Methods: The study included 16 male patients who underwent coronary artery bypass grafting (CABG) and had good left ventricular functions. The patients were randomly divided into two groups equal in number, depending on the administration of antegrade/retrograde cold blood cardioplegia with or without a leukocyte filter. To determine tissue myeloperoxidase (MPO) activity, an indicator of neutrophil accumulation, biopsies were obtained from the interventricular septum after institution of cardiopulmonary bypass (CPB), before placing the aortic cross-clamp, and one hour after its removal. Cardiac indices were calculated before the institution of CPB and four hours after the removal of the aortic cross-clamp. Creatine kinase-MB (CK-MB) activity was measured every six hours on the day of the operation.

Results: With the use of filtering, the mean leukocyte count in cardioplegia was significantly reduced (p<0.001). The two groups did not differ significantly with respect to cardiac indices, CK-MB levels, mechanical support, development of severe ventricular arrhythmias, and the use of inotropic agents (p>0.05). Tissue MPO activities before aortic crossclamping were 0.13±0.04 U/100 mg tissue and 0.11±0.04 U/100 mg tissue with and without leukocyte filtering, respectively. One hour after aortic cross-clamp removal, MPO activity showed a significant increase in both groups. Leukocyte filtering was associated with a smaller increase in MPO activity, but this did not reach significance (p>0.05).

Conclusion: Depletion of neutrophils from blood cardioplegia in patients undergoing elective CABG with good left ventricular functions yielded no additional benefits in terms of hemodynamic or biochemical parameters.