Outcomes of off-pump coronary artery bypass surgery in the elderly: A propensity-matched analysis

OBJECTIVE: Coronary artery bypass surgery (CABG) in the elderly is associated with increased mortality. Comorbidities are also more common in the elderly. The objective of this study was to ascertain the impact of comorbidities on mortality in elderly patients undergoing CABG. METHODS: All patients undergoing isolated off-pump CABG at a single-center from October 2014 to December 2021 were included. Patients were divided into two groups - <75 years and ≥75 years. Cox-regression analysis was done to assess for factors associated with mortality. Kaplan-Meier survival curves were used to assess survival. Due to unequal distribution of comorbidities between the two groups, 1:1 propensity score matching was done to assess the impact of age on outcomes. RESULTS: A total of 2200 patients who underwent off-pump CABG were included of which 139 were ≥75 years. Both operative mortality and intermediate-term mortality (mean 4.7 years) was higher in patients ≥75 years (6.5% vs 1.5% and 20.1% vs 8.9% p value < 0.001). Multivariate Cox-regression analysis showed re-exploration, high EuroSCORE II and the presence of chronic obstructive pulmonary disease to be associated with intermediate-term mortality. Overall survival was worse for patients ≥75 years (6-year survival 68.9% vs 89.6% p value < 0.001). However, on propensity matching these differences between the two groups disappeared. CONCLUSION: Factors other than age also contribute to mortality in elderly patients who undergo CABG. Comorbidity assessment should be an important focus of attention when evaluating risks for surgery in elderly patients.