Impact of the COVID-19 pandemic on cardiac magnetic resonance imaging practices: insights from the MRCT registry.

Purpose: To assess the relationship between the COVID-19 pandemic and the spectrum of indications for cardiac magnetic resonance imaging (MRI) with a focus on myocarditis.

Materials and methods: This was a retrospective analysis of data from the MRCT registry of the European Society of Cardiovascular Radiology (ESCR). Data regarding indications and diagnoses of myocarditis between January 1, 2018, and April 30, 2024, were extracted. Data was analyzed for the periods before and after the beginning (i.e., March 11, 2020) of the COVID-19 pandemic.

Results: Data from 112,361 cardiac MRI examinations was analyzed (63.5% male, median age 58 [IQR 44-69]). Over the entire period, assessment of myocarditis was the most common indication for cardiac MRI (31%, n = 34,906/112,361). Before the pandemic, this indication comprised 28% of examinations and increased to a maximum of 41% in 2022 after the onset of the pandemic. Simultaneously, the positivity rate of these examinations decreased from 21% before the pandemic to 14% in 2022. Male patients had a higher positivity rate than female patients both before and during the pandemic, with mirroring trends between sexes. The proportion of cardiac MRI examinations performed for suspected and known coronary artery disease showed an inverse relationship with those performed for myocarditis and decreased from 24% and 17% pre-pandemic to a minimum of 21% and 13% during the pandemic.

Conclusion: The COVID-19 pandemic considerably influenced the pattern of referrals for cardiac MRI examinations in Europe, leading to a higher proportion of examinations for suspected myocarditis but a reduced positivity rate, suggesting a lower referral threshold for this indication. At the same time, proportionally fewer examinations were performed for suspected and known coronary artery disease.

Key points: Question The COVID-19 pandemic may have influenced the spectrum and positivity rates of indications for cardiac MRI, especially examinations for myocarditis. Findings The COVID-19 pandemic led to a higher proportion of cardiac MRI examinations for suspected myocarditis but a reduced positivity rate. Clinical relevance The spectrum and proportions of indications for cardiac MRI give important information on the historical and current trends in cardiac imaging and provide insight into resource deployment.