[Cardiac involvement in idiopathic inflammatory myopathies]

Cardiac manifestations in idiopathic inflammatory myopathies (IIM) occur more frequently than they are clinically recognized and are associated with increased morbidity and mortality. In particular, subclinical myocarditis often remains undetected due to nonspecific or absent symptoms.

This review aims to summarize the prevalence, pathophysiology, clinical spectrum, diagnostic strategies and therapeutic options of cardiac involvement in IIM and to provide practical recommendations for rheumatologists.

A scoping review on cardiac manifestations in IIM was performed. A structured literature search was conducted using the PubMed database. The search strategy included combinations of relevant keywords and MeSH terms. Primarily, English language original studies, systematic reviews and current guideline publications related to cardiac involvement in IIM were considered. Studies were selected based on clinical relevance, methodological quality and recency.

The reported prevalence of cardiac involvement in IIM ranges from 4-26%, depending on the subtype and diagnostic approach. In addition to clinically overt myocarditis, subclinical abnormalities are common and can be detected in up to 50% of patients using cardiac magnetic resonance imaging (CMRI). Pathophysiological mechanisms include immune-mediated myocardial injury, microvascular dysfunction and fibrotic remodelling. The initial diagnostic work-up should comprise taking a medical history, electrocardiography, measurement of cardiac biomarkers and echocardiography. The use of CMRI represents the diagnostic gold standard and enables sensitive detection of inflammatory and fibrotic myocardial changes. Therapeutically, early initiation of drug treatment, typically high-dose glucocorticoids combined with additional immunomodulating agents, constitutes the cornerstone of management.

Cardiac manifestations in IIM are common, prognostically relevant and frequently underestimated in clinical practice. A structured diagnostic approach with early use of CMRI and interdisciplinary management is essential to detect subclinical disease and guide appropriate treatment.