Imaging Modalities Related to Cardiac Involvement in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic rheumatic disease characterized by the unique pathogenetic triad of microvasculopathy, autoimmunity, and fibrosis leading to significant morbidity/mortality. SSc has an annual incidence of 0.6 to 5.6/100 000, affects predominantly women and remains the most lethal of rheumatic diseases being the direct cause of death in >50% of patients. SSc with diffuse cutaneous involvement is defined as skin thickening proximal to the elbows/knees, whereas the limited form denotes cutaneous involvement limited to the distal extremities. Pulmonary fibrosis, pulmonary hypertension, and cardiac inflammation/fibrosis, although varying widely among patients in terms of severity, represent the main causes of death. Primary heart involvement occurs in the majority of patients at some disease stage but is overlooked. It may precede SSc diagnosis and should be carefully monitored using laboratory and imaging biomarkers. Among imaging biomarkers, echocardiography and cardiac magnetic resonance are the most commonly used. Echocardiography can provide functional information of both ventricles and assessment of pulmonary artery pressure. Additionally, strain echocardiography and cardiac magnetic resonance feature tracking can detect early systolic dysfunction before ejection fraction alterations take place. However, cardiac magnetic resonance, by providing functional assessment in parallel with tissue characterization, is the only imaging modality that has the potential to reveal early myocardial inflammation/replacement/diffuse fibrosis and coronary microvascular disease before any systolic alteration takes place. Prospective, multicenter studies that are currently under way will clarify the role of cardiac magnetic resonance in diagnosis, prognosis, and treatment decisions and will facilitate the conception of new imaging-based guidelines for cardiac involvement in SSc.