Methods: Between January 2018 and October 2018, a total of 51 patients (43 males, 8 females; mean age 61.8±8.7 years; range, 38 to 78 years) who underwent isolated on-pump coronary artery bypass grafting were included. Thiol-disulfide homeostasis parameters were studied in the preoperative period (T1), 30 min after the removal of cross-clamp (T2), and postoperative sixth h (T3). Hemodynamic parameters such as atrial fibrillation and inotropic support requirement of the patients were evaluated in the postoperative period.

Results: There were significant differences in the measured thiol-disulfide homeostasis parameters at different time points of surgery (p<0.001). Binary logistic regression analysis showed that T2-disulfide/native thiol ratio was an independent predictor of the development of postoperative atrial fibrillation (p=0.042). There were positive and significant correlations between the T2-disulfide levels and cross-clamp time (r:0.307, p=0.029).

Conclusion: Thiol-disulfide homeostasis in patients undergoing on-pump coronary artery bypass grafting changes toward to disulfide. Disulfide levels increase in parallel with prolonged ischemia time. Decreased native thiol and increased disulfide levels during ischemic period may be predictive of postoperative atrial fibrillation.