No Significant Association Between the Transfusion of Small Volumes of Leukocyte-Depleted Red Blood Cells and Mortality Over 7 Years of Follow-up in Patients Undergoing Cardiac Surgery: A Propensity Score Matched Analysis.

BACKGROUND

The impact of red blood cell (RBC) transfusion on long-term clinical outcome is controversial.

METHODS

We prospectively recorded follow-up data of 6124 cardiac surgical patients who received no transfusion (RBC- group) or 1-2 units of leukocyte-depleted RBC (RBC+ group) at our institution. The primary end point was overall mortality up to 7 years after cardiac surgery; secondary end point was coronary artery revascularization during follow-up. To correct for nonrandomized group assignment, propensity score (PS) matching was performed. A subgroup analysis was also performed in patients with preoperative anemia.

RESULTS

PS matching was possible in 4118 patients. During a mean follow-up of 4.05 years (range, 0.0-7.3 years), 140 patients (14.6%) died in the RBC- group and 173 (17.2%) died in the RBC+ group. The hazard ratio for the RBC+ group versus the RBC- group was 1.00 (95% confidence interval, 0.79-1.25; P = .969). The number of revascularizations was 96 (9.9%) and 125 (10.6%), respectively, with a hazard ratio of 1.21 (95% confidence interval, 0.92-1.58; P = .166) for the RBC+ group. Preoperative anemia was not a risk factor for postoperative mortality, even when patients were transfused.

CONCLUSIONS

This PS-matched analysis does not provide evidence for an association of the transfusion of small volumes of leukocyte-depleted RBCs with an increased postoperative mortality in cardiac surgical patients. Moreover, preoperative anemia could not be identified as a risk factor for increased postoperative mortality.