FROM THE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
Transfusing sex-mismatched red blood cells (RBCs) was associated with an increased risk of death in people undergoing heart bypass surgery or aortic valve replacement, based on results of a retrospective single-center study of almost 10,000 transfusions in cardiac surgery patients.
Each unit of sex-mismatched red blood cells (RBCs) transfused was associated with an increased risk of death (hazard ratio, 1.083; 95% confidence interval, 1.028-1.140; P = .003). In addition, transfusing 1-2 units of non–leukocyte depleted RBCs was associated with a significant increase in the risk of death during the first year after surgery (HR, 1.426; 95% CI, 1.004-2.024; P = .047).
Transfusion of 1-2 units of leukocyte-depleted RBCs and the age of blood products was not associated with increased mortality ( J Thorac Cardiovasc Surg. 2016;152:223-32.e1 ).
“Factors such as ABO group, Rh profile and sex of the PRBC [packed RBC] donor generally have been overlooked, as has the variation in postdonation treatment of blood,” in the outcomes of cardiac surgery patients, researchers led by Henrik Bjursten, MD, PhD, of Lund (Sweden) University, reported.
The study involved 9,907 patients at Lund University from 2002 to 2012: 7,696 had coronary artery bypass grafting (CABG); 1,216 had aortic valve replacement (AVR); and 995 concomitantly had both procedures. PRBC transfusions were given to nearly 51% of the patients. Compared with the group that did not receive PRBC transfusions, the transfused group had significantly higher rates of heart attack after surgery (1.5% vs. 0.6%), infection (0.6% vs. 0.3%), reoperation for bleeding (4.3% vs. 0.2%), 30-day death (0.7% vs. 0.2%), and overall death (25.9% vs. 12.6%).
Based on an analysis that factored in 24 different variables, transfusion of 1-2 units of non–leukocyte depleted PRBCs was associated with a HR of 1.426, but the same amount of leukocyte-depleted PRBCs did not increase risk (HR, 0.981). However, transfusion of 5-7 units of leukocyte-depleted RBCs was associated with decreased survival, as was transfusion of sex-mismatched PRBCs, associated with a HR of 1.046-1.133 per unit, Dr. Bjursten and colleagues wrote. “In this cohort, 58% of transfusions were sex mismatched, and thus we interpret the result as relatively robust and clinically relevant.”
Patients having combined CABG and AVR were more likely to have PRBC transfusions than patients who had a single procedure. Additionally, the increased death rate in the PRBC transfusion group may have been related to age and comorbidities such as diabetes, chronic obstructive pulmonary disease, and cardiac insufficiency. “Blood transfusion in part is a biomarker for advanced disease,” Dr. Bjursten and coauthors said. While patient who received PRBC transfusions may have been sicker, they did not require greater use of the ICU than patients who did not receive transfusions.
Dr. Bjursten disclosed receiving consulting fees from Boston Scientific. Coauthor Lars Algotsson, MD, PhD, disclosed receiving lecture fees from Abbott. All other authors had no financial disclosures.