CONGRESS ABSTRACT

Background: Myopericarditis is an inflammatory condition of the myocardium and pericardium, with potential associations to infections, autoimmune disorders, and drug-induced reactions. Among medications, mesalazine, a commonly prescribed agent for inflammatory bowel disease, is a rare but recognized cause. This case highlights the challenges in diagnosing and managing mesalazine-induced myopericarditis in the context of active ulcerative colitis (UC). Case description: A 20-year- old male presents to the Emergency Department with acute stabbing chest pain exacerbated by deep inspiration and supine positioning. His medical history included recently treated Strongyloides stercoralis parasitosis and active UC (Mayo score 2) managed with oral mesalazine 800 mg six times daily and daily mesalazine enemas. Three weeks prior to admission, he experienced pharyngitis with low-grade fever. COVID-19 testing was negative. Initial evaluation revealed no abnormalities on electrocardiogram (ECG) but elevated Troponin T high sensitivity (TnT-hs) at 45 ng/L, C-reactive protein (CRP) at 1.9 mg/dL, and leukocytosis (18,600/mm³, with neutrophilia). During hospitalization, the patient experienced episodes of angina associated with diffuse ST-segment elevation on ECG, effectively treated with non steroidal anti-inflammatory drugs. During episodes of fever with headache, four blood cultures yielded negative results. Blood cultures, virology panels, and autoimmunity tests were negative. Stool cultures were negative. Serial testing showed enzymatic fluctuation of TnT-hs (peak: 87 ng/L, discharge: 29 ng/L) and CRP (peak: 8 mg/dL), with resolution of leukocytosis. Elevated total IgE levels (716 kU/L, normal <170) were noted. Transthoracic echocardiography was unremarkable, but cardiac magnetic resonance imaging (CMR) revealed findings consistent with recent myopericarditis in resolution. A beta-blocker therapy was initiated and titrated. Given the high suspicion of myopericarditis secondary to mesalazine, the drug was discontinued in agreement with gastroenterology colleagues. A therapy consisting of azathioprine 50 mg/day and prednisone 5 mg/day was implemented to control UC. No further episodes of precordial pain were reported. A few months later an attempt to reintroduce mesalazine failed due to a recurrence of precordial pain. A one-year follow-up CMR confirmed resolution of myocardial edema with no fibrotic sequelae.