title: Postoperative activity, but not preoperative activity, of antithrombin is associated with major adverse cardiac events after coronary artery bypass graft surgery.
abstract: BACKGROUND
  Low levels of antithrombin (AT) have been independently associated with prolonged intensive care unit stay and an increased incidence of neurologic and thromboembolic events after cardiac surgery. We hypothesized that perioperative AT activity is independently associated with postoperative major adverse cardiac events (MACEs) in patients undergoing coronary artery bypass graft (CABG) surgery.
  
  
  METHODS
  We prospectively studied 1403 patients undergoing primary CABG surgery with cardiopulmonary bypass (CPB) (http://clinicaltrials.gov/show/NCT00281164). The primary clinical end point was occurrence of MACE, defined as a composite outcome of any one or more of the following: postoperative death, reoperation for coronary graft occlusion, myocardial infarction, stroke, pulmonary embolism, or cardiac arrest until first hospital discharge. Plasma AT activity was measured before surgery, after post-CPB protamine, and on postoperative days (PODs) 1-5. Multivariate logistic regression modeling was performed to estimate the independent effect of perioperative AT activity upon MACE.
  
  
  RESULTS
  MACE occurred in 146 patients (10.4%), consisting of postoperative mortality (n = 12), myocardial infarction (n = 108), stroke (n = 17), pulmonary embolism (n = 8), cardiac arrest (n = 16), or a subsequent postoperative or catheter-based treatment for graft occlusion (n = 6). AT activity at baseline did not differ between patients with (0.91 ± 0.13 IU/mL; n = 146) and without (0.92 ± 0.13 IU/mL; n = 1257) (P = 0.18) MACE. AT activity in both groups was markedly reduced immediately after CPB and recovered to baseline values over the ensuing 5 PODs. Postoperative AT activity was significantly lower in patients with MACE than those without MACE. After adjustment for clinical predictors of MACE, AT activity on PODs 2 and 3 was associated with MACE.
  
  
  CONCLUSIONS
  Preoperative AT activity is not associated with MACE after CABG surgery. MACE is independently associated with postoperative AT activity but only at time points occurring predominantly after the MACE.
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Garvin
authors.forename: Jochen D
authors.initials: JD
authors.lastname: Muehlschlegel
authors.forename: Tjörvi E
authors.initials: TE
authors.lastname: Perry
authors.forename: Junliang
authors.initials: J
authors.lastname: Chen
authors.forename: Kuang-Yu
authors.initials: KY
authors.lastname: Liu
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Fox
authors.forename: Charles D
authors.initials: CD
authors.lastname: Collard
authors.forename: Sary F
authors.initials: SF
authors.lastname: Aranki
authors.forename: Stanton K
authors.initials: SK
authors.lastname: Shernan
authors.forename: Simon C
authors.initials: SC
authors.lastname: Body
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000990:Antithrombin III / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D002417:Cattle; D015331:Cohort Studies; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000378:metabolism*; D011184:Postoperative Period; D011300:Preoperative Care; D057234:Preoperative Period; D011446:Prospective Studies; D013552:Swine
chemical_list: D000990:Antithrombin III; D006493:Heparin