Comparison of two heparin-coated extracorporeal circuits with reduced systemic anticoagulation in routine coronary...

The use of heparin-coated circuits for cardiopulmonary bypass attenuates the postperfusion inflammatory response. Postoperative bleeding and the need for allogeneic blood transfusions are reduced, particularly in combination with lowered systemic anticoagulation. The two most commonly used heparin-coated systems are the Carmeda BioActive Surface (Medtronic Inc, Minneapolis, Minn) and the Duraflo II coating (Baxter Healthcare Corp, Bentley Laboratories Division, Irvine, Calif). The 2 surfaces are technically unequal, and previous experimental studies have demonstrated disparities in effects on the immune system and the blood cells. However, no larger comparative studies of relevant clinical end points have thus far been reported.

Over a 24-month period, all patients undergoing coronary artery bypass were prospectively randomized to one of the two heparin-coated circuits. Altogether, 1336 consecutive patients were included. The heparin dose was reduced in all cases, with an activated coagulation time of more than 250 seconds. Clinical data were consecutively collected and stored on a computer for comparative analyses.

There were no statistically significant differences in any demographic or operative parameters. The Duraflo II patients required less heparin to keep the target-activated clotting time, confirming the previous finding of some leakage of heparin from the surface to the circulation. Otherwise, there were no significant differences in time for ventilatory support (Duraflo II, 1.7 +/- 1.3 hours; Carmeda BioActive Surface, 1.6 +/- 1.0 hours; P =.37), amount of postoperative mediastinal drainage (Duraflo II, 665 +/- 257 mL; Carmeda BioActive Surface, 688 +/- 243 mL; P =.07), need for allogeneic blood-plasma transfusions (Duraflo II, 4.2% of the patients; Carmeda BioActive Surface, 4.4% of the patients; P =.93), or hemoglobin concentration at hospital discharge (Duraflo II, 120 +/- 13 g/L; Carmeda BioActive Surface, 119 +/- 13 g/L; P =.08). The effects on renal function and platelets were similar, as were the incidences of perioperative myocardial infarction (Duraflo II, 1.5%; Carmeda BioActive Surface, 1.5%; P =.96), stroke (Duraflo II, 1.3%; Carmeda BioActive Surface, 1.2%; P =.47), and hospital mortality (Duraflo II, 1 [0.14%] patient; Carmeda BioActive Surface, 3 [0.45%] patients; P =.31).

Despite differences in technology, complexity, and effects on biologic markers, no clinical differences were observed between the Carmeda BioActive Surface system and the Duraflo II coating after coronary artery bypass operations. The overall clinical results were favorable in both groups, confirming the safety and feasibility of routine use of heparin-coated circuits in combination with reduced systemic anticoagulation.