Induced remote ischemic pre-conditioning on ischemia reperfusion injury in patients undergoing coronary artery bypass

ABSTRACT

To determine the role of remote ischemic pre-conditioning [rIPC] on myocardium, against ischemia reperfusion injury in patients undergoing coronary artery bypass graft [CABG] surgery by measuring CKMB levels. A randomized controlled trial. The Surgical Department of Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, from January to June 2008. One hundred patients with double and triple vessels coronary artery disease were randomized in two groups of 50 each. rIPC protocol consisted of 3 x 5 minutes of forearm ischemia, induced by a blood pressure cuff inflated to 200 mmHg, with an intervening 5 minutes of reperfusion, during which the cuff was deflated. Patients in the control group were not subjected to limb ischemia. The protocol of induced ischemia was completed before placing patients on extracorporeal bypass circuit. At the end of surgery serum CKMB levels were measured and compared at 8, 16, 24 and 48 hours from both the groups. Written informed consent was taken from patients. Study was approved by the hospital ethical committee. Remote ischemic pre-conditioning significantly reduced CKMB levels at 8, 16, 24 and 48 hours after surgery with p-values of 0.026, 0.021, 0.052 and 0.003 respectively. There was mean reduction of 3 iu/l in CKMB levels, in patients who underwent rIPC protocol prior to CABG surgery, compared to control group. This study showed a significant reduction of enzyme marker CKMB in patients subjected to rIPC prior to CABG surgery. This suggests lesser degree of myocardial damage compared to control group in CABG patients