Cardiac toxicity of 5FU: Does prophylactic telemetry monitoring of patients at increased risk for cardiac toxicity improve safety? A 10-year experience

Abstract

8107 Background: 5FU can cause cardiac toxicity as a result of induced coronary artery spasm. This risk appears to be amplified in patients with histories of coronary artery disease. Coronary vasospasm manifests as ST segment elevations during continuous ECG monitoring. The incidence of reported cardiac events has varied from less than 1% to as high as 8%. In the absence of established evidence-based guidelines, management practices vary. At our center selected patients felt to be at high risk have been prophylactically admitted to receive 5FU with inpatient telemetry monitoring. We now report a retrospective analysis of this practice. Our objectives were (1) to evaluate the incidence of cardiac events in high-risk patients admitted for telemetry during 5FU administration, and (2) to determine the utility of telemetry as a guide for coronary vasospasm in patients with cardiac risk. Methods: A retrospective chart review was conducted using the database at Memorial Sloan-Kettering Cancer Center to identify patients who received concurrent 5FU and telemetry as an inpatient between 10/93 and 1/03. Cardiac events were considered to be the development of any symptoms or telemetric ST changes consistent with vasospasm. Results: A total of 88 patients comprising of 463 telemetry days were evaluated. 82/88 (93%) patients had either 1 or more cardiac risk factors or a history of an arrhythmia or abnormal ECG. 3 patients were admitted for advanced age and 3 had no clearly identifiable risk factors. Of 88 patients, 4 patients (CI 1.2%–11.2%) developed chest pain while receiving 5FU. There were no patients in whom telemetric ST changes consistent with coronary vasospasm were found (CI 0–4.1%). In total, there were 0 events attributable to vasospasm in 463 telemetry days (CI 0–0.01 events/day) that were picked up by telemetry. Conclusions: Over a 10 year period, there were no patients in whom telemetry monitoring led to the detection of coronary vasospasm in selected high risk patients. Our experience does not support the routine use of elective telemetric monitoring in patients with significant cardiac risk factors receiving 5FU. No significant financial relationships to disclose.