DES Stent Fractures Linked to Worse Outcome  

      来自波士顿伊丽莎白医学中心的Jeffrey J. Popma医生指出，随着DES应用于复杂病变的增加，了解DES断裂的发生情况以及与其相关病变类型和临床结果是很重要的。

      支架断裂最初是在股浅动脉发现的，而在冠状动脉内支架断裂的识别很困难。因为支架断裂与多项因素相关。就支架设计而言，硬度大的支架较开环支架更易发生断裂。关于操作方面，已证实支架的过度后扩张和支架重叠是最有害的。从解剖方面来讲，支架断裂在钙化病变，成角较大的病变以及心脏运动导致高压的患者当中更易发生。

      Popma指出，Cypher支架（Cordis/Johnson & Johnson）在简单病变的发生率较低，但是有临床研究显示在复杂病变中Cypher支架断裂的发生率明显升高。SIRIUS研究显示，造影证实的支架断裂常为严重的断裂并与长支架有关。此外，支架断裂在开口病变、长病变、成角病变近段、扭曲病变、广泛钙化病变以及完全闭塞病变更为常见。更为重要的是，Taxus研究分析发现支架小梁断裂的患者再狭窄率明显增加（40% vs. 16.4%；P=0.07）。与不良临床结果相关，尤其是较高的TLR（靶病变重建率）和支架血栓的发生率。

      另一项与之相关的报告中，来自克里夫兰临床中心的Adnan Chhatriwalla医生回顾了文献和FDA数据库37项关于支架断裂的报道，2003年1月1日至2008年4月30日期间196例患者中共有202个DES发生了支架断裂。最后总结认为DES支架断裂可能难于识别，但是与支架血栓、不稳定性心绞痛和心肌梗死关系密切。

（来源：www.tctmd.com）

DES Stent Fractures Linked to Worse Outcome  

By TCT Daily Staff

As DES use in more complex lesions is increasing, it is important to understand the prevalence of fracture in these stents, as well as lesion type and associated clinical outcomes, according to Jeffrey J. Popma, MD, of St. Elizabeth’s Medical Center in Boston.

Initially recognized in superficial femoral arteries, stent fractures can be difficult to detect in the coronary tree, Popma said.
Causes of strut fracture are multifactorial. Regarding design, rigid stents appear predisposed to fracture more than open-cell designs. Among procedural issues, stent overexpansion and overlap have proven most deleterious. Anatomically, stent fracture is more common in vessels that have calcium nodules, are highly angulated, and are subject to high stress from cardiac motion.

Although there is a very low incidence of stent fracture with Cypher (Cordis/Johnson & Johnson) in simpler "workhorse" lesions, clinical reports point to higher rates of strut fracture in more complex patient subsets with this stent, Popma said.
In the SIRIUS study, angiographically proven stent fracture was linked to more severe fracture and longer stent length. In addition, fractures were more common with ostial location, longer lesions, angulation, proximal tortuosity, extensive vessel calcification and total occlusion. Importantly, in the Taxus analysis, patients with strut fracture had higher rates of binary restenosis (40% vs. 16.4% in patients without stent fracture; P=0.07). This was associated with worse clinical outcome, in particular, higher rates of TLR and stent thrombosis.

In a related presentation, Adnan Chhatriwalla, MD, of the Cleveland Clinic, provided results of a literature and FDA database review of 37 reports involving 202 DES fractures in 196 patients between January 1, 2003, and April 30, 2008. He concluded that DES stent fracture is likely underrecognized and is associated with stent thrombosis, unstable angina and MI.