Ecarin clotting time but not aPTT correlates with PEG-hirudin plasma activity

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Item Type:	Article
Title:	Ecarin clotting time but not aPTT correlates with PEG-hirudin plasma activity
Creators Name:	Moser, M., Ruef, J., Peter, K., Kohler, B., Gulba, D.C., Paterna, N., Nordt, T., Kuebler, W. and Bode, C.
Abstract:	Background: Novel antithrombotic agents such as hirudin have shown promise in the therapy of acute coronary syndromes. PEG-hirudin (polyethyleneglycol conjugated hirudin) has been developed to provide a longer plasma half-life and more stable antithrombotic plasma levels. Privious trials indicated a narrow therapeutic window for hirudin and a number of aPTT (activated partial thromboplastin time)-monitored trials investigating hirudin in acute coronary syndromes had to be stopped because of intracranial bleeding complications. Objectives: The present study evaluates the ecarin clotting time (ECT), a parameter based on the conversion of prothrombin by the snake venom enzyme ecarin, for the monitoring of PEG-hirudin therapy. Methods: Plasma from either healthy volunteers (n=20) or from patients (n=10) suffering from unstable angina pectoris (UAP) was spiked with increasing PEG-hirudin concentrations. In a prospective randomized clinical trial patients with UAP were treated with intravenous PEG-hirudin or heparin over 72 hours. Patients were randomized to the following treatment groups: (1) heparin control group, n=15; (2) PEG-hirudin low dose (0.1[emsp4 ]mg/kg bolus, 0.01[emsp4 ]mg/kg/h infusion), n=19; (3) intermediate dose (0.15[emsp4 ]mg/kg and 0.015[emsp4 ]mg/kg/h), n=17; 4) high-dose (0.2[emsp4 ]mg/kg and 0.02[emsp4 ]mg/kg/h), n=16. Spiked plasma samples and plasma from UAP patients treated with i.v. PEG-hirudin were analyzed for aPTT, ECT, and PEG-hirudin levels. Results: A linear correlation up to the highest therapeutic concentrations could be observed between PEG-hirudin plasma concentrations and the ECT. This was true for both plasma samples spiked with PEG-hirudin in vitro as well as for samples taken from patients treated with i.v. PEG-hirudin (correlation coefficient 0.9, respect.) In contrast the aPTT did not show a reliable linear correlation to PEG-hirudin concentrations. Conclusion: Monitoring of PEG-hirudin therapy by ECT may help to avoid inadequate anticoagulation or overdosing. Thus, the safety and efficacy profile of PEG-hirudin therapy is likely to be enhanced by ECT monitoring.
Keywords:	Anticoagulation, PEG-Hirudin, Ecarin Clotting Time, Activated Partial Thromboplastin Time
Source:	Journal of Thrombosis and Thrombolysis
ISSN:	0929-5305
Volume:	12
Number:	2
Page Range:	165-169
Date:	October 2001
Official Publication:	https://doi.org/10.1023/A:1012975522037
PubMed:	View item in PubMed

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