S2422 the Case of a Broken Heart: Mesalazine-Induced Myopericarditis Complicating Acute Severe Ulcerative Colitis

Introduction: Mr PH is a 33 yo man who was diagnosed with Ulcerative colitis (UC) in January 2021. He was commenced on prednisone enema and mesalazine 4.8g with partial improvement of symptoms. Case description/methods: He returned to our clinic a month later in February 2021 with new pleuritic chest pain. He was febrile to 38.2 deg and tachycardic to 110 bpm. An ECG showed normal sinus rhythm but had widespread ST elevation and PR depression. His cardiac enzyme troponin was elevated to 122ng/L (normal < 15) and a diagnosis of pericarditis was suspected. He had a transthoracic echocardiogram (TTE) which showed an estimated ejection fraction (EF) of 35-40%. He was commenced on colchicine 500mcg BD. Investigations for the cause of the myopericarditis including extended viral causes were non-contributable and mesalazine was thought to be the culprit and was ceased. He was also experiencing severe bloody diarrhoea of more than 10-15 times per day and met criteria for acute severe UC. He was commenced on intravenous (IV) hydrocortisone but continued to experience loose bowel motion of 8-10 per day. On day 2 of IV hydrocortisone, he underwent a flexible sigmoidoscopy which showed Mayo 3 Score of inflammation (left sided UC) and rescue therapy was mandated. Colchicine was ceased as it was thought to be contributing to the diarrhoea. His C-reactive protein (CRP) was 26.2mg/L. In Australia first line rescue therapy is infliximab, but, the ejection fraction of 35% was deemed a relative contraindication. We commenced a ciclosporin infusion instead. We used a 2mg/kg/24 hour dose following optimisation of electrolytes and check of patient’s cholesterol. We dose reduced the ciclosporin to 1.5mg/kg/24 hours on Day 3 as the ciclosporin level was noted to be 364 micrograms/L. He received IV ciclosporin for 7 days with resolution of his bowel symptoms and he was passing one formed non-bloody stools per day. His CRP had improved to 1.1mg/L. He was switched to oral ciclosporin 200mg BD and recommended to use this for a further 3 months with PJP prophylaxis. He also underwent a repeat TTE which showed EF improvement to 74%. Discussion: This is an interesting case of mesalazine associated myopericarditis and concurrent acute severe UC flare which was managed successfully with ciclosporin rescue in the setting of infliximab contraindication. Mesalazine myopericarditis was shown to be reversible on cessation of the offending medication. Ciclosporin appears to be a safe alternative to infliximab in severe UC with cardiac compromise.