Limited blood transfusion does not impact survival in octogenarians undergoing cardiac operations

Abstract

Background: We previously reported that transfusion of 1 to 2 units of red blood cells (RBCs) confers a 16% increased hazard of late death after cardiac surgical treatment. We explored whether a similar effect existed among octogenarians.

Methods: We enrolled 17,026 consecutive adult patients undergoing cardiac operations from 2001 to 2008 in northern New England. Patients receiving more than 2 units of RBCs or undergoing emergency operations were excluded. Early (to 6 months) and late (to 3 years, among those surviving longer than 6 months) survival was confirmed using the Social Security Death Index. We estimated the relationship between RBCs and survival, and any interaction by age (<80 years versus ≥80 years) or procedure. We calculated the adjusted hazard ratio (HR), and plotted adjusted survival curves.

Results: Patients receiving RBCs had more comorbidities irrespective of age. Patients 80 years of age or older underwent transfusion more often than patients younger than 80 years (51% versus 30%; p<0.001). There was no evidence of an interaction by age or procedure (p>0.05). Among patients younger than 80 years, RBCs significantly increased a patient's risk of early death [HR, 2.03; 95% confidence interval [CI], 1.47, 2.80] but not late death 1.21 (95%CI, 0.88, 1.67). RBCs did not increase the risk of early [HR, 1.47; 95% CI, 0.84, 2.56] or late (HR, 0.92 95% CI, 0.50, 1.69) death in patients 80 years or older.

Conclusions: Octogenarians receive RBCs more often than do younger patients. Although transfusion of 1 to 2 units of RBCs increases the risk of early death in patients younger than 80 years, this effect was not present among octogenarians. There was no significant effect of RBCs in late death in either age group.