A completely fractured zotarolimus‐eluting stent in an aortocoronary saphenous vein bypass graft

Drug‐eluting stents (DES) have significantly improved the rate of target vessel revascularization in comparison with bare metal stents. DES fracture was not reported in multicenter randomized clinical trials, but several case reports of DES fracture have been published, mostly with sirolimus‐eluting stents. DES fracture is associated with stent restenosis and thrombosis. We report a zotarolimus‐eluting stent fracture in an aortocoronary saphenous vein graft (SVG) bypass. The patient presented with chest pain and a non‐ST‐elevation myocardial infarction. He underwent cardiac catheterization that showed a complete fracture of a zotarolimus‐eluting stent in the ostium of a sequential SVG to the diagonal and obtuse coronary arteries. His management included coronary angioplasty and retrieval of the proximal fractured segment. We discuss the potential causes for this stent fracture and suggest caution when using a DES in an ostial location of a SVG bypass, especially in a highly mobile vessel. © 2012 Wiley Periodicals, Inc.     

药物涂层支架在复杂冠脉病变中的临床应用

复杂冠脉病变是冠心病介入治疗中的难点及热点,近年来的研究及临床实践表明,药物涂层支架在其中的临床应用取得了令人鼓舞的成绩,但也暴露出了许多问题。现主要针对药物涂层支架在复杂冠脉病变中应用的一些研究结果作一综述。     

Paclitaxel‐eluting balloon: From bench to bed

Since the first clinical angioplasty by Gruntzig in 1977, restenosis has been the primary drawback of percutaneous coronary intervention (PCI). In the balloon era. restenosis was correlated with elastic recoil and negative remodeling of the arterial wall. Later, introduction of stents proved to be a significant advance in reducing the elastic recoil and negative remodeling at the treatment site but stimulated proliferation, migration of smooth muscle cells, and neointimal hyperplasia, thereby generating a new type of restenosis, in‐stent restenosis. Brachytherapy and drug‐eluting stents (DES) may be considered the two breakthroughs against neointimal hyperplasia. However, concerns about stent thrombosis and incomplete elimination of in‐stent restenosis with DES in complex lesions and patients justify the pursuit of research in this field. Non‐stent based local drug delivery and particularly the use of paclitaxel‐eluting balloons could be one of these strategies. We aimed to review the concept, preclinical‐, and clinical data available with non‐stent based local drug delivery and, in particular, with paclitaxel‐eluting balloons. © 2009 Wiley‐Liss, Inc.     

Drug-Eluting Stent Restenosis: Incidence, Predictors, Mechanisms, and Treatment

Drug-eluting stents (DES) represent a major advance in percutaneous coronary intervention (PCI). Clinical trials have shown significant reductions in restenosis with both sirolimus- and paclitaxel-eluting stents, with subsequent revascularization rates in the single digit range in most studies. Predictors of restenosis and target lesion revascularization include diabetes, prior restenosis, smaller post-PCI minimal lumen diameter and complex lesion features, such as long lesions, smaller vessels, ostial lesions, and bifurcations. DES restenosis is most commonly focal (or multifocal) within the stent and less commonly is manifest as a diffuse or proliferative narrowing. The mechanisms of DES include stent under-expansion, nonuniform stent strut distribution or stent malapposition, polymer disruption due to difficult stent delivery, stent fracture, and possibly drug resistance or failure. Although only limited data are available regarding treatment of DES restenosis, reintervention appears to be associated with relatively low subsequent recurrence rates and repeat DES implantation is generally accepted as the treatment of choice for DES restenosis.     

Passive and Active Polymer Coatings for Intracoronary Stents: Novel Devices to Promote Arterial Healing

Coronary stent implantation is the second great advance in the treatment of obstructive coronary artery disease since the introduction of balloon catheter angioplasty. However, in-stent restenosis (ISR) caused by neointimal hyperplasia has been a major limitation of stents, occurring in up to 30% of cases. Advances in coronary stent technology both in terms of stent design and function and especially drug-eluting stents (DES) have significantly improved the safety and efficacy of percutaneous coronary intervention (PCI) with stenting, including marked reduction in ISR. This has led to use of DES for increasingly challenging clinical and lesional subsets, with potential for increased risk of stent-associated complications, especially late stent thrombosis (LST). Because restenosis and stent thrombosis are caused by multiple and often interrelated factors, ideal agents for stent coatings should inhibit thrombus formation, inflammatory reaction, and cellular proliferation, while supporting reendothelialization. To avoid undesirable effects of currently applied (durable) polymers, biocompatible, and bioabsorbable polymers as well as DES delivery systems that minimize polymer burden have been produced and tested. Bioabsorbable stents, both polymeric and metallic, have been developed to decrease potential late complications after stent implantation. Novel strategies to address some of these challenges are in various stages of research and development. In this article we outline developments in the field of passive and active stent coatings and evaluate the ongoing role of such coatings in the contemporary era of DES.     

Very late stent thrombosis due to DES fracture: Description of a case and review of potential causes

Stent fracture and subsequent stent thrombosis are known complications after stent implantation, especially in stents with closed cell design like the first generation sirolimus drug eluting stents (DES). Late stent thrombosis is very rarely encountered in our patient population, majority Chinese. We report a case of non‐ST elevation myocardial infarction as a result of very late stent thrombosis (three years after implantation) due to stent fracture at the site of overlap of two first generation sirolimus DES. There were initial difficulties in restoring coronary flow by conventional reperfusion therapies but a successful outcome after implantation of an endothelial progenitor cell capture stent, with no further recurrence of ischemic event after 12 months. An attempt was made to analyze all existing factors present and contributing to the stent fracture and stent thrombosis in this case, as reported in the literature. © 2011 Wiley Periodicals, Inc.     

Diagnosis and management challenges of in-stent restenosis in coronary arteries

Over the course of the 3 decades, percutaneous coronary intervention(PCI) with stent implantation transformed the practice of cardiology. PCI with stenting is currently the most widely performed procedure for the treatment of symptomatic coronary disease. In large trials, drugeluting stents(DES) have led to a significant reduction in in-stent restenosis(ISR) rates, one of the major limitations of bare-metal stents. Due to these favorable findings, DES was rapidly and widely adopted enabling more complex coronary interventions. Nevertheless, ISR remains a serious concern as late stent complications. ISR mainly results from aggressive neointimal proliferation and neoatherosclerosis. DES-ISR treatment continues to be challenging complications for interventional cardiologists.     

Restenosis after PCI: Battered but not beaten

• In patients with bare‐metal stent (BMS) restenosis, drug‐eluting stents (DES) are superior to vascular brachytherapy (VBT), leading to a lower risk of clinical restenosis and target vessel revascularization, but not to less stent thrombosis, myocardial infarction, or death; these benefits persist for 2–5 years.
• The optimal management of DES restenosis is unknown, but recent studies suggest that drug‐eluting balloons (DEB) and DES have similar efficacy and safety.
• Since DEB are not commercially available in the United States, VBT may be a reasonable alternative to repeated DES.

     

Drug-eluting stent-supported percutaneous coronary intervention for chronic total coronary occlusion.

OBJECTIVES: This study sought to determine the clinical and angiographic outcomes after drug-eluting stent (DES)-supported percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO). BACKGROUND: There are few data about the efficacy of DES-supported PCI for CTO. METHODS: All consecutive patients who had a sirolimus-eluting stent or a paclitaxel-eluting stent implanted for CTO from December 2003 to December 2004 were analyzed. Clinical and angiographic outcomes of patients treated with DES were compared with a case-matched control group of patients treated with bare metal stents (BMS) in the 12 months before the routine use of DES. RESULTS: Successful DES-supported PCI was performed in 92 patients and 104 CTO. The case-matched control group consisted of 26 patients and 27 CTO successfully treated with BMS. There were no differences between groups in baseline clinical and angiographic characteristics. Stent length in the DES group was higher as compared with that of BMS group (51+/-28 mm vs. 40+/-19 mm, P=0.073). The 6-month major adverse cardiac event (MACE) rate was lower in the DES group as compared with that of BMS group (9.8% vs. 23%, P=0.072). The angiographic follow-rate was 80% in the DES group and 81% in the BMS group. The 6-month restenosis rate was 19% in the DES group and 45% in the BMS group (P<0.001). By multivariate analysis, it was found that in the DES group, the only predictors of restenosis were stented segment length (OR 1.031, 95% CI 1.01-1.06, P=0.009) and a target vessel reference diameter<2.5 mm (OR 6.48, 95% CI 1.51-27.83, P=0.012), while the only predictor of MACE was stent length (OR 1.04, 95% CI 1.01-1.08, P=0.006). CONCLUSIONS: DES implantation for CTO decreases the risk of mid-term restenosis and MACE. Small vessels and diffuse disease requiring the implantation of multiple stents and very long stents for full coverage of the target lesion are still associated with a relatively high risk of restenosis.     

Cardiac CTA,three‐dimensions,and the chronic total occlusion: A window to the future

Objectives: To assess the procedural and clinical outcomes from a modified subintimal tracking and re‐entry (STAR) procedure performed using contrast guidance. Background: Previous data showed that recanalizing a chronic total occlusion (CTO) with the STAR technique was possible. However, this technique was considered difficult and therefore has only been adopted by a limited number of experienced operators. Methods: Patients (n = 68) with a CTO of a native coronary artery treated by a single operator with this technique were included. Results: The right coronary artery was involved in 79.4%, the morphology was blunt in 77.9%, and CTO length was longer than 20 mm in 67.6%. Angiographic success rate was 80.9% with a 70.6% rate of complete recanalization. Stent implantation was performed in 82.3% of cases, with drug‐eluting stents (DES) implanted in the majority (92.7%). Procedural complications occurred in 10.3% of cases. There were no episodes of myocardial infarction during follow‐up, with 1 case (1.5%) of cardiac death. There were no cases of definite or probable stent thrombosis, and there was 1 (1.5%) possible stent thrombosis. The overall rate of in‐segment binary restenosis was 44.7%, and target lesion revascularization (TLR) was performed in 25% of lesions. The rate of TLR in lesions treated with DES was 29.4% and in those treated with bare‐metal stents was 50%. Conclusion: The contrast‐guided STAR technique appears to be feasible and relatively safe. However, this procedure is limited by a high rate of restenosis even with DES, and a second procedure may be necessary to obtain a definitive result. © 2008 Wiley‐Liss, Inc.     

药物洗脱支架和金属裸支架治疗弥漫病变的比较研究

目的比较冠心病患者弥漫病变采用药物洗脱支架和金属裸支架治疗的近期和远期预后,分析影响这类病变介入治疗预后的危险因素。方法研究对象为我院2004年4月至2005年8月接受置入单个长度>25.0mm支架治疗并且进行冠状动脉造影随访的205例患者,排除支架置入失败及支架置入位置不理想者。分为置入药物洗脱支架(DES)组(n=128)和置入金属裸支架(BMS)组(n=77)。所有的患者术后均接受阿司匹林300mg、氯吡格雷75mg等规范药物治疗。手术成功判定标准为至少用相互垂直的两个投照体位行冠状动脉造影,肉眼判定残余狭窄<20%和前向血流TIMI3级。再狭窄判定标准以复查冠状动脉造影定量分析支架内或支架邻近血管管腔直径狭窄程度≥50%。患者在支架术后6个月左右接受冠状动脉造影随访。结果共205例患者(男性181例,女性24例)227个靶病变置入382枚支架完成造影随访。其中C型病变占总数的93.8%,B2型病变为6.2%。双支或双支以上血管病变的患者比例达到86.8%。平均术前参考血管直径(2.88±0.43)mm。平均每个病变支架长度(40.09±12.94)mm,54.2%的病变接受了重叠置入支架。比较置入DES组和置入BMS组,两组的患者基本条件差异无统计学意义,在病变基本条件方面,DES组术前参考血管直径明显小于BMS组[(2.80±0.37)mm比(3.10±0.48)mm,P=0.005]。6个月随访结果显示再狭窄率DES组(15.4%)小于BMS组(48.4%),P<0.001。晚期支架内腔径丢失BMS组明显大于DES组[(0.94±0.76)mm比(0.39±0.53)mm,P<0.001]。靶病变血管重建率DES要明显好于BMS(11.6%比38.5%,P<0.001)。支架内再狭窄在置入DES组的局限性再狭窄比例大于置入BMS组(33.3%比18.2%,P=0.029)。对影响复杂弥漫病变支架再狭窄因素的多元logistic回归分析发现,采用支架重叠置入(OR=2.82,P=0.017)和支架类型(OR=5.71,P<0.001)是对复杂弥漫病变支架内再狭窄影响最大的危险因素。结论我们的研究发现对于复杂弥漫病变的治疗,药物洗脱支架有着良好的治疗效果,较金属裸支架能明显减低再狭窄率。对于弥漫病变,我们应该使用长支架,尽可能减少支架重叠置入的数量。     

Drug-eluting stents and acute myocardial infarction:A lethal combination or friends?

Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction(STEMI). First generation drug-eluting stents(DES),(sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.     

In-stent neoatherosclerosis: a final common pathway of late stent failure

Percutaneous coronary intervention with stenting is the most widely performed procedure for the treatment of symptomatic coronary disease, and drug-eluting stents (DES) have minimized the limitations of bare-metal stents (BMS). Nevertheless, there remain serious concerns about late complications such as in-stent restenosis and late stent thrombosis. Although in-stent restenosis of BMS was considered as a stable condition with an early peak of intimal hyperplasia, followed by a regression period beyond 1 year, recent studies have reported that one-third of patients with in-stent restenosis of BMS presented with acute coronary syndrome that is not regarded as clinically benign. Furthermore, both clinical and histologic studies of DES have demonstrated evidence of continuous neointimal growth during long-term follow-up, which is designated as "late catch-up" phenomenon. Here, we present emerging evidence of de novo neoatherosclerosis based on histology, angioscopy, and intravascular images that provide a new insight for the mechanism of late stent failure. In-stent neoatherosclerosis is an important substrate for late stent failure for both BMS and DES, especially in the extended phase. In light of the rapid progression in DES, early detection of neoatherosclerosis may be beneficial to improving long-term outcome of patients with DES implants.     

In‐Stent Restenosis

The introduction of coronary stents marked a major turning point in the practice of interventional cardiology. Whereas the efficacy of balloon angioplasty was challenged both by immediate mechanical complications and by a high incidence of restenosis, coronary stents offered cardiologists a means by which to not only augment immediate procedural success, but also to reduce the incidence of restenosis following coronary intervention. However, despite technological advances and an improved understanding of the restenotic process, the overall rate of in‐stent restenosis following bare metal stent implantation remains high. Although the introduction of drug‐eluting stents has further reduced the incidence of restenosis, the “real‐world” application of drug‐eluting stents in increasingly complex lesion and patient subsets has given way to the even greater clinical challenge of managing drug‐eluting stent restenosis. Although the standard treatment of bare metal stent restenosis typically involves placement of a drug‐eluting stent, the optimal therapeutic approach to drug‐eluting stent restenosis remains less defined. The issue of in‐stent restenosis (especially following implantation of a drug‐eluting stent) remains a clinical challenge, and investigation into therapeutic options remains ongoing. As technology evolves, such investigation will likely incorporate novel approaches including drug‐coated balloons novel stent designs.     

Stent thrombosis after complex multivessel stenting in an elderly patient

We report a challenging case in terms of procedural difficulty as well as long‐term patency. Multivessel stenting procedures for long subtotal occlusions in the right coronary artery (RCA) and left anterior descending coronary artery (LAD) were successfully performed in an 84‐year‐old female who had complications of severe left ventricular dysfunction and a recent history of gastric ulcer bleeding. Two bare‐metal stents were successfully deployed in the mid and distal RCA. A drug‐eluting stent could only be deployed in the proximal RCA. Two drug‐eluting stents were deployed in the proximal LAD and LMT. Late stent thrombosis in the proximal RCA occurred about 3 months later. We speculated that a lack of aspirin and bare metal stent restenosis were the reasons for the late stent thrombosis. This case was very challenging in terms of balancing the risk of ischemia and bleeding after coronary stent deployment. © 2010 Wiley‐Liss, Inc.     

Facilitated stent delivery using applied topical lubrication.

OBJECTIVES: The goal of this study was to assess the utility of topical lubrication to aid stent delivery in challenging anatomy and its effects on long-term clinical outcome. BACKGROUND: Failed stent delivery is encountered in up to 5% of percutaneous coronary interventions (PCI). METHODS: The effectiveness of topically applied lubrication to facilitate stent delivery after failed stent placement was evaluated in 20 (2.5%) out of 813 consecutive patients undergoing PCI. Initial attempts at stent delivery failed despite balloon predilatation and use of moderate-to-stiff guidewires in all patients. The lubricious solution used was Rotaglide, a phospholipid emulsion originally designed to reduce catheter friction during rotational atherectomy. Following unsuccessful delivery, stents were removed from the guiding catheters, topically saturated with Rotaglide, and deployment immediately reattempted. Procedural efficacy and long-term clinical outcomes were assessed. RESULTS: The study population included 20 patients aged 69 +/- 10 years, all of whom had complex lesions (ACC/AHA Class B(2) or C). Rotaglide lubricated stents were successfully deployed at the target lesions in 17 of the 20 patients (85%). Patients were followed 19.5 +/- 3.2 months after their index procedure. There were no periprocedural complications or subacute stent thromboses. Of the 14 patients with drug-eluting stents, none had clinical restenosis or target vessel revascularization. Target lesion revascularization secondary to restenosis was required in 1 of 3 patients treated with bare-metal stents. CONCLUSIONS: Topical lubrication is a simple and effective aid for stent delivery in complex lesions. Rotaglide appears safe and biocompatible with drug-eluting stents.     

Stent thrombosis and drug-eluting stents

Coronary stents have been used for the treatment of patients with coronary artery disease (CAD), and significantly improved procedural safety and are associated with a lower rate of restenosis compared with balloon angioplasty alone. Drug-eluting stents (DES) have been dominant for the treatment of CAD with efficacy in significantly reducing both restenosis and target lesion revascularization. However, late and very late stent thrombosis have become a major concern in DES-implanted arteries compared with those treated with bare-metal stents (BMS). This review focuses on the feature of DES thrombosis and pathological examination and dual antiplatelet therapy for prevention of stent thrombosis.Currently, the incidence of stent thrombosis associated with first-generation and second-generation DES remains unclear in data from real-world cohort registry studies. Further studies of larger multicenter trials would give us insight into the specific mechanisms of stent thrombosis among different generations of DES.     

Drug-eluting stent thrombosis

When compared to bare metal stents (BMS), drug-eluting stents (DES) are associated with a dramatic reduction in restenosis and target lesion revascularization. However, the benefit of DES is limited to restenosis, and DES utilization does not translate into reductions in death or myocardial infarction. Additionally, concern exists regarding the long-term safety of DES, as there appears to be a small but real increase in late (LST) and very late stent thrombosis (VLST), seen particularly after the discontinuation of antiplatelet therapy. The specter of LST and VLST has curtailed enthusiasm for widespread DES utilization mandating critical appraisal of DES and the optimal role they play in percutaneous coronary intervention. The incidence of DES thrombosis is debated and varies somewhat by definition. The mechanisms are multifactorial, and involve patient, lesion, stent and physician related factors. Some of these factors are modifiable at the physician-patient level, while others are not. This review focuses on DES thrombosis, with particular attention paid to the definitions, incidence, mechanisms and clinical implications.     

药物洗脱支架在冠心病介入治疗中的有效性与安全性研究

目的评价药物洗脱支架在冠心病介入治疗中的有效性和安全性。方法回顾性分析复旦大学附属华山医院心内科2003年11月～2006年12月应用药物洗脱支架的346例冠心病患者,收集15～52个月的临床资料,评价经皮冠脉介入治疗（PCI）术后临床症状的改善情况;主要心脏不良事件（MACE）。MACE包括心源性死亡、非致命性心肌梗死和靶血管重建（TVR）;其中72例复查冠脉造影,对其支架内再狭窄、支架内血栓形成、靶血管动脉瘤的发生率进行统计分析。结果346例冠心病患者共成功植入药物洗脱支架674枚,PCI术后207例患者临床症状完全缓解,109例患者的临床症状明显改善,临床症状缓解率达91．3％。DES植入术后住院期间MACE发生率为0．9％（3／346）,院外随访期间MACE发生率为3．7％（11／346）。冠状动脉造影复查发现晚期支架内血栓形成发生率为0．8％（1／132）;靶血管动脉瘤形成0．8％（1／132）;支架内再狭窄发生率为4．5％（6／132）,其中4例再次于靶病变处植入DES。PCI术后应用双联抗血小板药物过程中的出血并发症37例,白细胞减少2例。结论药物洗脱支架在冠心病介入治疗中应用是安全、有效的,MACE、支架内再狭窄和支架内血栓形成的发生率很低。     

Predictors and variability of drug‐eluting vs bare‐metal stent selection in contemporary percutaneous coronary intervention: Insights from the PRISM study

Drug‐eluting stents (DES ) reduce risk of in‐stent restenosis after percutaneous coronary intervention (PCI ) but require dual antiplatelet therapy (DAPT ) for a longer term than bare‐metal stents (BMS ). Few studies have examined clinical predictors of DES vs BMS , and variability in provider selection between DES and BMS in clinical practice has not been well described. These insights can inform our understanding of current practice and may identify opportunities to improve decision‐making stent selection decinsion‐making. In a multicenter registry, 3295 consecutive patients underwent PCI by 158 interventional cardiologists across 10 US sites. Eighty percent of patients with treated with DES. Using hierarchical regression, diabetes mellitus, multivessel disease, health insurance, and white race were independently associated with greater DES use, whereas increasing age, history of hypertension, anticipated surgery, use of warfarin, lower hemoglobin, prior history of bleeding, and treatment of right coronary and left circumflex artery lesions as compared with PCI of left anterior descending artery were associated with lower likelihood of receiving DES . Adjusted rates of DES use across providers varied from 52.3% to 94.6%, and adjusted median odds ratio for DES selection was 1.69. DES selection appeared to reflect physicians’ attempts to balance benefits of DES against risks of prolonged DAPT . Nevertheless, marked residual variability in DES selection across providers persisted after adjusting for predictors of restenosis, bleeding, and other factors. Further studies are needed to better understand drivers of this variability and identify the impact of patient and provider preferences on stent selection at the time of PCI .