Fluorouracil-Associated Coronary Vasospasm and Reversible Cardiomyopathy Mimicking ST-Elevation Myocardial Infarction During a First Cycle of FOLFOX: A Case Report

Objective:Unusual clinical course Background:5-Fluorouracil (5-FU) is a mainstay chemotherapeutic agent for gastrointestinal malignancies but carries a recognized risk of cardiotoxicity, most often manifesting as coronary vasospasm that can mimic acute myocardial infarction.This report describes the case of a 50-year-old woman with ST-elevation myocardial infarction (STEMI) due to coronary artery vasospasm during continuous infusion of 5-FU as part of the first round of FOLinic acid (leucovorin), Fluorouracil (5-FU), and OXaliplatin (FOLFOX) chemotherapy for colorectal carcinoma. Case Report:A 50-year-old woman with colorectal carcinoma receiving her first cycle of FOLFOX developed severe chest pain during a continuous infusion of 5-FU.Initial emergency department evaluation was reportedly unremarkable, and she was discharged after symptomatic improvement with ketorolac.She returned emergently with recurrent crushing chest pain; a repeat electrocardiogram showed hyperacute T waves and ST-segment elevation, prompting ST-elevation myocardial infarction activation and transfer for emergent catheterization.Coronary angiography revealed no obstructive coronary artery disease.Echocardiography demonstrated a severely reduced left ventricular ejection fraction (LVEF) of 30% to 35% with apical akinesis, consistent with 5-FU-induced cardiomyopathy.5-FU was permanently discontinued, and the patient was treated with vasodilator therapy, with complete resolution of symptoms and normalization of ventricular function on follow-up echocardiography.Conclusions:5-FU can precipitate life-threatening coronary vasospasm and a fully reversible cardiomyopathy even during a first chemotherapy cycle, in the absence of obstructive coronary artery disease.Early recognition, prompt drug interruption, and a multidisciplinary cardio-oncology approach, including an individualized decision between permanent discontinuation and carefully supervised rechallenge, are essential to guide safe oncologic decision-making.