Enoxaparin anticoagulation monitoring in the catheterization laboratory using a new bedside test.
OBJECTIVE
This study evaluated the ability of the bedside test Hemochron Jr. Hemonox (International Technidyne Corporation, Edison, New Jersey) to identify patients with insufficient anti-Xa activity level in the catheterization laboratory.


BACKGROUND
Inadequate anticoagulation in patients undergoing percutaneous coronary intervention (PCI) is associated with increased periprocedural ischemic events.


METHODS
In 296 unselected patients undergoing catheterization and/or PCI, whole blood Hemonox clotting time (CT) and activated partial thromboplastin time (aPTT) were measured at baseline (T1) and 10 min after the intravenous administration of enoxaparin (T2) in patients receiving additional enoxaparin and compared with plasma chromogenic anti-Xa activity level.


RESULTS
Median values were 0.1 IU/ml (interquartile range [IQR]: 0.1 to 0.1 IU/ml) and 0.87 IU/ml (IQR: 0.74 to 1.03 IU/ml) for anti-Xa; 74 s (IQR: 70 to 81 s) and 143 s (IQR: 114 to 206 s) for Hemonox CT; and 44 s (IQR: 39 to 50 s) and 72 s (IQR: 58 to 93 s) for aPTT at T1 and T2, respectively. When using Hemonox CT to discriminate patients with anti-Xa level <0.5 IU/ml, the area under the receiver operating characteristic curve was 0.95 +/- 0.01 (95% confidence interval [CI]: 0.93 to 0.97) versus 0.89 +/- 0.01 (95% CI: 0.86 to 0.92) for aPTT. The threshold value of 120 s was associated with a 94.9% (95% CI: 91.1% to 97.4%) sensitivity and a 73.3% (95% CI: 67.6% to 78.5%) specificity to detect patients with inadequate anti-Xa level (<0.5 IU/ml) and positive predictive and negative predictive values of 73.9% (95% CI: 68.7% to 79.0%) and 94.78% (95% CI: 91.8% to 97.8%), respectively.


CONCLUSIONS
Hemonox CT appears to be a fast and reliable bedside test for detecting patients insufficiently anticoagulated and needing adjustment of anticoagulation therapy with enoxaparin before PCI.
Silvain
Johanne
J
Institut de Cardiologie, Institut National de la Santé et de la Recherche Médicale (INSERM) CMR937, Pitié-Salpêtrière Hospital (AP-HP), Université Paris 6, Paris, France.
Beygui
Farzin
F
Ankri
Annick
A
Bellemain-Appaix
Anne
A
Pena
Ana
A
Barthelemy
Olivier
O
Cayla
Guillaume
G
Gallois
Vanessa
V
Galier
Sophie
S
Costagliola
Dominique
D
Collet
Jean-Philippe
JP
Montalescot
Gilles
G
D000367:Age Factors; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000008:administration & dosage*; D001780:Blood Coagulation Tests / Q000295:instrumentation*; D006328:Cardiac Catheterization; D016903:Drug Monitoring / Q000295:instrumentation*; D017984:Enoxaparin / Q000008:administration & dosage*; D015951:Factor Xa / Q000032:analysis; D065427:Factor Xa Inhibitors; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D010314:Partial Thromboplastin Time; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D012372:ROC Curve; D051437:Renal Insufficiency / Q000097:blood; D012680:Sensitivity and Specificity
D000925:Anticoagulants; D017984:Enoxaparin; D065427:Factor Xa Inhibitors; D015951:Factor Xa