Diabetes is a big risk factor for surgical site infections - and it is highest for cardiac patients.
The increased risk of sternal wound infections in patients with diabetes was confirmed by a publication last month in the Journal of Infection Control & Hospital Epidemiology: Diabetes and Risk of Surgical Site Infection: A Systematic Review and Meta-analysis. Martin ET, Kaye KS, Knott C, et al. (Volume 37 / Issue 01 / January 2016, pp 88-99)