randomized trials to support treatment recommendations. Recommendations for management of AM in the guidelines have largely been developed from expert opinion rather than trial data.

Cellular Immunology of Myocarditis: Lights and Shades-A Literature Review

Myocarditis is an inflammatory disease of the myocardium with heterogeneous etiology, clinical presentation, and prognosis; when it is associated with myocardial dysfunction, this identifies the entity of inflammatory cardiomyopathy. In the last few decades, the relevance of the immune system in myocarditis onset and progression has become evident, thus having crucial clinical relevance in terms of treatment and prognostic stratification. In fact, the advances in cardiac immunology have led to a better characterization of the cellular subtypes involved in the pathogenesis of inflammatory cardiomyopathy, whether the etiology is infectious or autoimmune/immune-mediated. The difference in the clinical course between spontaneous recovery to acute, subacute, or chronic progression to end-stage heart failure may be explained not only by classical prognostic markers but also through immune-pathological mechanisms at a cellular level. Nevertheless, much still needs to be clarified in terms of immune characterization and molecular mechanisms especially in biopsy-proven myocarditis. The aims of this review are to (1) describe inflammatory cardiomyopathy etiology, especially immune-mediated/autoimmune forms, (2) analyze recent findings on the role of different immune cells subtypes in myocarditis, (3) illustrate the potential clinical relevance of such findings, and (4) highlight the need of further studies in pivotal areas of myocarditis cellular immunology.

Long-term prognostic performance of cardiac magnetic resonance imaging markers versus complicated clinical presentation after an acute myocarditis

BACKGROUND

Identifying markers associated with adverse events after acute myocarditis (AM) is relevant to plan follow-up. We assessed the prognostic performance of previously described cardiac magnetic resonance imaging (CMRI) markers and their combination: septal late gadolinium enhancement (LGE) localization and left ventricular ejection fraction (LVEF) < 50 % on baseline CMRI versus complicated clinical presentation (CCP: the presence of sustained ventricular tachycardia, or LVEF<50 % on the first echocardiogram or fulminant presentation).

METHODS

We retrospectively assessed 248 AM patients (median age of 34 years, 87.1 % male) from 6 hospitals with onset of cardiac symptoms<30 days, increased troponin, and CMRI/histology consistent with myocarditis to identify those at risk of major cardiac events (cardiac death, heart transplantation, aborted sudden cardiac death, sustained ventricular tachycardia, or heart failure hospitalization).

RESULTS

Thirteen patients (5.2 %) experienced at least one major cardiac event after a median follow-up of 4.7 years with a significant hazard ratio of 35.8 for CCP vs. 9.2 for septal LGE vs. 12.4 for LVEF<50 % on baseline CMRI (p = 0.001). CCP had the best c-index to identify patients with events: 0.836 vs. 0.786 for septal LGE and 0.762 for LVEF<50 %, while the combination of CCP plus LVEF<50 % or septal LGE has the highest c-index of 0.866. All 3 markers had high negative predictive value (NPV) of ≥0.98.

CONCLUSIONS

Major cardiac events after an AM are relatively low, and CCP, septal LGE, and LVEF<50 % are significantly associated with events. These markers have especially high NPV to identify patients without events after an AM. These observations can help clinicians to monitor the patients after an AM.

Clinical Characteristics and Outcomes of Acute Myocarditis: An Analysis of Korean Multicenter Registry

BACKGROUND AND OBJECTIVES

Data are limited on the clinical manifestations and outcomes of acute myocarditis from a large-scale registry. We investigated acute myocarditis's clinical characteristics and prognosis from a large-scale, multi-center registry in the Republic of Korea.

METHODS

We collected data from seven hospitals between 2001 and 2021. Clinical variables and outcomes during the index hospitalization and follow-up periods were analyzed. We also evaluated inter-center and temporal differences in diagnostic and treatment patterns.

RESULTS

Eight hundred forty-one patients diagnosed with acute myocarditis were included. Common symptoms included chest pain (60.4%), followed by fever or myalgia (46.3%), and dyspnea (45.7%). Fulminant myocarditis occurred in 421 (50.1%), with 217 requiring extracorporeal membrane oxygenation (ECMO) support. Endomyocardial biopsy (EMB) was performed in 276 (32.8%) patients, and biopsy-proven diagnosis was made in 234 (27.8%). Based on the EMB results, lymphocytic myocarditis was the predominant form (69.6%), followed by eosinophilic (13.8%) and giant cell myocarditis (1.4%). Eighty-three in-hospital (9.9%) and 16 (1.9%) additional mortality during the follow-up occurred. An increase in the use of EMB, cardiac imaging, and immunosuppressive therapy was noted over time, but in-hospital mortality remained unchanged. Remarkable variations in diagnosis and treatment were observed across different centers.

CONCLUSIONS

This study unveiled clinical features of acute myocarditis in the Republic of Korea, including a high incidence of fulminant myocarditis and complex cases requiring ECMO. Given the considerable inter-center variation in diagnostic and treatment patterns and prognosis, protocolized future trials are needed to clarify diagnosis and treatment in patients with acute myocarditis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05933902.

Clinical features, myocardial injury and systolic impairment in acute myocarditis

OBJECTIVE

Cardiovascular magnetic resonance (CMR) is increasingly used in the diagnosis of myocarditis, with myocardial injury and systolic dysfunction playing key roles in the prognosis of this clinical setting. The clinical determinants of myocardial injury and systolic impairment in acute myocarditis are poorly defined. The aim of the current study is to assess the association of laboratory markers, late gadolinium enhancement (LGE) and left ventricular ejection fraction (LVEF) in patients with acute myocarditis.

METHODS

We completed a retrospective cohort study from a tertiary referral centre in London with CMR and acute myocarditis. Cases with cardiomyopathy were excluded. Missing data was imputed for selected clinical variables. We evaluated the association between peak troponin and LGE extent and LVEF. We adjusted the models for age, sex and time to CMR with a sensitivity analysis adjusting for body mass index and cardiovascular risk factors including hypertension, dyslipidaemia, diabetes mellitus and smoking.

RESULTS

127 patients had abnormal T2-weighted imaging/mapping results with 118 (93%) presenting with chest pain and/or shortness of breath. Left ventricular LGE was identified in 118 (93%) patients and LVEF was 58±11%. The median time from the peak troponin to CMR was 1 day (IQR 0-6 days). The highest tertile of peak troponin was associated with more LGE (incident rate ratio 1.33, 95% CI: 1.07 to 1.64) and a lower LVEF (coefficient -5.3%, 95% CI: -9.5% to -1.1%). Diabetes was also associated with more LGE (incident rate ratio 1.90, 95% CI: 1.37 to 2.61) and lower LVEF (coefficient -8.9%, 95% CI: -14.7% to -1.8%).

CONCLUSIONS

Peak troponin is associated with more LGE and a lower LVEF even after accounting for demographics and comorbidities. Myocardial injury and systolic dysfunction play key roles in prognosis and future work incorporating clinical features into a risk prediction model may enable better risk stratification in acute myocarditis.

Novel Therapeutics and Upcoming Clinical Trials Targeting Inflammation in Cardiovascular Diseases

Cardiovascular disease (CVD) remains a major health burden despite significant therapeutic advances accomplished over the last decades. It is widely and increasingly recognized that systemic inflammation not only represents a major cardiovascular risk and prognostic factor but also plays key pathogenic roles in CVD development and progression. Despite compelling preclinical evidence suggesting large potential of anti-inflammatory pharmacological interventions across numerous CVDs, clinical translation remains incomplete, mainly due to (1) yet undefined molecular signaling; (2) challenges of safety and efficacy profile of anti-inflammatory drugs; and (3) difficulties in identifying optimal patient candidates and responders to anti-inflammatory therapeutics, as well as optimal therapeutic windows. Randomized controlled trials demonstrated the safety/efficacy of canakinumab and colchicine in secondary cardiovascular prevention, providing confirmation for the involvement of a specific inflammatory pathway (NLRP3 [NACHT, LRR, and PYD domain-containing protein 3] inflammasome/IL [interleukin]-1β) in atherosclerotic CVD. Colchicine was recently approved by the US Food and Drug Administration for this indication. Diverse anti-inflammatory drugs targeting distinct inflammatory pathways are widely used for the management of other CVDs including myocarditis and pericarditis. Ongoing research efforts are directed to implementing anti-inflammatory therapeutic strategies across a growing number of CVDs, through repurposing of available anti-inflammatory drugs and development of novel anti-inflammatory compounds, which are herein concisely discussed. This review also summarizes the main characteristics and findings of completed and upcoming randomized controlled trials directly targeting inflammation in CVDs, and discusses major challenges and future perspectives in the exciting and constantly expanding landscape of cardioimmunology.

Management Status of Myocarditis-Related Sudden Cardiac Death

Myocarditis, a life-threatening disease that can result in cardiac arrest and sudden cardiac death, has garnered significant attention in recent years. This review provides a comprehensive overview of the management of myocarditis-related sudden cardiac death, encompassing its pathology, diagnostic methods, therapeutic strategies, preventive measures, prognostic factors, and risk stratification. Additionally, the review highlights current challenges and future directions in this field. The aim is to enhance understanding of myocarditis-related sudden cardiac death and inform clinical practice, ultimately leading to improved patient outcomes.

Changing Epidemiology of Myocarditis in Australia: A Population-Based Cohort Study

Background: Myocarditis is a serious disease that has drawn increasing attention due to its association with COVID-19 and vaccination. This study investigates the epidemiology of myocarditis beyond the COVID-19 pandemic, including its incidence and outcomes over time. Methods: We analyzed the population-wide retrospective data from the Admitted-Patient-Data-Collection database of patients admitted to hospitals in New South Wales (NSW), Australia, with a diagnosis of myocarditis from 2001 to 2022. The incidence of myocarditis, changing classification of myocarditis over time, and complications of myocarditis over time were all calculated. Results: There were 4071 patients diagnosed with their first episode of myocarditis, with a median age of 42 years old, and 66% were male. The incidence of myocarditis in NSW has tripled over 20-years to 8.3 per-100,000-persons by 2022. Reactive myocarditis (i.e., myocarditis within 30-days of a respiratory or digestive illness) accounted for 38% of first presentations of myocarditis. Post COVID-19 myocarditis, a subset of reactive myocarditis, accounted for 42% of myocarditis admissions since the onset of the COVID-19 pandemic in Australia. Eight percent of patients had a background history of malignancy, and 6% had a history of autoimmune disease. In-hospital mortality was 4.5% during the entire study period but has been falling by 11% per year. During follow up, most readmissions for myocarditis occurred within 6-months; with 5.1% recurrence at 6-months compared to only 6.7% at 5-years. Conclusions: Myocarditis is an important condition with increasing incidence in Australia and with markedly changing characteristics in the pandemic and post pandemic era.

Outbreak of Acute Fulminant Myocarditis in Children in Campania Region, Italy: A Case Series

Acute fulminant myocarditis is a rare event in children, accounting for about 10% of all cases of acute myocarditis. Its lack of specific onset patterns and unpredictable evolution make diagnosis and prompt treatment challenging. We observed six cases of fulminant myocarditis admitted to our Pediatric Emergency Unit (Campania region, Sothern Italy) within a very short timeframe (50 days, from July to September 2024). Three of them died, and two are still under treatment in a Pediatric Cardiologic Intensive Care Unit in critical condition. In only one case, cardiac function improved. The described cases were not geographically linked, belonging to different areas of Southern Italy. No common etiological agent was found. Given the relatively low incidence of the condition, the occurrence of six pediatric myocarditis within approximately two months should be considered exceptional. Careful monitoring of further cases in the next few months should be warranted.

Endomyocardial biopsy in patients with myocarditis-still justified in the CMR era? A single-centre experience

BACKGROUND

In the past decades, cardiovascular magnetic resonance (CMR) was established as a non-invasive tool supporting the diagnosis of myocarditis and there is often reluctance in performing EMB due to potentially severe complications. We sought to identify patient subgroups that could still benefit from EMB in the CMR era.

METHODS

Data of patients presenting with myocarditis between 01/2016 and 06/2023 were analysed according to patient risks. Prespecified risk factors were (i) left ventricular ejection fraction (LVEF) ≤ 30%; (ii) severe arrhythmias; or (iii) pre-existing autoimmune disease. Furthermore, the subgroup of recurrent myocarditis cases was analysed separately.

RESULTS

A total of 137 patients (35.5 ± 14.8 years, 80.3% male) were included. 26/137 patients had a documented LVEF ≤ 30%, 13/137 a LVEF > 30% with at least one other risk factor and 98/137 a LVEF > 30% without risk factors. EMB was performed in 21/26 patients with LVEF ≤ 30% (80.8%), in 7/13 patients with LVEF > 30% and risk factors (53.8%) and in 16/98 (16%) patients without risk factors. EMB led to the initiation of immunosuppressive therapy in 11/28 patients with risk factors (39.3%) and in none of the patients without risk factors (0/16, 0%, p = 0.003). With respect to the subgroup of patients presenting with recurrent myocarditis (n = 10), no specific therapy was initiated.

CONCLUSIONS

Due to a high therapeutic yield for initiation of immunosuppressive therapy in non-infectious myocarditis, performing EMB should be considered in all high-risk patients. In patients without clinical risk factors including cases of recurrent or relapsing myocarditis no specific therapy was initiated.

Sudden cardiac death after acute myocarditis with arrhythmic presentation: hunting for risk predictors - a systematic review and meta-analysis

BACKGROUND

Ventricular arrhythmias (VAs) frequently occur in the acute phase of myocarditis. Possible arrhythmic recurrences and the risk of sudden cardiac death (SCD) in this setting are reasons for concern, and limited data have been published to guide clinical management of these patients. The aim of the present paper is to report the incidence of major arrhythmic events, defined as sustained VA, SCD and appropriate implantable cardiac-defibrillator (ICD) treatment, in patients with acute myocarditis and ventricular arrhythmic phenotype.

METHODS

We conducted a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to evaluate studies reporting long-term outcomes in patients with acute myocarditis and arrhythmic presentation. We systematically searched PubMed, EMBASE and Scopus databases for relevant studies up to 2 August 2024. Study quality was assessed by the Newcastle-Ottawa Scale. The primary outcome was a composite of SCD, VA recurrence and appropriate ICD therapy. Random-effect models were used to calculate pooled ORs and CIs.

RESULTS

Five observational studies enrolling 322 patients were identified. The pooled proportion of patients who experienced VA recurrence was 0.41 (95% CI 0.30 to 0.53, p=0.13). An increased risk of adverse outcomes during follow-up was observed in patients presenting with monomorphic ventricular tachycardia (OR 3.77, 95% CI 1.23 to 11.53) and left ventricular ejection fraction (LVEF) <50% (OR 2.74, 95% CI 0.78 to 9.63). Gender and anteroseptal late gadolinium enhancement were not found as potential risk factors in this analysis.

CONCLUSIONS

Patients with myocarditis with arrhythmic ventricular presentation have a high recurrence rate of VA, underscoring the importance of careful monitoring and management in this patient population. Risk stratification for SCD during follow-up should be individualised, and monomorphic VA at presentation or a reduced LVEF may be markers of poor prognosis. In these cases, an ICD implantation may be cautious pending further dedicated studies.

Sex-Based Differences in Clinical Characteristics of Patients with Acute Myocarditis: A Cohort Study

BACKGROUND

This study investigated sex differences in acute myocarditis patients during index hospitalization.

METHODS

We included 365 patients with acute myocarditis, hospitalized with continuous monitoring at the intensive care unit from 2000-2023 into the Basel Myocarditis Cohort study. We compared sex differences in clinical presentation, the presenting electrocardiogram, prior medical history, inflammatory and cardiac biomarkers, cardiac imaging, arrhythmia occurrence, and short- to midterm outcomes.

RESULTS

Mean age was 41.3 years, and 26.3% were female. Compared with men, women were older (median 49.7 vs 38.3 years, P < .001) at the time of diagnosis and presented more frequently with dyspnea (41 vs 26%, P = .013) and a higher Killip class (P = .011). In the presenting electrocardiogram, men had a higher occurrence of diffuse ST-elevation (38 vs 9%, P < .001) and PQ-depression (31 vs 20%, P = .042), compared with women. Women had higher N-terminal pro B-type natriuretic peptide levels (1180 vs 387 ng/L, P = .015), lower cardiac troponin T levels (389 vs 726 ng/L, P = .006), and fewer segments with nonischemic late gadolinium enhancement on cardiac magnetic resonance imaging (1 vs 3, P = .005), but similar left ventricular ejection fraction (55 vs 55%, P = .629), compared with men. Overall, hospital stay was longer in women compared with men (7 vs 5 days, P = .018), with a similar length of intensive care unit stay (2.6 vs 2.7 days, P = .922). Women more often developed severe arrhythmia (8.3 vs 2.2%, P = .015) and heart failure during the hospitalization (31.3 vs 16.4%, P = .003).

CONCLUSION

Compared with men, women with acute myocarditis were older at the time of diagnosis, presented more often with heart failure, and had an increased frequency of severe arrhythmia.

[Acute myocarditis secondary to Graves' disease: A case report]

The relationships between the thyroid and the heart are close and complex. In rare cases, hyperthyroidism induced by Graves' disease can be complicated by an acute myocarditis, which may be life-threatening. We report the case of a 41-year-old woman with Graves' disease not controlled by antithyroid drugs, hospitalized for odynophagia, palpitations due to atrial fibrillation, diffuse ST elevation on ECG and an increase in cardiac troponin. Coronary angiography was normal, cardiac MRI confirmed acute myocarditis. The evolution was favorable after a phase marked by supraventricular and ventricular rhythm disorders. The diagnostic and therapeutic challenge of this association are discussed, with a review of the literature.

Myocarditis: Differences in Clinical Expression between Patients with ST-Segment Elevation in Electrocardiogram vs. Patients without ST-Segment Elevation

BACKGROUND/OBJECTIVES

In cases of myocarditis, electrocardiograms (ECGs) may suggest a pattern of ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI). NSTEMI patterns are less frequent in myocarditis cases, but it remains unclear if the presence of ST-segment elevation in myocarditis cases is related to a more severe condition and more damage in the myocardium.

METHODS

This is a retrospective study involving 38 patients admitted to hospital with myocarditis. Patients were divided into two groups: patients with ST-segment elevation (STE) patterns in the ECG (25), and patients without ST-segment elevation (non-STE) patterns (13). The data compared included results from epidemiological, laboratory, and instrumental tests. Data were analysed using IBM SPSS Statistics v26.0. A p value of <0.05 was established as the threshold for statistical significance.

RESULTS

C-reactive protein (CRP) levels were higher in the STE group (103.40 ± 82.04 mg/L vs. 43.54 ± 61.93 mg/L, p = 0.017). The left ventricle ejection fraction (LVEF) was significantly higher in the non-STE pattern group (49.71 ± 4.14 vs. 56.58 ± 3.99, p < 0.001). A lower LVEF correlates with higher TnI levels (r= -0.353, p = 0.032) and higher CRP levels (r = -0.554, p < 0.001). Lower left ventricle (LV) strain correlates with higher levels of Troponin I (TnI) (r = -0.641, p = 0.013).

CONCLUSIONS

LVEFs in the STE group were lower compared to those in the non-STE pattern group. STE pattern was associated with higher CRP levels. Higher TnI levels in cases of myocarditis were associated with lower LV strain and lower LVEF; higher CRP levels also correlated with lower LVEF. Based on a 6-month echocardiographic follow-up, the prognosis of myocarditis was favourable.

Cardiac MRI in infarct-like myocarditis: transmural extension of late gadolinium enhancement is associated with worse outcomes

OBJECTIVES

To assess the prognostic value of cardiac MRI (CMR) parameters for the occurrence of major adverse cardiac events (MACE) in patients with infarct-like myocarditis.

METHODS

In this retrospective single-center study, patients with CMR-confirmed acute myocarditis with infarct-like presentation were identified (2007-2020). Functional and structural parameters were analyzed including late gadolinium enhancement (LGE). The primary endpoint was the occurrence of MACE up to 5 years after discharge.

RESULTS

In total, 130 patients (mean age, 40 ± 19 years; 97 men, 75%) with infarct-like myocarditis were included. CMR was conducted a median of 3 days (interquartile range [IQR], 1-5) after symptom onset. MACE occurred in 18/130 patients (14%) during a median follow-up of 19.3 months (IQR, 4.5-53). The median extent of LGE was 7% (IQR, 4-10). LGE affected the subepicardium in 111/130 patients (85%), the midwall in 45/130 patients (35%), and both the subepicardium and midwall in 27/130 patients (21%). Transmural extension of non-ischemic LGE lesions was observed in 15/130 patients (12%) and septal LGE in 42/130 patients (32%). In univariable Cox regression analysis, a significant association was found between the occurrence of MACE and both, quantified LGE extent and transmural LGE pattern. In multivariable analysis, transmural extension of LGE was an independent predictor for MACE (hazard ratio, 6.34; 95% confidence interval: 2.29-17.49; p < 0.001). Patients with the transmural extension of LGE had a shorter event-free time on Kaplan-Meier analysis (log-rank p < 0.001).

CONCLUSIONS

MACE occurred in 14% of patients with infarct-like myocarditis during follow-up. A transmural extension of non-ischemic LGE was associated with a worse long-term prognosis.

CRITICAL RELEVANCE STATEMENT

CMR-based assessment of transmural extension of non-ischemic LGE holds the potential to serve as an easily assessable marker for risk stratification in patients with infarct-like myocarditis.

KEY POINTS

The prognostic value of CMR was studied in patients with infarct-like myocarditis. The extent of LGE and transmural extension were linked to adverse cardiac events. Transmural non-ischemic LGE can serve as an easily assessable prognostic marker.

Return-to-Play Post-Myocarditis for Athletes: To Play or Not to Play?

Myocarditis is a condition marked by inflammation of the heart muscle, which can lead to serious outcomes such as sudden cardiac death (SCD) and life-threatening arrhythmias. While myocarditis can affect any population, athletes, especially those engaged in high-intensity training, are at increased risk due to factors such as reduced immunity and increased exposure to pathogens. This review examines the clinical presentation, current guidelines, diagnostic challenges, and the significance of cardiac magnetic resonance imaging (CMR) in detecting myocardial inflammation and scarring. Current guidelines recommend a period of exercise restriction followed by thorough reassessment before athletes can return-to-play (RTP). However, there are several knowledge gaps, including the implications of persistent late gadolinium enhancement (LGE) on CMR and the optimal duration of exercise restriction. Additionally, the psychological impact of myocarditis on athletes highlights the importance of incorporating mental health support in the recovery process. A shared decision-making approach should be encouraged in RTP, considering the athlete's overall health, personal preferences, and the potential risks of resuming competitive sports. We have proposed an algorithm for RTP in athletes following myocarditis, incorporating CMR. Future research is warranted to refine RTP protocols and improve risk stratification, particularly through longitudinal studies that examine recovery and outcomes in athletes.

What are the early warning signs of myocarditis during the pathway of care?

INTRODUCTION

Myocarditis is an inflammatory disease of the myocardial layer of the heart that can be prone to dilation of chambers with presentation as heart failure secondary to dilated cardiomyopathy. Myocarditis can lead to remodeling and fibrosis that can affect the heart's relaxation-lusitropy and chronotropic function. The current techniques for identifying myocarditis, such as endomyocardial biopsy and imaging, are costly, and intrusive. The current literature aims to identify reliable, accurate, and prognostically educative biomarkers of myocarditis.

AREAS COVERED

This review covers the definition, clinical features, diagnostic markers, cardiac imaging, prognosis, and complications of myocarditis. PubMed, Embase, and the Cochrane data bank were searched from inception to 1 January 2024 for relevant articles.

EXPERT OPINION

By adopting these diagnostic and prognostic biomarkers, clinicians can have a better comprehension of the progression of the disease and provide early diagnosis and treatment for myocarditis.

Prognosis of myocarditis stratified by initial clinical presentation: Does "intermediate" risk still play a role?

Background/aims

Myocarditis is an inflammatory disease with diverse clinical presentations. It is known that low-risk patients have a good prognosis compared to high-risk patients. There are few data regarding the prognosis of intermediate-risk patients. This study aimed to analyze the long-term outcomes of patients with acute myocarditis with different risk profiles at presentation, focusing on the intermediate risk one.

Methods

A retrospective multicenter study was conducted, enrolling patients who met the diagnostic criteria for clinically suspected myocarditis with acute presentation. Patients were stratified into high, intermediate and low risk, according to the classification proposed by Sinagra and his team. Cardiovascular adverse events (AEs) were assessed after a median follow-up of 19 months. Echocardiographic and cardiac magnetic resonance (CMR) parameters predictive of adverse events have been reported.

Results

We enrolled 127 patients (mean age 30 ± 13 years; 103 men, 24 women). High-risk patients had a higher frequency of adverse events (80 %) compared to other groups (16 %-16 %, p < 0.0001). An association was observed between the number of segments with late gadolinium enhancement (LGE) at baseline CMR and the occurrence of adverse events (p < 0.0037). The sum of segments with LGE was statistically correlated with lower left ventricular GLS (p < 0.009). The number of segments with LGE that most accurately identified the occurrence of adverse events was 2.5 [AUC 0.5; p = 0.24].

Conclusions

Our study confirms the higher incidence of AE in the high group; the prognosis of patients at intermediate risk is not very different from those at low risk. It can be hypothesized that the extent of LGE at baseline is the main predictor of adverse events in patients at intermediate risk.

New insights gained from cellular landscape changes in myocarditis and inflammatory cardiomyopathy

Advances in the etiological classification of myocarditis and inflammatory cardiomyopathy (ICM) have reached a consensus. However, the mechanism of myocarditis/ICM remains unclear, which affects the development of treatment and the improvement of outcome. Cellular transcription and metabolic reprogramming, and the interactions between cardiomyocytes and non-cardiomyocytes, such as the immune cells, contribute to the process of myocarditis/ICM. Recent efforts have been made by multi-omics techniques, particularly in single-cell RNA sequencing, to gain a better understanding of the cellular landscape alteration occurring in disease during the progression. This article aims to provide a comprehensive overview of the latest studies in myocarditis/ICM, particularly as revealed by single-cell sequencing.

Fatal ventricular arrhythmias in myocarditis: A review of current indications for defibrillator devices

Historically, patients with myocarditis were considered for implantable cardioverter defibrillator (ICD) utilization only in the chronic phase of the disease following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease, challenging the long-standing perception that this disease process was largely reversible. Given this changing environment of information, the latest US and European guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. Additionally, several studies with small subgroups of patients have demonstrated a possible benefit of wearable cardioverter defibrillators (WCDs) in this patient demographic. Assuming that larger studies confirm their utility, it is possible that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation, while providing temporary protection for a small percentage of patients before the development of a major arrhythmic event. This review ultimately serves as a comprehensive review of the most recent guidelines for defibrillator use in acute and chronic myocarditis. OPINION STATEMENT: The latest US and European guidelines support ICD use for myocarditis patients following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. Previously, patients in the acute phase were excluded from ICD utilization even after experiencing malignant ventricular tachycardia or ventricular fibrillation due to the long-standing perception that this disease process was largely reversible. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease. Additionally, we found that the myocardial damage that is inflicted persists many years after the initial episode. Given this changing environment of information, guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. We support possible ICD utilization for secondary prevention during the acute phase of myocarditis given the elevated risk of arrhythmia recurrence and the fact that any ventricular arrhythmia can induce sudden cardiac death. Future prospective studies are needed to assess which patients may benefit most from early ICD implantation. WCDs have improved survival in patient populations at high-risk for sudden cardiac death who are not candidates for ICD implantation. After analyzing several recent studies with small subgroups of patients, WCDs appear to demonstrate similar efficacy for myocarditis patients as well. Assuming that larger studies confirm their utility, we believe that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation. Furthermore, WCDs have the additional benefit of acting as primary prevention by providing temporary protection for a small percentage of myocarditis patients before they develop a major arrhythmic event.

Myocarditis - A silent killer in athletes: Comparative analysis on the evidence before and after COVID-19 pandemic

Myocarditis is a rare cardiomyocyte inflammatory process, typically caused by viruses, with potentially devastating cardiac sequalae in both competitive athletes and in the general population. Investigation into myocarditis prevalence in the Coronavirus disease 2019 (COVID-19) era suggests that infection with Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is an independent risk factor for myocarditis, which is confirmed mainly through cardiovascular magnetic resonance imaging. Recent studies indicated that athletes have a decreased risk of myocarditis after recent COVID-19 infection compared to the general population. However, given the unique nature of competitive athletics with their frequent participation in high-intensity exercise, athletes possess distinct factors of susceptibility for the development of myocarditis and its subsequent severe cardiac complications (e.g., sudden cardiac death, fulminant heart failure, etc.). Under this context, this review focuses on comparing myocarditis in athletes versus non-athletes, owing special attention to the distinct clinical presentations and outcomes of myocarditis caused by different viral pathogens such as cytomegalovirus, Epstein-Barr virus, human herpesvirus-6, human immunodeficiency virus, and Parvovirus B19, both before and after the COVID-19 pandemic, as compared with SARS-CoV-2. By illustrating distinct clinical presentations and outcomes of myocarditis in athletes versus non-athletes, we also highlight the critical importance of early detection, vigilant monitoring, and effective management of viral and non-viral myocarditis in athletes and the necessity for further optimization of the return-to-play guidelines for athletes in the COVID-19 era, in order to minimize the risks for the rare but devastating cardiac fatality.

A retrospective analysis of clinical characteristics and outcomes of pediatric fulminant myocarditis

BACKGROUND

The study aimed to explore clinical indicators that can predict the prognosis of children with acute fulminant myocarditis (AFM) through a retrospective analysis.

METHODS

A retrospective analysis was conducted on the clinical indices of 79 children diagnosed with AFM and hospitalized from March 2013 to March 2023. Relevant demographic and clinical data, including symptoms at admission, laboratory results, and outcomes were extracted to identify factors associated with in-hospital mortality.

RESULTS

A total of 79 children with AFM were analyzed. The survival group (n = 61) had a longer median hospital stay and higher medical expenses compared to the death group (n = 18). Significant differences in the levels of left ventricular ejection fraction (LVEF)(P < 0.001), myoglobin (MYO)(P < 0.001), aspartate aminotransferase (AST)(P < 0.001), lactate dehydrogenase (LDH)(P = 0.004), B-type natriuretic peptide (BNP)(P = 0.005), arterial potential hydrogen (PH)(P < 0.001), bicarbonate (HCO3-)(P = 0.003), serum lactate (Lac)(P = 0.001), peripheral oxygen saturation (SpO2)(P = 0.008), and white blood cell count (WBC)(P = 0.007) were observed between the two groups. Additionally, there were significant differences in the incidences of multi-organ failure (P = 0.003) and respiratory failure (P = 0.001) between the two groups.

CONCLUSIONS

Severe myocardial injury (AST > 194.00 U/L, LDH > 637.50 U/L, MYO > 265.75 µg/L, BNP > 1738.50 ng/L), acidosis (PH < 7.29, HCO3- <18.45 mmol/L, Lac > 12.30 mmol/L), hypoxia (SpO2 < 97.50%), inflammatory response (WBC > 9.69*109/L), left ventricular systolic dysfunction (LVEF < 28.25%), multi-organ failure, and respiratory failure are significantly associated with higher mortality rates. These factors can accurately identify AFM children at an increased risk of death.

Imaging for the diagnosis of acute myocarditis: can artificial intelligence improve diagnostic performance?

Myocarditis is a cardiovascular disease characterised by inflammation of the heart muscle which can lead to heart failure. There is heterogeneity in the mode of presentation, underlying aetiologies, and clinical outcome with impact on a wide range of age groups which lead to diagnostic challenges. Cardiovascular magnetic resonance (CMR) is the preferred imaging modality in the diagnostic work-up of those with acute myocarditis. There is a need for systematic analytical approaches to improve diagnosis. Artificial intelligence (AI) and machine learning (ML) are increasingly used in CMR and has been shown to match human diagnostic performance in multiple disease categories. In this review article, we will describe the role of CMR in the diagnosis of acute myocarditis followed by a literature review on the applications of AI and ML to diagnose acute myocarditis. Only a few papers were identified with limitations in cases and control size and a lack of detail regarding cohort characteristics in addition to the absence of relevant cardiovascular disease controls. Furthermore, often CMR datasets did not include contemporary tissue characterisation parameters such as T1 and T2 mapping techniques, which are central to the diagnosis of acute myocarditis. Future work may include the use of explainability tools to enhance our confidence and understanding of the machine learning models with large, better characterised cohorts and clinical context improving the diagnosis of acute myocarditis.

Comparison of diagnostic algorithms in clinically suspected viral myocarditis: Agreement between cardiovascular magnetic resonance, endomyocardial biopsy, and troponin T

AIMS

Myocardial inflammation is increasingly detected noninvasively by tissue mapping with cardiovascular magnetic resonance (CMR). Intraindividual agreement with endomyocardial biopsy (EMB) or markers of myocardial injury, high-sensitive cardiac troponin (hs-cTnT) in patients with clinically suspected viral myocarditis is incompletely understood.

METHODS

Prospective multicenter study of consecutive patients with clinically suspected myocarditis who underwent blood testing for hs-cTnT, CMR, and EMB as a part of diagnostic workup. EMB was considered positive based on immunohistological criteria in line with the European Society of Cardiology (ESC) definitions. CMR diagnoses employed tissue mapping using sequence-specific cut-off for native T1 and T2 mapping; active inflammation was defined as T1 ≥2 standard deviation (SD) and T2 ≥2 SD above the mean of normal range. Hs-cTnT of greater than 13.9 ng/L was considered significant.

RESULTS

A total of 114 patients (age (mean ± SD) 54 ± 16, 65% males) were included, of which 79 (69%) had positive EMB criteria, 64 (56%) CMR criteria, and a total of 58 (51%) positive troponin. Agreement between EMB and CMR diagnostic criteria was poor (CMR vs ESC: area under the curve (AUC): 0.51 (0.39-0.62)). The agreement between a significant hs-cTnT rise and CMR-based diagnosis of myocarditis was good (AUC: 0.84 (0.68-0.92); p < 0.001), but poor for EMB (0.50 (0.40-0.61). Hs-cTnT was significantly associated with native T1 and T2, high-sensitive C-reactive protein, and N-terminal pro-hormone brain natriuretic peptide (r = 0.37, r = 0.35, r = 0.30, r = 0.25; p < 0.001), but not immunohistochemical criteria or viral presence.

CONCLUSION

In clinically suspected viral myocarditis, all diagnostic approaches reflect the pathophysiological elements of myocardial inflammation; however, the differing underlying drivers only partially overlap. The EMB and CMR diagnostic algorithms are neither interchangeable in terms of interpretation of myocardial inflammation nor in their relationship with myocardial injury.

Yohimbine Treatment Alleviates Cardiac Inflammation/Injury and Improves Cardiac Hemodynamics by Modulating Pro-Inflammatory and Oxidative Stress Indicators

Acute myocarditis, also known as myocardial inflammation, is a self-limited condition caused by systemic infection with cardiotropic pathogens, primarily viruses, bacteria, or fungi. Despite significant research, inflammatory cardiomyopathy exacerbated by heart failure, arrhythmia, or left ventricular dysfunction and it has a dismal prognosis. In this study, we aimed to evaluate the therapeutic effect of yohimbine against lipopolysaccharide (LPS) induced myocarditis in rat model. The anti-inflammatory activity of yohimbine was assessed in in-vitro using RAW 264.7 and H9C2 cells. Myocarditis was induced in rats by injecting LPS (10 mg/kg), following the rats were treated with dexamethasone (2 mg/kg) or yohimbine (2.5, 5, and 10 mg/kg) for 12 h and their therapeutic activity was examined using various techniques. Yohimbine treatment significantly attenuated the LPS-mediated inflammatory markers expression in the in-vitro model. In-vivo studies proved that yohimbine treatment significantly reduced the LPS-induced increase of cardiac-specific markers, inflammatory cell counts, and pro-inflammatory markers expression compared to LPS-control samples. LPS administration considerably affected the ECG, RR, PR, QRS, QT, ST intervals, and hemodynamic parameters, and caused abnormal pathological parameters, in contrast, yohimbine treatment substantially improved the cardiac parameters, mitigated the apoptosis in myocardial cells and ameliorated the histopathological abnormalities that resulted in an improved survival rate. LPS-induced elevation of cardiac troponin-I, myeloperoxidase, CD-68, and neutrophil elastase levels were significantly attenuated upon yohimbine treatment. Further investigation showed that yohimbine exerts an anti-inflammatory effect partly by modulating the MAPK pathway. This study emphasizes yohimbine's therapeutic benefit against LPS-induced myocarditis and associated inflammatory markers response by regulating the MAPK pathway.

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.

European Association of Cardiovascular Imaging survey on cardiovascular multimodality imaging in acute myocarditis

AIMS

To assess the current role of cardiac imaging in the diagnosis, management, and follow-up of patients with acute myocarditis (AM) through a European Association of Cardiovascular Imaging survey.

METHODS AND RESULTS

A total of 412 volunteers from 74 countries responded to the survey. Most participants worked in tertiary centres (56%). All participants had access to echocardiography, while 79 and 75% had access to cardiac computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR), respectively. Less than half (47%) had access to myocardial biopsy, and only 5% used this test routinely. CMR was performed within 7 days of presentation in 73% of cases. Non-ischaemic late gadolinium enhancement (LGE, 88%) and high-signal intensity in T2-weighted images (74%) were the most used diagnostic criteria for AM. CCTA was preferred to coronary angiography by 47% of participants to exclude coronary artery disease. Systematic prescription of beta-blockers and angiotensin-converting enzyme inhibitors was reported by 38 and 32% of participants. Around a quarter of participants declared considering LGE burden as a reason to treat. Most participants (90%) reported performing a follow-up echocardiogram, while 63% scheduled a follow-up CMR. The main reason for treatment discontinuation was improvement of left ventricular ejection fraction (89%), followed by LGE regression (60%). In two-thirds of participants, the decision to resume high-intensity sport was influenced by residual LGE.

CONCLUSION

This survey confirms the high utilization of cardiac imaging in AM but reveals major differences in how cardiac imaging is used and how the condition is managed between centres, underlining the need for recommendation statements in this topic.

Diagnostic accuracy, clinical characteristics, and prognostic differences of patients with acute myocarditis according to inclusion criteria

INTRODUCTION

The diagnosis of acute myocarditis (AM) is complex due to its heterogeneity and typically is defined by either Electronic Healthcare Records (EHRs) or advanced imaging and endomyocardial biopsy, but there is no consensus. We aimed to investigate the diagnostic accuracy of these approaches for AM.

METHODS

Data on ICD 10th Revision(ICD-10) codes corresponding to AM were collected from two hospitals and compared to cardiac magnetic resonance (CMR)-confirmed or clinically suspected (CS)-AM cases with respect to diagnostic accuracy, clinical characteristics, and all-cause mortality. Next, we performed a review of published AM studies according to inclusion criteria.

RESULTS

We identified 291 unique admissions with ICD-10 codes corresponding to AM in the first three diagnostic positions. The positive predictive value of ICD-10 codes for CMR-confirmed or CS-AM was 36%, and patients with CMR-confirmed or CS-AM had a lower all-cause mortality than those with a refuted diagnosis (P = 0.019). Using an unstructured approach, patients with CMR-confirmed and CS-AM had similar demographics, comorbidity profiles and survival over a median follow-up of 52 months (P = 0.72). Our review of the literature confirmed our findings. Outcomes for patients included in studies using CMR-confirmed criteria were favourable compared to studies with endomyocardial biopsy-confirmed AM cases.

CONCLUSION

ICD-10 codes have poor accuracy in identification of AM cases and should be used with caution in clinical research. There are important differences in management and outcomes of patients according to the selection criteria used to diagnose AM. Potential selection biases must be considered when interpreting AM cohorts and requires standardization of inclusion criteria for AM studies.

Autoimmune Myocarditis, Old Dogs and New Tricks

Autoimmunity significantly contributes to the pathogenesis of myocarditis, underscored by its increased frequency in autoimmune diseases such as systemic lupus erythematosus and polymyositis. Even in cases of myocarditis caused by viral infections, dysregulated immune responses contribute to pathogenesis. However, whether triggered by existing autoimmune conditions or viral infections, the precise antigens and immunologic pathways driving myocarditis remain incompletely understood. The emergence of myocarditis associated with immune checkpoint inhibitor therapy, commonly used for treating cancer, has afforded an opportunity to understand autoimmune mechanisms in myocarditis, with autoreactive T cells specific for cardiac myosin playing a pivotal role. Despite their self-antigen recognition, cardiac myosin-specific T cells can be present in healthy individuals due to bypassing the thymic selection stage. In recent studies, novel modalities in suppressing the activity of pathogenic T cells including cardiac myosin-specific T cells have proven effective in treating autoimmune myocarditis. This review offers an overview of the current understanding of heart antigens, autoantibodies, and immune cells as the autoimmune mechanisms underlying various forms of myocarditis, along with the latest updates on clinical management and prospects for future research.

Rationale and design of the French cohort of acute myocarditis diagnosed by cardiac magnetic resonance imaging (MyocarditIRM)

BACKGROUND

Acute myocarditis usually presents as chest pain with rising troponin and normal coronary arteries. Despite frequent favourable evolution at the acute phase, it is associated with heart failure and ventricular rhythm disorders, and is considered the leading cause of sudden cardiac death in young, apparently healthy, adults. There are no specific recommendations for acute myocarditis diagnosis and management, only expert consensus, given the lack of large databases.

AIM

The main objective is to describe the contemporary presentation of acute myocarditis, its management and in-hospital outcomes. Secondary objectives are to investigate survival and event-free survival for up to 10years of follow-up, the determinants of prognosis, the modalities of treatment and follow-up and the gaps between expert consensus and real-life management.

METHODS

MyocarditIRM is a prospective multicentre cohort that enrolled 803 consecutive patients with acute myocarditis in 49 participating centres in France between 01 May 2016 and 28 February 2019. The diagnosis of acute myocarditis was acknowledged by cardiac magnetic resonance, using the Lake Louise Criteria. Exclusion criteria were age<18years, lack of health coverage, contraindication to cardiac magnetic resonance and refusal to participate. Detailed information was collected prospectively, starting at admission. Cardiac magnetic resonance imaging (diagnosis and follow-up) is analysed centrally by the certified core laboratory IHU ICAN. Ten years of follow-up for each patient is ensured by linking with the French National Health Database, and includes information on death, hospital admissions, major clinical events and drug consumption.

CONCLUSION

This prospective cohort with long-term follow-up represents the largest database on acute myocarditis worldwide, and will improve knowledge about its presentation, management and outcomes.

Fulminant myocarditis induced by SARS-CoV-2 infection without severe lung involvement: insights into COVID-19 pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection often leads to pulmonary complications. Cardiovascular sequelae, including myocarditis and heart failure, have also been reported. Here, the study presents two fulminant myocarditis cases infected by SARS-CoV-2 exhibiting remarkable elevation of cardiac biomarkers without significant pulmonary injury, as determined by imaging examinations. Immunohistochemical staining reveals the viral antigen within cardiomyocytes, indicating that SARS-CoV-2 could directly infect the myocardium. The full viral genomes from respiratory, anal, and myocardial specimens are obtained via next-generation sequencing. Phylogenetic analyses of the whole genome and spike gene indicate that viruses in the myocardium/pericardial effusion and anal swabs are closely related and cluster together yet diverge from those in the respiratory samples. In addition, unique mutations are found in the anal/myocardial strains compared to the respiratory strains, suggesting tissue-specific virus mutation and adaptation. These findings indicate genetically distinct SARS-CoV-2 variants have infiltrated and disseminated within myocardial tissues, independent of pulmonary injury, and point to different infection routes between the myocardium and respiratory tract, with myocardial infections potentially arising from intestinal infection. These findings highlight the potential for systemic SARS-CoV-2 infection and the importance of a thorough multi-organ assessment in patients for a comprehensive understanding of the pathogenesis of COVID-19.

Acute myocarditis: an overview of pathogenesis, diagnosis and management

Acute myocarditis encompasses a diverse presentation of inflammatory cardiomyopathies with infectious and non-infectious triggers. The clinical presentation is heterogeneous, from subtle symptoms like mild chest pain to life-threatening fulminant heart failure requiring urgent advanced hemodynamic support. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, diagnostic approach, management strategies, and directions for future research in acute myocarditis. The pathogenesis of myocarditis involves interplay between the inciting factors and the subsequent host immune response. Infectious causes, especially cardiotropic viruses, are the most frequently identified precipitants. However, autoimmune processes independent of microbial triggers, as well as toxic myocardial injury from drugs, chemicals or metabolic derangements also contribute to the development of myocarditis through diverse mechanisms. Furthermore, medications like immune checkpoint inhibitor therapies are increasingly recognized as causes of myocarditis. Elucidating the nuances of viral, autoimmune, hypersensitivity, and toxic subtypes of myocarditis is key to guiding appropriate therapy. The heterogeneous clinical presentation coupled with non-specific symptoms creates diagnostic challenges. A multifaceted approach is required, incorporating clinical evaluation, electrocardiography, biomarkers, imaging studies, and endomyocardial biopsy. Cardiovascular magnetic resonance imaging has become pivotal for non-invasive assessment of myocardial inflammation and fibrosis. However, biopsy remains the gold standard for histological classification and definitively establishing the underlying etiology. Management relies on supportive care, while disease-specific therapies are limited. Although some patients recover well with conservative measures, severe or fulminant myocarditis necessitates aggressive interventions such as mechanical circulatory support devices and transplantation. While immunosuppression is beneficial in certain histological subtypes, clear evidence supporting antiviral or immunomodulatory therapies for the majority of acute viral myocarditis cases remains insufficient. Substantial knowledge gaps persist regarding validated diagnostic biomarkers, optimal imaging surveillance strategies, evidence-based medical therapies, and risk stratification schema. A deeper understanding of the immunopathological mechanisms, rigorous clinical trials of targeted therapies, and longitudinal outcome studies are imperative to advance management and improve the prognosis across the myocarditis spectrum.

Innate and adaptive immunity in acute myocarditis

Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.

Role of the Lymphatics in Cardiac Disease

Cardiovascular diseases remain the largest cause of death worldwide with recent evidence increasingly attributing the development and progression of these diseases to an exacerbated inflammatory response. As a result, significant research is now focused on modifying the immune environment to prevent the disease progression. This in turn has highlighted the lymphatic system in the pathophysiology of cardiovascular diseases owing, in part, to its established function in immune cell surveillance and trafficking. In this review, we highlight the role of the cardiac lymphatic system and its potential as an immunomodulatory therapeutic target in selected cardiovascular diseases.