title: Comparison of MAX-ACT and K-ACT values when using bivalirudin anticoagulation during minimally invasive hybrid off-pump coronary artery bypass graft surgery.
abstract: OBJECTIVE
  To compare the kaolin-activated coagulation time (K-ACT) to the MAX-ACT for monitoring anticoagulation with bivalirudin in patients undergoing hybrid off-pump coronary artery revascularization procedures.
  
  
  METHODS
  A prospective, observational study.
  
  
  METHODS
  A cardiac surgical operating room of a university-affiliated hospital.
  
  
  METHODS
  Twelve patients undergoing off-pump coronary artery bypass graft surgery and percutaneous coronary intervention during the same procedure anticoagulated with bivalirudin to a target K-ACT of >300 seconds.
  
  
  METHODS
  At baseline and at frequent intervals during anticoagulation, K-ACT and MAX-ACT assays were run contemporaneously, and the pairs of results were analyzed with descriptive statistics, by correlation analysis, and with Bland-Altman analysis.
  
  
  RESULTS
  The MAX-ACT and K-ACT assays were highly correlated, but the MAX-ACT assay consistently reported significantly lower ACT values compared with the K-ACT. The mean bias (K-ACT minus MAX-ACT) was 94 seconds (limits of agreement, 51-138 seconds).
  
  
  CONCLUSIONS
  To maximize patient safety, centers using bivalirudin for anticoagulation during cardiac surgical procedures need to be aware of the different performance characteristics of ACT assay subtypes.
authors.affiliation: Department of Anesthesia & Perioperative Medicine, University of Western Ontario, London, Ontario, Canada. philip.jones@lhsc.on.ca
authors.forename: Philip M
authors.initials: PM
authors.lastname: Jones
authors.forename: Daniel
authors.initials: D
authors.lastname: Bainbridge
authors.forename: Wojciech
authors.initials: W
authors.lastname: Dobkowski
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Harle
authors.forename: John M
authors.initials: JM
authors.lastname: Murkin
authors.forename: Philip S
authors.initials: PS
authors.lastname: Fernandes
authors.forename: Bob
authors.initials: B
authors.lastname: Kiaii
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects / Q000502:physiology; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods; D005260:Female; D006629:Hirudins / Q000494:pharmacology; D006801:Humans; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D010314:Partial Thromboplastin Time / Q000592:standards*; D010446:Peptide Fragments / Q000494:pharmacology / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D014914:Whole Blood Coagulation Time / Q000592:standards*
chemical_list: D006629:Hirudins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C074619:bivalirudin