REDUCED COMPLEMENT AND GRANULOCYTE ACTIVATION WITH HEPARIN-COATED CARDIOPULMONARY BYPASS

Plasma concentrations of the complement activation products C3b, iC3b, and C3c; the terminal C5b-9 complement complex; and the granulocyte p roteins calprotectin, myeloperoxidase, and lactoferrin were assessed i n two groups of patients undergoing aortocoronary bypass procedures. I n 10 patients operated on, the bypass circuits were coated by the Carm eda Bio-Active Surface and systemic heparinization was reduced to 1.5 mg/kg; in another 10, the systems were uncoated and the dosage of syst emic heparinization was 4 mg/kg. In both groups, significant complemen t activation was observed after the onset of cardiopulmonary bypass, b ut the maximum levels of C3b, iC3b, and C3c and the terminal C5b-9 com plement complex were significantly lower in the heparin-coated group. In both groups, a significant increase in calprotectin, myeloperoxidas e, and lactoferrin release was observed by the end of operation. The m aximum myeloperoxidase levels were significantly lower in the heparin- coated group than those in the uncoated group (p = 0.03). There was a correlation of borderline significance between the formation of termin al C5b-9 complement complex and lactoferrin release, as well as betwee n the formation of terminal C5b-9 complement complex and myeloperoxida se release (p = 0.05). The postoperative blood loss did not differ sig nificantly between the two groups. We conclude that coating by end poi nt-attached and functionally active heparin allows a significant reduc tion in the amount of systemic heparinization, and significantly reduc es complement and granulocyte activation.