Laboratory Monitoring of a Low Molecular Weight Heparin (Enoxaparin) with a New Clotting Test (Heptest)

Bara, L.; Combe-Tamzali, S; Conard, J; Horellou, Marie‐Hélène; Samama, M

doi:10.1159/000215570

Cited by 22 publications

(19 citation statements)

References 4 publications

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“…As unfrac tionated heparin, LMW heparins are mea sured with the anti-thrombin and anti-factor Xa tests. In those cases one observes that the anti-factor Xa test is more sensitive for LMW heparins than anti-thrombin tests [15][16][17], and that the sensitivity for one LMW heparin is different from another one [ 17], A relatively new test is the so-called heptest [18][19][20][21][22], In this test factor Xa is added to plasma and the clotting time is recorded. This test resembles the APTT, which up to now is the best assay for heparins.…”

Section: Introductionmentioning

confidence: 99%

Development of a Rapid and Sensitive Chromogenic Heparin Assay for Clinical Use

Wagenvoord¹,

Hendrix²,

Kolde

et al. 1993

Pathophysiol Haemos Thromb

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A new sensitive chromogenic heparin assay is developed, which is well suited for clinical use. For the assay two reaction mixtures are required which can be lyophilized and reconstituted on the day of use. These reagents are stable during at least 6 h. Only two time-dependent pipetting steps are necessary. Any compound that inactivates thrombin, or can potentiate thrombin inactivation by an inhibitor, can be measured with this assay, including standard heparin, low molecular weight heparins, hirudin, α-NAPAP, pentosan polysulphate and dermatan sulphate. It is shown that heparin can be measured accurately in whole blood and in plasma. By addition of dextran sulphate to one of the reagents a platelet factor 4-insensitive assay is developed, so heparin can be measured even in blood that is partially activated and thus contains platelet factor 4 which neutralizes heparin.

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Section: Introductionmentioning

confidence: 99%

Development of a Rapid and Sensitive Chromogenic Heparin Assay for Clinical Use

Wagenvoord¹,

Hendrix²,

Kolde

et al. 1993

Pathophysiol Haemos Thromb

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“…Anti‐Xa activity measurement has been the most widely used method for assessing LMWHs activity and to establish a therapeutic range for a particular LMWH. Even if anti‐Xa and anti‐IIa activities have been well correlated with the dose of subcutaneous (s.c.) injection of LMWH (Hirsh et al , 1987; Frydman et al , 1988; Bara et al , 1987, 1990), experimental studies in animals have not demonstrated a strong correlation between antithrombotic activity and ex vivo anti‐Xa plasma levels (Holmer et al , 1982; Buchanan et al , 1985; Carter et al , 1982; Ockelford et al , 1982a; Fernandez et al , 1986). In contrast, some studies have found a significant statistical relationship between anti‐Xa plasma levels and both thrombotic and haemorrhagic outcomes with different LMWHs (Levine et al , 1989; Koller et al , 1986).…”

mentioning

confidence: 99%

Occurrence of thrombosis and haemorrhage, relationship with anti‐Xa, anti‐IIa activities, and D‐dimer plasma levels in patients receiving a low molecular weight heparin, enoxaparin or tinzaparin, to prevent deep vein thrombosis after hip surgery

1999

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Summary. Studies in experimental animal models and in patients receiving low molecular weight heparin (LMWH) to prevent thromboembolic events after surgery have not demonstrated a clear relationship between anti-Xa and anti-IIa activities in plasma and either bleeding or prevention of thrombosis. The relationship between these clinical outcomes and ex vivo anti-Xa and anti-IIa activities, activated partial thromboplastin time (APTT) and D-dimers were evaluated in 440 patients undergoing total hip replacement and given prophylaxis once daily with a LMWH (tinzaparin or enoxaparin) in a multicentre doubleblind randomized study. 221 patients received 4500 anti-Xa IU of tinzaparin; 219 patients received 40 mg (4000 anti-Xa IU) of enoxaparin. Both regimens were administered subcutaneously once daily. Blood samples for anti-IIa, antiXa, D-dimers levels and APTT were taken at baseline, on day 1, day 5 and on the day of discharge (days 8-14) and clinical assessments were performed daily until day 14. All patients had bilateral venography between days 8 and 14.All coagulation tests were performed in central laboratories. A significant correlation was observed between anti-IIa activity and anti-Xa activity and the dose of each LMWH injected. The anti-Xa activity was significantly higher with enoxaparin and the anti-IIa activity was significantly higher with tinzaparin. No clear relationship between these two activities and the clinical outcomes was observed. This was also true with regards to APTT. Before and after surgery, Ddimers were significantly higher in patients with deep vein thrombosis (DVT) than in those without DVT but had no predictive value. Interestingly, a significant post-operative increase of D-dimers persisted in both groups of patients during the whole observation period, possibly suggesting that a longer duration of prophylactic treatment may be appropriate.

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“…The HEPTEST (Haemachem, St Louis, MO, USA) is a recently introduced clotting assay for anti-Xa activity which can be performed on automated coagulometers (Yin 1985). Good correlations between CS anti-Xa and the HEPTEST assays have been documented using both unfractionated and low molecular weight heparins (Baa et al 1987;Havenberg et al 1989). Use of the HEPTEST in pregnancy has not been validated.…”

Section: Introductionmentioning

confidence: 99%

HEPTEST: a suitable method for monitoring heparin during pregnancy

Campbell

Tirvengadum

Pickering

et al. 1999

Clinical &Amp; Laboratory Haematology

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Methods of monitoring heparin in pregnancy are problematic. The aim of this study was to assess the plasma HEPTEST as a rapid and reliable test for heparin monitoring in pregnancy. HEPTEST, activated partial thromboplastin time (APTT) and chromogenic anti-Xa assays were performed on individual heparin-spiked plasma samples from two groups: normal non-pregnant women (n = 6) and normal pregnant women during the third trimester (n = 6). Heparin activity curves were established in plasma from both groups for low (< 0.3 IU/ml), intermediate (0.3-0.7 IU/ml) and high (> 0.7 IU/ml) heparin concentrations and validated by comparison with the anti-Xa chromogenic assay. Both the APTT and HEPTEST demonstrated good correlation with anti-Xa levels across all heparin concentrations in both plasma groups (r range = 0.879-0.945). In comparison with the APTT, the HEPTEST showed better correlation with anti-Xa levels at low concentrations of heparin (r values 0.933 vs. 0.772, respectively). For both the APTT and HEPTEST there were significant differences between the clotting times in pregnant and non-pregnant plasma at a number of heparin concentrations. This data supports the plasma HEPTEST as an acceptable alternative to the chromogenic anti-Xa assay for monitoring heparin thromboprophylaxis in pregnancy.

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Laboratory Monitoring of a Low Molecular Weight Heparin (Enoxaparin) with a New Clotting Test (Heptest)

Cited by 22 publications

References 4 publications

Development of a Rapid and Sensitive Chromogenic Heparin Assay for Clinical Use

Development of a Rapid and Sensitive Chromogenic Heparin Assay for Clinical Use

Occurrence of thrombosis and haemorrhage, relationship with anti‐Xa, anti‐IIa activities, and D‐dimer plasma levels in patients receiving a low molecular weight heparin, enoxaparin or tinzaparin, to prevent deep vein thrombosis after hip surgery

HEPTEST: a suitable method for monitoring heparin during pregnancy

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