Heparin-coated circuit in coronary surgery : a clinical study

We performed a randomized study in 101 patients who underwent routine isolated coronary bypass graft surgery. In 50 cases an entire coated Carmeda circuit was used (coated group), and an uncoated circuit in the remaining 51 (uncoated group). A Medtronic Maxima oxygenator and a Biomedicus Biohead were used in all cases. Patients with coated circuits received low systemic heparinization with a heparin loading dose of 200 IU/kg, and 300 IU/kg for the control. Activated coagulation time was maintained at more than 275 s for the coated group versus more than 400 s for the uncoated one. The mean age of patients was 64.1±9.6 for coated and 63.5±9.7 for the uncoated group. The number of coronary grafts was 3.1±0.7 for the coated group and 3.1±0. for the uncoated one. Cross-clamp and bypass times were 53±14 and 98±24 min for the coated, versus 57±15 and 104±24 for the uncoated, group. Chest drainage was 989.4±509.5 ml for the coated group versus 1435±1027 for the uncoated one (P<0.02). The amount of transfused homologous blood was 723±597 ml for the coated group versus 1071±831 ml for the uncoated one (P<0.03). Postoperative endotracheal intubation time was 12.1±3.6 h for the coated and 14.6±4.5 h for the uncoated group (P<0.05). Bleeding required rethoracotomy in 1/50 of the coated group, and in 4/51 of the uncoated one. Hospital mortality was 1/50 in the coated, and 4/51 in the uncoated, group. In our preliminary experience, heparin coating of an extracorporeal circuit reduces post-operative blood loss and blood transfusions in routine coronary bypass operations.