Adults diagnosed with COVID-19 infections may have nearly three times the risk of developing myocarditis compared with those with influenza, with young males facing the highest incidence rates, according to a recent study.
In the retrospective cohort study, published in Open Heart, investigators utilized U.S. health claims data reports that adult patients with COVID-19 infections have an approximately threefold higher risk of myocarditis compared with those with influenza. The analysis, which included over 1.1 million patients with COVID-19 infections and nearly 440,000 patients with influenza, indicated myocarditis rates of 0.73 per 1,000 person-years for COVID-19 infections and 0.24 per 1,000 person-years for influenza. In pediatric patients, COVID-19 infections were associated with nearly nine times the myocarditis risk relative to influenza.
The investigators found that younger male adults aged 18 to 29 years with COVID-19 infections had the highest myocarditis rates, reaching 1.16 per 1,000 person-years. After adjusting for age, sex, and other clinical factors, the investigators found that COVID-19 infections, male sex, and younger age were independently associated with an increased risk of myocarditis within 1 year postdiagnosis.
Regarding diagnostic practices, the study showed that 94% of adult patients with COVID-19 infections with myocarditis and 79% of adult patients with influenza with myocarditis received at least one diagnostic evaluation, commonly echocardiography or ECG. Cardiac magnetic resonance imaging (CMR) was used in approximately 25% of myocarditis cases among patients with COVID-19 infections, despite CMR’s established role in myocarditis assessment. Gadobutrol was the primary contrast agent used, though not specifically approved for myocarditis assessment in patients with COVID-19 infections.
The study’s findings indicated an association between COVID-19 infections and increased myocarditis risk, particularly in younger male adults, and suggested that standardized diagnostic approaches, including CMR, could aid in the management of post–COVID-19 myocarditis.
Full disclosures can be found in the published study.