Escalated Single Platelet Inhibition for One Month Plus NOAC in Patients With Atrial Fibrillation and ACS Undergoing PCI

The selection of the optimal antithrombotic therapy in patients with nonvalvular atrial fibrillation (AF) and acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) is challenging. Until recently, triple antithrombotic therapy (TAT) consisting in Aspirin plus Clopidogrel plus OAC was considered the treatment of choice. While efficiently preventing ischaemic events, TAT is associated with an increase in bleeding complications. Therefore, in the past years several randomized controlled trials challenged TAT by comparing a triple antithrombotic therapy (TAT) regimen based on Vitamin K antagonists (VKA) to a dual antithrombotic regimen (DAT) based on non-vitamin K antagonist oral anticoagulants (NOACs) and P2Y12-inhibitors, mainly Clopidogrel in patients with AF undergoing PCI.

However, approximately 30-40% of patients show low response to Clopidogrel and are not adequately protected against ischaemic events, in particular when presenting with ACS. This is supported by a recent meta-analysis reporting that TAT compared to DAT is associated with lower rates of stent thrombosis within 30 days after PCI. It is therefore reasonable to assume that a more potent platelet inhibition within the first month after PCI might reduce the rate of ischaemic complications observed in AF patients undergoing PCI, when receiving DAT. Moreover, a subsequent de-escalation to a less potent platelet inhibition one month after PCI might prevent an increase in bleeding complications.

In EPIDAURUS the investigators will therefore test the hypothesis that DAT using NOAC plus an escalated antiplatelet therapy with a potent P2Y12-inhibitor for one month followed by Clopidogrel reduces ischaemic events without a relevant increase in bleeding complications in patients with AF and ACS undergoing PCI compared to standard DAT with NOAC plus Clopidogrel.