[Real-world data on novel oral anticoagulants: the added value of registries and observational studies. Focus on apixaban].

Anticoagulant therapy has been used with great effect for decades for the prevention of stroke among patients with atrial fibrillation. In recent years, the therapeutic armamentarium has been strengthened considerably, with the addition of anticoagulants acting through novel pathways. The currently available novel agents are apixaban, rivaroxaban and dabigatran. These novel oral anticoagulants (NOACs) were approved for use on the basis of major clinical trials clearly demonstrating improved risk reductions compared to warfarin for stroke and/or major bleeding events. In these studies, apixaban and dabigatran 150 mg each significantly reduced the risk of stroke, while apixaban and dabigatran 110 mg reduced the risk of major bleeding compared to warfarin. Extrapolating the results of the randomized clinical trials on NOACs to all patients is not possible, as the strict design of clinical trials yields information that is directly applicable to a relatively narrow spectrum of patients. To control for confounding variables, randomized studies restrict enrolment to a prespecified set of criteria that do not necessarily reflect the profiles of all those who could potentially benefit from these agents. Research continues using the trial databases, in an attempt to better identify patient subgroups who do or do not benefit from each of the agents. At the European Society of Cardiology (ESC) annual meetings in London in 2015 and in Rome in 2016, there were several presentations and posters providing this type of evidence. Perhaps more important, as real-world experience with these agents grows, we are beginning to obtain meaningful new information about the NOACs in everyday use. This has involved the study of large databases including patients receiving these medications in clinical situations less stringently defined than in the randomized clinical trials. These include purpose-built registries, observational studies, and analyses of healthcare administrative databases. At both ESC meetings in 2015 and 2016, a wealth of information was presented using these types of sources. In many cases, these new data reinforce the key learnings from the randomized clinical trials. The following report provides highlights of registry and other post-marketing data presented at both ESC meetings in 2015 and 2016.