Current challenges and future prospects in oral anticoagulant therapy.

The choice for oral anticoagulant (OAC) therapy was previously limited to the vitamin K antagonists (VKAs). The advent of the direct oral anticoagulants (DOACs) brought with it the expectation that oral anticoagulation would become simpler (with the elimination of routine monitoring and introduction of a fixed-dose anticoagulant), and that the use of VKAs would be slowly phased out. Although DOACs have made anticoagulation more convenient and accessible, we are now faced with what can be described as a tyranny of choice, together with many unanswered questions relating to DOAC use. These include optimal DOAC selection and dosing, use in complex 'real-world' patients, the role for monitoring and issues surrounding adherence. Warfarin remains the anticoagulant of choice in certain scenarios (e.g. metallic heart valves). The future holds much excitement: clinical studies are underway to expand the indications for DOACs and experience continues to grow outside the trials setting.