Comparative analysis of postoperative complications and 30-day readmissions after CABG in diabetic vs. non-diabetic...

Diabetes mellitus is a known risk factor for long-term adverse outcomes after coronary artery bypass grafting (CABG); however, its impact on 30-day readmission is less characterized. This study aimed to compare 30-day readmission rates and index hospitalization outcomes between diabetic and non-diabetic patients undergoing CABG and to identify independent predictors of readmission.

A retrospective cohort study was conducted using the 2016 and 2017 Nationwide Readmissions Database (NRD). In keeping with HCUP guidance, each data year was analyzed as a separate sample rather than pooled. Adult patients undergoing CABG were identified in each year and stratified by diabetes status. The primary outcome was 30-day all-cause readmission. Secondary outcomes included in-hospital mortality, length of stay (LOS), hospital charges, and complications. Survey-weighted multivariable logistic regression, adjusted for demographic, socioeconomic, hospital, and comorbidity characteristics as well as index-hospitalization complications and discharge disposition, was used to identify independent risk factors for readmission.

In the 2016 (weighted N = 100,010) and 2017 (weighted N = 100,669) cohorts, diabetes was present in 47.7% and 48.9% of patients, respectively. In both years the 30-day readmission rate was higher among patients with diabetes (2016: 10.0% vs. 8.3%; 2017: 9.3% vs. 7.3%; both p < 0.001), corresponding to adjusted odds ratios of 1.14 (95% CI 1.07-1.22) in 2016 and 1.15 (95% CI 1.07-1.24) in 2017. In each year, patients with diabetes had more complex index hospitalizations, with longer stays, higher complication rates, and greater hospital charges. Non-home discharge was the strongest independent predictor of readmission in both years (OR 1.66 in 2016 and 1.67 in 2017), with anemia, congestive heart failure, and chronic pulmonary disease also independently associated.

In both the 2016 and 2017 cohorts, diabetes was independently associated with 30-day readmission after CABG, even after accounting for index complications and discharge disposition, and was accompanied by a greater comorbidity burden and postoperative complexity. The strong association with non-home discharge suggests that care transitions warrant further study. These findings identify a high-risk population that may benefit from enhanced discharge planning and close post-discharge monitoring, although whether such measures reduce readmission requires prospective evaluation.

The online version contains supplementary material available at https://doi.org/10.1007/s40200-026-02103-2.