Effects of Different Heart Positions During Off-pump Coronary Artery Bypass Surgery on Serum Ischemia Modified Albumin Level and Cardiac Output

Objectives: We aimed to evaluate the potential effects of heart positioning during off-pump CABG (OPCAB) without cardiac stabilizer device on serum levels of IMA and cardiac output. Materials and Methods: This was a prospective study, in which consecutive patients who underwent isolated OPCAB were included. Data including electrocardiography and intraarterial hemodynamic monitoring parameters were recorded. Arterial pressure waveform (APW) was analyzed. Cardiac output was measured for circumflex coronary artery (Cx), diagonal coronary artery (D1), left anterior descending coronary artery (LAD), and right coronary artery (RCA) positions. Preoperative and postoperative 1, 2, 4, and 12-hour blood samples were taken for serum ischemia modified albumin measurements. Results: Forty patients who underwent OPCAB were included in the study. The mean age was 60.3 ± 10.2 years. Hospital mortality, stroke, postoperative myocardial infarction, acute kidney injury, sternal infection and re-operation for bleeding/tamponade were not observed postoperatively. Six patients (15%) who developed postoperative AF had a significantly higher mean serum IMA level compared with patients who did not.There was no statistically significant difference in preoperative and postoperative mean serum IMA levels (p = 0.925). Mean CO values measured at four different positions of the heart were not significantly different from each other except a difference between LAD and Cx(p=0.002). Conclusion: Our results showed that when the heart was in Cx anastomosis position, the cardiac output was significantly lower than LAD position; however, there was no significant serum IMA raise despite cardiac output decrease. IMA levels did not change significantly from baseline values. Patients who developed postoperative AF had higher IMA levels than patients who did not develop AF.