Efficacy of new oral anticoagulants in patients with atrial fibrillation previously treated with warfarin: A meta-analysis of randomized controlled trials

Vitamin K antagonists (VKAs), together with newer oral anticoagulants (NOACs) such as dabigatran, rivaroxaban, or apixaban, reduce the risk of stroke in patients with atrial fibrillation (AF). However, patients with no prior exposure to anticoagulation (i.e., VKA naive) may be at higher risk for adverse outcomes (thromboembolic events and/or bleeding) than patients who are VKA experienced. When adjusted-dose VKA (INR 2–3) cannot be used in a patient with AF where an oral anticoagulant (OAC) is recommended, due to difficulties in keeping INR within therapeutic range of 2 to 3, experiencing side effects of VKAs, or inability to attend INR monitoring, most recent guidelines indicate that one of the NOACs should be chosen. Whether a clear benefit also exists with NOACs in AF patients who have been doing well with a previous treatment with warfarin remains a matter of debate. Beyond reimbursement issues, regulatory agencies in some countries recommend keeping vitamin K antagonist in AF patients with stable INR. We aimed to evaluate whether the treatment effects of NOACs compared with warfarin were also beneficial for patients who were VKA experienced.
Source: International Journal of Cardiology - Category: Cardiology Authors: Tags: Letters to the Editor Source Type: research