In a recent study published in Immunity, researchers studied a full range of outcomes in patients diagnosed with myocarditis after vaccination against coronavirus disease 2019 (COVID-19) in the United States (US). They followed these adolescent and young male patients after receiving a COVID-19 vaccine based on a messenger ribonucleic acid (mRNA) platform for at least 90 days from the onset of myocarditis.
As of July 2022, the US Vaccine Adverse Event Reporting System (VAERS) has reported over 1,500 cases of myocarditis that emerged after COVID-19 mRNA vaccination. Systemic reviews have suggested that the risk of myocarditis is highest in adolescents and young men after a second dose of vaccine. However, in most cases the symptoms resolved soon after discharge from a short hospital stay. However, there is little evidence of the medium-term prognoses for adolescents and young adults diagnosed with myocarditis after COVID-19 mRNA vaccination.
About the study
The present study used a two-pronged telephone survey to assess patient myocarditis outcomes between August 24, 2021 and January 12, 2022.
The first part of the survey determined quality of life (QoL), medical history, and need for myocarditis medication. In addition, he inquired about their clinical symptoms two weeks prior to the survey date or whether they were absent from work. These clinical symptoms included chest pain, shortness of breath, fatigue, palpitations, hospitalizations, and days missed from school or work in the two weeks prior to the survey.
After the diagnosis of myocarditis, they assessed whether the patient’s health across five parameters – self-care, pain, mobility, ability to perform daily activities and anxiety or depression, using the questionnaire 5-dimensional, 5-level EuroQol (EQ-5D-5L). The researchers compared patient responses to the EQ-5D-5L survey with published responses to the EQ-5D-5L survey. This helped them understand how these responses differed before and during the COVID-19 pandemic.
The QoL questionnaire had five response levels, in which patients could give dichotomous responses. Severity level 1 indicated no problem, while severity levels 2 to 5 indicated “n” number of clinical symptoms of myocarditis. The patient self-rated his general health using the EuroQol Visual Analogue Scale (EQ-VAS). His scores ranged from 0 to 100, indicating the worst and best health, respectively.
The second part of the investigation aimed to determine the patient’s cardiac health and functional status. Follow-up cardiac assessments covered cardiac biomarkers, cardiac magnetic resonance imaging (MRI), echocardiograms, troponin levels, exercise testing, ambulatory rhythm monitoring, and electrocardiograms (ECG). Health care providers informed the researchers of the patient’s cardiac recovery or myocarditis status. They also informed the researchers if these patients had previously been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The team compared the demographic and clinical characteristics of survey respondents with nonrespondents. Additionally, they compared their health care provider, census geographic region, age, gender, initial ECG results, and race/ethnicity. Finally, the researchers performed descriptive analyzes to determine frequencies, percentages, means, and standard deviations (SDs) to characterize cases of myocarditis.
The researchers analyzed 519 patients between the ages of 12 and 29 who met a predefined case definition for myocarditis according to the Centers for Disease and Prevention criteria. Of the 393 patients who were assessed by a healthcare professional, 320 had recovered from myocarditis and their quality of life measures were similar to pre-pandemic levels and better than quality measures life of the general population of the United States. However, no diagnostic test or clinical symptom appeared to be associated with restored status.
Fewer patients with myocarditis reported anxiety or depression than individuals during the pandemic (46% vs. 60.2%). In addition, nearly 1% of patients had the same cardiac condition as when initially diagnosed with myocarditis. Consistent with this finding, another recent report demonstrated better outcomes for COVID-19 vaccine-related myocarditis and faster cardiac recovery in people younger than 21.
In a small subset of 151 patients, the initial cardiac MRI at diagnosis was normal; however, follow-up MRI was abnormal in 54% of participants. Of 151, 71 patients had late residual gadolinium enhancement, indicating myocardial scarring on follow-up cardiac MRIs. A possible explanation is that the clinical signs in these patients continued to evolve after diagnosis. Another reason could be that different health care providers performed initial and follow-up cardiac imaging and arrived at different interpretations.
The study showed that while myocarditis was rare after COVID-19 mRNA vaccination, those who had it had potentially serious manifestations. Healthcare providers considered most patients to recover within 90 days; yet nearly 50% reported having chest pain, 25% of whom required heart medications. Therefore, ongoing monitoring and evaluation of myocarditis is required after COVID-19 mRNA vaccination.