Apixaban Versus Rivaroxaban in Non Valvular Atrial Fibrillation

Atrial fibrillation (AF) is the most common heart rhythm disorder with an estimated global prevalence of between 1 and 2%. It is a serious pathology that considerably increases morbidity and mortality. Thromboembolic events are a major complication . Thus, effective anticoagulation is one of the major pillars of the management of atrial fibrillation. This anticoagulation was for a long time based on vitamin K antagonists (VKAs) which have proven their effectiveness in significantly reducing the risk of thromboembolic complications. However, VKAs have several drawbacks, mainly related to their narrow therapeutic range, their high inter-individual variability and their multiple drug interactions. As a result, the use of VKAs is restrictive because of the need for a delicate, regular and individual adjustment of the effective dose based on the result of the INR (need for regular and close biological monitoring) . Since 2007, a new class of oral anticoagulant encompassing direct oral anticoagulants has emerged and is increasingly beginning to take the place of VKAs in several pathologies, including AF. Indeed, DOACs are currently the first-line treatment during AF thanks to the results of randomized controlled clinical trials that have proven an efficacy at least equivalent to VKA without increasing the risk of serious bleeding. In addition, DOACs are simpler to use compared to VKAs because of their predictable pharmacodynamics and pharmacokinetics, which make it possible to use a fixed dose and dispense with biological monitoring of their plasma levels in the majority of cases. However, it seems that there is a significant inter- and intra-individual variability related to the use of DOACs. In addition, the theory of a single dose and the non-need for monitoring is beginning to be debated. Indeed, the indications requiring an AOD assay seem to be broadening. Recently, studies have been identified in the literature that are interested in assessing the impact of the maximum and residual activity of DOAC on its efficacy and safety. Despite significant results, especially in relation to the fluctuation of residual activity, there are so far no strong conclusions of a high level of evidence that can rule on the usefulness of adjusting the dose according to the dosage of activity.