Evaluation of heparin-coated circuits with full heparin dose strategy.

Heparin-coated cardiopulmonary circuits (HCC) in combination with a reduced systemic heparin dose has been demonstrated to reduce postoperative hemorrhage after cardiac surgery. But, it has still been equivocal whether this effect was related to the improved bio-compatibility or to the reduced exposure of the circulating heparin. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into two groups either to be operated by HCC (30 patients) or uncoated but otherwise identical circuits (NHCC). Full systemic heparinization was induced in both groups. Hemodynamic parameters, hematological and biocompatibility tests were monitored within 24 hours. Postoperative blood loss, requirements for transfusions, clinical performance were recorded. Arterial filters were examined electron microscopically. Platelet levels remained significantly higher in the HCC group starting at the tenth minute following the institution of cardiopulmonary bypass until postoperative 24 hours. Electron microscopy showed significantly more platelet adhesion and pseudopod formation in the NHCC group. The mean amount of shed pleural and mediastinal blood measured from the time of the sternal closure was significantly lower in the HCC group (316 +/- 30 cc for HCC and 550 +/- 35 cc for NHCC). Mean postoperative transfusion requirements were also lower in the HCC group (230 +/- 23 cc for HCC and 320 +/- 25 cc for NHCC). The use of HCC and full systemic heparinization did not change the inflammatory response or biocompatibility but demonstrated benefits in platelet preservation and postoperative bleeding.