Preventing 5-fluorouracil-induced ischemic events in very high-risk cardiac patients with documented ischemic heart disease: a retrospective cohort analysis

Introduction. 5-fluorouracil (5-FU), a potent chemotherapy agent for various cancers, is linked to cardiotoxicity, particularly in patients with pre-existing ischemic heart diseases. The incidence varies, which necessitates effective preventive strategies. Among several mechanisms responsible for 5-FU-induced myocardial ischemia are coronary vasospasm and endothelial injury. Therefore, preventing vasospasm and endothelial injury may reduce the incidence of these adverse events. We aimed 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. Material and methods. 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 (non-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, and chest pain with p-values of 0.009 for both outcomes. Additionally, the frequency of ECG changes post-5-FU and an increase in troponin levels were significantly lower in the 5-FU protocol group, with p-values of 0.036 for both parameters. 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. Monitoring cardiotoxicity with maximum tolerated medical treatment and dedicated hospital protocols may be a good prophylactic approach. Further studies are needed to confirm the efficacy of this approach in a larger population.