S3534 FOLFOX Causing Fatal Cardiac Adverse Event While Managing Colorectal Cancer

Abstract

Introduction: Colorectal cancer (CRC) is the 3rd most common cancer worldwide and the 3rd leading cause of cancer death in women and the 4th in men. 5-fluorouracil (5-FU)–based regimens remain a cornerstone in managing CRC. Given the high incidence of CRC and ultimately the high rate of utilization of 5-FU, the adverse events of 5-FU must be well addressed – including the rare ones. We present a 36-year-old man with no prior cardiac history who had nearly fatal cardiac complications after receiving 5-FU. Case Description/Methods: A 36-year-old man with type 1 Diabetes Mellitus, end-stage renal disease (secondary to hemolytic uremic syndrome) status-post (s/p) transplant, and stage III mucinous adenocarcinoma of the ascending colon s/p partial colectomy presented with chest pain while receiving 5-FU bolus as part of his first FOLFOX cycle. Initial troponin I was elevated at 0.14 and kept up trending. EKG was suggestive of myopericarditis (Fig. 1A). Transthoracic echocardiogram showed reduced ejection fraction of 25-30% and global hypokinesis. 24 hours later, the patient had pulseless electrical activity and was resuscitated followed by another 2 episodes of polymorphic ventricular tachycardia (pVT) arrest. Cardiac catheterization was done subsequently and a 5 cm clot was removed from the left circumflex artery (LCX) (Fig. 1B). Post-clot removal, he suffered 3 more pVT arrests. Repeat coronary angiogram revealed small clot had embolized to the distal first obtuse marginal vessel which was not able to be retrieved. An implantable cardioverter-defibrillator was discussed for secondary prevention but ultimately the patient decided against it given his immunosuppressive state and the high likelihood of infections. He had no further cardiac events and was discharged. His upcoming oncologic management of CRC will not involve 5-FU based regimens. Discussion: We presented a young patient with no prior cardiac history who had 6 cardiac arrests, secondary to myopericarditis, within 48 hours of receiving 5-FU. It is highly unlikely that the patient had ischemic cardiomyopathy given his age and the lack of other risk factors. The clot in the LCX is mostly secondary to coronary vasospasms due to 5-FU. This case aims to highlight an extreme – yet possible – complication of 5-FU in CRC patients. More research is needed to help risk stratify patients with CRC before receiving 5-FU.Figure 1.: (A) Diffuse ST Elevations with Diffuse PR Depressions That are Most Consistent with Pericarditis (B) 5 cm Clot in Left Circumflex Artery.