Dual antiplatelet therapy after drug-eluting stents: defining the proper duration

As compared with bare-metal stents, drug-eluting stents (DESs) reduce restenosis in every clinical situation and every type of lesion studied. Therefore, DESs have been in widespread use for more than a decade and are used in the majority of patients receiving intracoronary stents. However, several studies have suggested that early discontinuation of dual antiplatelet therapy (DAPT; the combination of aspirin and an inhibitor of platelet P2Y12) is associated with a greater risk for 'late' stent thrombosis in patients with DESs. Because of the relative risk and benefit associated with DESs and the use of DAPT, perhaps the most common question for the treating physicians and patients are with regard to the appropriate duration of DAPT for patients treated with DES implantation. Several observational studies have shown inconsistent findings with respect to the optimal duration of DAPT after DES implantation. Subsequent randomized clinical trials have indicated that courses of clopidogrel exceeding 12 months do not contribute favorably to patient outcomes and may in fact be detrimental. No sound evidence is available to support prolongation of DAPT beyond 12 months. On the basis of recent clinical studies, a shorter course of DAPT than recommended by the guidelines (at least 12 months in the ACCF/AHA/SCAI guideline and 6-12 months in the European Society of Cardiology guidelines) may be considered, especially with second-generation or newer-generation DESs being associated with a significant reduction in stent thrombosis compared with first-generation DES. However, as these trials also had insufficient statistical power to allow for a firm decision with regard to the optimal DAPT duration after DES implantation, the results of larger ongoing clinical trials are necessary to resolve this issue before changing the practice. This article systematically reviews the cumulative evidence from key clinical studies and tries to help guide the physician in making informed decisions on the optimal duration of DAPT for patients who are undergoing DES implantation.