188 The complex relationship between preoperative hemoglobin and the risks of cardiac surgery: An age- and gender-based analysis

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BackgroundLow serum hemoglobin is not uncommon in elderly and female patients undergoing cardiac surgery. Recent studies suggest preoperative anemia is associated with increased mortality and morbidity following cardiac surgery. The purpose of this study was to investigate the impact of preoperative hemoglobin on short-term outcomes following cardiac surgery with special attention to age and gender.MethodsThree thousand five hundred and seventy one patients underwent urgent or elective coronary artery bypass grafting (CABG) and/or valve surgery between April 2003 and December 2008. The patients who received preoperative blood transfusion were excluded. The primary outcome to be compared, with adjustment of age, gender, the Ontario Cardiac Care Network risk score and perioperative transfusion, was postoperative major adverse events (MAEs), which included death, MI, stroke, and renal failure requiring hemodialysis.ResultsOverall 30-day mortality was 2.5%, and the incidence of MAEs was 5.8%. Preoperative hemoglobin was not associated with MAEs in male patients equal to or above 75 years and in female patients regardless of age. Among male patients below 75 years, incidence of MAEs increased with decreasing preoperative hemoglobin levels, and became significant if a hemoglobin was below 11 g/dL, compared with that of patients with a hemoglobin above 13 g/dL within the same group (10-11 g/dL: odds ratio = 2.52, P = 0.03; < 10 g/dL: odds ratio = 2.87, P = 0.03).ConclusionsA low preoperative hemoglobin is not associated with increased surgical risks in female patients regardless of age, whereas its relationship with surgical outcomes of male patients is inconsistent with increasing age. Further investigation is warranted to determine an age- and gender-specific “safe” preoperative hemoglobin level. BackgroundLow serum hemoglobin is not uncommon in elderly and female patients undergoing cardiac surgery. Recent studies suggest preoperative anemia is associated with increased mortality and morbidity following cardiac surgery. The purpose of this study was to investigate the impact of preoperative hemoglobin on short-term outcomes following cardiac surgery with special attention to age and gender. Low serum hemoglobin is not uncommon in elderly and female patients undergoing cardiac surgery. Recent studies suggest preoperative anemia is associated with increased mortality and morbidity following cardiac surgery. The purpose of this study was to investigate the impact of preoperative hemoglobin on short-term outcomes following cardiac surgery with special attention to age and gender. MethodsThree thousand five hundred and seventy one patients underwent urgent or elective coronary artery bypass grafting (CABG) and/or valve surgery between April 2003 and December 2008. The patients who received preoperative blood transfusion were excluded. The primary outcome to be compared, with adjustment of age, gender, the Ontario Cardiac Care Network risk score and perioperative transfusion, was postoperative major adverse events (MAEs), which included death, MI, stroke, and renal failure requiring hemodialysis. Three thousand five hundred and seventy one patients underwent urgent or elective coronary artery bypass grafting (CABG) and/or valve surgery between April 2003 and December 2008. The patients who received preoperative blood transfusion were excluded. The primary outcome to be compared, with adjustment of age, gender, the Ontario Cardiac Care Network risk score and perioperative transfusion, was postoperative major adverse events (MAEs), which included death, MI, stroke, and renal failure requiring hemodialysis. ResultsOverall 30-day mortality was 2.5%, and the incidence of MAEs was 5.8%. Preoperative hemoglobin was not associated with MAEs in male patients equal to or above 75 years and in female patients regardless of age. Among male patients below 75 years, incidence of MAEs increased with decreasing preoperative hemoglobin levels, and became significant if a hemoglobin was below 11 g/dL, compared with that of patients with a hemoglobin above 13 g/dL within the same group (10-11 g/dL: odds ratio = 2.52, P = 0.03; < 10 g/dL: odds ratio = 2.87, P = 0.03). Overall 30-day mortality was 2.5%, and the incidence of MAEs was 5.8%. Preoperative hemoglobin was not associated with MAEs in male patients equal to or above 75 years and in female patients regardless of age. Among male patients below 75 years, incidence of MAEs increased with decreasing preoperative hemoglobin levels, and became significant if a hemoglobin was below 11 g/dL, compared with that of patients with a hemoglobin above 13 g/dL within the same group (10-11 g/dL: odds ratio = 2.52, P = 0.03; < 10 g/dL: odds ratio = 2.87, P = 0.03). ConclusionsA low preoperative hemoglobin is not associated with increased surgical risks in female patients regardless of age, whereas its relationship with surgical outcomes of male patients is inconsistent with increasing age. Further investigation is warranted to determine an age- and gender-specific “safe” preoperative hemoglobin level. A low preoperative hemoglobin is not associated with increased surgical risks in female patients regardless of age, whereas its relationship with surgical outcomes of male patients is inconsistent with increasing age. Further investigation is warranted to determine an age- and gender-specific “safe” preoperative hemoglobin level.