Cardiac protection during on-pump coronary artery bypass grafting: ischemic versus isoflurane preconditioning.

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.