COVID-19 Vaccination-Associated Myocarditis in Adolescents

Healthcare use in 12-18-year-old adolescents vaccinated against SARS-CoV-2 versus unvaccinated in a national register-based Danish cohort

Healthcare use among adolescents after vaccination against SARS-CoV-2 is unknown. In a real-life register-based cohort study (trial NCT04786353), healthcare use was compared among Pfizer-BioNTech BNT162b2 COVID-19 vaccinated and unvaccinated 12-18-year-olds. First-dose-vaccinated (between 1 May and 30 September 2021) adolescents were sex and age matched 1:1 with unvaccinated adolescents. Outcomes were visits to emergency rooms, hospitalization, and visits to general practitioners and specialist practitioners. The prior event rate ratio (PERR) was applied. The study finds that boys had fewer visits to general practitioners (PERR 0.93, 95% confidence interval (CI) 0.89-0.99) after the first vaccine. Up to 56 days after the second dose, vaccinated boys had lower rates of visits to specialist practitioners (0.88, 95% CI 0.79-0.99); after 57-182 days, vaccinated girls and boys had higher rates of visits to emergency rooms (1.22, 95% CI 1.08-1.39; 1.17, 95% CI 1.07-1.31) and to general practitioners (1.17, 95% CI 1.12-1.21; 1.17, 95% CI 1.13-1.22). Furthermore, vaccinated boys had higher rates of visits to specialist practitioners (1.23, 95% CI 1.08-1.39). Estimates were close to one and do not indicate that BNT162b2 leads to a practically meaningful increase in healthcare use among vaccinated adolescents.

Design and rationale of the COVID vaccine-associated myocarditis/pericarditis (CAMP) study

BACKGROUND

Minimal data are available on mid- and long-term outcomes following COVID-19 vaccine-associated myocarditis/pericarditis. The COVID Vaccine-Associated Myocarditis/Pericarditis (CAMP) study aims to characterize the mid- and long-term sequelae of myocarditis/pericarditis following administration of any Pfizer-BioNTech COVID-19 vaccine (herein referred to as COMIRNATY®). Herein we describe the rationale and design of CAMP.

METHODS

This ongoing and actively enrolling multicenter observational cohort study across 32 North American pediatric cardiac centers will include at least 200 patients <21 years-old who presented ≤21 days from COMIRNATY® vaccination and meet the Centers for Disease Control and Prevention (CDC) case definition of probable or confirmed myocarditis/pericarditis or isolated pericarditis. The comparison cohort will consist of 100 patients <21 years-old with COVID-19 associated myocarditis/pericarditis, including those who meet the contemporaneous CDC case definition of multisystem inflammatory syndrome (MIS-C). The study will collect detailed hospital and follow-up data for up to 5 years following illness onset. Electrocardiograms, echocardiograms, and cardiac magnetic resonance (CMR) examinations will be interpreted in core laboratories. The primary outcomes are 1) composite of left ventricular ejection fraction <55% by echocardiogram, findings of myocarditis by original or revised Lake Louise criteria on CMR, and/or the presence of high-grade arrhythmias or conduction system disturbances at 6 months after myocarditis/pericarditis onset; 2) complications, such as death, and non-cardiac morbidities; and 3) patient-reported outcomes of global health, functional status, and quality of life. Analyses will include descriptive statistics and regression modeling.

CURRENT STATUS

Still enrolling, with 273 participants currently enrolled as of 10/16/2024 (173 vaccine-associated myocarditis/pericarditis, 100 COVID-19-associated myocarditis/pericarditis) CONCLUSIONS: With long-term follow-up and core laboratories for standardized assessments of cardiac testing, the CAMP study will make important contributions to our understanding of the mid- and long-term cardiac and non-cardiac sequelae of COVID-19 vaccine-associated myocarditis/pericarditis.

Systematic Review of COVID-19 and COVID-19 mRNA Vaccine Myocarditis in Athletes: Incidence, Diagnosis, Prognosis, and Return-to-Play Principles

OBJECTIVE

The purpose of this systematic review is to evaluate the original peer-reviewed studies on athletes who developed myocarditis after coronavirus disease (COVID-19) infection or after COVID-19 mRNA vaccination. Both entities likely have an immunologic component. We discuss elite, professional, college, and adolescent athletes. The athletes are generally young and healthy, representing a distinctive population group that differs from the general population. This review includes diagnosis of myocarditis, incidence, complications, prognosis, and return-to-play guidance for sports medicine clinicians and coaches.

DATA SOURCES

We surveyed the PUBMED, Embase, and Web of Science databases for the relevant peer-reviewed articles in the English language published from the onset of the pandemic until April 2023. Included were original observational studies and case series. Excluded were individual case reports and a small series with incomplete data. The resulting search yielded 30 original articles.

MAIN RESULTS

Reported myocardial abnormalities in athletes were rare after COVID-19 infection and even less frequent after COVID-19 mRNA vaccination. True incidence, however, may be higher because of under-reporting and frequent asymptomatic presentation. Male gender was prevalent for both manifestations; postvaccination myocarditis occurrence was the highest after the second vaccine dose. Diagnostic and return-to-play algorithms were developed and should be adopted and followed.

CONCLUSIONS

The risk of myocarditis from COVID-19 infection and COVID-19 mRNA vaccination is very low. The long-term prognosis and evolution of the observed cardiac magnetic resonance abnormalities are currently unknown. Although inferences can be made from the published data, COVID-19 and postvaccine myocarditis in athletes may represent only a small fraction of the true incidence of those who have been affected worldwide and not evaluated.

Unraveling Cardiovascular Risks and Benefits of COVID-19 Vaccines: A Systematic Review

The rapid development and deployment of mRNA and non-mRNA COVID-19 vaccines have played a pivotal role in mitigating the global pandemic. Despite their success in reducing severe disease outcomes, emerging concerns about cardiovascular complications have raised questions regarding their safety. This systematic review critically evaluates the evidence on the cardiovascular effects of COVID-19 vaccines, assessing both their protective and adverse impacts, while considering the challenges posed by the limited availability of randomized controlled trial (RCT) data on these rare adverse events. In adherence to PRISMA 2020 guidelines, we conducted a systematic review using the Scopus database, incorporating articles published from January 2020 to July 2024. Our search included terms related to COVID-19 vaccines and cardiovascular conditions. We selected relevant studies from case-control studies, cohort studies, and clinical trials, while excluding descriptive analyses, cross-sectional studies, and conference reports. Case reports were also included due to the limited availability of extensive RCT data on the rare cardiovascular adverse events associated with COVID-19 vaccines. Of the 6037 articles initially screened, 410 were assessed in detail and 175 studies were ultimately included. The review identified a variety of cardiovascular adverse effects associated with COVID-19 vaccines. mRNA vaccines were primarily linked to myocarditis and pericarditis, particularly in younger males, with lower cardiac risks compared to COVID-19 infection. Adenoviral vector vaccines were associated with thrombosis and thrombocytopenia. Inactivated vaccines had fewer severe cardiovascular reports but still presented risks. Takotsubo cardiomyopathy was most commonly observed following mRNA vaccination. Case reports provided valuable additional insights into these rare events, highlighting clinical presentations and potential risk factors not fully captured by larger epidemiological studies. This review reveals a nuanced cardiovascular risk profile for COVID-19 vaccines, with mRNA vaccines linked to rare myocarditis and pericarditis in young males and a higher incidence of Takotsubo cardiomyopathy in females. Adenoviral vaccines show a notable association with thrombosis. Despite these risks, the benefits of vaccination in preventing severe COVID-19 outcomes outweigh the potential complications, underscoring the importance of continued surveillance, case report documentation, and personalized risk assessment. The inclusion of case reports was critical, as they provided valuable real-world data that complemented the findings from large-scale studies and RCTs.

Cardiac manifestations and outcomes of COVID-19 vaccine-associated myocarditis in the young in the USA: longitudinal results from the Myocarditis After COVID Vaccination (MACiV) multicenter study

Background

We aimed to study the clinical characteristics, myocardial injury, and longitudinal outcomes of COVID-19 vaccine-associated myocarditis (C-VAM).

Methods

In this longitudinal retrospective observational cohort multicenter study across 38 hospitals in the United States, 333 patients with C-VAM were compared with 100 patients with multisystem inflammatory syndrome in children (MIS-C). We included patients ≤30 years of age with a clinical diagnosis of acute myocarditis after COVID-19 vaccination based on clinical presentation, abnormal biomarkers and/or cardiovascular imaging findings. Demographics, past medical history, hospital course, biochemistry results, cardiovascular imaging, and follow-up information from April 2021 to November 2022 were collected. The primary outcome was presence of myocardial injury as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging.

Findings

Patients with C-VAM were predominantly white (67%) adolescent males (91%, 15.7 ± 2.8 years). Their initial clinical course was more likely to be mild (80% vs. 23%, p < 0.001) and cardiac dysfunction was less common (17% vs. 68%, p < 0.0001), compared to MIS-C. In contrast, LGE on CMR was more prevalent in C-VAM (82% vs. 16%, p < 0.001). The probability of LGE was higher in males (OR 3.28 [95% CI: 0.99, 10.6, p = 0.052]), in older patients (>15 years, OR 2.74 [95% CI: 1.28, 5.83, p = 0.009]) and when C-VAM occurred after the first or second dose as compared to the third dose of mRNA vaccine. Mid-term clinical outcomes of C-VAM at a median follow-up of 178 days (IQR 114-285 days) were reassuring. No cardiac deaths or heart transplantations were reported until the time of submission of this report. LGE persisted in 60% of the patients at follow up.

Interpretation

Myocardial injury at initial presentation and its persistence at follow up, despite a mild initial course and favorable mid-term clinical outcome, warrants continued clinical surveillance and long-term studies in affected patients with C-VAM.

Funding

The U.S. Food and Drug Administration.

MRI of cardiac involvement in COVID-19

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to a diverse pattern of myocardial injuries, including myocarditis, which is linked to adverse outcomes in patients. Research indicates that myocardial injury is associated with higher mortality in hospitalized severe COVID-19 patients (75.8% vs 9.7%). Cardiovascular Magnetic Resonance (CMR) has emerged as a crucial tool in diagnosing both ischaemic and non-ischaemic myocardial injuries, providing detailed insights into the impact of COVID-19 on myocardial tissue and function. This review synthesizes existing studies on the histopathological findings and CMR imaging patterns of myocardial injuries in COVID-19 patients. CMR imaging has revealed a complex pattern of cardiac damage in these patients, including myocardial inflammation, oedema, fibrosis, and ischaemic injury, due to coronary microthrombi. This review also highlights the role of LLC criteria in diagnosis of COVID-related myocarditis and the importance of CMR in detecting cardiac complications of COVID-19 in specific groups, such as children, manifesting multisystem inflammatory syndrome in children (MIS-C) and athletes, as well as myocardial injuries post-COVID-19 infection or following COVID-19 vaccination. By summarizing existing studies on CMR in COVID-19 patients and highlighting ongoing research, this review contributes to a deeper understanding of the cardiac impacts of COVID-19. It emphasizes the effectiveness of CMR in assessing a broad spectrum of myocardial injuries, thereby enhancing the management and prognosis of patients with COVID-19 related cardiac complications.

Myocarditis in children 2024, new themes and continued questions

PURPOSE OF REVIEW

While pediatric myocarditis incidence has increased since the coronavirus disease 2019 (COVID-19) pandemic, there remain questions regarding diagnosis, risk stratification, and optimal therapy. This review highlights recent publications and continued unanswered questions related to myocarditis in children.

RECENT FINDINGS

Emergence from the COVID-19 era has allowed more accurate description of the incidence and prognosis of myocarditis adjacent to COVID-19 infection and vaccine administration as well that of multi-system inflammatory disease in children (MIS-C). As cardiac magnetic resonance technology has shown increased availability and evidence in pediatric myocarditis, it is important to understand conclusions from adult imaging studies and define the use of this imaging biomarker in children. Precision medicine has begun to allow real-time molecular evaluations to help diagnose and risk-stratify cardiovascular diseases, with emerging evidence of these modalities in myocarditis.

SUMMARY

Recent information regarding COVID-19 associated myocarditis, cardiac magnetic resonance, and molecular biomarkers may help clinicians caring for children with myocarditis and identify needs for future investigations.

Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

High Cardiac Troponin Levels in Infants with Acute SARS-CoV-2 Infection: A Prospective Comparative Study

OBJECTIVE

To investigate the specific role of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in inducing elevation of marker of myocardial injury in infants with acute coronavirus disease 2019 (COVID-19).

STUDY DESIGN

A prospective, multicentric 3-arm comparative study (March 2020 through March 2022) enrolling 152 infants hospitalized for COVID-19, 79 children with acute infections other than SARS-CoV-2, and 71 healthy controls. Determination of high-sensitivity cardiac troponin (hs-cTn) levels was the primary outcome.

RESULTS

The proportion of children with hs-cTn values above the upper limit of normal (44 [28.9%]), as well as with a 3-fold increased value (20 [13.2%]) were significantly higher in the COVID-19 group than those in both control groups. The risk of presenting a 3-fold increased hs-cTn value was higher in children with SARS-CoV-2 infection compared with either healthy children (OR, 5.23; 95% CI, 1.19-23.02) or those with other infections (OR, 11.89; 95% CI, 1.56-89.79). In children with COVID-19, hs-cTn elevation was associated with neither clinical nor biochemical characteristics, nor perinatal risk factors, but with an age of <3 months (P < .001). After adjustment for age, sex, and underlying clinical conditions, elevated hs-cTn was independently associated with COVID-19 in a multivariable regression model. All children showed a progressive reduction of hs-cTn until normalization over time, without clinical, ECG, or echocardiographic manifestations up to 1 year of follow-up.

CONCLUSIONS

Infants with acute SARS-CoV-2 infection may show a subclinical and transient alteration of myocardial injury markers, especially in the first months of life. hs-cTn levels normalized during follow-up and were not associated with cardiac functional impairment; nevertheless, long-term consequences are unknown and should be followed carefully.

Fulminant Myocarditis Temporally Associated with COVID-19 Vaccination

PURPOSE OF REVIEW

Coronavirus disease-2019 (COVID-19) vaccines have been related to rare cases of acute myocarditis, occurring between 1 in 10,000 and 1 in 100,000 individuals, approximately. Incidence of COVID-19 vaccine-associated myocarditis varies with age, sex, and type of vaccine. Although most patients with acute myocarditis temporally associated with COVID-19 vaccines have an uneventful course, a small subpopulation presents with cardiogenic shock (termed fulminant myocarditis [FM]). This review explored the prevalence, clinical presentation, management, and prognosis of COVID-19 vaccine-associated acute myocarditis, specifically focusing on FM and comparing patients with fulminant versus non-fulminant myocarditis.

RECENT FINDINGS

Cases of FM represent about 2-4% (0 to 7.5%) of COVID-19 vaccine-associated acute myocarditis cases, and mortality is around 1%, ranging between 0 and 4.4%. First, we identified 40 cases of FM up to February 2023 with sufficient granular data from case reports and case series of COVID-19 vaccine-associated acute myocarditis that occurred within 30 days from the last vaccine injection. This population was compared with 294 cases of non-fulminant acute myocarditis identified in the literature during a similar time. Patients with FM were older (48 vs. 27 years), had a larger proportion of women (58% vs. 9%), and mainly occurred after the first shot compared with non-fulminant cases (58% vs. 16%). The reported mortality was 27% (11 out of 40), in line with non-vaccine-associated fulminant myocarditis. These data were in agreement with 36 cases of FM from a large Korean registry. Herein, we reviewed the clinical features, imaging results, and histological findings of COVID-19 vaccine-associated fulminant myocarditis. In conclusion, COVID-19 vaccine-associated FM differs from non-fulminant forms, suggesting potential specific mechanisms in these rare and severe forms. Mortality in vaccine-associated FM remains high, in line with other forms of FM.

Emergency department presentations for chest complaints after mRNA COVID-19 vaccinations in children and adolescents

OBJECTIVE

To investigate characteristics and management of children presenting with chest complaints to a tertiary paediatric ED post-mRNA COVID-19 vaccine.

METHODS

This was a retrospective medical record review with data linkage to the Australian Immunisation Register. The study setting was the Royal Children's Hospital, Melbourne, Australia. Children <18 years who had a troponin blood test performed in hospital within 14 days of receiving mRNA COVID-19 vaccination were included. Elevated troponin and myocarditis or pericarditis as per Brighton criteria was the primary outcome. Vaccination status, length of stay, investigations and clinical management were secondary outcomes.

RESULTS

Six hundred and ten patients had a troponin test in 13 months. After exclusion of trauma-related tests (n = 31), known cardiac patients (n = 75) and others (n = 145), 359 troponins were obtained due to chest complaints and related symptoms, with 283 troponins assessed to be mRNA vaccination-related. There was a temporal peak in presentations with a 30-fold monthly increase in troponin post-commencement of mRNA COVID-19 vaccines. In those with chest complaints following mRNA vaccination, mean age was 14 years and 50.4% were female. Fourteen out of 283 (5%) vaccine-related troponins were abnormal with 14 patients assessed to have vaccine-associated myocarditis. No patients had pericarditis.

CONCLUSIONS

There was a large number of possible mRNA COVID-19 vaccine-related chest complaints presenting to the ED. Few patients had abnormal troponins or myocarditis.

Cardiac Magnetic Resonance Imaging Findings and Clinical Features of COVID-19 Vaccine-Associated Myocarditis, Compared With Those of Other Types of Myocarditis

BACKGROUND

To compare the clinical and cardiac magnetic resonance (CMR) imaging findings of coronavirus disease 2019 (COVID-19) vaccine-associated myocarditis (VAM) with those of other types of myocarditis.

METHODS

From January 2020 to March 2022, a total of 39 patients diagnosed with myocarditis via CMR according to the Modified Lake Louise criteria were included in the present study. The patients were classified into two groups based on their vaccination status: COVID-19 VAM and other types of myocarditis not associated with COVID-19 vaccination. Clinical outcomes, including the development of clinically significant arrhythmias, sudden cardiac arrest, and death, and CMR imaging features were compared between COVID-19 VAM and other types of myocarditis.

RESULTS

Of the 39 included patients (mean age, 39 years ± 16.4 [standard deviation]; 23 men), 23 (59%) had COVID-19 VAM and 16 (41%) had other types of myocarditis. The occurrence of clinical adverse events did not differ significantly between the two groups. As per the CMR imaging findings, the presence and dominant pattern of late gadolinium enhancement did not differ significantly between the two groups. The presence of high native T1 or T2 values was not significantly different between the two groups. Although the native T1 and T2 values tended to be lower in COVID-19 VAM than in other types of myocarditis, there were no statistically significant differences between the native T1 and T2 values in the two groups.

CONCLUSION

The present study demonstrated that the CMR imaging findings and clinical outcomes of COVID-19 VAM did not differ significantly from those of other types of myocarditis during hospitalization.

Echocardiographic function evaluation in adolescents following BNT162b2 Pfizer-BioNTech mRNA vaccination: A preliminary prospective study

BACKGROUND

Vaccination against coronavirus disease 2019 (COVID-19) is crucial for preventing and minimizing illness. Myocarditis and pericarditis after messenger RNA (mRNA) COVID-19 vaccination in adolescents and young adult males have been reported. Most of the studies in this area rely on retrospective symptom reporting, especially for adolescents experiencing myocarditis as a potential side effect. However, prospective postvaccination echocardiographic evaluation is rare.

METHODS

The study enrolled adolescents aged 12 to 15 years who received the second dose of the BNT162b2 Pfizer-BioNTech mRNA (BNT) vaccine. Serial echocardiographic examinations were conducted at baseline before vaccination, followed by subsequent assessments on days 2, 7, 14, and 28 to identify any notable differences or abnormal changes in cardiac function. Clinical symptom assessments were also recorded during each follow-up.

RESULTS

The study included 25 adolescents, comprising 14 males and 11 females, who completed the four follow-ups. Their mean age was 14 ± 1 years. The average interval between the first and second BNT vaccine doses was 90 ± 7 days. Ejection fraction values were 73.8% ± 5.2% at baseline, followed by 75.7% ± 5.3%, 75.5% ± 4.6%, 75.7% ± 4.5%, and 77.8% ± 5.8% at day 2, 7, 14, and 28, respectively. The cardiac function remained stable across all time points, with no significant differences observed between male and female participants. Within postvaccination 48 hours, 18 (72%) of the enrolled adolescents experienced temporary discomfort symptoms, which completely resolved by the final follow-up on the 28th day after vaccination.

CONCLUSION

Although adolescents vaccinated with the second dose of BNT vaccine commonly experienced transient postvaccination discomfort, the serial echocardiographic examinations did not reveal any significant deterioration of cardiac function within 28 days. Further studies are required to investigate the incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccination-associated myocarditis in adolescents and the related mechanisms.

Clinical course and follow-up of pediatric patients with COVID-19 vaccine-associated myocarditis compared to non-vaccine-associated myocarditis within the prospective multicenter registry-"MYKKE"

BACKGROUND

Since the onset of widespread COVID-19 vaccination, increased incidence of COVID-19 vaccine-associated myocarditis (VA-myocarditis) has been noted, particularly in male adolescents.

METHODS

Patients <18 years with suspected myocarditis following COVID-19 vaccination within 21 days were enrolled in the PedMYCVAC cohort, a substudy within the prospective multicenter registry for pediatric myocarditis "MYKKE." Clinical data at initial admission, 3- and 9-months follow-up were monitored and compared to pediatric patients with confirmed non-vaccine-associated myocarditis (NVA-myocarditis) adjusting for various baseline characteristics.

RESULTS

From July 2021 to December 2022, 56 patients with VA-myocarditis across 15 centers were enrolled (median age 16.3 years, 91% male). Initially, 11 patients (20%) had mildly reduced left ventricular ejection fraction (LVEF; 45%-54%). No incidents of severe heart failure, transplantation or death were observed. Of 49 patients at 3-months follow-up (median (IQR) 94 (63-118) days), residual symptoms were registered in 14 patients (29%), most commonly atypical intermittent chest pain and fatigue. Diagnostic abnormalities remained in 23 patients (47%). Of 21 patients at 9-months follow-up (259 (218-319) days), all were free of symptoms and diagnostic abnormalities remained in 9 patients (43%). These residuals were mostly residual late gadolinium enhancement in magnetic resonance imaging. Patients with NVA-myocarditis (n=108) more often had symptoms of heart failure (P = .003), arrhythmias (P = .031), left ventricular dilatation (P = .045), lower LVEF (P < .001) and major cardiac adverse events (P = .102).

CONCLUSIONS

Course of COVID-19 vaccine-associated myocarditis in pediatric patients seems to be mild and differs from non-vaccine-associated myocarditis. Due to a considerable number of residual symptoms and diagnostic abnormalities at follow-up, further studies are needed to define its long-term implications.

Society for Cardiovascular Magnetic Resonance 2022 Cases of SCMR case series

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.

COVID-19 vaccine-associated myocarditis: Analysis of the suspected cases reported to the EudraVigilance and a systematic review of the published literature

Background

Myocarditis secondary to Coronavirus Disease 2019 (COVID-19) vaccination has been reported in the literature.

Objective

This study aimed to characterize the reported cases of myocarditis after COVID-19 vaccination based on age, gender, doses, and vaccine type from published literature and the EudraVigilance database.

Methods

We performed an analysis in the EudraVigilance database (until December 18, 2021) and a systematic review of published literature for reported cases of suspected myocarditis and pericarditis (until 30th June 2022) after the COVID-19 vaccination.

Results

EudraVigilance database analysis revealed 16,514 reported cases of myocarditis or pericarditis due to the vaccination with COVID-19 vaccines. The cases of myo- or pericarditis were reported predominantly in the age group of 18-64 (n = 12,214), and in males with a male-to-female (M: F) ratio of 1.7:1. The mortality among myocarditis patients was low, with 128 deaths (2 cases per 10.000.000 administered doses) being reported. For the systematic review, 72 studies with 1026 cases of myocarditis due to the vaccination with COVID-19 vaccines were included. The analysis of published cases has revealed that the male gender was primarily affected with myocarditis post-COVID-vaccination. The median (IQR) age of the myocarditis cases was 24.6 [19.5-34.6] years, according to the systematic review of the literature. Myocarditis cases were most frequently published after the vaccination with m-RNA vaccines and after the second vaccination dose. The overall mortality of published cases was low (n = 5).

Conclusion

Myocarditis is a rare serious adverse event associated with a COVID-19 vaccination. With early recognition and management, the prognosis of COVID-19 vaccine-induced myocarditis is favorable.

Clinical Syndromes Related to SARS-CoV-2 Infection and Vaccination in Pediatric Age: A Narrative Review

This narrative review aims to report the main clinical manifestations, therapeutic strategies, outcomes, and complications of acute SARS-CoV-2 infection in childhood and to summarize the data relating the SARS-CoV-2 vaccination efficacy and safety in pediatric age. SARS-CoV-2 infection mostly occurs asymptomatically in the pediatric population, while multisystem inflammatory syndrome in children (MIS-C) represents the most severe coronavirus disease 2019 (COVID-19)-related illness, a life-threatening event with a high morbidity rate. After the development of SARS-CoV-2 vaccines and their subsequent approval in children, the rate of infection as well as the number of its related complications have shown a drastic decrease. Fully vaccinated children are protected from the risk of developing a severe disease and a similar protective role has been observed in the reduction of complications, in particular MIS-C. However, long-lasting immunity has not been demonstrated, booster doses have been required, and reinfection has been observed. With regards to vaccine safety, adverse events were generally mild to moderate in all age groups: local adverse events were the most commonly reported. Nevertheless, a potential association between SARS-CoV-2 vaccine and the subsequent development of inflammatory manifestations has been suggested. Myocarditis has rarely been observed following vaccination; it appeared to be more frequent among adolescent males with a mild clinical course leading to a complete recovery. SARS-CoV-2 vaccine-related MIS-C cases have been described, although a univocal definition and an exact time interval with respect to vaccination has not been reported, thus not establishing a direct causal link. Current evidence about COVID-19 vaccination in children and adolescents suggest that benefits outweigh potential risks. Long-term data collection of the post-authorization safety surveillance programs will better define the real incidence of SARS-CoV-2 vaccine-related complications in the pediatric population.

Cardiac Magnetic Resonance Findings of Coronavirus Disease 2019 (COVID-19) Vaccine-Associated Myopericarditis at Intermediate Follow-Up: A Comparison with Classic Myocarditis

OBJECTIVE

To report intermediate cardiac magnetic resonance (CMR) findings of coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis (C-VAM) and compare with classic myocarditis.

STUDY DESIGN

Retrospective cohort study including children diagnosed with C-VAM from May 2021 through December 2021 with early and intermediate CMR. Patients with classic myocarditis from January 2015 through December 2021 and intermediate CMR were included for comparison.

RESULTS

There were 8 patients with C-VAM and 20 with classic myocarditis. Among those with C-VAM, CMR performed at a median 3 days (IQR 3, 7) revealed 2 of 8 patients with left ventricular ejection fraction <55%, 7 of 7 patients receiving contrast with late gadolinium enhancement (LGE), and 5 of 8 patients with elevated native T1 values. Borderline T2 values suggestive of myocardial edema were present in 6 of 8 patients. Follow-up CMRs performed at a median 107 days (IQR 97, 177) showed normal ventricular systolic function, T1, and T2 values; 3 of 7 patients had LGE. At intermediate follow-up, patients with C-VAM had fewer myocardial segments with LGE than patients with classic myocarditis (4/119 vs 42/340, P = .004). Patients with C-VAM also had a lower frequency of LGE (42.9 vs 75.0%) and lower percentage of left ventricular ejection fraction <55% compared with classic myocarditis (0.0 vs 30.0%), although these differences were not statistically significant. Five patients with classic myocarditis did not receive an early CMR, leading to some selection bias in study design.

CONCLUSIONS

Patients with C-VAM had no evidence of active inflammation or ventricular dysfunction on intermediate CMR, although a minority had persistent LGE. Intermediate findings in C-VAM revealed less LGE burden compared with classic myocarditis.

Characteristics of Teenagers Presenting with Chest Pain after COVID-19 mRNA Vaccination

In this study, we evaluated the clinical and radiological manifestations of teenagers presenting with chest pain after coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccination. We retrospectively enrolled 61 teenage patients, aged 13 to 19 years, who underwent echocardiography and cardiac magnetic resonance imaging (CMR) for chest pain after COVID-19 mRNA vaccination, from November 2021 to April 2022. Medical records, laboratory results, echocardiographic, and CMR findings were analyzed. The mean age of the participants was 14.4 ± 1.9 years, with a male:female ratio of 28:33. Among the sixty-one patients with chest pain after COVID-19 vaccination, only two (3.3%) were diagnosed as confirmed myocarditis, and almost all of them recovered with conservative treatments. However, on CMR, 24 (39.3%) presented with mild myocardial abnormalities; 22 (36.1%) showed myocardial edema, and 19 (31.1%) were found to have a myocardial injury. Multivariate logistic analyses revealed that older age and female sex were significantly associated with myocardial abnormalities. In teenagers who present with chest pain after COVID-19 mRNA vaccination, confirmed myocarditis is uncommon. However, myocardial abnormalities on CMR might occur frequently, and females in their late teens might be more vulnerable to myocardial abnormalities.

Systematic review and meta-analysis of myocarditis and pericarditis in adolescents following COVID-19 BNT162b2 vaccination

Myocarditis and pericarditis are frequent complications of COVID-19, but have also been reported following vaccination against COVID-19 in adolescents. To build vaccine confidence and inform policy, we characterized the incidence of myocarditis/pericarditis in adolescents following BNT162b2 vaccination and explored the association with dose and sex. We searched national and international databases for studies reporting the incidence of myocarditis/pericarditis following BNT162b2 vaccination as the primary endpoint. The intra-study risk of bias was appraised, and random-effects meta-analyses were performed to estimate the pooled incidence by dose stratified by sex. The pooled incidence of myocarditis/pericarditis was 4.5 (95%CI: 3.14-6.11) per 100,000 vaccinations across all doses. Compared to dose 1, the risk was significantly higher after dose 2 (RR: 8.62, 95%CI: 5.71-13.03). However, adolescents experienced a low risk after a booster dose than after dose 2 (RR: 0.06; 95%CI: 0.04-0.09). Males were approximately seven times (RR: 6.66, 95%CI: 4.77-4.29) more likely than females to present myocarditis/pericarditis. In conclusion, we found a low frequency of myocarditis/pericarditis after BNT162b2, which occurred predominantly after the second dose in male adolescents. The prognosis appears to be favorable, with full recovery in both males and females. National programs are recommended to adopt the causality framework to reduce overreporting, which undercuts the value of the COVID-19 vaccine on adolescent life, as well as to extend the inter-dose interval policy, which has been linked to a lower frequency of myocarditis/pericarditis.

Patients with Post-COVID-19 Vaccination Myocarditis Have More Favorable Strain in Cardiac Magnetic Resonance Than Those With Viral Myocarditis

There have been reports of myocarditis following vaccination against COVID-19. We sought to describe cardiac magnetic resonance (CMR) findings among pediatric patients. Retrospective review at a large academic center of patients clinically diagnosed with post-vaccine myocarditis (PVM) undergoing CMR. Data collected included parametric mapping, ventricular function, and degree of late gadolinium enhancement (LGE). Post-processing strain analysis was performed using feature tracking. Strain values, T1/T2 values, and ventricular function were compared to age- and gender-matched controls with viral myocarditis using a Wilcoxon Signed Rank test. Among 12 patients with presumed PVM, 11 were male and 11 presented after the second vaccination dose, typically within 4 days. All presented with chest pain and elevated troponin. 10 met MRI criteria for acute myocarditis. All had LGE typically seen in the lateral and inferior walls; only five had prolonged T1 values. 10 met criteria for edema based on skeletal muscle to myocardium signal intensity ratio and only 5 had prolonged T2 mapping values. Patients with PVM had greater short-axis global circumferential and radial strain, right ventricle function, and cardiac output when compared to those with viral myocarditis. Patients with PVM have greater short-axis global circumferential and radial strains compared to those with viral myocarditis. LGE was universal in our cohort. Signal intensity ratios between skeletal muscle and myocardium may be more sensitive in identifying edema than T2 mapping. Overall, the impact on myocardial strain by CMR is less significant in PVM compared to more classic viral myocarditis.

Benefits v. risks of COVID-19 vaccination: an examination of vaccination policy impact on the occurrence of myocarditis and pericarditis

Studies of myocarditis/pericarditis following mRNA COVID-19 vaccines in Hong Kong have been published. Data are consistent with data from other active surveillance or healthcare databases. The mRNA COVID-19 vaccines have been shown to rarely increase risk of myocarditis, with the highest risk among males aged 12-17 after the second dose. An increased risk of pericarditis has also been shown after the second dose, though less common than myocarditis and more evenly distributed among different sex and age groups. Because of the increased risk of post-vaccine myocarditis, Hong Kong implemented a single dose mRNA COVID-19 vaccine policy on September 15, 2021 for adolescents (age 12-17 years). Post-policy, there were no cases of carditis. 40,167 first dose patients did not receive a second dose. This policy was highly successful in the reduction of carditis, but the trade-off is the potential risk of disease and cost to population-level immunity. This commentary brings forward some important global policy considerations.

Vaccination-Associated Myocarditis and Myocardial Injury

SARS-CoV-2 vaccine-associated myocarditis/myocardial injury should be evaluated in the contexts of COVID-19 infection, other types of viral myocarditis, and other vaccine-associated cardiac disorders. COVID-19 vaccine-associated myocardial injury can be caused by an inflammatory immune cell infiltrate, but other etiologies such as microvascular thrombosis are also possible. The clinical diagnosis is typically based on symptoms and cardiac magnetic resonance imaging. Endomyocardial biopsy is confirmatory for myocarditis, but may not show an inflammatory infiltrate because of rapid resolution or a non-inflammatory etiology. Myocarditis associated with SARS-COVID-19 vaccines occurs primarily with mRNA platform vaccines, which are also the most effective. In persons aged >16 or >12 years the myocarditis estimated crude incidences after the first 2 doses of BNT162b2 and mRNA-1273 are approximately 1.9 and 3.5 per 100 000 individuals, respectively. These rates equate to excess incidences above control populations of approximately 1.2 (BNT162b2) and 1.9 (mRNA-1273) per 100 000 persons, which are lower than the myocarditis rate for smallpox but higher than that for influenza vaccines. In the studies that have included mRNA vaccine and SARS-COVID-19 myocarditis measured by the same methodology, the incidence rate was increased by 3.5-fold over control in COVID-19 compared with 1.5-fold for BNT162b2 and 6.2-fold for mRNA-1273. However, mortality and major morbidity are less and recovery is faster with mRNA vaccine-associated myocarditis compared to COVID-19 infection. The reasons for this include vaccine-associated myocarditis having a higher incidence in young adults and adolescents, typically no involvement of other organs in vaccine-associated myocarditis, and based on comparisons to non-COVID viral myocarditis an inherently more benign clinical course.

Short term outcome of myocarditis and pericarditis following COVID-19 vaccines: a cardiac magnetic resonance imaging study

To evaluate clinical and cardiac magnetic resonance (CMR) short-term follow-up (FU) in patients with vaccine-associated myocarditis, pericarditis or myo-pericarditis (VAMP) following COVID-19 vaccination. We retrospectively analyzed 44 patients (2 women, mean age: 31.7 ± 15.1 years) with clinical and CMR manifestations of VAMP, recruited from 13 large tertiary national centers. Inclusion criteria were troponin raise, interval between the last vaccination dose and onset of symptoms < 25 days and symptoms-to-CMR < 20 days. 29/44 patients underwent a short-term FU-CMR with a median time of 3.3 months. Ventricular volumes and CMR findings of cardiac injury were collected in all exams. Mean interval between the last vaccination dose and the onset of symptoms was 6.2 ± 5.6 days. 30/44 patients received a vaccination with Comirnaty, 12/44 with Spikevax, 1/44 with Vaxzevria and 1/44 with Janssen (18 after the first dose of vaccine, 20 after the second and 6 after the "booster" dose). Chest pain was the most frequent symptom (41/44), followed by fever (29/44), myalgia (17/44), dyspnea (13/44) and palpitations (11/44). At baseline, left ventricular ejection fraction (LV-EF) was reduced in 7 patients; wall motion abnormalities have been detected in 10. Myocardial edema was found in 35 (79.5%) and LGE in 40 (90.9%) patients. Clinical FU revealed symptoms persistence in 8/44 patients. At FU-CMR, LV-EF was reduced only in 2 patients, myocardial edema was present in 8/29 patients and LGE in 26/29. VAMPs appear to have a mild clinical presentation, with self-limiting course and resolution of CMR signs of active inflammation at short-term follow-up in most of the cases.

The incidence and clinical characteristics of myocarditis and pericarditis following mRNA-based COVID-19 vaccination in Republic of Korea adolescents from July 2021 to September 2022

OBJECTIVES

Age-specific information regarding myocarditis/pericarditis in adolescents following mRNA-based coronavirus disease 2019 (COVID-19) vaccination in Asia remains insufficient. This study investigated the incidence and clinical characteristics of myocarditis/pericarditis in Republic of Korea adolescents after mRNA-based COVID-19 vaccination.

METHODS

This retrospective descriptive study utilized patient data from the Korea Immunization Management System. Incidence rates were calculated according to age and sex. Clinical characteristics (symptoms/signs, laboratory values, and imaging results) were compared between mild and severe cases.

RESULTS

Between July 19, 2021 and September 30, 2022, 3,728,224 individuals aged 12 to 19 years received 6,484,165 mRNA-based COVID-19 vaccines, and 173 cases met the case definition for myocarditis/pericarditis: 151 mild (87.3%) and 22 severe (12.7%). The incidence was 3.8-fold higher in males than in females. Troponin I/ troponin T was elevated in 96% of myocarditis cases, demonstrating higher sensitivity than creatine kinase-myocardial band (67.6%) or C-reactive protein (75.2%). ST-segment or Twave on electrography abnormalities were found in 60.3% (85/141). Paroxysmal/sustained atrial/ventricular arrhythmias were more common in severe than in mild cases (45.5% vs. 16.8%, p=0.008). Edema on T2-weighted magnetic imaging occurred in 21.6% (8/37) and 62.5% (5/8) of mild and severe cases, respectively (p=0.03). Abnormal pericardial fluid collection or pericardial inflammation was found in 75.4% of pericarditis cases (49/65).

CONCLUSION

Myocarditis/pericarditis occurred in rare cases following mRNA-based COVID-19 vaccination. Most cases were mild, but the incidence was higher in adolescent males and after the second dose. As bivalent severe acute respiratory syndrome coronavirus 2 mRNA vaccination started in Republic of Korea in October 2022, the post-vaccination incidence of myocarditis/pericarditis should be closely monitored, considering clinical characteristics.

Myocarditis Following COVID-19 Vaccination: A Systematic Review

COVID-19 vaccination has significantly reduced both the morbidity and mortality rates associated with SARS-CoV-2 infection. Vaccines, especially mRNA vaccines, have been proposed in several studies to complicate viral myocarditis. Thus, our systematic and meta-analysis review aims to further investigate the possibility of an association between COVID-19 vaccines and myocarditis. We systematically searched PubMed, Web of Science, Scopus, Ovid, and Google Scholar and did a gray search of other databases using the following keywords and terms: "Myocarditis ("Myocarditis" Mesh) OR "Chagas Cardiomyopathy" Mesh) AND "COVID-19 Vaccines" Mesh. The studies were limited to only English articles that reported myocardial inflammation or myocarditis associated with COVID-19 vaccines. Pooled risk ratio with its 95% confidence interval was analyzed by RevMan software (5.4) to perform the meta-analysis. Our study included 671 patients from 44 studies with a mean age of 14-40 years. Nevertheless, myocarditis was noted in a mean of (3.227) days, and 4.19 per million vaccination recipients experienced myocarditis. Most cases were clinically presented with manifestations of cough, chest pain, and fever. Laboratory tests revealed increased C-reactive protein, and troponin with all other cardiac markers in most patients. Cardiac magnetic resonance imaging (MRI) revealed late gadolinium enhancement with myocardial edema and cardiomegaly. Also, electrocardiograms revealed ST-segment elevation in most patients. Furthermore, the incidence of myocarditis was statistically significantly lower in the COVID-19 vaccine group as compared with the control group (RR = 0.15, 95% CI = 0.10-0.23, p-value < 0.00001). No significant association was found between COVID-19 vaccines and the incidence of myocarditis. The study's findings highlight the importance of implementing evidence-based COVID-19 prevention strategies, such as vaccination, to reduce the public health impact of COVID-19 and its associated complications.

Ventricular Arrhythmia and COVID-19 Vaccine-associated Myocarditis

17-year-old male presented with COVID-19 vaccine-associated myocarditis. Six months later, due to chest discomfort with exercise, the patient underwent an exercise stress test that revealed a 3-beat run of nonsustained ventricular tachycardia at 230 bpm at peak exercise. The long-term outcomes of COVID-19 vaccine-associated myocarditis are unclear. This patient had nonsustained ventricular tachycardia over 6 months after diagnosis.

Myocarditis Following COVID-19 Vaccination

Myocarditis is an established but rare adverse event following administration of messenger RNA-based coronavirus disease 2019 (COVID-19) vaccines and is most common in male adolescents and young adults. Symptoms typically develop within a few days of vaccine administration. Most patients have mild abnormalities on cardiac imaging with rapid clinical improvement with standard treatment. However, longer term follow-up is needed to determine whether imaging abnormalities persist, to evaluate for adverse outcomes, and to understand the risk associated with subsequent vaccination. The purpose of the review is to evaluate the current literature related to myocarditis following COVID-19 vaccination, including the incidence, risk factors, clinical course, imaging findings, and proposed pathophysiologic mechanisms.

Cardiovascular magnetic resonance for evaluation of cardiac involvement in COVID-19: recommendations by the Society for Cardiovascular Magnetic Resonance

Coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has affected nearly 600 million people to date across the world. While COVID-19 is primarily a respiratory illness, cardiac injury is also known to occur. Cardiovascular magnetic resonance (CMR) imaging is uniquely capable of characterizing myocardial tissue properties in-vivo, enabling insights into the pattern and degree of cardiac injury. The reported prevalence of myocardial involvement identified by CMR in the context of COVID-19 infection among previously hospitalized patients ranges from 26 to 60%. Variations in the reported prevalence of myocardial involvement may result from differing patient populations (e.g. differences in severity of illness) and the varying intervals between acute infection and CMR evaluation. Standardized methodologies in image acquisition, analysis, interpretation, and reporting of CMR abnormalities across would likely improve concordance between studies. This consensus document by the Society for Cardiovascular Magnetic Resonance (SCMR) provides recommendations on CMR imaging and reporting metrics towards the goal of improved standardization and uniform data acquisition and analytic approaches when performing CMR in patients with COVID-19 infection.

Pediatric Myocarditis

Myocarditis is a condition caused by acute or chronic inflammation of the cardiac myocytes, resulting in associated myocardial edema and myocardial injury or necrosis. The exact incidence is unknown, but is likely underestimated, with more mild cases going unreported. Diagnosis and appropriate management are paramount in pediatric myocarditis, as it remains a recognized cause of sudden cardiac death in children and athletes. Myocarditis in children is most often caused by a viral or infectious etiology. In addition, there are now two highly recognized etiologies related to Coronavirus disease of 2019 (COVID-19) infection and the COVID-19 mRNA vaccine. The clinic presentation of children with myocarditis can range from asymptomatic to critically ill. Related to severe acute respiratory syndrome-Coronavirus 2 (SARs-CoV-2), children are at greater risk of developing myocarditis secondary to COVID-19 compared to the mRNA COVID-19 vaccine. Diagnosis of myocarditis typically includes laboratory testing, electrocardiography (ECG), chest X-ray, and additional non-invasive imaging studies with echocardiogram typically being the first-line imaging modality. While the reference standard for diagnosing myocarditis was previously endomyocardial biopsy, with the new revised Lake Louise Criteria, cardiac magnetic resonance (CMR) has emerged as an integral non-invasive imaging tool to assist in the diagnosis. CMR remains critical, as it allows for assessment of ventricular function and tissue characterization, with newer techniques, such as myocardial strain, to help guide management both acutely and long term.

Myocarditis or Pericarditis Events After BNT162b2 Vaccination in Individuals Aged 12 to 17 Years in Ontario, Canada

Importance

The risk of myocarditis or pericarditis after COVID-19 messenger RNA vaccines varies by age and sex, and there is some evidence to suggest increasing risk with shorter intervals between dose 1 and 2 (ie, interdose interval).

Objective

To estimate the incidence of reported myocarditis or pericarditis after BNT162b2 vaccine among adolescents and to describe the clinical information associated with these events.

Design, Setting, and Participants

This was a population-based cohort study using passive vaccine safety surveillance data linked to the provincial COVID-19 vaccine registry. Included in the study were all adolescents aged 12 to 17 years in Ontario, Canada, who received 1 or more doses of BNT162b2 vaccine between December 14, 2020, and November 21, 2021, and reported an episode of myocarditis or pericarditis. Data were analyzed from December 15, 2021, to April 22, 2022.

Exposure

Receipt of BNT162b2 (Comirnaty [Pfizer-BioNTech]) vaccine.

Main Outcomes and Measure

Reported incidence of myocarditis or pericarditis meeting level 1 to 3 of the Brighton Collaboration case definition per 100 000 doses of BNT162b2 administered by age group (12-15 years vs 16-17 years), sex, dose number, and interdose interval. All clinical information associated with symptoms, health care usage, diagnostic test results, and treatment at the time of the acute event were summarized.

Results

There were approximately 1.65 million doses of BNT162b2 administered and 77 reports of myocarditis or pericarditis among those aged 12 to 17 years, which met the inclusion criteria during the study period. Of the 77 adolescents (mean [SD] age, 15.0 [1.7] years; 63 male individuals [81.8%]), 51 (66.2%) developed myocarditis or pericarditis after dose 2 of BNT162b2. Overall, 74 individuals (96.1%) with an event were assessed in the emergency department, and 34 (44.2%) were hospitalized (median [IQR] length of stay, 1 [1-2] day). The majority of adolescents (57 [74.0%]) were treated with nonsteroidal anti-inflammatory drugs only, and 11 (14.3%) required no treatment. The highest reported incidence was observed among male adolescents aged 16 to 17 years after dose 2 (15.7 per 100 000; 95% CI, 9.7-23.9). Among those aged 16 to 17 years, the reporting rate was highest in those with a short (ie, ≤30 days) interdose interval (21.3 per 100 000; 95% CI, 11.0-37.2).

Conclusions and Relevance

Results of this cohort study suggest that there was variation in the reported incidence of myocarditis or pericarditis after BNT162b2 vaccine among adolescent age groups. However, the risk of these events after vaccination remains very rare and should be considered in relation to the benefits of COVID-19 vaccination.

Myocarditis post-SARS-CoV-2 vaccination: a systematic review

Variable clinical criteria taken by medical professionals across the world for myocarditis following coronavirus disease 2019 (COVID-19) vaccination along with wide variation in treatment necessitates understanding and reviewing the same. A systematic review was conducted to elucidate the clinical findings, laboratory parameters, treatment and outcomes of individuals with myocarditis after COVID-19 vaccination after registering with PROSPERO. Electronic databases including MEDLINE, EMBASE, PubMed, LitCovid, Scopus, ScienceDirect, Cochrane Library, Google Scholar and Web of Science were searched. A total of 85 articles encompassing 2184 patients were analysed. It was a predominantly male (73.4%) and young population (mean age: 25.5 ± 14.2 years) with most having taken an mRNA-based vaccine (99.4%). The mean duration from vaccination to symptom onset was 4.01 ± 6.99 days. Chest pain (90.1%), dyspnoea (25.7%) and fever (11.9%) were the most common symptoms. Only 2.3% had comorbidities. CRP was elevated in 83.3% and cardiac troponin in 97.6% patients. An abnormal ECG was reported in 979/1313 (74.6%) patients with ST-segment elevation being most common (34.9%). Echocardiographic data were available for 1243 patients (56.9%), of whom 288 (23.2%) had reduced left ventricular ejection fraction. Non-steroidal antiinflammatory drugs (76.5%), steroids (14.1%) followed by colchicine (7.3%) were used for treatment. Only 6 patients died among 1317 of whom data were available. Myocarditis following COVID-19 vaccination is often mild, seen more commonly in young healthy males and is followed by rapid recovery with conservative treatment. The emergence of this adverse event calls for harmonizing case definitions and definite treatment guidelines, which require wider research.

Comparison of COVID-19 Vaccine-Associated Myocarditis and Viral Myocarditis Pathology

The COVID-19 pandemic has led to significant loss of life and severe disability, justifying the expedited testing and approval of messenger RNA (mRNA) vaccines. While found to be safe and effective, there have been increasing reports of myocarditis after COVID-19 mRNA vaccine administration. The acute events have been severe enough to require admission to the intensive care unit in some, but most patients fully recover with only rare deaths reported. The pathways involved in the development of vaccine-associated myocarditis are highly dependent on the specific vaccine. COVID-19 vaccine-associated myocarditis is believed to be primarily caused by uncontrolled cytokine-mediated inflammation with possible genetic components in the interleukin-6 signaling pathway. There is also a potential autoimmune component via molecular mimicry. Many of these pathways are similar to those seen in viral myocarditis, indicating a common pathophysiology. There is concern for residual cardiac fibrosis and increased risk for the development of cardiomyopathies later in life. This is of particular interest for patients with congenital heart defects who are already at increased risk for fibrotic cardiomyopathies. Though the risk for vaccine-associated myocarditis is important to consider, the risk of viral myocarditis and other injury is far greater with COVID-19 infection. Considering these relative risks, it is still recommended that the general public receive vaccination against COVID-19, and it is particularly important for congenital heart defect patients to receive vaccination for COVID-19.

The impact of COVID-19 and COVID vaccination on cardiovascular outcomes

COVID-19 is an independent risk factor for cardiovascular disease. COVID-19 vaccination may prevent this, but in some cases, COVID-19 vaccination may cause myocarditis or pericarditis. Patients with COVID-19 may present with non-specific symptoms that have a cardiac origin. This review examines the cardiovascular complications of COVID-19 infection and the impact of COVID-19 vaccination. COVID-19 cardiovascular complications include myocardial injury, pericarditis, coagulopathy, myocardial infarction, heart failure, arrhythmias, and persistent post-acute risk of adverse cardiovascular outcomes. Diagnostic and referral pathways for non-specific symptoms, such as dyspnoea and fatigue, remain unclear. COVID-19 vaccination is cardioprotective overall but is associated with myopericarditis in young males, though at a lower rate than following SARS-CoV-2 infection. Increased awareness among primary care physicians of potential cardiovascular causes of non-specific post-COVID-19 symptoms, including in younger adults, such as fatigue, dyspnoea, and chest pain, is essential. We recommend full vaccination with scheduled booster doses, optimal management of cardiovascular risk factors, rapid treatment of COVID-19, and clear diagnostic, referral, and management pathways for patients presenting with non-specific symptoms to rule out cardiac complications.

COVID vaccine-associated myocarditis in an 8-year-old patient

COVID vaccine-associated myocarditis was first identified in March 2021. There have been numerous case reports that detail the clinical course of paediatric patients older than age 12 with COVID vaccine-associated myocarditis. There are still very few reports of children between the ages of 5 and 11 with COVID vaccine-associated myocarditis. We present an 8 year- old with COVID vaccine-associated myocarditis after his second vaccination against SARS-CoV-2.

Prognosis of Myocarditis Developing After mRNA COVID-19 Vaccination Compared With Viral Myocarditis

BACKGROUND

Association between messenger RNA (mRNA) COVID-19 vaccines and myocarditis has aroused public concern over vaccine safety.

OBJECTIVES

The goal of this study was to compare the prognosis of this condition with viral infection-related myocarditis over 180 days.

METHODS

A territory-wide electronic public health care database in Hong Kong linked with population-based vaccination records was used to conduct a retrospective cohort study. Since the roll-out of BNT162b2 (Pfizer-BioNTech), patients aged ≥12 years hospitalized with myocarditis within 28 days after BNT162b2 vaccination were compared against viral infection-related myocarditis recorded before the pandemic (2000-2019), over a 180-day follow-up period (starting from diagnosis of myocarditis). All-cause mortality, heart failure, dilated cardiomyopathy, heart transplant, and postdischarge health care utilization were examined with Cox proportional hazards models.

RESULTS

A total of 866 patients were included for analysis. Over the follow-up period, 1 death (1.0%) of 104 patients with postvaccination myocarditis and 84 deaths (11.0%) of 762 patients with viral infection-related myocarditis were identified. One case (1.0%) of dilated cardiomyopathy and 2 cases (1.9%) of heart failure were identified in the postvaccination group, compared with 28 (3.7%) and 93 (12.2%) in the viral infection-related myocarditis group, respectively. Adjusted analysis showed that the postvaccination myocarditis group had a 92% lower mortality risk (adjusted HR: 0.08; 95% CI: 0.01-0.57). No significant differences in other prognostic outcomes were seen.

CONCLUSIONS

This study found a significantly lower rate of mortality among individuals with myocarditis after mRNA vaccination compared with those with viral infection-related myocarditis. Prognosis of this iatrogenic condition may be less severe than naturally acquired viral infection-related myocarditis.

Myopericarditis After COVID-19 mRNA Vaccination Among Adolescents and Young Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Published data on COVID-19 mRNA vaccine-associated myopericarditis in adolescents and young adults have been derived from small case series, national population-based studies, or passive reporting systems. Pooled evidence from a larger, international cohort is scarce.

OBJECTIVE

To investigate the clinical features and early outcomes associated with myopericarditis after COVID-19 mRNA vaccination in a heterogeneous population of adolescents and young adults.

DATA SOURCES

PubMed and EMBASE were searched through August 2022. Language restrictions were not applied.

STUDY SELECTION

Observational studies and case series describing COVID-19 vaccine-associated myopericarditis in adolescents and young adults aged 12 to 20 years and reporting clinical characteristics and early outcomes were included.

DATA EXTRACTION AND SYNTHESIS

Two independent investigators extracted relevant data from each study. One-group meta-analysis in a random effects model was performed. The Preferred Reporting Items for Systematic Reviews and Meta-analysis and Meta-analysis of Observational Studies in Epidemiology reporting guidelines were followed.

MAIN OUTCOMES AND MEASURES

The primary outcomes were clinical features and early outcomes for COVID-19 mRNA vaccine-associated myopericarditis, including incident rate, cardiac findings, hospitalization, intensive care unit (ICU) admission, and in-hospital mortality.

RESULTS

A total of 23 observational studies were identified, including 854 individuals (mean age, 15.9 [95% CI, 15.5-16.2] years) with COVID-19 vaccine-associated myopericarditis. Male sex was predominant, at 90.3% (95% CI, 87.3%-93.2%) of individuals. The incident rate was higher after the second dose than the first dose, with 74.4% (95% CI, 58.2%-90.5%) of events occurring after the second dose. Most patients (84.4% [95% CI, 80.5%-88.3%] of patients) had preserved left ventricular (LV) function. Of the 15.6% (95% CI, 11.7%-19.5%) of patients with LV systolic dysfunction (LV ejection fraction [LVEF] <55%), most (14.1% [95% CI, 10.2%-18.1%]) were mild (ie, LVEF 45%-54%), and only 1.3% (95% CI, 0%-2.6%) of patients had severe LV systolic dysfunction (ie, LVEF<35%). Interestingly, cardiac magnetic resonance imaging revealed late gadolinium enhancement in 87.2% (95% CI, 79.8%-94.7%) of patients. Although 92.6% (95% CI, 87.8%-97.3%) of patients were hospitalized and 23.2% (95% CI, 11.7%-34.7%) of patients required ICU admission, inotropes were used in only 1.3% (95% CI, 0%-2.7%) of patients, no patients died or required mechanical support, and the hospital length of stay was 2.8 (95% CI, 2.1-3.5) days.

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis found low incidence rate and largely favorable early outcomes of COVID-19 mRNA vaccine-associated myopericarditis in adolescents and young adults from a wide range of populations. These findings are reassuring but continued follow-up is warranted.

Medium-term outcomes of myocarditis and pericarditis following BNT162b2 vaccination among adolescents in Hong Kong

In this study, we examined the clinical and electrophysiological outcomes of adolescents in Hong Kong who developed myocarditis or pericarditis following BNT162b2 vaccination for COVID-19, and followed-up for 60-180 days after their initial diagnosis. Clinical assessments included electrocardiogram (ECG) and echocardiogram at the initial admission and follow-up were compared. Treadmill testing was also performed in some cases. Between 14 June 2021 and 16 February 2022, 53 subjects were approached to participate in this follow-up study, of which 28 patients were followed up for >60 days with a median follow-up period of 100 days (range, 61-178 days) and were included in this study. On admission, 23 patients had ECG abnormalities but no high-grade atrioventricular block. Six patients had echocardiogram abnormalities, including reduced contractility, small rim pericardial effusions, and hyperechoic ventricular walls. All patients achieved complete recovery on follow-up. After discharge, 10 patients (35.7%) reported symptoms, including occasional chest pain, shortness of breath, reduced exercise tolerance, and recurrent vasovagal near-syncope. At follow-up, assessments, including ECGs, were almost all normal. Among the three patients with possible ECG abnormalities, all their echocardiograms or treadmill testings were normal. Sixteen patients (57.1%) underwent treadmill testing at a median of 117 days post-admission, which were also normal. However, at follow-up, there was a significant mean bodyweight increase of 1.81 kg (95%CI 0.47-3.1 kg, p = 0.01), possibly due to exercise restriction. In conclusion, most adolescents experiencing myocarditis and pericarditis following BNT162b2 vaccination achieved complete recovery. Some patients developed non-specific persistent symptoms, and bodyweight changes shall be monitored.

Intricacies Affiliated With Post-COVID Vaccine Complications in Makkah Province, Saudi Arabia

Introduction COVID-19 vaccine side effects have a fundamental role in public confidence in the vaccine and its uptake process. Thus far, evidence on vaccine safety has been exclusively obtained from manufacturer-sponsored studies; therefore, this study is designed to assess post-COVID-19 vaccine complications in Makkah province, Saudi Arabia. Method A cross-sectional study included 840 subjects conducted from August to November 2022 to collect data about COVID-19 vaccine side effects. A validated questionnaire was used with 21 multiple-choice items covering demographic data, COVID-19 vaccination type, side effects, and medication used to relieve side effects. The online Raosoft sample size calculator (Raosoft Inc., Seattle, Washington) was utilized for sample size calculation. The Statistical Package for the Social Sciences version 22.0 (IBM Inc., Armonk, New York) was utilized to carry out descriptive statistics. The Shapiro-Wilk test was used to evaluate normal data distribution. Significance of categorized data made by the Pearson's Chi-Squared test and of the vaccination side effects experienced in general wellbeing on a scale of 1-10 by the Kruskal-Wallis test. Result The survey found that most participants in the 18-26 age group were from Jeddah, women, and Saudis. Only 7.1% of participants had comorbidities alone, and 63.1% of participants had previously had COVID-19. The vaccine types used in this study were primarily Pfizer (83.3%), AstraZeneca (9.5%), Moderna (3.6%), and combination vaccines (3.6%). The majority of the participants received vaccination up to the third dose. No side effects were reported by 9.5% of participants, while mild and severe side effects were reported by 90.5% and 23.8% of participants, respectively. Mild side effects included injection site pain, redness, tenderness, or itching (34.5%), fatigue (22.6%), low-grade fever, chills, diarrhea, headache (17.9%), and myalgia (14.3%). Conclusion The majority of the side effects of COVID-19 vaccination were minor reactions (90.5%), but 23.8% were found to be serious side effects, most of which lasted one to three days. More independent studies are needed to investigate gender differences, COVID-19 vaccine efficacy, and the prevalence of side effects in other populations conducted by academic institutions. Additional independent research on vaccine safety is urgently needed to increase public confidence in vaccines and to better understand risk factors for vaccine side effects.

Multisystem inflammatory syndrome in a male adolescent after his second Pfizer-BioNTech COVID-19 vaccine: a report from Turkey

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread rapidly through human populations, presenting across a continuum of severity from a symptomatic carriage to multi-organ failure and death. Multisystem inflammatory syndrome in children (MIS-C) is a new phenomenon reported worldwide with temporal association with SARS-CoV-2. Multisystem inflammatory syndrome in children is a complication of the SARS-CoV-2 infection, while myocarditis is a rare adverse effect to messenger ribonucleic acid (mRNA) SARS-CoV-2 vaccines, especially in males aged 12–17 years . On the other hand, postimmunization myocarditis is a known rare adverse event after other vaccinations, such as smallpox . Today, rare cases of MIS-C and myocarditis after mRNA SARS-CoV-2 vaccinations have been reported in children or adolescents . We present details on a 15-year-old previously healthy Turkish male adolescent who fulfilled the diagnostic criteria for MIS-C after the Pfizer-BioNTech vaccine.

Two adolescent cases of acute tubulointerstitial nephritis after second dose of COVID-19 mRNA vaccine

The Food and Drug Administration (FDA) expanded the emergency use authorization for the BNT162b2 messenger RNA (mRNA) vaccine (Pfizer-BioNTech) for children aged 12-15 years on 10 May 2021. To date, less than a year has passed since vaccination against COVID-19 has been used in children and adolescents, and the overall effects and safety of these vaccines are still being assessed. The BNT162b2 vaccine originally had a favorable profile in 12-17-year-old recipients compared with older ages, and no serious adverse events had previously been reported. Despite various adverse events, the benefit of reducing the infection rate or the frequency of severe COVID-19 has been evaluated to outweigh the harm caused by COVID-19 vaccination. Additionally, several cases of sudden development of new-onset or relapsing glomerular diseases, including acute kidney injury (AKI), have been reported in adults following the BNT162b2 SARS-CoV-2 mRNA vaccine. Herein, we present two cases of adolescents who developed AKI following the second administration of the BNT162b2. These are the first pediatric cases of acute tubulointerstitial nephritis temporarily linked to SARS-CoV-2 vaccination.

Cardiac magnetic resonance follow-up of COVID-19 vaccine associated acute myocarditis

BACKGROUND

Mass COVID-19 vaccination campaigns have helped impede the COVID-19 pandemic. In rare cases, some vaccines have led to vaccine associated myocarditis in a specific subset of the population, usually young males. Cardiac magnetic resonance (CMR) can reliably diagnose vaccine associated myocarditis, but follow-up data of CMR proven acute myocarditis is scarce.

MATERIALS AND METHODS

Nine patients with acute vaccine associated myocarditis underwent baseline and follow-up CMR examinations and were compared to baseline parameters at initial presentation and to a group of 20 healthy controls. CMR protocol included functional assessment, T1 and T2 mapping, T2 signal intensity ratio, strain feature tracking, and late gadolinium enhancement (LGE).

RESULTS

Myocarditis patients (n = 9, aged 24 ± 6 years, 8 males) underwent CMR follow-up after an average of 5.8 ± 4.3 months. All patients showed a complete resolution of visual myocardial edema while also demonstrating a reduction in overall LGE extent from baseline to follow-up (4.2 ± 2.1 vs. 0.9 ± 0.8%, p < 0.001), although visual LGE was still noted in all patients. Left ventricular ejection fraction was normal at baseline and at follow-up (58 ± 6 vs. 62 ± 4%, p = 0.10) as well as compared to a healthy control group (60 ± 4%, p = 0.24). T1 (1024 ± 77 vs. 971 ± 34 ms, p = 0.05) and T2 relaxations times (57 ± 6 vs. 51 ± 3 ms, p = 0.03) normalized at follow-up. Most patients reported a resolution of clinical symptoms, while two (22%) reported new onset of exertional dyspnea.

CONCLUSION

Patients with COVID-19 vaccine associated acute myocarditis showed a complete, uncomplicated resolution of myocardial inflammation on follow-up CMR, which was associated with a near complete resolution of symptoms. Minor, residual myocardial scarring was present on follow-up LGE imaging. The long-term implications of the remaining myocardial scar-tissue after vaccine associated myocarditis remain unknown warranting further studies.

COVID-19 Vaccination-Associated Myocarditis: A Literature Review

Myocarditis is defined as a non-ischemic inflammation of the middle layer of the heart. It ensues changes that can lead to acute heart failure, dilated cardiomyopathy, and sudden death. Myocarditis is caused by several infectious and non-infectious agents. Vaccines are also known to cause myocarditis. The use of the coronavirus disease (COVID-19) vaccination was started to combat the severity of the COVID-19 infection and reduce the mortality and morbidity associated with it. The vaccination, however, caused side effects like myocarditis, among others. In order to investigate the association between the COVID-19 vaccination and myocarditis in adults and adolescents, we conducted a literature review by searching three databases: Google Scholar, PubMed, and ScienceDirect. From the published literature, we found that, though it is rare, the various vaccinations available can cause symptoms of myocarditis as a side effect more commonly in patients who have received both doses of a particular vaccine and that there are significant changes in cardiac magnetic resonance imaging (CMRI) and other biochemical markers, with young males being more commonly affected. Further prospective trial-based studies are required to establish a concrete relationship between myocarditis and the COVID-19 vaccine.

COVID-19 vaccine update: vaccine effectiveness, SARS-CoV-2 variants, boosters, adverse effects, and immune correlates of protection

Coronavirus Disease 2019 (COVID-19) has been the most severe public health challenge in this century. Two years after its emergence, the rapid development and deployment of effective COVID-19 vaccines have successfully controlled this pandemic and greatly reduced the risk of severe illness and death associated with COVID-19. However, due to its ability to rapidly evolve, the SARS-CoV-2 virus may never be eradicated, and there are many important new topics to work on if we need to live with this virus for a long time. To this end, we hope to provide essential knowledge for researchers who work on the improvement of future COVID-19 vaccines. In this review, we provided an up-to-date summary for current COVID-19 vaccines, discussed the biological basis and clinical impact of SARS-CoV-2 variants and subvariants, and analyzed the effectiveness of various vaccine booster regimens against different SARS-CoV-2 strains. Additionally, we reviewed potential mechanisms of vaccine-induced severe adverse events, summarized current studies regarding immune correlates of protection, and finally, discussed the development of next-generation vaccines.

Cardiac MRI Findings in COVID-19 Vaccine-Related Myocarditis: A Pooled Analysis of 468 Patients

Understanding the pattern and severity of myocarditis caused by the coronavirus disease 2019 (COVID-19) vaccine is imperative for improving the care of the patients, and cardiac evaluation by MRI plays a key role in this regard. Our systematic review and meta-analysis aimed to summarize cardiac MRI findings in COVID-19 vaccine-related myocarditis. We performed a comprehensive systematic review of literature in PubMed, Scopus, and Google Scholar databases using key terms covering COVID-19 vaccine, myocarditis, and cardiac MRI. Individual-level patient data (IPD) and aggregated-level data (AD) studies were pooled through a two-stage analysis method. For this purpose, all IPD were first gathered into a single data set and reduced to AD, and then this AD (from IPD studies) was pooled with existing AD (from the AD studies) using fixed/random effect models. I2 was used to assess the degree of heterogeneity, and the prespecified level of statistical significance (P value for heterogeneity) was <0.1. Based on meta-analysis of 102 studies (n = 468 patients), 79% (95% confidence interval [CI]: 54%-97%) of patients fulfilled Lake Louise criteria (LLC) for diagnosis of myocarditis. Cardiac MRI abnormalities included elevated T2 in 72% (95% CI: 50%-90%), myocardial late gadolinium enhancement (LGE) in 93% (95% CI: 83%-99%; nearly all with a subepicardial and/or midwall pattern), impaired left ventricular ejection fraction (LVEF) (<50%) in 4% (95% CI: 1.0%-9.0%). Moreover, elevated T1 and extracellular volume fraction (ECV) (>30), reported only by some IPD studies, were detected in 74.5% (76/102) and 32% (16/50) of patients, respectively. In conclusion, our findings may suggest that over two-thirds of patients with clinically suspected myocarditis following COVID-19 vaccination meet the LLC. COVID-19 vaccine-associated myocarditis may show a similar pattern compared to other acute myocarditis entities. Notably, preserved LVEF is probably a common finding in these patients. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

Myocarditis or Pericarditis Following the COVID-19 Vaccination in Adolescents: A Systematic Review

Background: By 16 May 2022, 12,186,798,032 people had been vaccinated with COVID-19 vaccines. Our study found that myocarditis/pericarditis may occur in adolescents after COVID-19 vaccination. Methods: In this regard, we conducted a meta-analysis of seven groups of adolescents aged 12–19 years to compare the incidence of myocarditis/pericarditis after vaccination and compare the relative risk incidence after the first and second doses of a COVID-19 vaccine, and between males and females for risk incidence. Results: We analyzed 22,020,997 subjects from seven studies, including 130 cases of confirmed myocarditis/pericarditis. The overall mean incidence rate was 1.69 cases per 100,000 person-years. Of these, 19 of the 12,122,244 people who received a first dose of a COVID-19 vaccine had myocarditis/pericarditis, an incidence rate of 0.0022% (95% CI 0.0001–0.0034), and 111 of the 1,008,753 people who received a second dose had myocarditis/pericarditis, an incidence rate of 0.0107% (95% CI 0.0059–0.0155). The prevalence relative ratio (RR) after the first and second doses was RR = 5.53 (95% CI: 3.01–10.16), with a higher prevalence after the second dose than after the first dose of a COVID-19 vaccine. After a second dose of a COVID-19 vaccine, the RR for males relative to females was RR = 13.91 (95% CI: 4.30–44.95), with a more pronounced risk of disease in males than in females. Conclusions: Our study showed that myocarditis/pericarditis occurred after vaccination with the BNT162b2 or Comirnaty vaccine, especially after the second vaccination in male adolescents, but the incidence of myocarditis/pericarditis after vaccination with the above vaccines was very rare (0.0022%). Therefore, it is recommended that adolescents should be vaccinated with the COVID-19 universal vaccine as soon as possible and closely monitored for subsequent adverse reactions, which can be treated promptly.