Clinically Suspected Myocarditis Temporally Related to COVID-19 Vaccination in Adolescents and Young Adults: Suspected Myocarditis After COVID-19 Vaccination
Creators: name: Lombardi, K.C.
name: Frosch, O.H.
name: Miyata, K.
name: Thacker, D.
name: Lambert, L.M.
name: Johnston, P.
name: Elias, M.D.
name: Votava-Smith, J.K.
name: Srivastava, S.
name: Frank, L.H.
name: Schauer, J.
name: Sabati, A.A.
name: Shekerdemian, L.S.
name: Toro-Salazar, O.H.
name: Ronai, C.
name: Mitchell, E.C.
name: Muniz, J.C.
name: Forsha, D.
name: Dummer, K.B.
name: Jain, S.S.
name: Portman, M.A.
name: McHugh, K.E.
name: Campbell, M.J.
name: Hebson, C.
name: Dionne, A.
name: D'Addese, L.
name: Truong, D.T.
name: Newburger, J.W.
name: Tejtel, S.K.S.
name: McCrindle, B.W.
name: Shea, J.R.
name: Chrisant, M.
name: Gelehrter, S.K.
name: Patel, J.K.
name: Bohun, C.M.
name: Giglia, T.M.
name: Atz, A.M.
name: Parker, R.M.
name: Anderson, B.R.
name: White, S.
name: Mizzi, T.
name: Li, J.S.
name: Krishnan, A.
Publisher: name: Lippincott Williams and Wilkins
Year: 2022

description: BACKGROUND: Understanding the clinical course and short-term outcomes of suspected myocarditis after the coronavirus disease 2019 (COVID-19) vaccination has important public health implications in the decision to vaccinate youth. METHODS: We retrospectively collected data on patients <21 years old presenting before July 4, 2021, with suspected myocarditis within 30 days of COVID-19 vaccination. Lake Louise criteria were used for cardiac MRI findings. Myocarditis cases were classified as confirmed or probable on the basis of the Centers for Disease Control and Prevention definitions. RESULTS: We report on 139 adolescents and young adults with 140 episodes of suspected myocarditis (49 confirmed, 91 probable) at 26 centers. Most patients were male (n=126, 90.6%) and White (n=92, 66.2%); 29 (20.9%) were Hispanic; and the median age was 15.8 years (range, 12.1-20.3; interquartile range [IQR], 14.5-17.0). Suspected myocarditis occurred in 136 patients (97.8%) after the mRNA vaccine, with 131 (94.2%) after the Pfizer-BioNTech vaccine; 128 (91.4%) occurred after the second dose. Symptoms started at a median of 2 days (range, 0-22; IQR, 1-3) after vaccination. The most common symptom was chest pain (99.3%). Patients were treated with nonsteroidal anti-inflammatory drugs (81.3%), intravenous immunoglobulin (21.6%), glucocorticoids (21.6%), colchicine (7.9%), or no anti-inflammatory therapies (8.6%). Twenty-six patients (18.7%) were in the intensive care unit, 2 were treated with inotropic/vasoactive support, and none required extracorporeal membrane oxygenation or died. Median hospital stay was 2 days (range, 0-10; IQR, 2-3). All patients had elevated troponin I (n=111, 8.12 ng/mL; IQR, 3.50-15.90) or T (n=28, 0.61 ng/mL; IQR, 0.25-1.30); 69.8% had abnormal ECGs and arrhythmias (7 with nonsustained ventricular tachycardia); and 18.7% had left ventricular ejection fraction <55% on echocardiogram. Of 97 patients who underwent cardiac MRI at a median 5 days (range, 0-88; IQR, 3-17) from symptom onset, 75 (77.3%) had abnormal findings: 74 (76.3%) had late gadolinium enhancement, 54 (55.7%) had myocardial edema, and 49 (50.5%) met Lake Louise criteria. Among 26 patients with left ventricular ejection fraction <55% on echocardiogram, all with follow-up had normalized function (n=25). CONCLUSIONS: Most cases of suspected COVID-19 vaccine myocarditis occurring in persons <21 years have a mild clinical course with rapid resolution of symptoms. Abnormal findings on cardiac MRI were frequent. Future studies should evaluate risk factors, mechanisms, and long-term outcomes.