Descriptive analysis of patients with myocarditis admitted to a cardiac intensive care unit: clinical characteristics, management, and follow-up cardiac magnetic resonance findings

Introduction Inflammatory Myopericardial Syndrome (IMPS) encompasses myocarditis and pericarditis as a continuum of inflammatory phenotypes. While endomyocardial biopsy was once the diagnostic standard, current guidelines highlight cardiac magnetic resonance (CMR) as the cornerstone for diagnosis. Purpose To describe the clinical, imaging, and therapeutic characteristics of patients admitted to our cardiac care unit (CCU) with suspected myocarditis, and to explore mid-term follow-up findings regarding residual myocardial inflammation or fibrosis. Methods This single-centre retrospective study included consecutive patients with suspected myocarditis (September 2019–March 2025). Diagnosis combined clinical features, biomarkers, and CMR findings. Data included demographics, ECG, coronary and inflammatory evaluation, ventricular function, support, and therapy. Follow-up assessed profiles suggesting recurrent myocarditis or underlying cardiomyopathy. Results Seventy-one patients were included (mean age 34.5 years, 87.3% male). ST-segment elevation was present in 83.1%, and 36.6% underwent coronary evaluation. Systemic autoinflammatory disease was found in 8.5%, and prior myocarditis in 15.5%. CMR was performed in 84.5%, showing late gadolinium enhancement compatible with myocarditis in 85%. During admission, LVEF <50% occurred in 8.5%, and heart failure in 9.9%. Two patients required inotropic support, one of them also needing vasopressors and mechanical circulatory support. Corticosteroids or immunosuppressive therapy were administered to 9.9% patients. At follow-up, 22.5% patients underwent a control CMR after discharge, and among these, only one achieved complete resolution of both LGE and edema. Conclusions CMR was essential for diagnosis, revealing inflammation in most cases. Despite preserved ventricular function and limited need for support, residual inflammation or fibrosis persisted at follow-up, supporting the value of continued monitoring.