Mesalazine–associated Myopericarditis in a Young Patient With Ulcerative Colitis: A Case Report

Ulcerative colitis (UC) is primarily a gastrointestinal disorder, but 25–40% of patients may develop extraintestinal manifestations. Cardiac involvement is rare (‹1%), with pericarditis and, more infrequently, myocarditis. Mesalazine is a common first–line therapy for mild–to–moderate UC and is generally well tolerated, though rare cases of drug–induced myopericarditis have been described. Distinguishing UC–related cardiac inflammation from mesalazine–induced toxicity can be challenging. Awareness of this uncommon adverse reaction is essential, as prompt withdrawal of mesalazine and initiation of anti–inflammatory treatment can facilitate recovery of cardiac function and help prevent further complications. We report the case of a 20–year–old male with a recent diagnosis of UC treated with oral mesalazine, who presented to the emergency department with pharyngeal pain, intermittent low–grade fever, and recurrent chest pain. Laboratory tests showed mild anemia and hypokalemia, neutrophilic leukocytosis, elevated transaminases, troponin I (994 pg/mL), NT–proBNP (5404 pg/mL) and CRP. Electrocardiography revealed tachycardia with ST–segment elevation and T–wave inversion in the inferior leads (Figure 3). Echocardiography showed hypokinesia of the mid–distal inferior septum and mid anterolateral and posterior walls, mild left ventricular systolic dysfunction (LVEF 44%), moderate mitral regurgitation, and a non–tamponade pericardial effusion. The patient was admitted to the Cardiology Unit. Cardiac CT excluded coronary artery disease. Infectious etiologies were ruled out. Suspecting mesalazine–induced myopericarditis, the drug was promptly discontinued. The patient was started on ibuprofen, colchicine, low–dose bisoprolol and potassium canrenoate. Cardiac MRI revealed myocardial edema with subepicardial late gadolinium enhancement in the inferolateral walls (Figure 1 and 2), supporting the diagnosis of myopericarditis. Endomyocardial biopsy was not performed given the low–risk status of the patient. Upon clinical stabilization, 30 days later the patient was discharged asymptomatic and with normalization of inflammatory and myocardial injury markers. LVEF improved to 60% This case highlights a rare association between mesalazine therapy and acute myopericarditis in young patients with ulcerative colitis. Discontinuation of mesalazine and early administration of anti–inflammatory therapy is associated with clinical recovery and normalization of cardiac function.Figure 1 Figure 2 Figure 3