Abstract 9693: The Least of Three Evils: Anemia, Transfusion, or Both?
Objectives: Anemia and red blood cell (RBC) transfusion have been associated with increased perioperative morbidity. Patients with anemia undergoing cardiac surgery are the most likely to receive RBCs, which results in a double negative exposure. We sought to clarify the independent effects of anemia, RBC transfusion, and their combination on risk of organ dysfunction and mortality.
Methods: From 11/1/2004 to 10/30/2009, 7,942 patients underwent cardiac surgery and did not receive RBCs, and 1,202 received only intraoperative transfusions. Patients were divided into 4 groups: intraoperative hematocrit (HCT) >25% and <25% without RBC transfusion and >25% and <25% with transfusion. The relationship between HCT, transfusion, and outcome was studied using propensity-score analysis. Outcomes included eGFR, troponin, ventilation time, hospital stay and mortality.
Results: Following risk adjustment, comparison of all 4 groups showed that lower HCT and RBC transfusion were independently associated with increased risk of morbidity and mortality. However, patients with severe anemia (HCT <25%) and transfusion had the worst renal function (lowest eGFR, P=.0008), most myocardial injury (highest troponin values, P=.01), longest postoperative ventilator requirement (P<.0001), longest stay (P<.0001) and highest mortality (P=.007; Figure).
Conclusions: The least of 3 evils is to tolerate mild to moderate anemia, followed by transfusion, if severe anemia can be avoided. Exposure to both anemia and transfusion is associated with the highest risk of adverse outcome.
- © 2012 by American Heart Association, Inc.