Leukoreduction program for red blood cell transfusions in coronary surgery: Association with reduced acute kidney injury and in-hospital mortality

Objective: Leukocytes in allogeneic blood transfusions cause several immunomodulatory events. This before-and-after cohort study evaluated clinical outcomes after adoption of prestorage leukoreduction program for blood transfusions, with particular focus on acute kidney injury. Methods: One thousand thirty-four consecutive patients who underwent on-pump coronary artery bypass grafting between January 2004 and December 2007 were included. Propensity score analysis for transfusion was performed in the whole population; patients who were actually transfused were then divided according to leukoreduction. From these 2 groups, 147 pairs matched for propensity score were considered to evaluate with bivariate and multivariable analyses the effects of leukoreduction, with all-cause in-hospital mortality and morbidity as main outcomes. Results: Unadjusted in-hospital mortalities were 6.6% for the entire cohort and 44.2% for those with acute kidney injury. In the matched population, after introduction of leukoreduction, mortality rates decreased to 5.4% (vs 11.4%) and acute kidney injury (RIFLE [Risk, Injury, Failure, Loss of function, End-stage renal disease] class R or greater) dropped from 51.7% to 41.5% (relative risk -20%, P < .045). No difference emerged regarding other major complications. At multivariable analysis, intra-aortic balloon pump, RIFLE score, and propensity score for transfusion proved independent predictors of in-hospital mortality. Intra-aortic balloon pump and non-leukodepleted transfusion emerged as independent predictors of acute kidney injury. Multivariable analysis on the overall cohort of transfused patients confirmed that nonleukodepleted transfusion was an independent predictor of acute kidney injury. Conclusions: Leukoreduction of allogeneic blood products is associated with decreased acute kidney injury and mortality in highly transfused patients. (J Thorac Cardiovasc Surg 2010; 140: 188-95)