Ventricular fibrillation as a likely consequence of capecitabine-induced coronary vasospasm

Capecitabine is a member of the fluoropyrimidine family of chemotherapeutic agents that selectively delivers 5-fluorouracil (5-FU) to tumors. It is increasingly used as part of combined modality treatment for gastrointestinal malignancies. Cardiotoxicity has been documented to occur with 5-FU, but due to an expansion in capecitabine use, reports exist of its propensity to coronary vasospasm. We report the case of a 28-year-old man, with no preceding angina, presenting with a reversible episode of ventricular fibrillation (VF) at rest in his fifth course of capecitabine chemotherapy for metastatic colorectal cancer. Emergency resuscitation successfully restored spontaneous circulation, with initial ST segment elevation in the inferolateral leads on electrocardiogram prompting emergency coronary angiography. This demonstrated normal coronary arteries. ST segments normalized post-angiography and the patient rapidly recovered with no myocardial damage sustained. An implantable cardioverter-defibrillator was placed for secondary prevention of sudden death, and capecitabine was implicated as the cause of coronary vasospasm which resulted in his presentation of VF. To our knowledge, this is the first episode of VF as a consequence of suspected capecitabine-induced coronary vasospasm occurring at rest. Our case highlights the potential for severe cardiotoxic consequences of capecitabine including sudden death from VF, and given the multi-disciplinary approach to managing oncology patients, health professionals should be aware of this.