Chemotherapy and adverse cardiovascular events in colorectal cancer patients undergoing surgical resection

ABSTRACT: BACKGROUND: Colorectal cancer patients undergoing surgical resection are at increased short-term risk of post-operative adverse events. However, specific predictors for long-term major adverse cardiac and cerebrovascular events (MACCE) are unclear. We hypothesised that patients who receive chemotherapy are at higher risk of MACCE than those who did not. METHODS: In this retrospective study, 412 patients who underwent surgical resection for newly diagnosed colorectal cancer from January 2013 to April 2015 were grouped according to chemotherapy status. MACCE was defined as a composite of cardiovascular death, myocardial infarction, stroke, unplanned revascularisation, hospitalisation for heart failure or angina. Predictors of MACCE were identified using competing risks regression, with non-cardiovascular death a competing risk. RESULTS: There were 200 patients in the chemotherapy group and 212 patients in the non-chemotherapy group. The overall prevalence of prior cardiovascular disease was 20.9%. Over a median follow-up duration of 5.1 years from diagnosis, the incidence of MACCE was 13.3%. Diabetes mellitus and prior cardiovascular disease were associated with an increased risk of MACCE (subdistribution hazard ratio, 2.56; 95% CI, 1.48-4.42) and 2.38 (95% CI, 1.36-4.18) respectively. The chemotherapy group was associated with a lower risk of MACCE (subdistribution hazard ratio, 0.37; 95% CI, 0.19-0.75) compared to the non-chemotherapy group. CONCLUSIONS: Amongst colorectal cancer patients undergoing surgical resection, there was a high incidence of MACCE. Diabetes mellitus and prior cardiovascular disease were associated with an increased risk of MACCE. Chemotherapy was associated with a lower risk of MACCE, but further research is required to clarify this association.