Baricitinib Combination Therapy Demonstrates Significant Improvement in Cardiac Conduction Defects in Rapidly Progressive Systemic Sclerosis: A Case Report.

Objective: To evaluate the efficacy of baricitinib in combination therapy for managing refractory, rapidly progressive systemic sclerosis (SSc) with severe cardiac conduction defects and interstitial lung disease (ILD). Methods: A 48-year-old male patient with SSc complicated by significant cardiac enlargement, third-degree atrioventricular block, heart failure, progressive ILD, and partial intestinal obstruction was included in the study. Prior treatments with mycophenolate mofetil (MMF), tacrolimus, and cyclophosphamide (CTX) had shown limited efficacy. The patient subsequently received a combination regimen of glucocorticoids, intravenous immunoglobulins, CTX, and baricitinib (4 mg daily). Results: The patient exhibited significant clinical improvements, including a reduction in cardiac size, restoration of sinus rhythm, and resolution of heart failure symptoms. ILD and skin sclerosis showed substantial regression. Pulmonary function tests indicated significant recovery in lung capacity and diffusion capacity. Additionally, gastrointestinal symptoms such as abdominal pain and bloating were completely resolved. Conclusion: This case highlights the potential of baricitinib as an adjunctive therapy for refractory SSc with multiorgan involvement. The observed improvements in cardiac conduction defects, ILD, and skin fibrosis suggest that JAK inhibitors may offer a promising therapeutic avenue for severe SSc cases resistant to conventional treatments.