Transfusion of 1 and 2 units of red blood cells does not increase mortality and organ failure in patients undergoing isolated coronary artery bypass grafting.

Abstract

In cardiac surgery, the association between red blood cell (RBC) transfusion and clinical outcome is elusive. We investigated in a large cohort of patients who underwent isolated coronary artery bypass grafting (CABG) the effect of transfusion of 1-2 units of leucocyte-depleted RBCs on mortality and multiorgan failure. The investigation included all patients from July 2009 to June 2014 who underwent CABG at our institution and received no (n = 1478) or 1-2 units of RBCs (n = 1528). The primary end-point was 30-day mortality; secondary end-points were major organ dysfunction. A subgroup analysis assessed the effect of the duration of RBC storage on patient outcome. Statistical analysis was performed using propensity score (PS) adjustment. The 30-day mortality rate was 0.3% in the RBC- group and 0.2% in the RBC+ group. Compared with the RBC- group, PS-adjusted odds ratio (OR) of 30-day mortality in the RBC+ group was 0.29 [95% confidence interval (CI): 0.06-1.50; P = 0.14]. PS-adjusted OR of a 'prolonged intensive care unit (ICU) stay' (>48 h) was significantly higher in the RBC+ group than in the RBC- group [OR 1.49 (95% CI: 1.14-1.95); P = 0.004], but major clinical complications such as low cardiac output syndrome, stroke, haemofiltration, wound infection and prolonged mechanical ventilator support (>24 h) did not differ significantly between groups. Duration of blood storage was not independently associated with clinical outcome. Our data do not indicate a transfusion-related increase in mortality and multiorgan failure in patients undergoing isolated CABG.