Relapsing myocarditis following initial recovery of post COVID-19 vaccination in two adolescent males - Case reports.

Whilst there has been significant public health benefits associated with global use of COVID-19 spike protein vaccines, potential serious adverse events following immunization have been reported. Acute myocarditis is a rare complication of COVID19 vaccines and often it is self-limiting. We describe two cases experiencing recurrent myocarditis following mRNA COVID-19 vaccine despite a prior episode with full clinical recovery. Between September 2021-September 2022 we observed two male adolescents with recurrent myocarditis related to mRNA-based-COVID19 vaccine. During the first episode both patients presented with fever and chest pain few days after their second dose of BNT162b2 mRNA Covid-19 Vaccine (Comirnaty®). The blood exams showed increased cardiac enzymes. In addition, complete viral panel was run, showing HHV7 positivity in a single case. The left ventricular ejection fraction (LVEF) was normal at echocardiogram but cardiac magnetic resonance scanning (CMR) was consistent with myocarditis. They were treated with supportive treatment with full recovery. The 6 months follow-up demonstrated good clinical conditions with normal cardiological findings. The CMR showed persistent lesions in left ventricle 's wall with LGE. After some months the patients presented at emergency department with fever and chest pain and increased cardiac enzymes. No decreased LVEF was observed. The CMR showed new focal areas of edema in the first case report and stable lesions in the second one. They reached full recovery with normalization of cardiac enzymes after few days. These case reports outline the need of strict follow-up in patients with CMR consistent with myocarditis after mRNA-based-COVID19 vaccine. More efforts are necessary to depict the underlying mechanisms of myocarditis after SARS-CoV2 vaccination to understand the risk of relapsing and the long-term sequelae.

Higher Troponin Levels on Admission are associated With Persistent Cardiac Magnetic Resonance Lesions in Children Developing Myocarditis After mRNA-Based COVID-19 Vaccination.

BACKGROUND: Acute pericarditis/myocarditis is a rare complication of the mRNA-based vaccines and although mostly self-limiting, long-term sequelae remain unclear. METHODS: We enrolled all patients admitted to the emergency department between September 2021 and February 2022 meeting the CDC work case definition, with symptoms onset after mRNA-based COVID-19 vaccine. Alternative virologic causes were excluded. Clinical data, laboratory values, cardiologic evaluation, electrocardiogram (ECG), and echocardiogram (ECHO) were collected on admission, at discharge, and during follow-up in all patients. Cardiac Magnetic Resonance (CMR) was performed only in those with signs consistent with myocarditis. RESULTS: We observed 13 patients (11M and 2F), median age 15 years, affected by acute pericarditis/myocarditis after COVID-19 mRNA vaccination (11 after Comirnaty® and 2 after Spikevax®). Symptoms'onset occurred at a median of 5 days (range, 1 to 41 days) after receiving mRNA vaccine (13 Prizer 2 Moderna): 4 patients (31%) after the 1st dose, 6 (46%) after the 2nd, and 3 (23%) after 3rd dose. Increased levels of high-sensitive troponin T (hsTnT) (median 519,5 ng/mL) and N-terminal-pro hormone BNP (NT-proBNP) (median 268 pg/mL) and pathognomonic ECG and ECHO abnormalities were detected. On admission, 7 of 13 (54%) presented with myopericarditis, 3 (23%) with myocarditis, and 3 (23%) with pericarditis; CMR was performed in 5 patients upon pediatric cardiologist prescription and findings were consistent with myocarditis. At 12 weeks of follow-up, all but one patient (92%), still presenting mild pericardial effusion at ECHO, were asymptomatic with normal hsTnT and NT-proBNP levels and ECG. On CMR 6 of 9 patients showed persistent, although decreased, myocardial injury. Higher hsTnT levels on admission significantly correlated with persistent CMR lesions. CONCLUSION: Evidence of persistent CMR lesions highlights the need for a close and standardized follow-up for those patients who present high hsTnT levels on admission.

What Is New on Paediatric Echocardiography for the Diagnosis, Management and Follow-Up of the Multisystem Inflammatory Syndrome Associated with COVID-19?

Conventional echocardiography is an essential tool for the diagnosis, bedside management and follow-up evaluations of children with multisystem inflammatory syndrome associated with COVID-19. However, a more comprehensive echocardiographic exam, including myocardial deformation parameters, may allow early identification of subtle changes in ventricular function, provide risk stratification and, identify sub-clinical cardiac dysfunction at follow-up. Thus, myocardial deformation analysis should be routinely integrated to conventional echocardiography assessment in these patients.