Heparin monitoring: clinical outcome and practical approach

Traditional anticoagulant agents such as unfractionated heparin (UFH), low molecular weight heparins (LMWHs), fondaparinux, danaparoid and bivalirudine are used in the prevention and treatment of thromboembolic diseases. However, these agents have limitations: their constraining parenteral route of administration and the need for regular coagulation monitoring for HNF. The LMWHs, with their more predictable anticoagulant response, don't require a systematic monitoring. The usefulness of LMWHs monitoring in several clinical situations such as pregnancy, obesity and renal insufficiency is a matter of debate. Indeed, there is no agreement between French and American recommendations on this question. Others aspects are also controversial: the measure of trough anti-Xa activity during pregnancy and the optimal monitoring of LMWHs for patients with antithrombin deficiency (hepatic disease, new-borns). Different tests are available to ensure the monitoring of these drugs, we will see in this review their principle, their advantages and inconvenients. The management of heparin induced thrombocytopenia also needs parenteral anticoagulants: danaparoïd, bivalirudine or argatroban. The modalities of their monitoring are relatively unknown and are presented. Furthermore, platelet monitoring is capital. This article aims to provide guidance about laboratory testing of classic parenteral anticoagulants.