Introduction:
The correlation between OPCAB procedures and obesity-related outcomes has not been clarified. We assessed the preoperative, operative and postoperative short-term outcomes between obese and non-obese patients undergoing OPCAB surgery. As such, we focused on the relationship between obesity and short-term in-hospital outcomes in patients undergoing off-pump bypass 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 266 (non-obese (n=129) and obese (n=86)) patients underwent OPCAB procedures due to the coronary artery disease. Primary outcome was all-cause in-hospital mortality. Secondary outcomes were transient ischaemic attack, low cardiac output after surgery, bleeding requiring reoperation, wound infection rate and postoperative delirium.

Results:
Mean age of the study population was 66.0 ± 9.9 years. Mean EuroSCORE II predicted mortality was 3.8 ± 2.9. Dialysis rate was significantly lower in the non-obese group (0.8% vs. 8.2%, p=0.005). Additionally, the duration of mechanical ventilation was significantly higher in the obese patients in the postoperative period (p=0.016). Regarding the secondary outcome parameters (transient ischaemic attack, low cardiac output after surgery, bleeding requiring reoperation, wound infection rate, postoperative delirium), no significant differences were found between the non-obese and the obese group. All-cause in-hospital mortality rate also did not differ between the two groups (non-obese group (2.3%) vs. obese group (5.9%), p=0.165).

Conclusion:
Obesity is not associated with increased in-hospital mortality in patients undergoing OPCAB surgery. Moreover, obesity did not significantly increase the risk of secondary outcomes during short-term follow-up. Thus, OPCAB surgery is a safe procedure even in obese patients.