Transfusion after coronary artery bypass surgery: the impact of heparin-bonded circuits

OBJECTIVE: To identify the impact of heparin bonded (Carmeda) circuits on the need for transfusion of packed red blood cells (PRBC) after CABG independent of the influence of patient, procedural, and surgical experience variables. METHODS: A prospective, randomized trial examined the impact of heparin-bonded circuits in 210 patients undergoing coronary artery bypass surgery at Medical Center of Delaware (Christiana Care Health Services). Patients were randomized to either non-bonded circuits or heparin-bonded (Carmeda) circuits. There were no significant differences in patient characteristics between the treatment and control group. A multivariate analysis was performed to identify the independent predictors of both the need for transfusion (logistic) and number of units of PRBC transfused (OLS). RESULTS: The only significant (P < 0.05) independent predictors of need for transfusion were gender (odds ratio (OR) = 0.35 for males), use of anticoagulants prior to surgery (OR = 2.09), cross-clamp time (OR = 1.03 for each extra minute), and use of heparin-bonded circuits (OR = 0.50 for patients in the heparin-bonded; Carmeda, circuit group). The only significant independent predictors of number of PRBCs were anticoagulants prior to surgery, cross-clamp time, catheterization procedure on the same day, body surface area, and use of heparin-bonded circuits. Other patient demographic variables, comorbidities, and surgical variables were not significant independent predictors of the need for transfusion or the number of units transfused. CONCLUSIONS: Several factors influence the probability of transfusion that patients face following coronary artery bypass surgery. The probability of transfusion is 50% less and the number of PRBCs transfused are 1.42 units less when heparin-bonded (Carmeda) circuits are used, adjusted for patient demographics, comorbidities, or surgical variables.