CARDIOPULMONARY BYPASS WITH HEPARIN-COATED CIRCUITS AND REDUCED SYSTEMIC ANTICOAGULATION

Background. The improved biocompatibility of the cardiopulmonary bypas s circuits made possible by the use of surface-immobilized heparin may allow for a reduction in the amount of heparin administered systemica lly. This study was performed to elucidate the effects of cardiopulmon ary bypass using heparin-coated circuits and reduced heparinization on hemostatic variables and clinical outcome. Methods. Thirty patients s cheduled to undergo myocardial revascularization were randomized to ha ve either a heparin-coated or an uncoated cardiopulmonary bypass circu it. Anticoagulation was induced with heparin (100 IU/kg in the coated group and 300 IU/kg in the uncoated group) and the activated clotting time was kept over 200 and 480 seconds in the coated and uncoated grou ps, respectively. Results. The postoperative overnight loss of hemoglo bin through the drains was lower in the heparin-coated group (43.6 g; range, 18.5-69.0 g) than in the uncoated group (73.0 g; range, 32.2-13 7.7 g) (p = 0.0015). Plasma concentrations of prothrombin fragment 1 2 and D-dimer were significantly more elevated after cardiopulmonary bypass in the coated group than they were in the uncoated group. Two p atients in the coated group had a stroke post operatively. Conclusions . The reduction in systemic heparinization was associated with thrombi n formation, which may predispose to intravascular and cardiopulmonary bypass circuit clotting. Therefore, generous systemic heparinization may still be prudent despite the improved biocompatibility offered by heparin-coated surface. (C) 1997 by The Society of Thoracic Surgeons.