Antithrombins and the importance of good control.

The generation of thrombin and the formation of platelet rich intra-coronary thrombus in response to atherosclerotic plaque rupture is pathognomonic of acute coronary syndromes. An understanding of the process of thrombin generation and the unique relationship between the structure and function of thrombin is essential to developing more effective anti-thrombotic strategies than the use of standard unfractionated heparin in the acute coronary syndromes. The mechanisms of action of heparin, low molecular weight heparins (LMWHs) and the newer direct anti-thrombins, recombinant hirudin and Hirulog, are reviewed. Evidence from the currently available phase 2 and 3 trials of these drugs regarding their efficacy in the acute coronary syndromes is also reviewed.