Introduction:
Deep sternal wound infection (DSWI) is one of the most feared complications by patients undergoing open-heart surgery. This devastating complication leads to prolonged hospital stay, higher mortality and affects healthcare costs. Impact of the wound infection on short-term outcomes has not been fully examined across the spectrum of off-pump coronary artery bypass grafting (OPCAB) surgery. We aimed to investigate the association between DSWI and short-term in-hospital outcomes by patients undergoing OPCAB surgery.

Methods:
The study was designed as a retrospective double center non-randomized analysis of
OPCAB cohort.  From January 2017 to August 2022 a total of 215 patients underwent OPCAB procedure due to the coronary artery disease. Patients were divided into two categories: non-DSWI group (n=191) and DSWI group (n=63). All relevant data was analysed retrospectively after extraction from our institutional database. The primary outcome in our study was all-cause in-hospital mortality after OPCAB surgery. Secondary outcomes were stroke, acute kidney injury requiring dialysis, heart block requiring pacemaker implantation and red blood cell transfusion rate.

Results:
Mean age of the study population was 66.0±9.9 years. Mean EuroSCORE II predicted mortality was 3.8±2.9. Reoperation rate was significantly higher in the DSWI group (25.0% vs. 5.0%, p=0.003) compared to non-DSWI group. Moreover, diabetes rate was significantly higher in the DSWI group (54.2% vs. 43.8%, p=0.043). In addition, the use of both ITA grafts was significantly higher in the DSWI group compared to non-DSWI group (54.2% vs. 42.6%, p=0.047). Bleeding requiring reoperation was significantly higher in the DSWI group (25.0% vs. 2.0%, p<0.001). Moreover, the length of ICU (4.5±8.1 vs. 3.3±4.3, p=0.038) and hospital stay (20.4±12.6 vs. 9.8±4.7, p<0.001) was significant higher in the DSWI group. Furthermore, stroke, acute kidney injury requiring dialysis, heart block requiring pacemaker implantation and red blood cell transfusion rate showed no significant differences between non-DSWI and DSWI group. Likewise, in-hospital mortality rate did not differ in both groups (non-DSWI group (4.0%) vs. DSWI group (0.0%), p=0.399).

Conclusion:
Diabetes mellitus, previous open-heart surgery, use of both ITA grafts and bleeding requiring reoperation in the postoperative period are associated with significantly higher risk of wound infection prevalence after OPCAB procedure.