Hemoglobin Optimization for Coronary Bypass: A 10-Year Canadian Multicenter Experience

Background: We report our 10-year experience of a multicenter hemoglobin optimization program with the aim to reduce red blood cell transfusion in patients undergoing coronary artery bypass grafting (CABG).

Methods: From 2006 to 2016, patients undergoing CABG at 10 centers in Ontario were referred to the Ontario Transfusion Coordinators (ONTraC) program. Of these, we present data on the first 60 consecutive patients per center, per year (n = 6,145).

Results: Overall, 45.7% patients were assessed <14 days preoperatively, 16.4% were assessed ≥14 days preoperatively, and 37.9% were not assessed by ONTraC preoperatively. Transfusion rates fell from 40.1% in 2006 to 26.2% in 2016 (p < 0.01). Patients undergoing assessment were more likely to be older (p < 0.01), female (p < 0.01), and anemic (p < 0.01) versus nonassessed patients. Those patients assessed were more likely to be treated with iron (p < 0.01) and erythropoietin (p < 0.01) preoperatively versus nonassessed patients. Transfusion rates were 26%, 28%, and 28% for patients undergoing assessment ≥14 days prior to operation, <14 days prior to operation, or not at all. After baseline covariate adjustment, patients assessed ≥14 days preoperatively had shorter length of stay (effect -0.83, 95% confidence interval [CI] -1.41 to -0.25; p < 0.01) and a trend towards lower risk of red blood cell transfusion (odds ratio [OR] 0.83, 95% CI 0.68 to 1.00; p = 0.06). Blood transfusion was independently associated with an increased risk of death (OR 1.49, 95% CI 1.37 to 1.60; p < 0.01), infection (OR 1.24, 95% CI 1.18 to 1.30; p < 0.01), and longer hospital length of stay (effect 1.49, 95% CI 1.35 to 1.62; p < 0.01).

Conclusions: The results of this study suggest that preoperative hemoglobin optimization may be effective in reducing red blood cell transfusion after CABG, particularly for patients assessed ≥14 days preoperatively.