In vitro comparison of dabigatran, unfractionated heparin, and low-molecular-weight heparin in preventing thrombus formation on mechanical heart valves.

Abstract

INTRODUCTION:

Lifelong oral anticoagulation (OAC) therapy is required for the prevention of thromboembolic events after implantation of an artificial heart valve. Thromboembolism and anticoagulant-related bleedings account for approximately 75% of all complications experienced by heart valve recipients (2-9% of patients per year). The present study investigated the efficacy of dabigatran, a new direct thrombin inhibitor for oral use, as compared to unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) in preventing thrombus formation on mechanical heart valves in vitro.

MATERIAL AND METHODS:

Blood (230 ml) from healthy young male volunteers was anticoagulated either by dabigatran (1 micromol/l), UFH (150 IU), or LMWH (100 IU). Mechanical heart valve prostheses were placed in an in vitro thrombosis tester and exposed to the anticoagulated blood samples under continuous circulation at a rate of 75 beats per minute.

RESULTS:

In whole blood with no anticoagulant, the apparatus completely clotted in 15-20 minutes. When blood was treated with dabigatran, the mean thrombus weight was 164+/-55 mg, in the UFH group 159+/-69 mg, and in the LMWH group 182+/-82 mg (p-value: 0.704). Electron microscopy showed no significant difference in thrombus formation in any group.

CONCLUSIONS:

Dabigatran was as effective as UFH and LMWH in preventing thrombus formation on mechanical heart valves in our in vitro investigation. Thus, we hypothesize that dabigatran etexilate might potentially be a useful and competitive orally administered alternative to UFH and LMWH for recipients of alloplastic heart valve prostheses.

• Authors: Lars Maegdefessel, Torsten Linde, Franziska Krapiec, Kathrin Hamilton, Ulrich Steinseifer, Joanne van Ryn, Uwe Raaz, Michael Buerke, Karl Werdan, Axel Schlitt
• Journal: Thrombosis research (Thromb Res) Vol. 126 Issue 3 Pg. e196-200 (Sep 2010) ISSN: 1879-2472 [Electronic] United States
• PMID: 20659761 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Anticoagulants
• Benzimidazoles
• Fibrinolytic Agents
• Heparin, Low-Molecular-Weight
• Pyridines
• Heparin
• Dabigatran

Topics

• Administration, Oral
• Anticoagulants (administration & dosage, pharmacology)
• Benzimidazoles (administration & dosage, pharmacology)
• Blood Coagulation (drug effects)
• Dabigatran
• Fibrinolytic Agents (administration & dosage, pharmacology)
• Heart Valve Prosthesis (adverse effects)
• Heparin (administration & dosage, pharmacology)
• Heparin, Low-Molecular-Weight (administration & dosage, pharmacology)
• Humans
• Male
• Prosthesis Design
• Pyridines (administration & dosage, pharmacology)
• Thrombosis (blood, etiology, prevention & control)
• Time Factors