Assessment of the anti-Xa activities of Low Molecular Weight Heparins in Patients with Acute Coronary Syndrome

Abstract

Background and Objectives:Standard unfractionated heparin (UFH has long been used to prevent death and myocardial infarction in patients with acute coronary syndrome and acute occlusion undergoing percutaneous revascularization. However, UFH binds to several plasma proteins, platelets, and endothelial cells producing a highly variable anticoagulant response. In contrast, Low molecular weight heparin (LMWH exhibits less protein binding and provides more predictable anticoagulant response with reduced need for patient monitoring and dosage adjustment. The purpose of this study was to assess the anti-Xa activities of LMWH in Korean patients with acute coronary syndrome after recommended dose for caucasians and to determine an optimal method of administration of LMWH. Materials and Methods:Twenty five patients with acute coronary syndrome were enrolled and allocated to five separate groups (5 patients in each group by types according to molecular weight (LMWH (A: molecular weight of 4500 daltons, LMWH (B: molecular weight of 6400 daltons and methods of administration (Group 1A and 1B:Subcutaneous and subcutaneous injections (SC-SC, Group 2:Intravenous and subcutaneous injections (IV-SC, Group 3A and 3B:Intravenous, subcutaneous and subcutaneous injections (IV-SC-SC. Five groups were as follows: Group 1A;LMWH (A 1 mg/kg SC every 12 hours, Group 1B;LMWH (B 100 IU/kg SC every 12 hours, Group 2;LMWH (A 1 mg/kg IV bolus and 1 mg/kg SC 12 hours later, Group 3A;LMWH (A 0.5 mg/kg IV bolus, 3 hours later 1 mg/kg SC every 12 hours, Group 3B;LMWH (B 50 IU/kg IV bolus, 3 hours later 100 IU/kg SC every 12 hours. Anti-Xa activity was measured by amidolytic assay method (Rotachrome, Stago, France in 555 samples from 25 patients. All the data of anti-Xa activity in each group were plotted