Coronary vasospasm is a recognized side effect of 5-FU (fluorouracil). There are limited and conflicting data on the incidence, risk factors and prognostic effect of 5-FU associated vasospasm.

To assess the incidence, risk factors and prognostic implications of 5-FU coronary vasospasm among patients receiving 5-FU regimens at a single tertiary care center.

We conducted a retrospective analysis of all patients who received 5-FU at a single academic center from January 2009 to July 2019. Vasospasm was defined as the occurrence of a typical chest pain syndrome in the presence of 5-FU. The presence of associated electrocardiogram (ECG) changes and/or elevated biomarkers was used to further confirm the diagnosis. Patients with vasospasm were compared to patients treated with 5-FU without vasospasm in a 1:2 ratio. Data regarding demographics, medical history, and follow-up were collected by manual chart review.

From approximately 4019 individual patients who received 5-FU from 2009 to 2019 at a single center, 87 (2.16%) developed vasospasm. Patients who developed vasospasm were younger (58±13 vs. 64±13 years, P = 0.001), and were less likely to have any cardiovascular risk factors (70.1% vs. 84.5%, P = 0.007). Patients with vasospasm and patients without vasospasm were otherwise similar in terms of types of cancer, stage of cancer, sex, and race. There was no significant difference in progression-free survival, overall mortality or cancer specific mortality between patients who developed vasospasm versus those who did not.

In a large, single-center report of 5-FU associated vasospasm, patients who developed vasospasm were younger, had lower rates of traditional cardiovascular risk factors and had no significant difference in progression-free or overall survival compared to those who did not develop vasospasm.