Fondaparinux in acute coronary syndromes

Antithrombotic therapies form the cornerstone of management of acute coronary syndromes (ACS). An ideal antithrombotic agent should reduce ischemic complications while keeping bleeding events to a minimum. Heparins, both unfractionated and low molecular weight, reduce ischemic outcomes but also significantly increase the risk of major and minor bleeding. Moreover, they do not reduce mortality. Therefore, there is a need for newer agents that preserve the benefits of ischemia reduction while decreasing mortality and bleeding risk. Fondaparinux is a synthetic pentasaccharide which specifically targets factor Xa of the coagulation cascade. It has been effectively used in the prevention of and treatment of venous thromboembolic disease. Two large randomized controlled trials of fondaparinux compared to unfractionated and low molecular weight heparins, among patients with ACS have recently been completed. These studies have shown a significantly lower risk of bleeding with fondaparinux compared to heparins, with equivalent or greater reductions in ischemic outcomes. A small but definite increase in the risk of catheter-related thrombosis has been found among patients undergoing coronary interventions, which is ameliorated by the administration of unfractionated heparin. This review outlines the pharmacological properties of fondaparinux and critically examines the available clinical trial data for fondaparinux in ACS.