Extended Duration of Dual‐Antiplatelet Therapy After Percutaneous Coronary Intervention: How Long Is Too Long?

T hemost recent American College of Cardiology/American Heart Association guidelines on duration of dualantiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) give a class I recommendation to continue DAPT for at least 12 months after an acute coronary syndrome (ACS) and at least 6 months after revascularization in the setting of stable ischemic heart disease. These guidelines also give a class IIb recommendation for continuation of DAPT beyond 6 and 12 months in patients with stable ischemic heart disease and ACS, respectively, if these patients have tolerated DAPT without a bleeding event and are at low risk for bleeding in the future. However, they do not provide any guidance with respect to how long DAPT should be continued and leave it to the clinician to discuss the risks versus benefits with the patient and individualize antiplatelet therapy. Therefore, in clinical practice, we often see patients on DAPT several years after a PCI as they are instructed by their providers to never discontinue them. In fact, given how much the importance of taking DAPT in the early period after PCI is emphasized, patients at times are uncomfortable stopping the second antiplatelet agent at any time. The lack of a clear recommendation is not surprising, despite multiple recent randomized controlled trials evaluating differing durations of extended DAPT given several evolving factors and the overall risk/benefits of DAPT. Guidelines commenting on DAPT duration have largely included trials using clopidogrel and early-generation stents. The advent of more potent P2Y12 inhibitors, such as prasugrel and ticagrelor, has reduced major adverse cardiovascular events, but at the cost of increased bleeding. On the other hand, the newer-generation DESs, with their thinner stent struts, a more biocompatible polymer, and favorable drugeluting characteristics, have considerably decreased the risk of stent thrombosis, particularly late stent thrombosis. Although extended DAPT duration has been associated with reduction in recurrent myocardial infarction (MI) and cardiovascular death, there are statistically significant increases in major bleeding events. With the increased recognition of bleeding events and advancements in DES technology, it has been hypothesized that shorter durations of DAPT may be more appropriate. The European and American College of Cardiology/American Heart Association guidelines have already reduced the minimum absolutely required duration of DAPT by incorporating short DAPT into their recommendations. However, the question about the value of extended DAPT duration in selected patients still remains to be answered. To our knowledge, there are 4 randomized controlled trials that have compared the efficacy and bleeding outcomes of standard 12-month therapy versus extended-duration DAPT (>24 months), which are listed below: