Epidemiology, Clinical Characteristics, and Prognosis of Acute Myocarditis in a High–volume Non–transplant Cardiology Center

Background Myocarditis and pericarditis are inflammatory cardiac diseases with heterogeneous clinical presentations, ranging from mild to life–threatening conditions, and occur more frequently in young adult males. Purpose and Methods This observational study included adult patients with cardiac magnetic resonance (CMR)–confirmed myocarditis admitted to a high–volume cardiology center between March 2017 and July 2025. The aim was to evaluate in–hospital management and mid– to long–term follow–up in accordance with the 2020 ANMCO/SIC protocol and the 2025 ESC Guidelines for the management of myocarditis and pericarditis. Results Seventy patients were enrolled (mean age 34 years, 87% male). Infarct–like chest pain was the predominant presentation (97%). Initial suspicion was myocarditis or myopericarditis in 68.6%, while 27.1% were initially managed as acute coronary syndrome, including STEMI and NSTEMI, with normal coronary angiography. Most patients were classified as intermediate risk (84.3%) (Figure 1), 14.3% as low risk, and one as high risk with fulminant myocarditis. ST–segment elevation was observed in 41.4%, and reduced LVEF (‹55%) in 18.6%. CMR detected late gadolinium enhancement (LGE) in 98.6% of patients, involving ≥2 segments in 72.9%. At discharge, 60 patients were diagnosed with myocarditis and 10 with myopericarditis. At six–month follow–up, residual LV dysfunction was rare (2.9%), while LGE persisted in most cases, though with reduced extension. Holter monitoring and stress testing were largely normal. During follow–up, one recurrence occurred at one year and five at three years; genetic testing identified a pathogenic variant in one recurrent case (Figure 2). Conclusions In a non–transplant cardiology center, myocarditis patients predominantly exhibited low– to intermediate–risk profiles and favorable outcomes. These findings support the real–world applicability of the 2025 ESC guideline recommendations.Figure 1 Figure 2