Myocarditis following COVID-19 vaccination in adolescents and adults: a cumulative experience of 2021

Abstract

Clinical course and outcomes of myocarditis after COVID-19 vaccination remain variable. We retrospectively collected data on patients > 12 years old from 01/01/2021 to 12/30/2021 who received COVID-19 messenger RNA (mRNA) vaccination and were diagnosed with myocarditis within 60 days of vaccination. Myocarditis cases were based on case definitions by authors. We report on 238 patients of whom most were male (n = 208; 87.1%). The mean age was 27.4 ± 16 (range 12-80) years. Females presented at older ages (41.3 ± 21.5 years) than men 25.7 ± 14 years (p = 0.001). In patients > 20 years of age, the mean duration from vaccination to symptoms was 4.8 days ± 5.5 days, but in < 20, it was 3.0 ± 3.3 days (p = 0.04). Myocarditis occurred most commonly after the Pfizer-BioNTech mRNA vaccine (n = 183; 76.45) and after the second dose (n = 182; 80%). Symptoms started 3.95 ± 4.5 days after vaccination. The commonest symptom was chest pain (n = 221; 93%). Patients were treated with non-steroidal anti-inflammatory drugs (n = 105; 58.3%), colchicine (n = 38; 21.1%), or glucocorticoids (n = 23; 12.7%). About 30% of the patients had left ventricular ejection fraction but more than half recovered the on repeat imaging. Abnormal cardiac MRIs were common; 168 patients (96% of 175 patients that had MRI) had late gadolinium enhancement, while 120 patients (68.5%) had myocardial edema. Heart failure guideline-directed medical therapy use was common (n = 27; 15%). Eleven patients had cardiogenic shock; and 4 patients required mechanical circulatory support. Five patients (1.7%) died; of these, 3 patients had endomyocardial biopsy/autopsy-confirmed myocarditis. Most cases of COVID-19 vaccine myocarditis are mild. Females presented at older ages than men and duration from vaccination to symptoms was longer in patients > 20 years. Cardiogenic shock requiring mechanical circulatory support was seen and mortality was low. Future studies are needed to better evaluate risk factors, and long-term outcomes of COVID-19 mRNA vaccine myocarditis.

Adverse Events and Safety Profile of the COVID-19 Vaccines in Adolescents: Safety Monitoring for Adverse Events Using Real-World Data

“…According to Israel’s Ministry of Health, there were 148 cases of myocarditis within 30 days of vaccination among 10.4 million vaccinated individuals. The prevalence of myocarditis was five times higher in the 16–30-year-old group (1/20,000) compared to that in the general population (1/100,000) vaccinated with the same vaccine [ 33 , 34 ]. In Danish adolescents, the incidence of myopericarditis after BNT162b2 vaccination was revealed as 97 males and 16 females per million among individuals 12–17 years of age [ 35 ].…”

Vaccine‐Triggered Acute Autoimmune Myocarditis: Defining, Detecting, and Managing an Apparently Novel Condition

“…Clinical presentations share yet other strikingly similar features, including sex (overwhelmingly male), young age (more clearly defined when adult cases are studied), when vaccine exposure occurred (within 5 days of a second mRNA vaccine is typical; intriguingly, some data infer that presentations after the first dose can develop if infection with COVID‐19 acts as the first ”vaccine” 10 ), and medium‐term outcomes appear to be overwhelmingly benign. 10 , 11 , 12 , 13 , 14 , 15 …”

“…Overwhelmingly, available data indicate mild, self‐limited clinical disease with clinical and imaging data suggesting fairly complete resolution in most. Reviewing the literature is to be done with caution: the many published case reports and series inevitably include reporting bias, and the several systematic reviews 10 , 11 , 12 , 13 draw from the same pool of published cases, creating a sort of repetition bias. Other sources include safety surveillance, 14 , 17 insurance claims, 18 and national registry databases; these are also likely to underreport milder cases, and a truer disease representation will likely include greater incidence with lower severity.…”

“…Regardless, an approach like that described by Sandeep and colleagues would almost certainly have identified most of the complicated (adult) cases summarized in one of the systematic reviews. 13 Given the apparent low risk of the condition, however, future iterations of such pathways are likely to include higher thresholds for admission, lower thresholds for discharge, and additional diagnostic work‐ups when myocardial injury is severe or relentless. In our Institute's pathway for suspected myocarditis in adults, early CMR (sometimes repeated days later in aggressive disease) has a prominent role in diagnosis as well as prognosis.…”

Letter to the Editor Regarding: “Myocarditis and Cardiac Complications Associated With COVID-19 and mRNA Vaccination” by Holland et al., Heart Lung Circ. 2022;31(7):924-33.

“…Therefore although COVID-19 and mRNA vaccine associated myocarditis may significantly differ from other forms myocarditis (and from each other) in terms of pathophysiology, until this has been clearly elucidated there should remain at least some degree of caution with the use of NSAIDS in all forms of myocarditis [ 5 ]. In a systematic review of SARS-CoV-2 vaccination associated myocarditis, most (76.5%) received NSAIDs as part of their treatment [ 6 ] and in another more recent study, 58% of individuals received NSAIDs for COVID-19 vaccination associated myocarditis [ 7 ]. Despite these observations, there are still insufficient data to draw clear conclusions regarding the efficacy of NSAIDs in this setting.…”