Myocarditis in adults: a systematic review of epidemiology, etiologies, diagnosis, and management – ​​updated 2025

Abstract

Myocarditis is defined as inflammation of the heart muscle with non-ischemic myocyte injury and may present clinically from subclinical disease to cardiogenic shock and sudden death. Viral infection remains the predominant cause, but autoimmune, hypersensitivity and immune-mediated forms have been increasingly recognized, especially after the advent of cancer immunotherapy and the COVID-19 pandemic. The aim of this systematic review was to summarize recent evidence on the epidemiology, etiologies, pathophysiology, diagnosis and treatment of myocarditis in adults, focusing on studies published between 2019 and 2025. Searches were performed in PubMed/MEDLINE, Embase, Scopus and the Cochrane Library, including clinical trials, meta-analyses, cohort studies and international guidelines, and excluding case reports and very small series. Of the 4,312 records initially identified, 172 studies were deemed eligible. The results show an estimated annual incidence ranging from 10 to 105 cases per 100,000 adults, with higher prevalence in young men. Cardiac magnetic resonance imaging, particularly with the updated Lake Louise Criteria, has become the main noninvasive diagnostic modality, with high sensitivity and specificity. Treatment is based on hemodynamic support, etiology-directed therapies and careful use of immunosuppressive drugs in autoimmune and immune-mediated forms. We conclude that, although myocarditis remains a diagnostic challenge, advances in cardiovascular imaging and immunomodulatory therapies have enabled more accurate approaches and improved prognosis in selected subgroups.