The impact of red blood cell (RBC) transfusion on long-term clinical outcome is controversial.
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.
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.
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.
From the *Institute for Anesthesiology and †Clinic for Thoracic and Cardiovascular Surgery, Herz- und Diabeteszentrum NRW, Bad Oeynhausen, Ruhr-University of Bochum, Germany.
Accepted for publication September 6, 2017.
Funding: This work was supported by the Herz- und Diabeteszentrum NRW, Bad Oeynhausen, Ruhr-University of Bochum, Germany.
The authors declare no conflicts of interest.
The first two authors contributed equally to this study.
Reprints will not be available from the authors.
Address correspondence to Armin Zittermann, PhD, Clinic for Thoracic and Cardiovascular Surgery, Herz- und Diabeteszentrum NRW, Ruhr-University of Bochum, Georgstr 11, D-32545 Bad Oeynhausen, Germany. Address e-mail to firstname.lastname@example.org.