Does Preoperative Transfusion in Anemic Patients Prior to CABG Prevent Postoperative Transfusion?

A. Nissen¹, J. Wei¹, J. Binongo², M. Halkos¹, W. Brent. Keeling^1
1Emory University, Atlanta, Georgia ²Emory University Rollins School of Public Health, Atlanta, Georgia

Purpose: The Society of Thoracic Surgeons (STS) coronary artery bypass grafting (CABG) composite outcome score includes blood transfusion. The STS metric captures intraoperative and postoperative transfusions, which are negatively correlated with CABG composite scores. Our research aim was to evaluate whether preoperative transfusion on anemic patients undergoing CABG prevented perioperative transfusion.

Methods: From January 2018–December 2022, 3970 patients underwent isolated CABG at a multi-hospital academic institution. We identified anemic patients, defined by preoperative hemoglobin < 12mg/dl according to the World Health Organization, and matched them in a 3:1 fashion among surgeons who did not preoperatively transfuse (15 surgeons) vs. those who did (6). Patients were matched based on preoperative STS predicted risk of mortality . Using univariate statistics, we assessed short-term outcomes including total blood product utilization, as well as a composite outcome of death, stroke, and new renal failure between groups.

Results: 701 (17.7%) patients had a preoperative hemoglobin < 12mg/dl, 310 (44.2%) of whom were operated on by surgeons who routinely preoperatively transfuse. Among these 310 patients, 31 (10%) patients received at least 1 unit of packed red cells preoperatively and were matched to 87 anemic patients treated by surgeons who did not receive preoperative transfusion. . Importantly, no differences were detected between groups for either intra- or postoperative transfusion rates (Table 1). Composite rate of new stroke, renal failure, and/or mortality was statistically similar between transfused and non-transfused groups (3.2% vs. 6.9%, p=0.457). After including all pre-, intra-, and postoperative blood products, the group of patients receiving preoperative blood products received significantly more total packed red cells during their hospitalization (4.1±2.0 units vs. 2.1±2.1 units, p< 0.001). Intra- and postoperative blood product transfusion rates were similar between groups.

Conclusion: A strategy of preoperative transfusion for anemic patients undergoing isolated CABG does not improve postoperative outcomes and leads to similar rates of transfusion during and after CABG. Preoperative transfusion for anemic patients undergoing CABG does not improve postoperative outcomes and leads to higher overall transfusion rates, in a manner not captured by current STS metrics.

Identify the source of the funding for this research project: None.