title: Measurement of patients' bivalirudin plasma levels by a thrombelastograph ecarin clotting time assay: a comparison to a standard activated clotting time.
abstract: Standard activated clotting time (ACT) tests have a poor correlation to bivalirudin levels, leading to uncertainty regarding adequate anticoagulation in percutaneous coronary intervention patients. We tested a Thrombelastograph (TEG) ecarin clotting time (ECT) assay for sensitivity to bivalirudin using blood from 80 patients undergoing interventional cardiology procedures with bivalirudin anticoagulation. This was compared to a standard Hemochron ACT assay using diatomaceous earth. With the TEG assay, the direct thrombin activator, ecarin, was used to initiate coagulation and measured as the reaction time. Plasma samples were evaluated for bivalirudin by a chromogenic assay at an independent hematological laboratory. Linear regression of the standard ACT versus bivalirudin level gave an r = 0.306 whereas the TEG ECT gave a much higher r2 = 0.746 (both P < 0.0001). The TEG ECT should prove more useful than the standard ACT for monitoring bivalirudin anticoagulation across the clinically therapeutic range.
authors.affiliation: Department of Anesthesiology, University of Tennessee Graduate School of Medicine, Knoxville, Tennessee 37920, USA.
authors.forename: Roger C
authors.initials: RC
authors.lastname: Carroll
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Chavez
authors.forename: Jeffery W
authors.initials: JW
authors.lastname: Simmons
authors.forename: Carolyn C
authors.initials: CC
authors.lastname: Snider
authors.forename: Dale C
authors.initials: DC
authors.lastname: Wortham
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Bresee
authors.forename: Eli
authors.initials: E
authors.lastname: Cohen
mesh_terms: D001777:Blood Coagulation / Q000502:physiology*; D001780:Blood Coagulation Tests / Q000379:methods; D010450:Endopeptidases; D006629:Hirudins; D006801:Humans; D016014:Linear Models; D010446:Peptide Fragments; D011994:Recombinant Proteins; D013916:Thrombelastography / Q000379:methods*; D014914:Whole Blood Coagulation Time / Q000379:methods
chemical_list: D006629:Hirudins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D010450:Endopeptidases; C020097:ecarin; C074619:bivalirudin