Cardiac Protection During On-Pump Coronary Artery Bypass Grafting: Ischemic Versus Isoflurane Preconditioning

Abstract

Objectives. To compare the cardioprotective effects of anesthetic preconditioning by isoflurane with ischemic preconditioning. Methods. A total of 45 patients scheduled for elective coronary artery bypass graft (CABG) surgery were randomized to preconditioning either by 3 episodes of 1-minute aortic cross-clamping followed by 4 minutes of reperfusion after each episode, a 10-minute exposure to isoflurane 2.5% followed by 5 minutes of washout, or no preconditioning technique (control group). Hemodynamic data, cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB) release, need for inotropic support, hospital stay, and adverse cardiac events were measured and recorded. Results. Preconditioned patients showed marked improvement in hemodynamic data, less need for inotropic support, and less postoperative increase in the serum levels of CK-MB and cTnI. No significant difference in hospital stay was found. Also, 4 patients in the control group had adverse cardiac events versus 1 patient in the isoflurane and ischemic groups in 1 year of follow-up. Conclusions. Based on this very small sample size, these data support a cardioprotective effect of isoflurane and ischemic preconditioning during CABG surgery.