Balancing ischaemia and bleeding risks with novel oral anticoagulants

Vitamin K antagonists (VKAs) have long been the standard of care for treatment of venous thromboembolism (VTE), and thromboprophylaxis in atrial fibrillation (AF). Despite their efficacy, their use requires frequent monitoring and is complicated by drug-drug interactions and the need to maintain a narrow therapeutic window. Since 2009, novel oral anticoagulants (NOACs), including the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors apixaban, edoxaban, and rivaroxaban, have become alternative options to VKAs owing to their predictable and safe pharmacological profiles. The overall clinical effect of these drugs, which is a balance between ischaemic benefit and bleeding harm, varies according to the clinical scenario. As adjunctive therapy to dual antiplatelet therapy in patients with acute coronary syndrome, NOACs are associated with incremental bleeding risks and modest benefits. For treatment of VTE, NOACs have a safer profile than VKAs and a similar efficacy. In thromboprophylaxis in AF, NOACs are associated with the greatest benefits by reducing both ischaemic events and haemorrhagic complications and might reduce mortality compared with VKAs. The role of NOACs continues to evolve as these drugs are evaluated in different patient populations, including those with renal impairment or with AF and undergoing percutaneous coronary intervention.