Rituximab-Associated Myocardial Injury in a Young Woman with Granulomatosis with Polyangiitis: A Case Report

Background: Rituximab is a monoclonal antibody targeting CD20, commonly used to treat autoimmune diseases such as granulomatosis with polyangiitis (GPA) and rheumatoid arthritis. While generally well-tolerated, serious adverse events, including infusion reactions and infections, are well-documented. Case Summary: We report a rare case of rituximab-induced ST-elevation myocardial infarction (STEMI) in a 26-year-old woman with no cardiovascular risk factors. She developed crushing chest pain after her first 1 g rituximab infusion, with recurrent symptoms upon re-exposure. Cardiac catheterization revealed a left circumflex artery occlusion. Additional workup showed c-ANCA positivity, cryoglobulinemia, pauci-immune glomerulonephritis, and findings consistent with GPA. Rituximab was discontinued, and she was transitioned to steroids, cyclophosphamide, and leuprolide, with no further cardiac events. Discussion: This is the first reported case in a young, previously healthy woman. Clinicians should consider rituximab-associated myocardial injury, especially in autoimmune or hypercoagulable states. Take-Home Message: Remain vigilant for cardiac events during rituximab infusions in patients with inflammatory diseases.