Optimizing the Duration of Dual Antiplatelet Therapy After Implantation of Drug-eluting Coronary Stents

Editorial Percutaneous coronary intervention (PCI) with implantation of drug‑eluting stents (DESs) has become the standard of care for coronary artery disease and gives a great impetus to device industry. In 2013, approximately half million patients with coronary artery disease underwent PCI in China, with a penetration rate of DES reaching beyond 95%. The use of DES including domestic ones is highly effective in preventing coronary restenosis, but there is a collateral cost to be borne in terms of delayed healing or re‑endothelialization of the stented arterial segment and risk of stent thrombosis. [4] Therefore, dual antiplatelet therapy (DAPT) with aspirin and P2Y12 receptor antagonist for at least 12 months after DES implantation is strongly recommended by Chinese guidelines on PCI. Since prolonged DAPT may increase major bleeding and subsequent mortality, balancing ischemia (or thrombotic events) and bleeding with DAPT is always important for improving overall clinical outcome after DES‑based PCI. Premature discontinuation of DAPT has been proved to be a major determinant of stent thrombosis, [7] but trials with the newer generation DES have suggested low thrombotic event rates despite a relatively short DAPT duration. [8‑10] Currently, two kinds of imported second‑generation DES (zotarolimus‑ and everolimus‑eluting stents) and more than 10 different types of home‑made sirolimus‑eluting stents with or without biodegradable polymer coating are used in daily clinical practice. The PROTACT trial demonstrated that adherence to DAPT modifies the outcome of stent thrombosis to a great extent after sirolimus‑eluting stent deployment than after zotarolimus‑eluting stent deployment, most likely due to different healing characteristics. Likewise, Silber et al. found a lack of association between DAPT use and stent thrombosis between 1 and 12 months in a pooled population of patients receiving resolute zotarolimus‑eluting stent implantation. The EXCELLENT trial indicated that 6‑month DAPT did not increase the risk of target vessel failure defined as the composite of cardiac death, myocardial infarction, or ischemia‑driven target vessel revascularization at 12 months after everolimus‑eluting stent placement compared with 12‑month DAPT. In this issue of Chinese Medical Journal, Zhang et al. investigated the relationship between DAPT use and clinical safety in Chinese patients undergoing everolimus‑eluting stent implantation (the SEEDS study). The major strength of this elegant study was that it included a large cohort of high‑risk patients with small vessel disease, long lesions, or multi‑vessel disease and assessed outcomes during long‑term follow‑up. Discontinuation of DAPT defined as any interruption of aspirin and/or clopidogrel more than 14 …