Perioperative myocardial injury following off-pump and on-pump coronary bypass surgery: A prospective single-blind comparative study

Aim: In our study, we aimed to demonstrate the relationship between myocardial damage and surgical technique in the perioperative period in patients who underwent off-pump and on-pump coronary artery bypass grafting (CABG). 

Material and Methods: This prospective single-blind comparative study included a total of 49 patients undergoing on-pump CABG (Group 1, n=12), off-pump CABG (Group 2, n=30), and thoracotomy (Group 3 (as the study group), n=7). The groups were compared in terms of the preoperative basic clinical characteristics, intraoperative data, and postoperative outcomes and complications. In addition, the course of serum levels of creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and Troponin Ic as biomarkers of myocardial injury was analyzed during the postoperative period.

Results: There were no significant differences between off-pump and on-pump CABG groups in terms of preoperative basic clinical characteristics, except for diabetes mellitus and significant left ventricular dysfunction. There were no significant differences between off-pump and on-pump CABG groups in terms of intraoperative data, except for number of distal bypass. Compared to off-pump CABG group, in on-pump CABG group the mean durations of extubation, ICU and hospital stay were significantly longer and the mean amounts of blood transfusion and hemorrhagic drainage were significantly higher. As the most spesific biomarker of myocardial injury in this study, Troponin Ic values were detected to be significantly higher in on-pump CABG group than in off-pump CABG group in blood samples taken at the times of postoperative 30th minute, and second, fourth and sixth hours.

Conclusion: We suggest that providing adequate myocardial stabilization, shortening the duration of coronary occlusion and thus avoiding major myocardial ischemia during off-pump CABG surgery are important points for achieving successful results with less myocardial injury.