Major Adverse Cardiovascular Events After Colorectal Cancer Surgery, Oncological Outcomes, and Long-term Mortality: A Nationwide Retrospective Propensity Score-Matched Cohort Study.

Objective: To investigate the occurrence of major adverse cardiovascular events (MACE) following colorectal cancer (CRC) surgery and its association with long-term mortality and oncological outcomes.

Background: Cardiovascular complications after noncardiac surgery are a leading cause of perioperative mortality. However, limited knowledge exists on how these complications impact on long-term mortality.

Methods: This retrospective cohort study used data from 4 nationwide Danish health registries and included all patients undergoing elective surgery with curative intent for CRC between 2001 and 2019. Patients experiencing MACE, defined as acute myocardial infarction, stroke, new-onset heart failure, or nonfatal cardiac arrest, within 30 days of surgery were matched with those who did not using 1:1 propensity score matching (PSM). The outcomes were all-cause mortality within 1, 3, or 5 years of surgery, as well as 5-year cancer recurrence and disease-free survival.

Results: Out of 39,747 patients, 900 (2.3%) had MACE. PSM resulted in 809 pairs of matched patients. Within 1 year of surgery, 110 (13.6%) patients with MACE and 2063 (5.4%) without MACE died (PSM-adjusted hazard ratio [HR] = 1.36; 95% confidence interval [CI] = 1.02-1.83). Within 3 years, 248 (30.6%) patients with MACE and 6268 (16.5%) without MACE died (PSM-adjusted HR = 1.32; 95% CI = 1.07-1.62). Within 5 years, 333 (41.1%) patients with MACE and 9232 (24.3%) without MACE died (PSM-adjusted HR = 1.25; 95% CI = 1.04-1.50). For recurrence and disease-free survival, no statistically significant differences were observed.

Conclusions: MACE within 30 days of CRC surgery is associated with higher overall long-term mortality. Investigating causality and preventive measures is urgent in this group.