title: Is transfusion associated with graft occlusion after cardiac operations?
abstract: BACKGROUND
  Packed red blood cell (RBC) transfusions are associated with increased mortality after coronary artery bypass grafting (CABG) but not after cardiac valve operations. Transfusions are associated with increased strokes and deep venous thromboses after cardiac operations as well as increased peripheral vascular graft thrombosis. The purpose of this study was to determine if RBC transfusions were associated with a greater hazard of an occluded graft developing after CABG.
  
  
  METHODS
  Patients who underwent symptom-driven coronary artery angiography after CABG were analyzed using Cox models and propensity scoring to compare outcomes based on the RBC transfusion status during their index CABG hospitalization.
  
  
  RESULTS
  We analyzed 940 patients. We found that patients who received transfusions were more likely to have occluded grafts on angiography (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.03-1.50; p = 0.02). After adjusting for other factors, we found that RBC transfusion was associated with about a 20% increased hazard of graft occlusion (HR, 1.21; 95% CI,1.07-1.37; p = 0.003).
  
  
  CONCLUSIONS
  Perioperative RBC transfusion is associated with graft occlusion after CABG at both the patient and graft levels. These results add to the growing body of evidence that homologous RBC transfusion is not risk free but is associated with a variety of adverse effects including midterm graft failure.
authors.affiliation: Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan; Department of Anesthesiology, Mercy St. Vincent Medical Center, Toledo, Ohio. Electronic address: engorenm@med.umich.edu.
authors.forename: Milo
authors.initials: M
authors.lastname: Engoren
authors.affiliation: Department of Cardiothoracic Surgery, University of Toledo, Toledo, Ohio.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Schwann
authors.affiliation: Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Jewell
authors.affiliation: Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Sean
authors.initials: S
authors.lastname: Neill
authors.affiliation: Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Patrick
authors.initials: P
authors.lastname: Benedict
authors.affiliation: Section of Health Services Research and Quality, Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Donald S
authors.initials: DS
authors.lastname: Likosky
authors.affiliation: Department of Internal Medicine, Outcomes Research Unit, American University of Beirut, Beirut, Lebanon.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Habib
mesh_terms: D001026:Coronary Artery Bypass; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology*