Department of Medical Sciences, Patras Highest Institute of Education and Technology, Patras, Greece.
Int J Cardiol. 2012 Apr 19;156(2):125-32. doi: 10.1016/j.ijcard.2011.05.052. Epub 2011 Jun 22.
The use of drug eluting stents constitutes a major breakthrough in current interventional cardiology because it is more than halves the need of repeat interventions. It is incontrovertible that coronary stents, in general, have been beneficial for the vast majority of patients. A small increase in thrombosis, following DES implantation, is offset by a diminished risk of complications associated with repeat vascularization. However, late and, especially, very late stent thrombosis is a much feared complication because it is associated with myocardial infarction with increased mortality. Despite that stent thrombosis is thought to be multifactorial, so far clinical reports and reported pathology findings in patients died from coronary stent thrombosis as well as animal studies and experiments, point toward a hypersensitivity inflammation. The stented and thrombotic areas are infiltrated by interacting, via bidirectional stimuli inflammatory cells including eosinophils, macrophages, T-cells and mast cells. Stented regions constitute an ideal surrounding for endothelial damage and dysfunction, together with hemorheologic changes and turbulence as well as platelet dysfunction, coagulation and fibrinolytic disturbances. Drug eluting stent components include the metal strut which contains nickel, chromium, manganese, titanium, molybdenum, the polymer coating and the impregnated drugs which for the first generation stents are: the antimicrotubule antineoplastic agent paclitaxel and the anti-inflammatory, immunosuppressive and antiproliferative agent sirolimus. The newer stents which are called cobalt-chromiun stents and elute the sirolimus analogs everolimus and zotarolimus both contain nickel and other metals. All these components constitute an antigenic complex inside the coronary arteries which apply chronic, continuous, repetitive and persistent inflammatory action capable to induced Kounis syndrome and stent thrombosis. Allergic inflammation goes through three phases, the early phase, the late phase and the chronic phase and these three phases correspond temporally with early (acute and sub acute), late and very late stent thrombosis. Bioabsorbable allergy free poly lactic acid self expanding stents, nickel free stainless steel materials, stent coverage with nitric oxide donors and antibodies with endothelial progenitor cell capturing abilities as well as stents eluting anti-inflammatory and anti-allergic agents might be the solution of this so feared and devastating stent complication.
药物洗脱支架的使用是当前介入心脏病学的重大突破，因为它将重复介入的需求减少了一半以上。不可否认，冠状动脉支架一般来说对绝大多数患者都是有益的。DES 植入后血栓形成略有增加，但与再次血管化相关的并发症风险降低相抵消。然而，迟发性和特别是非常迟发性支架血栓形成是一种令人担忧的并发症，因为它与心肌梗死和死亡率增加有关。尽管支架血栓形成被认为是多因素的，但迄今为止，临床报告和报告的死于冠状动脉支架血栓形成的患者的病理学发现以及动物研究和实验都指向超敏炎症。支架和血栓形成区域被相互作用的炎症细胞浸润，包括嗜酸性粒细胞、巨噬细胞、T 细胞和肥大细胞。支架区域构成了内皮损伤和功能障碍的理想环境，同时还存在血液流变学变化和湍流以及血小板功能障碍、凝血和纤维蛋白溶解紊乱。药物洗脱支架的组成部分包括金属支架，其中含有镍、铬、锰、钛、钼，聚合物涂层和浸渍药物，第一代支架的药物为：抗微管抗肿瘤药物紫杉醇和抗炎、免疫抑制和抗增殖药物西罗莫司。较新的支架称为钴铬支架，洗脱西罗莫司类似物依维莫司和佐他莫司，两者都含有镍和其他金属。所有这些成分在冠状动脉内构成一个抗原性复合物，对炎症具有慢性、持续、重复和持久的作用，能够诱导 Koumis 综合征和支架血栓形成。过敏炎症分为三个阶段，即早期、晚期和慢性期，这三个阶段与早期（急性和亚急性）、晚期和非常晚期支架血栓形成相对应。无过敏反应的可生物吸收的聚乳酸自扩张支架、无镍不锈钢材料、支架覆盖一氧化氮供体和具有内皮祖细胞捕获能力的抗体以及洗脱抗炎和抗过敏药物的支架可能是解决这种可怕和破坏性支架并发症的方法。
