Biomarkers and Personalized Medicine in Cardiovascular Disease Symposium

Trends and Disparities in Cardiac Magnetic Resonance Utilization During Index Hospitalization for Myocarditis (2015–2025)

Oscar P. Levine, MD¹; Ido Avivi²; Mattheus Ramsis²; Ori Ben-Yehuda, MD²

Affiliations:

¹ Division of General Internal Medicine, Department of Medicine, University of California San Diego

402 Dickinson St, Ste 380

San Diego, CA 92103, USA

² Division of Cardiovascular Medicine, Department of Medicine, University of California San Diego

9434 Medical Center Drive

San Diego, CA 92037, USA

Background: Cardiac magnetic resonance (CMR) is a key tool in the diagnosis of myocarditis and provides valuable prognostic information. However, real-world utilization and variation in access remain incompletely characterized. We sought to evaluate temporal trends in CMR use and characterize variation in utilization across patient subgroups.

Methods: We conducted a retrospective cohort study using Epic Cosmos, a large, multicenter electronic health record database, to identify patients hospitalized with myocarditis in the U.S. between 2015 and 2025. The study population included index hospitalizations for myocarditis, defined by billed ICD-10 diagnosis codes (I40.x, B33.22, I51.4). CMR during index hospitalization was identified using billed procedure codes (CPT 75557, 75561, 75565). Temporal trends in CMR utilization were assessed using logistic regression with year modeled as a continuous variable. Variation in CMR use across patient characteristics (age, sex, race, ethnicity, insurance status, social vulnerability index [SVI], and ICU admission) was assessed using chi-square testing.

Results: A total of 61,791 index hospitalizations for myocarditis were identified. Overall, CMR was performed in 27.4% of cases. CMR utilization increased from 24.8% in 2015 to 32.2% in 2025 and was significantly associated with calendar year (OR per year 1.05, 95% CI 1.04–1.06; p < 0.001), with a transient decline in 2020 followed by increased use thereafter. CMR use differed across age groups (p < 0.001), peaking in patients aged 18–29 years (35.0%) and declining with older age. Use was modestly higher in males than females (28.2% vs 25.9%; p < 0.001). CMR use was similar across race groups, ranging from 25.4% (Asian) to 28.6% (Other), and did not differ significantly by ethnicity. CMR use differed across SVI quartiles, with lower use in the highest versus lowest quartile (25.3% vs 30.2%; p < 0.001), and by insurance, ranging from 19.6% in Medicare beneficiaries to 33.0% in privately insured patients (p < 0.001). CMR use was lower among patients with ICU admission (25.8% vs 28.4%; p < 0.001).

Conclusions: Despite increasing use over time, CMR use during index hospitalization for myocarditis remains limited and varies by demographic, clinical, and socioeconomic factors. Lower use among older, socially vulnerable, publicly insured, and critically ill patients suggests potential disparities in access to advanced cardiac imaging. Efforts to expand access to CMR may improve diagnostic evaluation and prognostication.

Keywords: Myocarditis, cardiac magnetic resonance, imaging biomarkers, health disparities

Disclosures: The authors report there are no competing interests to declare.