Trends in myocarditis incidence, complications and mortality in Sweden from 2000 to 2014

Characteristics and prognosis in acute myocarditis and unexplained acute chest pain: a nationwide longitudinal cohort study

AIMS

Acute myocarditis (AM) is a disease with variable prognosis, ranging from complete recovery to end-stage heart failure (HF) and death but often challenging to differentiate from unexplained acute chest pain (UCP) in the acute setting. This study examines the short-tem and long-term outcomes of AM compared with UCP, focusing on the risk of HF development.

METHODS

We used the Swedish Web System for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies-registry to identify patients >16 years admitted to hospital between 1 January 1998 and 31 December 2018 with either AM or UCP. Patients were followed for outcomes including mortality, rehospitalisation and HF development over both short-term (30 days) and long-term periods. Cox proportional hazards models were used to compare the risks, adjusting for demographic and clinical-related factors.

RESULTS

A total of 3792 patients with AM and 109 934 patients with UCP were included. Median follow-up time was 7.8 years (Q1, Q3; 3.4, 12.3). AM patients were younger compared with UCP patients, median age 37 years (Q1, Q3; 26, 52) vs 59 years (Q1, Q3; 49, 69) and more likely to be men (79.9% vs 51.4%, p<0.001). Comorbidity burden was less pronounced within the AM cohort. Chest pain was the most common presenting symptom in both groups. Mortality rate at 30 days (OR 3.75, 95% CI 1.9 to 7.3, p<0001) as well as long term (OR 2.0, 95% CI 1.69 to 2.39, p<0.001) were significantly higher in AM patients compared with UCP. AM patients were more likely to develop HF during follow-up (OR 2.3, 95% CI 1.81 to 2.93, p<0001).

CONCLUSIONS

AM is associated with worse short-term and long-term outcomes compared with UCP, including a higher risk of developing HF even after the first year.

Sex differences in mitochondrial gene expression during viral myocarditis

BACKGROUND

Myocarditis is an inflammation of the heart muscle most often caused by viral infections. Sex differences in the immune response during myocarditis have been well described but upstream mechanisms in the heart that might influence sex differences in disease are not completely understood.

METHODS

Male and female BALB/c wild type mice received an intraperitoneal injection of heart-passaged coxsackievirus B3 (CVB3) or vehicle control. Bulk-tissue RNA-sequencing was conducted to better understand sex differences in CVB3 myocarditis. We performed enrichment analysis and functional validation to understand sex differences in the transcriptional landscape of myocarditis and identify factors that might drive sex differences in myocarditis.

RESULTS

As expected, the hearts of male and female mice with myocarditis were significantly enriched for pathways related to an innate and adaptive immune response compared to uninfected controls. Unique to this study, we found that males were enriched for inflammatory pathways and gene changes that suggested worse mitochondrial electron transport function while females were enriched for pathways related to mitochondrial homeostasis. Mitochondria isolated from the heart of males were confirmed to have worse mitochondrial respiration than females during myocarditis. Unbiased TRANSFAC analysis identified estrogen-related receptor alpha (ERRα) as a transcription factor that may mediate sex differences in mitochondrial function during myocarditis. Transcript and protein levels of ERRα were confirmed as elevated in females with myocarditis compared to males. Differential binding analysis from chromatin immunoprecipitation (ChIP) sequencing confirmed that ERRα bound highly to select predicted respiratory chain genes in females more than males during myocarditis.

CONCLUSIONS

Females with viral myocarditis regulate mitochondrial homeostasis by upregulating master regulators of mitochondrial transcription including ERRα.

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.

Emerging Biomarkers in Cardiac Sarcoidosis and Other Inflammatory Cardiomyopathies

PURPOSE OF REVIEW

Cardiac sarcoidosis and other inflammatory cardiomyopathies are disorders causing cardiac inflammation and leading to heart failure, arrythmias and cardiac arrest. Diagnosis of these entities remains challenging and multimodal. Thus, there is a growing need to develop reliable biomarkers that can aid in the diagnosis. This review aims to summarize and highlight recent findings in the field of biomarkers for cardiac sarcoidosis and inflammatory cardiomyopathy.

RECENT FINDINGS

Multiple categories of biomarkers including novel molecules are being investigated with the latest evidence showing promising results. Some of these biomarkers are proven to be useful as diagnostic and prognostic aids in cardiac sarcoid and inflammatory cardiomyopathy. The identification of cost-effective and accurate biomarkers is useful not only for enhancing diagnostic accuracy but also for informing therapeutic decision-making processes. This advancement would facilitate the timely institution of immunosuppressive therapies, 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.

Artificial intelligence and myocarditis-a systematic review of current applications

Myocarditis, marked by heart muscle inflammation, poses significant clinical challenges. This study, guided by PRISMA guidelines, explores the expanding role of artificial intelligence (AI) in myocarditis, aiming to consolidate current knowledge and guide future research. Following PRISMA guidelines, a systematic review was conducted across PubMed, Cochrane Reviews, Scopus, Embase, and Web of Science databases. MeSH terms including artificial intelligence, deep learning, machine learning, myocarditis, and inflammatory cardiomyopathy were used. Inclusion criteria involved original articles utilizing AI for myocarditis, while exclusion criteria eliminated reviews, editorials, and non-AI-focused studies. The search yielded 616 articles, with 42 meeting inclusion criteria after screening. The identified articles, spanning diagnostic, survival prediction, and molecular analysis aspects, were analyzed in each subsection. Diagnostic studies showcased the versatility of AI algorithms, achieving high accuracies in myocarditis detection. Survival prediction models exhibited robust discriminatory power, particularly in emergency settings and pediatric populations. Molecular analyses demonstrated AI's potential in deciphering complex immune interactions. This systematic review provides a comprehensive overview of AI applications in myocarditis, highlighting transformative potential in diagnostics, survival prediction, and molecular understanding. Collaborative efforts are crucial for overcoming limitations and realizing AI's full potential in improving myocarditis care.

Long-Term Risk of Myocarditis in Patients With Inflammatory Bowel Disease: A Nationwide Cohort Study in Sweden

INTRODUCTION

Despite a suggested link between inflammatory bowel disease (IBD) and myocarditis, the association has not been well established. This study aimed to investigate the long-term risk of myocarditis in patients with IBD.

METHODS

This nationwide cohort involved all patients with biopsy-confirmed IBD in Sweden (1969-2017) (n = 83,264, Crohn's disease [CD, n = 24,738], ulcerative colitis [UC, n = 46,409], and IBD-unclassified [IBD-U, n = 12,117]), general population reference individuals (n = 391,344), and IBD-free full siblings (n = 96,149) and followed until 2019. Primary outcome was incident myocarditis, and secondary outcome was severe myocarditis (complicated with heart failure, death, or readmission). Flexible parametric survival models were used to estimate adjusted hazard ratios (aHRs) and cumulative incidence of outcomes, along with 95% confidence intervals.

RESULTS

During a median follow-up of 12 years, there were 256 myocarditis cases in patients with IBD (incidence rate [IR] = 22.6/100,000 person-years) and 710 in reference individuals (IR = 12.9), with an aHR of 1.55 (95% confidence interval 1.33-1.81). The increased risk persisted through 20 years after IBD diagnosis, corresponding to 1 extra myocarditis case in 735 patients with IBD until then. This increased risk was observed in CD (aHR = 1.48 [1.11-1.97]) and UC (aHR = 1.58 [1.30-1.93]). IBD was also associated with severe myocarditis (IR: 10.1 vs 3.5; aHR = 2.44 [1.89-3.15]), irrespective of IBD subtypes (CD: aHR = 2.39 [1.43-4.01], UC: aHR = 2.82 [1.99-4.00], and IBD-U: aHR = 3.14 [1.55-6.33]). Sibling comparison analyses yielded similar results.

DISCUSSION

Patients with IBD had an increased risk of myocarditis, especially severe myocarditis, for ≥20 years after diagnosis, but absolute risks were low.

Cardiomyopathy in First-Degree Relatives of Patients Presenting With Acute Myocarditis: Prevalence and Prognostic Significance

BACKGROUND

Acute myocarditis has been genetically linked to dilated cardiomyopathy (DCM), but the clinical significance remains uncertain. We investigated the prevalence and long-term prognosis of DCM and heart failure (HF) among unselected patients hospitalized with acute myocarditis and their first-degree relatives compared with an age- and sex-matched cohort.

METHODS

This was an observational study utilizing the Danish nationwide registries, where all patients with a first-time myocarditis diagnosis from 1995 to 2018 were identified and matched (on birth year and sex) with 10 controls from the general population.

RESULTS

Totally 3176 patients with acute myocarditis and 31 760 controls were included (median age, 49.8 [Q1-Q3, 32.5-70.2] years; 35.6% female). At baseline, patients with myocarditis had a higher prevalence of DCM (7 [0.2%] versus 8 [0.0%]) and HF (336 [10.6%] versus 695 [2.2%]) than controls; P<0.0001 for both. Patients with myocarditis more often had siblings with DCM (12 [0.4%] versus 17 [0.05%]) or HF (36 [1.1%] versus 89 [0.3%]); P<0.0001, odds ratios 7.09 (3.38-14.85) and 2.92 (1.25-6.80), respectively, whereas parental DCM and HF did not differ among patients with myocarditis and controls. Patients with myocarditis had greater 20-year incidence of DCM, HF, and all-cause mortality (0.5% [0.3%-0.9%], 15% [13%-17%], and 47% [44%-50%]) compared with controls (0.06% [0.03%-0.11%], 6.8% [6.4%-7.3%], and 34% [33%-35%]; P<0.0001). Having a first-degree relative with DCM or HF was associated with increased long-term mortality among the patients with myocarditis (hazard ratio, 1.40 [1.11-1.77]) but not among the controls (hazard ratio, 0.90 [0.81-1.01]; Pdifference=0.0008).

CONCLUSIONS

Acute myocarditis aggregates with DCM within families, where it carries a worsened prognosis. A differential association between parents and siblings (with sibling preponderance) could suggest that additional environmental factors are important for myocarditis development even in predisposed individuals.

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.

Rate of cardiovascular events up to 8 years after uncomplicated myocarditis: a nationwide cohort study

AIMS

While prognosis of acute myocarditis with uncomplicated presentation is perceived as benign, data on long-term outcomes are scarce. We evaluated rates of myocarditis-associated cardiovascular events after a first-time hospitalization with uncomplicated acute myocarditis in patients without known heart disease.

METHODS AND RESULTS

In this retrospective nationwide population-based cohort study from 2013 to 2020, hospitalized patients with uncomplicated acute myocarditis but without known heart disease were 1:1 propensity score-matched with surgical controls hospitalized for laparoscopic appendectomy. As assessed in time-to-event analyses, the primary outcome was a composite of rehospitalization for myocarditis, pericardial disease, heart failure and its complications, arrhythmias, implantation of cardiac devices, and heart transplant. After matching, we identified 1439 patients with uncomplicated acute myocarditis (median age of 35 years, 74.0% male) and 1439 surgical controls (median age of 36 years, 74.4% male). Over a median follow-up of 39 months, compared with surgical controls, the hazard ratio for the primary composite outcome was 42.3 [95% confidence interval (CI) 17.4-102.8], corresponding to an incidence rate of 43.7 vs. 0.9 per 1000 patient-years (py) and an incidence rate difference of 42.7 (95% CI 36.7-48.8) per 1000 py.

CONCLUSION

Patients hospitalized with uncomplicated acute myocarditis and no known prior heart disease were associated with substantial risk for cardiovascular events over a follow-up of up to 8 years. This calls for a more efficient therapeutic management of this population of patients.

COVID-19 vaccine safety: Background incidence rates of anaphylaxis, myocarditis, pericarditis, Guillain-Barré Syndrome, and mortality in South Korea using a nationwide population-based cohort study

BACKGROUND

To properly assess an association between vaccines and specific adverse events requires a comparison between the observed and background rates; however, studies in South Korea are currently limited. Therefore, in this study, we estimated the background incidence of anaphylaxis, myocarditis, pericarditis, Guillain-Barré syndrome (GBS), and mortality in South Korea.

METHODS

A retrospective cohort study was conducted using the National Sample Cohort (NSC) data. Using NSC, the background incidence rate was estimated by dividing the number of episodes during 2009-2019 by the total population by year and then multiplying by 100,000. Using Statistics Korea data, the background mortality rate was estimated by dividing the number of deaths, during 2009-2019 by the standard population for that year and then multiplying by 100,000. Using background mortality rates, we predicted mortality rates for 2021 using autoregressive integrated moving average models. Further, the expected mortality rates were compared with observed mortality rates.

RESULTS

The age-adjusted incidence rate (AIR) of anaphylaxis increased from 4.28 to 22.90 cases per 100,000 population (p = 0.003); myocarditis showed no significant increase, changing from 0.56 to 1.26 cases per 100,000 population (p = 0.276); pericarditis increased from 0.94 to 1.88 cases per 100,000 population (p = 0.005); and GBS increased from 0.78 to 1.21 cases per 100,000 population (p = 0.013). The age-adjusted mortality rate decreased from 645.24 to 475.70 deaths per 100,000 population (p <0.001). The 2021 observed/expected mortality rates for overall (ratio: 1.08, 95% confidence interval [CI]: 1.07-1.08), men (ratio: 1.07, 95% CI: 1.07-1.08), and women (ratio: 1.08, 95% CI: 1.07-1.09), were all significantly higher. When stratified by age group, those aged ≥80 (ratio: 1.16, 95% CI: 1.15-1.17), 60-69 (ratio: 1.11, 95% CI: 1.10-1.13), and 20-29 years old (ratio: 1.07, 95% CI: 1.02-1.13) were also significantly higher.

CONCLUSION

Through the estimation of background rates related to anaphylaxis, myocarditis, pericarditis, GBS, and mortality, we established a reference point for evaluating the potential excess occurrence of adverse events following COVID-19 vaccination. This reference point serves as substantive evidence supporting the safety profile of COVID-19 vaccines.

Mechanical Circulatory Support Systems in Fulminant Myocarditis: Recent Advances and Outlook

Background: Fulminant myocarditis (FM) constitutes a severe and life-threatening form of acute cardiac injury associated with cardiogenic shock. The condition is characterised by rapidly progressing myocardial inflammation, leading to significant impairment of cardiac function. Due to the acute and severe nature of the disease, affected patients require urgent medical attention to mitigate adverse outcomes. Besides symptom-oriented treatment in specialised intensive care units (ICUs), the necessity for temporary mechanical cardiac support (MCS) may arise. Numerous patients depend on these treatment methods as a bridge to recovery or heart transplantation, while, in certain situations, permanent MCS systems can also be utilised as a long-term treatment option. Methods: This review consolidates the existing evidence concerning the currently available MCS options. Notably, data on venoarterial extracorporeal membrane oxygenation (VA-ECMO), microaxial flow pump, and ventricular assist device (VAD) implantation are highlighted within the landscape of FM. Results: Indications for the use of MCS, strategies for ventricular unloading, and suggested weaning approaches are assessed and systematically reviewed. Conclusions: Besides general recommendations, emphasis is put on the differences in underlying pathomechanisms in FM. Focusing on specific aetiologies, such as lymphocytic-, giant cell-, eosinophilic-, and COVID-19-associated myocarditis, this review delineates the indications and efficacy of MCS strategies in this context.

Systematic Aetiological Assessment of Myocarditis: A Prospective Cohort Study

BACKGROUND

Myocarditis is commonly diagnosed in the intensive care cardiology unit (ICCU). No current recommendation nor guideline aids exist for aetiological assessments.

METHODS

From September 2021 to October 2023, 84 patients with acute myocarditis underwent thorough and systematic serum and blood cell panel evaluations to determine the most common causes of myocarditis.

RESULTS

Of the 84 patients (median age 34 years, range 22-41 years, 79% male), 16 presented with complicated myocarditis. The systematic aetiological assessment revealed that 36% of patients were positive for lupus anticoagulant, 12% for antinuclear antibodies, 8% for anti-heart antibodies, and 12% for anti-striated muscle antibodies. Viral serology did not yield any significant results. After the aetiological assessment, one patient was diagnosed with an autoimmune inflammatory disorder (Still's disease). T-cell subset analyses indicated that myocarditis severity tended to increase with the T-cell lymphopenia status.

CONCLUSIONS

A comprehensive, systematic aetiological assessment was of limited value in terms of predicting the clinical or therapeutic outcomes in myocarditis patients presenting to the ICCU.

Sex differences in mitochondrial gene expression during viral myocarditis

Background

Myocarditis is an inflammation of the heart muscle most often caused by an immune response to viral infections. Sex differences in the immune response during myocarditis have been well described but upstream mechanisms in the heart that might influence sex differences in disease are not completely understood.

Methods

Male and female BALB/c wild type mice received an intraperitoneal injection of heart-passaged coxsackievirus B3 (CVB3) or vehicle control. Bulk-tissue RNA-sequencing was conducted to better understand sex differences in CVB3 myocarditis. We performed enrichment analysis to understand sex differences in the transcriptional landscape of myocarditis and identify candidate transcription factors that might drive sex differences in myocarditis.

Results

The hearts of male and female mice with myocarditis were significantly enriched for pathways related to an innate and adaptive immune response compared to uninfected controls. When comparing females to males with myocarditis, males were enriched for inflammatory pathways and gene changes that suggested worse mitochondrial transcriptional support (e.g., mitochondrial electron transport genes). In contrast, females were enriched for pathways related to mitochondrial respiration and bioenergetics, which were confirmed by higher transcript levels of master regulators of mitochondrial function including peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1α), nuclear respiratory factor 1 (NRF1) and estrogen-related receptor alpha (ERRα). TRANSFAC analysis identified ERRa as a transcription factor that may mediate sex differences in mitochondrial function during myocarditis.

Conclusions

Master regulators of mitochondrial function were elevated in females with myocarditis compared to males and may promote sex differences in mitochondrial respiratory transcript expression during viral myocarditis resulting in less severe myocarditis in females following viral infection.

The Global Burden of premature cardiovascular disease, 1990-2019

Aims

Premature cardiovascular disease (pCVD) definition varies in literature, with age cut-offs ranging from 50-65 years. While there is some literature available on pCVD in North America, comprehensive data on its global burden is still lacking which hinders the development of efficient strategies for early detection and prevention. In this study we aimed to investigate the global trends in pCVD related morbidity and mortality from 1990 to 2019.

Methods

The 1990-2019 Global Burden of Disease (GBD) database was utilized to examine global trends in cardiovascular disease-related total mortality, mortality rates, and Disability-Adjusted Life Years (DALYs) within individuals aged 15-49 years. The findings were further analyzed based on factors such as age, sex, and Socio-Demographic Index (SDI).

Results

From 1990 to 2019, the number of global annual pCVD deaths increased by 25%, from 992,067 (95% UI 1,042,261 - 946,383) to 1,241,484 (95% UI 1,339,193 -1,146,252). The rate of associated mortality decreased by 13%. Metabolic conditions were the most significant risk factors for pCVD mortality. Ischemic heart disease and stroke are the leading causes of death across all age groups. pCVD mortality presented progressive widening between high and low SDI regions. Additionally, sex-specific disparities in CVD mortality were significantly greater in the premature age group as compared to all-age groups.

Conclusion

pCVD is an increasingly significant global cause of morbidity and mortality that disproportionately affects males and individuals living in less privileged regions. Furthermore, ischemic heart disease and stroke were identified as the main drivers of pCVD global burden.

Biomarkers in Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Updated Review of the Literature

Myocarditis is a disease caused by cardiac inflammation that can progress to dilated cardiomyopathy, heart failure, and eventually death. Several etiologies, including autoimmune, drug-induced, and infectious, lead to inflammation, which causes damage to the myocardium, followed by remodeling and fibrosis. Although there has been an increasing understanding of pathophysiology, early and accurate diagnosis, and effective treatment remain challenging due to the high heterogeneity. As a result, many patients have poor prognosis, with those surviving at risk of long-term sequelae. Current diagnostic methods, including imaging and endomyocardial biopsy, are, at times, expensive, invasive, and not always performed early enough to affect disease progression. Therefore, the identification of accurate, cost-effective, and prognostically informative biomarkers is critical for screening and treatment. The review then focuses on the biomarkers currently associated with these conditions, which have been extensively studied via blood tests and imaging techniques. The information within this review was retrieved through extensive literature research conducted on major publicly accessible databases and has been collated and revised by an international panel of experts. The biomarkers discussed in the article have shown great promise in clinical research studies and provide clinicians with essential tools for early diagnosis and improved outcomes.

Update on Myocarditis: From Etiology and Clinical Picture to Modern Diagnostics and Methods of Treatment

Although the frequency of myocarditis in the general population is very difficult to accurately determine due to the large number of asymptomatic cases, the incidence of this disease is increasing significantly due to better defined criteria for diagnosis and the development of modern diagnostic methods. The multitude of different etiological factors, the diversity of the clinical picture, and the variability of the diagnostic findings make this disease often demanding both for the selection of the diagnostic modality and for the proper therapeutic approach. The previously known most common viral etiology of this disease is today overshadowed by new findings based on immune-mediated processes, associated with diseases that in their natural course can lead to myocardial involvement, as well as the iatrogenic cause of myocarditis, which is due to use of immune checkpoint inhibitors in the treatment of cancer patients. Suspecting that a patient with polymorphic and non-specific clinical signs and symptoms, such as changes in ECG and echocardiography readings, has myocarditis is the starting point in the diagnostic algorithm. Cardio magnetic resonance imaging is non-invasive and is the gold standard for diagnosis and clinical follow-up of these patients. Endomyocardial biopsy as an invasive method is the diagnostic choice in life-threatening cases with suspicion of fulminant myocarditis where the diagnosis has not yet established or there is no adequate response to the applied therapeutic regimen. The treatment of myocarditis is increasingly demanding and includes conservative methods of treating heart failure, immunomodulatory and immunospressive therapy, methods of mechanical circulatory support, and heart transplantation. The goal of developing new diagnostic and therapeutic methods is to reduce mortality from this complex disease, which is still high.

Role of spontaneous reporting in investigating the relationship between mRNA COVID-19 vaccines and myocarditis: The French perspective

AIM OF THE STUDY

Post-mRNA coronavirus diseases 2019 (COVID-19) vaccines myocarditis emerged as a rare adverse effect, particularly in adolescents and young adults, and was labeled as such for both vaccines in the summer of 2021. This study aims to summarize the timeline and process of signal detection, substantiation, and quantification of myocarditis cases related to mRNA vaccines in France.

METHODS

The intensive monitoring plan for COVID-19 vaccine safety was based on case-by-case analysis of all cases collected in the French spontaneous reporting database (Base nationale de pharmacovigilance, BNPV). Cases were evaluated by drug safety medical professionals and discussed at a national level for signal detection purposes. Reported cases were compared to the number of vaccine-exposed persons up to September 30th, 2021. Reporting rates (Rr) of myocarditis per 100,000 injections were calculated and stratified according to age, gender, and injection rank of BNT162b2 and mRNA-1273 vaccines. Poisson distribution was used to compute Rrs 95% Confidence Interval (95% CI).

RESULTS

The case-by-case analysis detected a possible cluster of myocarditis in April 2021 (5 cases, 4 after the 2nd injection). In June 2021, the signal was substantiated with 12 cases (9 related to BNT162b2, and 3 to mRNA-1273). As of September 2021, almost 73 million BNT162b2 and 10 million mRNA-1273 doses had been injected. The Rr per 100,000 injections was 0.5 (0.5-0.6) for BNT162b2 and 1.1 (95% CI 0.9-1.3) for mRNA-1273. The difference among vaccines was more pronounced after the second injection, particularly in men aged 18-24 years (4.3 [3.4-5.5] for BNT162b2 vs. 13.9 [9.2-20.1] for mRNA-1273) and aged 25-29 years (1.9 [1.2-2.9] vs. 7.0 [3.4-12.9]).

CONCLUSION

The study highlighted the role of the spontaneous reporting system in the detection, assessment, and quantification of myocarditis related to m-RNA vaccines. It suggested from September 2021 that mRNA-1273 was reasonably related to a higher risk of myocarditis than BNT162b2 in people under 30, particularly after the second injection.

Cost-effectiveness of the adjuvanted quadrivalent influenza vaccine in the elderly Belgian population

BACKGROUND

Between 2015 and 2019, when 62% of Belgian adults aged ≥ 65 years were vaccinated with standard quadrivalent influenza vaccines, influenza caused an average of 3,905 hospitalizations and 347 premature deaths per year in older adults. The objective of the present analysis was to estimate the cost-effectiveness of the adjuvanted quadrivalent influenza vaccine (aQIV) compared to the standard (SD-QIV) and high-dose (HD-QIV) vaccines in elderly Belgians.

RESEARCH DESIGN AND METHODS

The analysis was based on a static cost-effectiveness model that captured the evolution of patients infected with influenza and was customized with available national data.

RESULTS

Vaccinating adults aged ≥ 65 years with aQIV instead of SD-QIV would decrease the number of hospitalizations by 530 and the number of deaths by 66 in the 2023-2024 influenza season. aQIV was cost-effective compared to SD-QIV with an incremental cost of €15,227/quality-adjusted life year (QALY). aQIV is cost-saving when compared to HD-QIV in the subgroup of institutionalized elderly adults who were granted reimbursement for this vaccine.

CONCLUSION

In a health care system striving to improve the prevention of infectious diseases, a cost-effective vaccine such as aQIV is a key asset to reduce the number of influenza-related hospitalizations and premature deaths in older adults.

PLAIN LANGUAGE SUMMARY

A flu vaccine containing a unique immune boosting additive reduces medical spending by reducing flu hospitalizations and early deaths in the elderly.

Cost-Effectiveness of Vaccination of Older Adults with an MF59®-Adjuvanted Quadrivalent Influenza Vaccine Compared to Standard-Dose and High-Dose Vaccines in Denmark, Norway, and Sweden

Individuals aged 65 years and above are at increased risk of complications and death from influenza compared with any other age group. Enhanced vaccines, as the MF59®-adjuvanted quadrivalent influenza vaccine (aQIV) and the high-dose quadrivalent influenza vaccine (HD-QIV), provide increased protection for older adults in comparison to the traditional standard-dose quadrivalent influenza vaccines (SD-QIV). This study aimed to assess the cost-effectiveness of aQIV compared to SD-QIV and HD-QIV in Denmark, Norway, and Sweden for adults aged ≥65 years. A static decision tree model was used to evaluate costs and outcomes of different vaccination strategies from healthcare payer and societal perspectives. This model projects that compared to SD-QIV, vaccination with aQIV could prevent a combined total of 18,772 symptomatic influenza infections, 925 hospitalizations, and 161 deaths in one influenza season across the three countries. From a healthcare payer perspective, the incremental costs per quality adjusted life year (QALY) gained with aQIV versus SD-QIV were EUR 10,170/QALY in Denmark, EUR 12,515/QALY in Norway, and EUR 9894/QALY in Sweden. The aQIV was cost saving compared with HD-QIV. This study found that introducing aQIV to the entire population aged ≥65 years may contribute to reducing the disease and economic burden associated with influenza in these countries.

Sex and gender differences in myocarditis and dilated cardiomyopathy: An update

In the past decade there has been a growing interest in understanding sex and gender differences in myocarditis and dilated cardiomyopathy (DCM), and the purpose of this review is to provide an update on this topic including epidemiology, pathogenesis and clinical presentation, diagnosis and management. Recently, many clinical studies have been conducted examining sex differences in myocarditis. Studies consistently report that myocarditis occurs more often in men than women with a sex ratio ranging from 1:2-4 female to male. Studies reveal that DCM also has a sex ratio of around 1:3 women to men and this is also true for familial/genetic forms of DCM. Animal models have demonstrated that DCM develops after myocarditis in susceptible mouse strains and evidence exists for this progress clinically as well. A consistent finding is that myocarditis occurs primarily in men under 50 years of age, but in women after age 50 or post-menopause. In contrast, DCM typically occurs after age 50, although the age that post-myocarditis DCM occurs has not been investigated. In a small study, more men with myocarditis presented with symptoms of chest pain while women presented with dyspnea. Men with myocarditis have been found to have higher levels of heart failure biomarkers soluble ST2, creatine kinase, myoglobin and T helper 17-associated cytokines while women develop a better regulatory immune response. Studies of the pathogenesis of disease have found that Toll-like receptor (TLR)2 and TLR4 signaling pathways play a central role in increasing inflammation during myocarditis and in promoting remodeling and fibrosis that leads to DCM, and all of these pathways are elevated in males. Management of myocarditis follows heart failure guidelines and there are currently no disease-specific therapies. Research on standard heart failure medications reveal important sex differences. Overall, many advances in our understanding of the effect of biologic sex on myocarditis and DCM have occurred over the past decade, but many gaps in our understanding remain. A better understanding of sex and gender effects are needed to develop disease-targeted and individualized medicine approaches in the future.

Evaluation of Military Recruits With Complaints of Palpitations After Physical Training: A Study From Turkey

Objective Recruits undergo medical examination before mandatory service. After enlistment, if recruits have health problems, they are sent to a medical board to establish fitness for their duties. We aimed to analyze the complaints of palpitations after physical training in recruits without a known history of cardiovascular disease (CVD) and determine whether the diagnoses were suitable for duty. Methods This cross-sectional descriptive study was conducted among 25,666 participants who were admitted to an outpatient cardiology clinic due to complaints of palpitations between August 2016 and June 2022. Information regarding socio-demographic characteristics was collected. Laboratory test results and electrocardiography (ECG) were analyzed. The diagnoses were evaluated. Results In total, 582 patients who were dismissed from the military were included in the study. The mean age of patients was 19.23±2.02 years. Among the patients, drug use (26; 6.2%) and history of addictive substance use (178; 30.6%) were low. The number of days of service under 10 was high (450; 77.3%). The prevalence of sleep disturbance (122; 21%) and hydration habits (154; 26.5%) were low. According to ECG findings, premature atrial contractions were high (250; 42.9%). There was a significant correlation between the ECG findings and seasons (p<0.001).Rheumatic valve disease (83; 14.26%) and supraventricular tachycardia (77; 13.23%) were the most common diagnoses. Conclusion 2.2 percent of all participants admitted to the hospital due to palpitations were dismissed from the military service, and 0.7 percent of them were diagnosed with cardiac conduction system disease.

Biomarkers for Myocarditis and Inflammatory Cardiomyopathy

Purpose of Review

Myocarditis is a disease caused by inflammation of the heart that can progress to dilated cardiomyopathy, heart failure, and eventually death in many patients. Several etiologies are implicated in the development of myocarditis including autoimmune, drug-induced, infectious, and others. All causes lead to inflammation which causes damage to the myocardium followed by remodeling and fibrosis. This review aims to summarize recent findings in biomarkers for myocarditis and highlight the most promising candidates.

Recent Findings

Current methods of diagnosing myocarditis, including imaging and endomyocardial biopsy, are invasive, expensive, and often not done early enough to affect progression. Research is being done to find biomarkers of myocarditis that are cost-effective, accurate, and prognostically informative. These biomarkers would allow for earlier screening for myocarditis, as well as earlier treatment, and a better understanding of the disease course for specific patients.

Summary

Early diagnosis of myocarditis with biomarkers may allow for prompt treatment to improve outcomes in patients.

SGLT2 inhibitor, canagliflozin, ameliorates cardiac inflammation in experimental autoimmune myocarditis

Myocarditis is an inflammatory cardiovascular disease which contributes to dilated cardiomyopathy (DCM) and heart failure. Canagliflozin (CANA) exerts anti-inflammatory and cardioprotective effects in heart failure besides its hypoglycemic effect. However, the role of CANA in myocarditis has not been elucidated. In this work, CANA treatment markedly alleviated cardiac inflammation and improved cardiac function in experimental autoimmune myocarditis (EAM) mice induced by α-myosin-heavy chain peptides. The expressions of NLRP3 inflammasome complexes (NLRP3, ASC, and Caspase-1) and their downstream molecules (IL-1β, IL-18) were significantly downregulated by CANA, accompanied with reduced Th17 cell infiltration in hearts. Furthermore, Bax/Bcl-2 ratio, Cleaved Caspase-3 protein level and the percentage of TUNEL-positive myocardial cells, which usually indicated apoptosis, were reduced by CANA treatment. These findings suggest CANA could be a valuable medication for myocarditis treatment.