Clinical Outcomes of Myocarditis after Moderate-Dose Steroid Therapy in Systemic Sclerosis: A Pilot Study

BACKGROUND: Myocarditis is reported in systemic sclerosis (SSc); however, treatment options and outcomes are limited. Our objective was to define cardiac outcomes after moderate-dose steroid therapy in SSc patients with myocarditis. METHOD: An open-label study was conducted among SSc patients with myocarditis—as defined by cardiovascular magnetic resonance (CMR), disease onset <5 years, and a NYHA functional class ≥II. All enrolled patients received prednisolone (30 mg/d) which would be tapered off by week 24, and CMR was followed up at the end of treatment. RESULTS: A total of 20 SSc patients were enrolled which 12 patients completed the study. At week 24, 8 of the 12 cases experienced improvement of myocarditis. Compared to those with no improvement, these 8 patients had significantly longer disease duration (p = 0.03), higher heart rate at baseline (p = 0.049) and week 24 (p = 0.04), lower left ventricular (LV) and right ventricular (RV) stroke volume at baseline (p = 0.002 and p = 0.01) and week 24 (p = 0.01 and p = 0.02), and lower LV and RV cardiac output at week 24 (p = 0.01 and p = 0.01). Four cases died during follow-up (3 due to cardiac complications, 1 due to renal crisis). The two who died from heart failure had very high NT-prohormone-brain natriuretic peptide (NT-proBNP) and impaired LV ejection fraction (LVEF), and the one who died from arrhythmia had very high sensitivity of cardiac Troponin-T (hs-cTnT). CONCLUSIONS: Moderate-dose steroid therapy may improve myocarditis in SSc. A proportion of patients died due to cardiac complications during treatment, particularly those with high hs-cTnT, high NT-proBNP, and impaired LVEF. This trial is registered with NCT03607071.