Cardiological features in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) represent a heterogeneous group of autoimmune systemic diseases characterized by chronic muscle weakness and inflammatory cell infiltrates in skeletal muscle. The most frequent IIMs, such as adult-onset polymyositis and dermatomyositis, display a wide range of clinical manifestations other than myositis, including skin changes, Raynaud's phenomenon and interstitial lung disease. Cardiac involvement is now well recognized as a clinically important manifestation in patients with polymyositis or dermatomyositis, although its actual frequency is still uncertain. Cardiovascular complications represent one of the most frequent causes of death in myositis, apart from cancer and lung involvement. Despite the fact that clinical manifestations are relatively rare, asymptomatic cardiovascular features are frequently reported in patients with polydermatomyositis and dermatomyositis. They are characterized by isolated electrocardiographic changes, valve disease, coronary vasculitis, ischemic abnormalities, heart failure and myocarditis. Chronic inflammation producing myocyte degeneration, tissues fibrosis and vascular alterations can explain the majority of reported cardiac features in myositic patients. Although previous works reported an association between heart involvement and some myositis-specific autoantibodies (namely anti-signal recognition particle), electrocardiography, echocardiography and, where necessary, heart magnetic resonance remain the mainstay for diagnosing and monitoring myocardial inflammation in these diseases. Anyway, a complete multiorgan assessment and a careful analysis of autoantibodies should be performed in every patient in order to define any possible distinct disease entities with different prognosis within the spectrum of IIMs.