LAUSR

OBJECTIVES Cardiac Magnetic Resonance (CMR) imaging is increasingly used to evaluate cardiac involvement in Systemic Sclerosis (SSc). We assessed changes, including inflammatory and/or fibrotic myocardial lesions detected by CMR, following therapeutic interventions for SSc-associated symptomatic myocarditis. METHODS In this retrospective study, myocarditis was diagnosed by CMR (2018 revised Lake Louise criteria) in 14 diffuse and 4 limited SSc patients (16/18 women, aged 56 ± 11 years, disease duration 8 ± 11 years, 17/18 with lung involvement) with cardiac symptoms and abnormal findings in echocardiography (4/18) and/or in 24-h Holter monitoring (12/14). CMR was repeated after 8 ± 3 months following administration of cyclophosphamide (n = 11, combined with corticosteroids in 3 and rituximab in 1), mycophenolate (n = 1), tocilizumab (n = 1), methotrexate/corticosteroids (n = 2), corticosteroids (n = 1) or autologous stem cell transplantation (n = 2). RESULTS Functional cardiac improvement was evident by increases in left (by 5.8%±7.8%, p= 0.006) and right ventricular ejection fraction (by 4.5%±11.4%, p= 0.085) in the second CMR compared with the first. Notably, Late Gadolinium Enhancement, currently considered to denote replacement fibrosis, decreased by 3.1%±3.8% (p= 0.003), resolving in 6 patients. Markers of myocardial oedema, namely T2-ratio and T2-mapping, decreased by 0.27 ± 0.40 (p= 0.013) and 6.0 ± 7 (p= 0.025), respectively. Conversely, both T1-mapping, considered to reflect acute oedema and diffuse fibrosis, and extracellular volume fraction, reflecting diffuse fibrosis, remained unchanged. CONCLUSIONS CMR may distinguish between reversible inflammatory/fibrotic and irreversible fibrotic lesions in SSc patients with active myocarditis, confirming the unique nature of primary cardiac involvement in SSc. Whether, and how, CMR should be used to monitor treatment effects in SSc-associated myocarditis warrants further study.