New directions in anticoagulant and antiplatelet treatment

New therapies for unstable angina and non-Q-wave myocardial infarction: recent clinical trials

Thrombosis after the rupture of an atherosclerotic plaque often precipitates the acute coronary syndromes of unstable angina and myocardial infarction. The combination of aspirin and heparin has been shown to reduce the occurrence of both symptomatic and asymptomatic ("silent") ischemia, myocardial infarction, and death in patients with these syndromes. However, heparin and aspirin each have significant limitations as antithrombotic drugs. Additionally, coagulation abnormalities may persist for several months after an acute ischemic event, and long-term anticoagulation may be beneficial. Because of the need for frequent anticoagulation monitoring and dosage adjustment, the use of heparin is limited to short-term treatment during the acute in-hospital phase. Recently several novel antithrombotic treatments have been developed. The benefits of direct thrombin inhibitors, platelet fibrinogen receptor antagonists, and low-molecular-weight heparins in the treatment of acute coronary syndromes have been demonstrated in randomized clinical trials.

Hirunorms, novel hirudin-like direct thrombin inhibitors

1. Hirunorms are new synthetic peptides designed to interact with thrombin in a similar way to the natural inhibitor hirudin. 2. Hirunorms are specific and efficient in vitro inhibitors of thrombin activity. 3. Hirunorms are potent anticoagulant and antithrombotic agents in in vivo experimental models devoid of hemorrhagic effects at doses that are active in preventing thrombosis.