The role of low-molecular-weight heparins in the management of unstable angina and non-ST elevation myocardial infarction

Abstract

Non-ST elevation myocardial infarction (NSTEMI) is a subset clinical manifestation of acute coronary syndrome (ACS), which is usually caused by disruption of vulnerable atherosclerotic plaque, followed by thrombosis resulting various degree of occlusions in coronary arteries. The exposure of tissue factors following the plaque rupture causes activation of coagulation cascades and formation of factor Xa. The thrombin formation will cause fibrin deposition, platelet activation and finally lead to the formation of a stable plaque. Given the central role of thrombin in the pathogenesis of ACs, and antithrombotic agent is an important element in therapy ACS. Low-molecular-weight heparin (LMWHs) is one of antithrombotic agents which has been widely studied in various clinical trials and has been proven useful in clinical efficacy, safety and practical characteristics for ACS treatment. They have been found to improve clinical outcomes in acute coronary syndromes and to provide a more predictable therapeutic response, longer and more stable anticoagulation, and a lower incidence of UFH-induced thrombocytopenia. Of the several LMWH agents that have been studied in large clinical trials, including enoxaparin, dalteparin, and nadroparin, not all have shown better efficacy than UFH. Enoxaparin is the only LMWH compound to have demonstrated sustained clinical and economic benefits in comparison with UFH in the management of unstable angina/non-ST-segment elevation myocardial infarction (NSTEMI).