Heparinized cardiopulmonary bypass and full heparin dose marginally improve clinical performance

Background. The use of completely heparin coated cardiopulmonary bypass circuits in combination with a reduced systemic heparin dose has previously been shown to reduce postoperative bleeding after cardiac operations. However, it has remained unknown whether this effect was related to the improved biocompatibility of the heparin-treated surfaces per se or to the reduced exposure to circulating heparin. Therefore we investigated patients undergoing heparin-coated extracorporeal circulation and full systemic heparinization. Methods. Two hundred seventeen patients having first-time myocardial revascularization were prospectively randomized either to a group in which a completely (''tip-to-tip'') heparin-coated circuit (Duraflo II) was used for perfusion (n = 107) or to a control group (n = 110) in which an uncoated, but otherwise identical, circuit was used. Full systemic heparinization was induced in both groups (activated clotting time, >480 seconds). The postoperative blood loss, requirements for homologous blood transfusions, clinical performance, and complications were recorded. Results. The amount of postoperative mediastinal drainage was nearly identical in the two groups. The mean 18-hour drainage was 694 +/- 313 mL in the heparin-coated group and 679 +/- 269 mL in the control group (p = not significant). Three patients in the heparin-coated group and 6 patients in the control group received homologous red blood cell transfusions (p = not significant). The incidence of postoperative atrial fibrillation was significantly lower in the heparin-coated group (21.8%) than in the control group (43.1%) (p = 0.002). Otherwise, there were no significant differences in the extubation times, the incidence of perioperative myocardial infarction, the creatinine concentration, the incidence of neurologic dysfunction, the progress in physical rehabilitation, or the hemoglobin concentration at discharge. Conclusions. The use of completely heparin coated cardiopulmonary bypass circuits and full systemic heparinization in patients undergoing coronary artery bypass procedures did not reduce postoperative bleeding or change clinical performance, except for a significant decrease in the incidence of postoperative atrial fibrillation.