<strong>Background</strong>: It has been suggested that off-pump coronary<br />artery bypass grafting (CABG) surgery reduces myocardial<br />ischemia-reperfusion injury, postoperative systemic<br />inflammatory response, and oxidative stress. The aim of this<br />study was to measure serum malondialdehyde (MDA), highsensitivity<br />C-reactive protein (hs-CRP), M30, and M65 levels<br />and to investigate the relationship between M30 levels and<br />oxidative stress and inflammation in patients undergoing onand<br />off-pump CABG surgery.<br /><strong>Methods</strong>: Fifty patients were randomly assigned to onpump<br />or off-pump CABG surgery (25 patients off-pump and<br />25 on-pump CABG surgery), and blood samples were collected<br />prior to surgery, and 30 minutes, 60 minutes, 6 hours,<br />and 24 hours after CABG surgery.<br /><strong>Results</strong>: Compared to the on-pump group, serum MDA<br />levels at 30 minutes, 60 minutes, 6 hours, and 24 hours after<br />the CABG surgery were significantly lower in the off-pump<br />group (P = .001, P = .001, P = .001, and P = .001, respectively).<br />Serum M30 levels were found to be elevated in both groups,<br />returning to baseline at 24 hours. When compared to baseline,<br />the hs-CRP level reached its peak at 24 hours at 13.28 ±<br />5.32 mg/dL in the on-pump group, and 15.44 ± 4.02 mg/dL<br />in the off-pump group.<br /><strong>Conclusion</strong>: CABG surgery is associated with an increase<br />in inflammatory markers and serum M30 levels, indicating<br />epithelial/endothelial apoptosis in the early period.