Preoperative Anemia in Elective Cardiac Surgery: Prevalence, Risk Factors, and Influence on Postoperative Outcome

Manuel Muñoz, PhD; Daniel Ariza, PhD; Susana Gómez-RamÍrez‡, MD; Paula Hernández, MD; José A. García-Erce§ PhD; Santiago R. Leal-Noval; PhD


Transfusion Alter Transfusion Med. 2010;11(2):47-56. 

In This Article

Abstract and Introduction


Preoperative anemia in patients undergoing cardiac surgery is associated with a higher transfusion risk and poorer outcomes. This retrospective study was undertaken to assess the prevalence of preoperative anemia and its associated risk factors, as well as its influence on postoperative outcomes, in 576 patients undergoing elective cardiac surgery (52.3% with cardiopulmonary bypass) for myocardial revascularization, valve replacement, coronary + valve, or miscellaneous pathology at a single institution. Perioperative data were reviewed according to the presence or absence of preoperative anemia (hemoglobin < 13 g/dL for men, hemoglobin < 12 g/dL for women). Overall, 210 patients (36.5%) presented with anemia. Logistic regression analysis revealed that age, chronic kidney disease, and consumption of proton pump inhibitors histamine H2 receptor antagonists and diuretics were independent risk factors for the presence of preoperative anemia. Postoperatively, anemic patients received transfusions and inotropic support and stayed longer than 4 days in the recovery unit more frequently than non-anemic patients, but there were no differences in the composite outcome variable (stroke, myocardial infarction, renal failure or death). In conclusion, our data seem to indicate that preoperative anemia has a high prevalence among elective cardiac surgical patients and increases postoperative morbidity. Therefore, we need to address two specific areas about preoperative anemia in these patients: early recognition and evaluation, and appropriate and timely treatment.


Cardiac surgery (CS) procedures, with or without cardiopulmonary bypass (CPB), are frequently associated with a substantial blood loss, and a significant proportion of patients receive perioperative allogeneic blood transfusion (ABT), which in turn may increase the risk for postoperative complications (e.g. increased rate of postoperative infections)[1–3] and mortality.[4] On the other hand, in the last few years there have been an increased demand for CS in elderly patients (> 65 years old), in spite of their higher rate of comorbidities.[5,6] All these had led to changes in the relative risk associated to well-known risk factors and to take into consideration new risk factors, such as preoperative anemia (PA).

Thus, preoperative hemoglobin (Hb) or hematocrit values are useful parameters for predicting the risk of receiving ABT,[7] whereas PA is associated not only with an increased risk of ABT,[8,9] but also with an increased risk for postoperative complications and lower survival rates after coronary bypass grafting surgery.[10–14] In addition, PA and low preoperative erythrocyte mass are among the few preoperative risk factors that can be modified to reduce the risk of perioperative ABT.[15]

Consequently, if patients at risk of receiving perioperative ABT can be identified early enough prior to CS, they can be targeted to specific preventive and therapeutic measures.[16] Among them, early detection of PA would most probably allows the implementation of therapeutic measures to reduce risks (level of evidence A, recommendation class I).[17] We therefore analyzed the prevalence of and risks factors for PA, as well as the influence of PA on transfusion rates and adverse postoperative outcomes, in patients undergoing elective CS.


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