title: Evaluation of a novel point-of-care enoxaparin monitor with central laboratory anti-Xa levels.
abstract: BACKGROUND
  Measurement of enoxaparin's anticoagulant activity has been limited to specialized coagulation laboratories and has been impractical for areas needing rapid results, such as during coronary angioplasty. A new point-of-care device, Rapidpoint ENOX, was recently developed to measure clotting times with enoxaparin use.
  
  
  OBJECTIVE
  To correlate ENOX times with anti-Xa levels among patients receiving enoxaparin.
  
  
  METHODS
  A total of 166 patients receiving enoxaparin for the prevention of deep venous thrombosis or as treatment during acute coronary syndromes or angioplasty were prospectively studied. Citrated and non-citrated whole-blood (CWB and NCWB) samples were obtained at baseline and peak enoxaparin activity. ENOX times were measured with whole-blood, and the Stachrom anti-Xa assay was performed on the plasma from the remainder of the samples. The Pearson correlation coefficient was used to assess the relationship between these two assays.
  
  
  RESULTS
  There was a strong linear correlation between the ENOX times and the anti-Xa activities for both CWB (r=0.89, p<0.001) and NCWB (r=0.82, p<0.001) when considering all 332 samples (baseline and peak). When baseline samples were excluded, the correlation remained strong for CWB ENOX times and anti-Xa levels (r=0.84, p<0.001), but was only moderate for NCWB (r=0.73, p<0.001). A CWB ENOX time of </=160 s corresponded to anti-Xa level of </=0.5 IU/ml in 95% (188/197) of patients. A CWB ENOX time >/=200 s corresponded to anti-Xa levels >/=0.8 IU/ml in 96% (93/96) of patients.
  
  
  CONCLUSIONS
  Rapidpoint ENOX times correlate strongly to anti-Xa activities measured by the Stachrom Heparin Assays for citrated whole-blood samples. This novel test can be used for rapid bedside measurements of enoxaparin anticoagulant activity.
authors.affiliation: Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Saw
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Kereiakes
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Applegate
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Braden
authors.forename: Bruce N
authors.initials: BN
authors.lastname: Brent
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Brodie
authors.forename: James B
authors.initials: JB
authors.lastname: Groce
authors.forename: Glenn N
authors.initials: GN
authors.lastname: Levine
authors.forename: Fred
authors.initials: F
authors.lastname: Leya
authors.forename: David J
authors.initials: DJ
authors.lastname: Moliterno
mesh_terms: D000368:Aged; D001780:Blood Coagulation Tests / Q000295:instrumentation; D019411:Clinical Laboratory Techniques; D016903:Drug Monitoring / Q000295:instrumentation* / Q000379:methods; D017984:Enoxaparin / Q000097:blood* / Q000627:therapeutic use; D004867:Equipment Design; D065427:Factor Xa Inhibitors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems
chemical_list: D017984:Enoxaparin; D065427:Factor Xa Inhibitors