Myocardial involvement in inflammatory myopathies: from subclinical disease to life-threatening myocarditis

Inflammatory myopathies (IM) are a heterogeneous group of systemic disorders characterized by chronic muscle inflammation. Cardiac involvement has historically been underrecognized, partially because of its subclinical presentation, and is associated with a poor prognosis, underscoring the urgent need for effective diagnostic strategies and therapeutic approaches. Cardiac magnetic resonance and its new mapping techniques appear as one of the most valuable instruments to detect myocardial involvement, thereby limiting the need for an endomyocardial biopsy when the underlying cause of cardiac dysfunction is unclear or when noninvasive imaging is inconclusive. Evidence-based data remains lacking regarding treatment strategies, and nowadays, immunosuppressive therapy constitutes the cornerstone of treatment.

In this review, we provide a summary of the current literature on myocarditis in the context of IM, with a focus on clinical manifestations, underlying pathophysiological mechanisms, diagnostic methods, and therapeutic strategies.

We are currently in a privileged moment regarding IM, as there has never been a time with so many ongoing clinical trials. With growing awareness of cardiac involvement in IM, now is the time to focus research efforts on cardiac involvement in IM to address this underrecognized manifestation that carries significant morbidity and prognostic implications in patients with IM.