title: Elevated levels of angiopoietin-2 as a biomarker for respiratory failure after cardiac surgery.
abstract: OBJECTIVE
  Angiopoietin-1 and angiopoietin-2 are important factors in regulating endothelial vascular permeability. This study evaluated perioperative changes in serum levels of angiopoietin-1 and -2 in patients undergoing cardiac surgery.
  
  
  METHODS
  Measurement of serum levels of angiopoietin-1 and angiopoietin-2 in samples collected during a previously conducted prospective, multicenter, observational study.
  
  
  METHODS
  Three university hospitals.
  
  
  METHODS
  Eighty-four adult patients undergoing cardiac surgery.
  
  
  METHODS
  Serum levels of angiopoietins were measured at baseline, immediately after surgery, and the day after surgery (POD-1).
  
  
  RESULTS
  Serum levels of angiopoietin-2 were elevated by POD-1 (median 3.3 ng/mL, interquartile range [IQR] 2.5-4.6 ng/mL) compared with baseline (median 1.6 ng/mL, IQR 1.3-2.1 ng/mL, p < 0.0001), and angiopoietin-1 levels were decreased immediately after surgery (baseline median 23.2 ng/mL, IQR 10.2-32.8 ng/mL; postoperative median 8.0 ng/mL, IQR 1.5-13.2 ng/mL, p<0.0001). Angiopoietin-2 levels on POD-1 in patients undergoing off-pump coronary artery bypass grafting were significantly lower than those in patients undergoing aortic surgery (p = 0.0009) and valve surgery (p = 0.008). Angiopoietin-2 levels on POD-1 had a predictive performance of the area under the curve (AUC) of the receiver operating characteristic curve 0.74 for mechanical ventilation>3 days. Angiopoietin-1 levels and the angiopoietin-2/angiopoietin-1 ratio showed lower predictive performance (AUC values 0.58 and 0.68, respectively).
  
  
  CONCLUSIONS
  Angiopoietin-2 serum levels were elevated after cardiac surgery. Elevated angiopoietin-2 had a good predictive performance for respiratory failure after cardiac surgery, perhaps reflecting the severity of lung dysfunction related to postoperative increases in vascular permeability.
authors.affiliation: Department of Anesthesiology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Tokyo, Japan. Electronic address: uchida.mane@tmd.ac.jp.
authors.forename: Tokujiro
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Department of Anesthesiology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Anesthesiology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Tokyo, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Anesthesiology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Nagara
authors.initials: N
authors.lastname: Ohno
authors.affiliation: Department of Anesthesiology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Asahara
authors.affiliation: Department of Anesthesiology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Critical Care Medicine, Yokohama City University Medical Center, Kanagawa, Tokyo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamaguchi
authors.affiliation: Clinical Research Center, Tokyo Medical and Dental University Hospital of Medicine, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Tomita
authors.affiliation: Department of Anesthesiology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, Tokyo, Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Makita
mesh_terms: D000368:Aged; D042702:Angiopoietin-2 / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology
chemical_list: C586513:ANGPT2 protein, human; D042702:Angiopoietin-2; D015415:Biomarkers
keywords: Tie-2 Receptors; angiopoietin-1; angiopoietin-2; biomarker; cardiac surgery; lung injury; vascular permeability