Risk Factors for Sternal Wound Infection after Coronary Artery Bypass Grafting in Patients with and without Diabetes

Diabetes mellitus (DM) is a well-known risk factor for sternal wound infections (SWIs). However, SWIs are also known to occur in patients without DM. This study aimed to examine the difference in risk factors for SWIs after coronary artery bypass grafting (CABG) between non-diabetic and diabetic patients.We conducted a retrospective observational study including 6,697 patients who underwent CABG at our hospital from 2015-2018. The patients were assigned to the non-diabetic (group N, n = 2,930) or diabetic (group D, n = 3,767) group. A total of 24 potential risk factors were evaluated using univariate and multivariate analyses. Differences between superficial and deep SWIs were also examined.A total of 209 (3.1%) CABG patients, comprising 47 (22.5%) and 162 (77.5%) in groups N and D, respectively, required surgical treatment for SWIs. Univariate analyses indicated that a body mass index (BMI) > 25 kg/m² was uniquely associated with superficial SWIs in group N. Moreover, married status may have lowered the risk of deep SWIs in group D. Renal failure, intra-aortic balloon pump (IABP) use, and reopening in group N, as well as female sex, emergency admission, and reopening in group D, were independent predictors of SWI in the multivariate analysis.In this study, reopening was a common risk factor associated with SWIs in patients who underwent CABG with and without DM. Female sex and emergency admission were independent predictors of deep SWIs in patients with DM, whereas renal failure and IABP use were independent predictors of deep SWIs in patients without DM.