Established venous thromboembolism therapies: heparin, low molecular weight heparins, and vitamin K antagonists, with a discussion of heparin-induced thrombocytopenia

Abstract

For a majority of patients with venous thromboembolism (VTE), initial treatment is straightforward and necessitates the immediate initiation of a parenteral anticoagulant (eg, heparin or low molecular weight heparin), simultaneous initiation of long-term therapy (eg, vitamin K antagonist), and discontinuation of the parenteral anticoagulant after 5 days assuming that the vitamin K antagonist is therapeutic. This standardized approach is based on numerous pivotal clinical trials completed over the past 3 decades. Yet, advances in standardized VTE treatment continue to evolve and include issues related to the selection and dosing of parenteral anticoagulants (eg, relative efficacy and dosing in the obese patient, patients with renal impairment, and pregnant patients), optimal location of initial care delivery, use of dosing initiation nomograms for vitamin K antagonists with the potential of gene-based dosing, and demonstration that longterm low molecular weight heparin therapy may be optimal for some patient populations (eg, those with active cancer). Further, in parallel with the evolution of VTE treatment, there have been remarkable advances in our understanding of heparin-induced thrombocytopenia, a prothrombotic complication of parenteral anticoagulant use.