Age-stratified predictors of mortality in coronary artery bypass grafting - a ten-year cohort study

The aim of this study was to assess the predictors of mortality associated with coronary artery bypass grafting (CABG) in elderly patients.

This retrospective cohort study included all adult patients who underwent isolated CABG at a single institution between January 2015 and October 2024. Patients were stratified into three age groups: < 65 years, 65-74 years, and > 74 years. Demographic, operative, and postoperative outcomes were compared across groups. Multivariable logistic regression was performed for the entire cohort and separately for patients ≥ 65 years to identify independent predictors of in-hospital mortality.

A total of 9,309 patients underwent isolated CABG, including 6,489 patients aged < 65 years and 2,820 patients aged ≥ 65 years. Older patients had a higher prevalence of peripheral vascular disease (6.8% vs. 4.3%, p < 0.0001) and hypertension (83.0% vs. 79.9%, p = 0.001). Postoperative complications were significantly more frequent in the ≥ 65 group, including respiratory (21.5% vs. 16.9%, p < 0.0001), cardiovascular (3.0% vs. 1.6%, p < 0.0001), renal (1.1% vs. 0.4%, p = 0.002), gastrointestinal (1.0% vs. 0.7%, p = 0.011), and neurological events (3.4% vs. 1.5%, p < 0.0001). In-hospital mortality was nearly doubled in patients ≥ 65 years (2.0% vs. 1.1%, p = 0.001). Among those > 74 years, the incidence of blood transfusion (93.3%, p < 0.0001), respiratory (24.7%, p < 0.0001), and gastrointestinal complications (2.0%, p = 0.011) was further elevated. Multivariable logistic regression confirmed age as an independent predictor of mortality (Odds Ratio 1.05, 95% Confidence Interval: 1.03-1.07, p < 0.0001).

Advancing age, along with chronic obstructive pulmonary disease, cardiopulmonary bypass use, and reduced ejection fraction, were independent predictors of in-hospital mortality following CABG.

The online version contains supplementary material available at 10.1007/s12055-025-02013-7.