Dipartimento Cardiovascolare, Policlinico S. Orsola, Bologna, Italy.
Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy.
J Am Coll Cardiol. 2013 Nov 19;62(21):1915-1921. doi: 10.1016/j.jacc.2013.08.725. Epub 2013 Sep 11.
First-generation drug-eluting stents (DES), which impart the controlled release of sirolimus or paclitaxel from durable polymers to the vessel wall, have been consistently shown to reduce the risk of restenosis and target vessel revascularization compared with bare metal stents (BMS). However, stent thrombosis (ST) emerged as a major safety concern with first-generation DES early after their adoption in clinical practice, requiring prolonged dual antiplatelet therapy. Pathological studies have shown that first-generation DES are associated with delayed arterial healing and polymer hypersensitivity reactions resulting in chronic inflammation, predisposing to late and very late ST. Second-generation DES have been developed to overcome these issues with improved stent designs and construction and the use of biocompatible and bioabsorbable polymers. Meta-analyses have shown that the thin-strut, fluoropolymer-coated cobalt-chromium everolimus-eluting stent (CoCr-EES) may be associated with lower rates of definite ST than other DES and, unexpectedly, even lower than BMS. The thin-strut structure of the stent platform, the thromboresistant properties of the fluoropolymer, and the reduced polymer and drug load may contribute to the low rate of ST with CoCr-EES. The notion of DES being safer than BMS represents a paradigm shift in the evolution of percutaneous coronary intervention. The relative safety and efficacy of fluoropolymer-coated CoCr-EES, DES with bioabsorbable polymers, and fully bioresorbable scaffolds are the subject of numerous ongoing large-scale trials.
第一代药物洗脱支架(DES)通过将西罗莫司或紫杉醇从耐用聚合物中受控释放到血管壁,与金属裸支架(BMS)相比,可降低再狭窄和靶血管血运重建的风险。然而,第一代 DES 在临床应用早期即出现支架血栓形成(ST)这一主要安全问题,需要长期双联抗血小板治疗。病理学研究表明,第一代 DES 与延迟的动脉愈合和聚合物过敏反应有关,导致慢性炎症,易发生晚期和极晚期 ST。第二代 DES 通过改进支架设计和结构以及使用生物相容性和可生物吸收聚合物来克服这些问题。荟萃分析表明,与其他 DES 相比,薄壁、含氟聚合物涂层的钴铬依维莫司洗脱支架(CoCr-EES)可能与较低的明确 ST 发生率相关,出乎意料的是,甚至低于 BMS。支架平台的薄壁结构、氟聚合物的抗血栓形成特性以及减少的聚合物和药物载量可能有助于 CoCr-EES 较低的 ST 发生率。DES 比 BMS 更安全的概念代表了经皮冠状动脉介入治疗演变中的一个范式转变。含氟聚合物涂层的 CoCr-EES、具有可生物吸收聚合物的 DES 和完全可生物吸收支架的相对安全性和疗效是众多正在进行的大规模试验的主题。