• Oral anticoagulants

In the development of new antithrombotic drugs the main target has become the improvement of the net clinical benefit (reduction of major bleeding complications as well as reduction of thromboembolic ischaemic complications), rather than a higher efficacy in terms of reduction of thromboembolic ischaemic events only.1 Standard antithrombin treatment of non-ST elevation acute coronary syndromes (NSTE-ACS) in recent years has consisted of unfractionated heparin (UFH) or low molecular weight heparin (LMWH), especially enoxaparin, which has been tested most extensively within this group of agents.^{w1 w2} In patients with ST elevation myocardial infarction (STEMI) the use of UFH is still the major antithrombotic regimen when primary percutaneous coronary intervention (PCI) is performed. As an adjunct antithrombin to thrombolytic therapy, enoxaparin has been proven to be more efficacious than UFH, with comparable bleeding rates, and is widely used.^w3

In the past few years, new antithrombins have been investigated in patients with acute coronary syndromes (ACS). Based on favourable data obtained from large prospective randomised clinical trials, the indirect anti-Xa inhibitor fondaparinux, as well as the direct thrombin inhibitor bivalirudin, have made it into the updated guidelines of the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) (tables 1 and 2).1–5 Moreover, new direct anti-Xa inhibitors such as apixaban, rivaroxaban, and otamixaban, as well as the direct antithrombin dabigatran, are still under clinical investigation, and the results of phase II dose finding and safety studies have been published recently.

Figure 1 shows the onset of action of the different antithrombins in the coagulation cascade. This article provides an overview of the results …