Myocarditis following COVID-19 vaccination in adolescents: Cardiac magnetic resonance imaging study.

Introduction: Vaccination-associated myocarditis was reported following COVID-19 vaccine initially among persons aged 16 or older and recently among adolescents aged 12-15. Objectives: To describe the clinical and cardiac magnetic resonance (CMR) characteristics of adolescents aged 12-15 with myocarditis following the administration of the BNT162b2 mRNA COVID-19 vaccine. Methods: CMR of adolescents (age 12-15) with a clinical diagnosis of myocarditis within 42 days following the first COVID-19 vaccine were analyzed. Results: A total of 182,605 adolescent were vaccinated, out of which 9 were diagnosed with clinically adjudicated myocarditis while CMR was performed in 5/9 patients (56%). Median age was 15 years (range 13-15), 4/5 (80%) males. All the patients we previously healthy. The ECG upon presentation was abnormal in 3/5 (60%) of patients. All cases were classified as clinically mild and no patient required inotropes or mechanical circulatory support treatment. The median follow-up time, for the 5-included patients, was 206 (IQR 192-229, range 179-233) days. During the follow-up, no re-admissions, deaths, or any other cardiac events have occurred.The median time between the diagnosis to the CMR was 104 days (range 27-149). The median left ventricular ejection fraction was within normal range 65% (range 62-69). Native T1 was available in four patients, the local T1 value was increased in three of them. T2 values were available in two patients and were all within normal range. The median late gadolinium enhancement (LGE) was 2% (range 0-6%) with inferolateral wall being the most common location (3/5). The patterns of the LGE were as following: (i) mid-wall in 3 patients; (ii) epicardial in 1-patient. LGE in the pericardium was present in 2/5 patients with pericardial effusion present in 4/5 patients with a median diameter of 4 mm (range 3-5 mm) at end-systole. Conclusions: CMR findings and clinical course of adolescents with COVID-19 vaccination associated myocarditis, are similar to those of older patients, being relatively mild and potentially implying favorable outcomes.

Myocarditis following COVID-19 vaccination in adolescents: Cardiac magnetic resonance imaging study

Introduction Vaccination-associated myocarditis was reported following COVID-19 vaccine initially among persons aged 16 or older and recently among adolescents aged 12–15. Objectives To describe the clinical and cardiac magnetic resonance (CMR) characteristics of adolescents aged 12–15 with myocarditis following the administration of the BNT162b2 mRNA COVID-19 vaccine. Methods CMR of adolescents (age 12–15) with a clinical diagnosis of myocarditis within 42 days following the first COVID-19 vaccine were analyzed. Results A total of 182,605 adolescent were vaccinated, out of which 9 were diagnosed with clinically adjudicated myocarditis while CMR was performed in 5/9 patients (56%). Median age was 15 years (range 13–15), 4/5 (80%) males. All the patients we previously healthy. The ECG upon presentation was abnormal in 3/5 (60%) of patients. All cases were classified as clinically mild and no patient required inotropes or mechanical circulatory support treatment. The median follow-up time, for the 5-included patients, was 206 (IQR 192–229, range 179–233) days. During the follow-up, no re-admissions, deaths, or any other cardiac events have occurred. The median time between the diagnosis to the CMR was 104 days (range 27–149). The median left ventricular ejection fraction was within normal range 65% (range 62–69). Native T1 was available in four patients, the local T1 value was increased in three of them. T2 values were available in two patients and were all within normal range. The median late gadolinium enhancement (LGE) was 2% (range 0–6%) with inferolateral wall being the most common location (3/5). The patterns of the LGE were as following: (i) mid-wall in 3 patients;(ii) epicardial in 1-patient. LGE in the pericardium was present in 2/5 patients with pericardial effusion present in 4/5 patients with a median diameter of 4 mm (range 3–5 mm) at end-systole. Conclusions CMR findings and clinical course of adolescents with COVID-19 vaccination associated myocarditis, are similar to those of older patients, being relatively mild and potentially implying favorable outcomes.

Myocarditis following COVID-19 vaccination: magnetic resonance imaging study.

AIMS: To describe the cardiac magnetic resonance (CMR) imaging findings of patients who developed myocarditis following messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccination. METHODS AND RESULTS: The present study retrospectively evaluated patients with clinically adjudicated myocarditis within 42 days of the first Pfizer-BNT162b2 mRNA COVID-19 vaccination, between 20 December 2020 and 24 May 2021 who underwent CMR. A total of 15 out 54 patients (28%) with myocarditis underwent a CMR and were included, 100% males, median age of 32 years (interquartile range = 22.5-40). Most patients presented with chest pain (87%) and had an abnormal electrocardiogram (79%). The severity of the disease was mild in 67% and intermediate in 33%. All patients survived and one patient was readmitted during the study period. CMR was performed at a median of 65 days (range 3-130 days) following diagnosis. Median ejection fraction was 58% (range 51-74%) global- and regional wall motion abnormalities were present in one and three patients, respectively. Native T1 was available in 13/15 patients (2/3 in 3 T and 11/12 in the 1.5 T), with increased values among 6/13. Late gadolinium enhancement (LGE) was found among 13/15 patients with a median of 2% (range 0-15%) with inferolateral wall being the most common location (8/13). The patterns of the LGE were: mid-wall in six patients; epicardial in five patients; and mid-wall and epicardial in two patients. CONCLUSIONS: Among patients who were diagnosed with post-vaccination clinical myocarditis, CMR imaging findings are mild and consistent with 'classical myocarditis'. The short-term clinical course and outcomes were favourable.

Myocarditis after Covid-19 Vaccination in a Large Health Care Organization.

BACKGROUND: Reports have suggested an association between the development of myocarditis and the receipt of messenger RNA (mRNA) vaccines against coronavirus disease 2019 (Covid-19), but the frequency and severity of myocarditis after vaccination have not been extensively explored. METHODS: We searched the database of Clalit Health Services, the largest health care organization (HCO) in Israel, for diagnoses of myocarditis in patients who had received at least one dose of the BNT162b2 mRNA vaccine (Pfizer-BioNTech). The diagnosis of myocarditis was adjudicated by cardiologists using the case definition used by the Centers for Disease Control and Prevention. We abstracted the presentation, clinical course, and outcome from the patient's electronic health record. We performed a Kaplan-Meier analysis of the incidence of myocarditis up to 42 days after the first vaccine dose. RESULTS: Among more than 2.5 million vaccinated HCO members who were 16 years of age or older, 54 cases met the criteria for myocarditis. The estimated incidence per 100,000 persons who had received at least one dose of vaccine was 2.13 cases (95% confidence interval [CI], 1.56 to 2.70). The highest incidence of myocarditis (10.69 cases per 100,000 persons; 95% CI, 6.93 to 14.46) was reported in male patients between the ages of 16 and 29 years. A total of 76% of cases of myocarditis were described as mild and 22% as intermediate; 1 case was associated with cardiogenic shock. After a median follow-up of 83 days after the onset of myocarditis, 1 patient had been readmitted to the hospital, and 1 had died of an unknown cause after discharge. Of 14 patients who had left ventricular dysfunction on echocardiography during admission, 10 still had such dysfunction at the time of hospital discharge. Of these patients, 5 underwent subsequent testing that revealed normal heart function. CONCLUSIONS: Among patients in a large Israeli health care system who had received at least one dose of the BNT162b2 mRNA vaccine, the estimated incidence of myocarditis was 2.13 cases per 100,000 persons; the highest incidence was among male patients between the ages of 16 and 29 years. Most cases of myocarditis were mild or moderate in severity. (Funded by the Ivan and Francesca Berkowitz Family Living Laboratory Collaboration at Harvard Medical School and Clalit Research Institute.).