title: Preoperative hemostatic testing and the risk of postoperative bleeding in coronary artery bypass surgery patients.
abstract: BACKGROUND
  We sought to assess predictability of excessive bleeding using thrombelastography (TEG), multiplate impedance aggregometry, and conventional coagulation tests including fibrinogen in patients undergoing coronary artery bypass graft (CABG) surgery.
  
  
  METHODS
  A total of 170 patients were enrolled in this prospective observational study. TEG, Multiplate aggregometry, and coagulation tests were sampled on the day before surgery. Excessive bleeding was defined as >1000 mL over 18 hours.
  
  
  RESULTS
  Multiplate-adenosine diphosphate (ADP) measurements were significantly lower in patients with excessive bleeding, 85.5AU ± 32.8 versus 108.5AU ± 30.0, p = 0.012. Bivariate analysis revealed body mass index, myocardial infarction, and multiplate-ADP as predictors of bleeding. In multivariable linear regression analysis, multiplate-ADP remained a significant predictor of bleeding (β: -6.2 [confidence interval: -12.0 to -0.3], p = 0.035). The lowest interval of multiplate-ADP (<50 AUC) was associated with significantly more bleeding and need for platelet concentrate transfusion. Fibrinogen levels <2.5 g/L were also found to be associated with excess bleeding (p = 0.020).
  
  
  CONCLUSIONS
  Multiplate impedance aggregometry identified patients at risk for excessive bleeding after CABG. Low fibrinogen levels were associated with increased bleeding. Neither routine TEG parameters nor conventional coagulation tests were correlated with bleeding.
authors.affiliation: Department of Cardiothoracic Surgery, the Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Sulman
authors.initials: S
authors.lastname: Rafiq
authors.affiliation: Capital Region Blood Bank, Section for Transfusion Medicine, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Pär I
authors.initials: PI
authors.lastname: Johansson
authors.affiliation: Department of Cardiology, the Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Kofoed
authors.affiliation: Department of Cardiothoracic Surgery, the Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Olsen
authors.affiliation: Department of Cardiothoracic Surgery, the Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Steinbrüchel
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001780:Blood Coagulation Tests; D001026:Coronary Artery Bypass; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006470:Hemorrhage / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D010979:Platelet Function Tests; D011183:Postoperative Complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D057234:Preoperative Period; D011446:Prospective Studies; D012306:Risk; D013916:Thrombelastography
chemical_list: D015415:Biomarkers; D005340:Fibrinogen