Comparison of m-RNA expression for inflammatory mediators in leukocytes between on-pump and off-pump coronary artery bypass grafting.

OBJECTIVE Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) is associated with a systemic inflammatory response. This is mainly attributed to cytokine release caused by CPB and global myocardial ischemia. Coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG, OPCAB) is now accepted as a less invasive technique than conventional CABG. This study was designed to compare the inflammatory response at the m-RNA level of proinflammatory cytokines and adhesion molecules before and after operation in patients undergoing CABG with and without CPB. METHODS Twenty patients who underwent isolated CABG with CPB (on-pump group, n=10) or without CPB (off-pump group, n=10) were studied. By utilizing a semiquantitative reverse transcription polymerase chain reaction (RT-PCR) technique, gene expression of cytokines, adhesion molecules, and vasoactive substances in leukocytes of peripheral blood were evaluated before and six hours after surgery. RESULTS Postoperative expression of m-RNA for interleukin (IL)-1, -8, and -10, tumor necrosis factor (TNF)-alpha, heme oxygenase (HO)-1, platelet endothelial cellular adhesion molecule (PECAM) and Mac-1 increased significantly in the on-pump group but not in the off-pump group (p<0.05). CONCLUSIONS In view of the m-RNA level of proinflammatory cytokines and adhesion molecules, it can be concluded that OPCAB is a less invasive technique than on-pump CABG. Direct contact of circulating blood with the synthetic surfaces of the CPB system may be the main cause of the systemic inflammation.