Preventing 5-fluorouracil-induced ischemic events in very high-risk cardiac patients: A retrospective cohort analysis (SQCCCRC protocol).

e24112 Background: 5-Fluorouracil (5-FU), a potent chemotherapy agent for various cancers, is linked to cardiotoxicity, particularly in patients with pre-existing ischemic heart disease. The incidence varies, necessitating effective preventive strategies. Among the several mechanisms responsible for 5-FU-induced myocardial ischemia are coronary vasospasm and endothelial injury. Therefore, prevention of ischemic events in very high-risk patients by controlling modifiable cardiac risk factors and good medical treatment including vasodilators are a potential strategy in preventing 5-FU ischemic events. Methods: To assess the effectiveness and safety of a protocol involving Amlodipine and Isosorbide dinitrate in preventing 5-FU-induced ischemic events in very high-risk cardiac patients with documented ischemic heart disease. Nineteen patients underwent 252 cycles of 5-FU chemotherapy, with 12 patients (181 cycles) following the pre-defined protocol (5-FU Protocol Group) and 7 patients (71 cycles) not adhering (Missed 5-FU Protocol Group). The primary outcome measure was the prevention of 5-FU-induced ischemic events, evidenced by the absence of chest pain, elevated Troponin levels, or ECG changes during 5-FU infusion. Results: The 5-FU Protocol Group demonstrated significant reductions in ischemic events, chest pain with p-values of 0.009 for both outcomes. Additionally, the occurrence of ECG changes post-5FU and an increase in Troponin levels was significantly lower in the 5-FU Protocol Group, with p-values of 0.036 for both parameters. Although not statistically significant, there was a lower 5FU-related mortality rate in the 5-FU Protocol Group compared to the missed 5-FU Protocol Group (0% vs. 14.3%, p = 0.37). The incidence of cancer-related mortality did not exhibit a statistically significant difference between the two groups. To evaluate this, we specifically examined and compared the occurrence of ischemic events in both the 5-FU Protocol Group and the Missed 5-FU Protocol Group. The comparison was conducted using the Fisher exact test. Conclusions: The use of vasodilators may be effective in preventing 5-Fluorouracil-Induced ischemic events in very high-risk cardiac patients with documented coronary artery disease. This approach may help reduce the risk of cardiac events and improve the safety of chemotherapy in this vulnerable patient population. Monitoring cardiotoxicity with maximum tolerated medical treatment and dedicated hospital protocols may be a good prophylaxis approach. Further studies are needed to confirm the safety and efficacy of this approach in a larger patient population, and to assess its impact on long-term cardiac outcomes.