How long should dual antiplatelet therapy be continued following implantation of drug eluting stents?

Drug eluting stents (DES) are now established in the treatment of coronary artery disease (1) and their development promised to improve upon limitations associated with original bare metal stents in particular that of late restenosis. Whilst restenosis rates have improved, DES have been claimed to be associated with a higher risk of late stent thrombosis (2). The administration of dual antiplatelet therapy (DAPT), consisting of aspirin and a P2Y12-receptor inhibitor following implantation of DES significantly reduces the likelihood of coronary stent thrombosis (ST) due to inflammation of the stented segmented during healing (3) and for this reason is deemed mandatory in all patients following DES implantation. DAPT is also associated with additional benefits (unrelated to the stented coronary artery segment) and has been associated with a reduction in ischemic events and an improvement of clinical outcomes (4). However, these benefits are limited by a significant increase in bleeding and therefore current guidelines recommend that DAPT should be administered for 6-12 months following DES (1) with recent studies investigating the feasibility of further reducing the length of DAPT in a bid to further improve safety without exposing patients to unnecessary risks (5-7). However, the current reality is that the most effective duration of DAPT to prevent both stent thrombosis and further ischemic events (e.g., myocardial infarction) remains to be determined and the effects of prolonged DAPT beyond the currently recommended 12 months are poorly characterised.