Heparin-coated cardiopulmonary bypass circuits: hemostatic alterations and postoperative blood loss.

This prospective, randomized study involving patients undergoing isolated coronary artery bypass grafting investigated whether the use of heparin-coated bypass circuits with an uncoated cardiotomy reservoir (n = 10) compared with standard uncoated bypass circuits (n = 10) resulted in differences in patient outcome and hemostatic alterations. There were no differences in postoperative blood loss, transfusion requirements, and routine coagulation test results between groups. Immunoassays for platelet alpha-granule constituents platelet factor 4 and beta-thromboglobulin, thrombin generation by-product F1.2, fibrinopeptide A, thrombin-antithrombin complex, and fibrinolysis by-product D-dimer also demonstrated no significant differences between groups, although trends for lower platelet secretion with heparin coating were noted. Increases were found in beta-thromboglobulin and platelet factor 4 concentrations at 10 (p < 0.03) and 30 minutes (p < 0.001) of CPB, respectively, and continuing throughout CPB (p < 0.001) for both groups versus values measured before incision. No significant differences were seen between levels 5 minutes prior to aortic cross-clamp release and those obtained 8 and 45 minutes after cross-clamp release. Conversely, no significant increases in F1.2, thrombin-antithrombin complex, and D-dimer were seen prior to release of the aortic cross-clamp, but afterward increases occurred that were highly significant (p < 0.001). The temporal data suggest that platelet activation occurs primarily as a result of contact with the cardiopulmonary bypass circuitry, whereas thrombin generation and fibrinolytic activity are not significant until reperfusion of the heart and lungs.(ABSTRACT TRUNCATED AT 250 WORDS)