Cardiac MRI for COVID-19-Related Late Myocarditis: Functional Parameters and T1 and T2 Mapping

Area of Science:

• Cardiology
• Radiology
• Infectious Diseases

Background:

• Myocarditis is a known COVID-19 complication with potential long-term cardiac effects.
• Late-stage myocardial impacts of COVID-19 are not well understood.
• Cardiac magnetic resonance (CMR) mapping offers non-invasive assessment of myocardial inflammation and fibrosis.

Purpose of the Study:

• To evaluate segmental myocardial tissue changes in late-stage COVID-19 myocarditis using CMR.
• To compare findings with non-COVID-19 myocarditis and healthy controls.
• To assess the role of CMR T1/T2 mapping and LGE in characterizing myocardial injury.

Main Methods:

• Retrospective single-center study of 25 COVID-19 myocarditis patients (36-565 days post-infection).
• Comparison with 14 non-COVID-19 myocarditis patients and 19 healthy controls.
• Assessment of CMR T1/T2 mapping values and late gadolinium enhancement (LGE) patterns.

Main Results:

• COVID-19 myocarditis patients showed elevated T1 values in most myocardial segments compared to controls.
• Late gadolinium enhancement (LGE) was observed in 61% of COVID-19 myocarditis patients, often subepicardial.
• No significant differences in T2 values or between vaccinated/unvaccinated groups.

Conclusions:

• Late-stage COVID-19 myocarditis is linked to persistent segmental myocardial abnormalities, notably elevated T1 values and subepicardial LGE.
• Segmental CMR mapping can help identify residual myocardial injury in post-COVID-19 patients.
• Findings suggest CMR mapping's value in managing long-term cardiac sequelae of COVID-19.