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.     

西罗莫司洗脱支架术后极晚期血栓形成四例分析

目的回顾性分析西罗莫司洗脱支架术后发生极晚期支架内血栓形成患者的临床资料。方法2002年10月至2005年8月,共612例患者置入835枚西罗莫司洗脱支架,其中4例患者（0．65％）于2006年1至8月发生极晚期支架内血栓形成,导致急性前壁ST段抬高的心肌梗死再次入院。回顾性分析该4例患者的临床情况、抗血小板药物应用情况、造影结果以及PCI过程等相关资料。结果4例患者均为男性,年龄40～69岁,血栓发生时间为术后31～37个月。患者第一次支架术后服用氯吡格雷7～12个月,其中1例患者血栓发生前18个月停用阿司匹林。支架置入部位均为前降支,急诊造影提示支架内闭塞,局部可见明显血栓征象,前向血流TIMI0级,均再次行PCI治疗后存活。结论药物洗脱支架术后可以发生极晚期血栓形成,药物洗脱支架术后的远期随访问题值得重视。     

Late acute thrombosis after implantation of sirolimus‐eluting stent to treat in‐stent restenosis

Drug‐eluting stents (DES) have significantly reduced the incidence of in‐stent restenosis (ISR) compared to bare metal stents (BMS). However, recent randomized trials comparing DES with BMS reported few cases of late DES thrombosis. We report the case of late sirolimus‐eluting stent thrombosis occurring 22 months after its elective implantation in a restenotic BMS and soon after the interruption of combined anti‐platelet therapy with aspirin and Clopidogrel.     

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.     

Very late thrombosis after implantation of sirolimus eluting stent

Stent thrombosis after sirolimus eluting stent implantation has been reported to occur at six hours to 375 days after the procedure and usually within the two weeks after discontinuation of antiplatelet medication. A case is reported of very late stent thrombosis after 17 months of sirolimus eluting stent implantation and eight months after clopidogrel discontinuation despite aspirin continuation. This case underlines the possible need for long term antiplatelet medication among patients receiving sirolimus eluting stents.     

Coronary stent strut fracture after drug-eluting stent implantation: a newly recognized complication

Stent strut fracture (SSF) after drug-eluting stent (DES) implantation may be an important complication after DES implantation particularly in patients undergoing sirolimus eluting stent implantation. Since SSF is a highly relevant adverse event which can result in in-stent restenosis and thrombosis, we believe that DES with flexible stent platform or biodegradable DES may be needed to prevent this potential catastrophic complication.     

药物洗脱支架置入后血栓形成的原因分析

目的探讨药物洗脱支架置入后血栓形成的发生率以及血栓形成的原因。方法本研究为单中心药物洗脱支架的注册研究,自2001年12月至2005年12月共计3345例冠心病患者接受了药物洗脱支架的治疗,其中使用雷帕霉素洗脱支架（SES）2165例,使用紫杉醇洗脱支架（PES）1180例,完成10个月临床随访为2296例;所有患者均同时口服阿司匹林和氯吡格雷至少9个月。结果3345例患者中9例发生急性血栓形成（O．27％）,其中7例为SES、2例为PES所致（0．32％比0．17％,P=0．637）;7例发生亚急性血栓形成（0．21％）,其中5例为SES、2例为PES所致（0．23％比0．17％,P=0．526）;急性和亚急性血栓发生率为0．48％（16／3345）;13例有晚期血栓形成,5例为SES、8例为PES所致（0．34％比0．95％,P=0．114）;4例晚期血栓形成的主要原因为提前中断抗血小板药物,既往患有心肌梗死病史,心功能差,药物洗脱支架置入后晚期发生血栓致猝死6例。结论支架置入不满意,特别是分叉病变以及支架未能完全覆盖受损伤的病变段是急性和亚急性血栓形成的主要原因;中断抗血小板药物和左心功能不全是晚期血栓形成的主要原因。     

Very late stent thrombosis associated with multiple stent fractures and peri-stent aneurysm formation after sirolimus-eluting stent implantation.

Previous randomized trials have shown that drug-eluting stents (DES) are superior to bare-metal stents in reducing the need for target lesion revascularization, but safety issues with DES have recently been raised. We report a rare case of very late stent thrombosis 35 months after sirolimus-eluting stent implantation associated with delayed 5-segment stent fractures and peri-stent aneurysm formation.     

Acute coronary syndrome due to early multiple and complete fractures in sirolimus‐eluting stent: A case report and brief literature review

Despite drug eluting stents (DES), as compared to bare metal stents, have reduced in‐stent restenosis, complex and long lesions remains a challenge for interventional cardiologist. Their treatment is often associated with an unfavorable outcome, related to in‐stent restenosis, stent thrombosis, and target lesion revascularization. These complications may derive from the contact between metallic structures and coronary artery endothelium, and consequent overexpression of platelet activating factors, growth factors, and inflammatory cytokines. Recently, an additional mechanism has emerged as new cause of these complications: “stent fracture.” Several factors are involved in this phenomenon including material and stent platform, target vessel features, stent implantation technique, and implant duration. We reported a case of 69 years old man with rare early and complex DES fractures on right coronary that caused acute coronary syndrome 36 hr after a previous percutaneous coronary intervention.© 2012 Wiley Periodicals, Inc.     

Eosinophilic responses to stent implantation and the risk of Kounis hypersensitivity associated coronary syndrome

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.     

The use of intra-coronary optical coherence tomography for the assessment of sirolimus-eluting stent fracture

Drug-eluting stents (DES) have made a tremendous impact on the practice of percutaneous coronary intervention. Recently however, long-term DES failures have become a focal point, particularly with restenosis and thrombosis. An uncommon, yet important cause of DES failure is stent fracture. Of the two established first generation DES, the sirolimus-eluting stent (SES) has been particularly linked to cases of stent fracture, likely as a result of its closed cell design compared with other DES employing an open cell system. We present 2 cases of SES fracture confirmed using high-resolution intravascular optical coherence tomography giving unique insights into the in-vivo appearance of this complication.     

Randomized evaluation of two drug‐eluting stents with identical metallic platform and biodegradable polymer but different agents (paclitaxel or sirolimus) compared against bare stents: 1‐Year results of the PAINT trial

Objectives: We tested two novel drug‐eluting stents (DES), covered with a biodegradable‐polymer carrier and releasing paclitaxel or sirolimus, which were compared against a bare metal stent (primary objective). The DES differed by the drug, but were identical otherwise, allowing to compare the anti‐restenosis effects of sirolimus versus paclitaxel (secondary objective). Background: The efficacy of novel DES with biodegradable polymers should be tested in the context of randomized trials, even when using drugs known to be effective, such as sirolimus and paclitaxel. Methods: Overall, 274 patients with de novo coronary lesions in native vessels scheduled for stent implantation were randomly assigned (2:2:1 ratio) for the paclitaxel (n = 111), sirolimus (n = 106), or bare metal stent (n = 57) groups. Angiographic follow‐up was obtained at 9 months and major cardiac adverse events up to 12 months. Results: Both paclitaxel and sirolimus stents reduced the 9‐month in‐stent late loss (0.54–0.44 mm, 0.32–0.43 mm, vs. 0.90–0.45 mm respectively), and 1‐year risk of target vessel revascularization and combined major adverse cardiac events (P < 0.05 for both, in all comparisons), compared with controls. Sirolimus stents had lower late loss than paclitaxel stents (P < 0.01), but similar 1‐year clinical outcomes. There were no differences in the risk of death, infarction, or stent thrombosis among the study groups. Conclusion: Both novel DES were effective in reducing neointimal hyperplasia and 1‐year re‐intervention, compared to bare metal stents. Our findings also suggest that sirolimus is more effective than paclitaxel in reducing angiographic neointima, although this effect was not associated with better clinical outcomes.© 2009 Wiley‐Liss, Inc.     

Die Stentthrombose im Fokus von Drug-eluting Stents

Coronary stent thrombosis is frequently associated with death or myocardial infarction (MI). New definitions according to the Academic Research Consortium (ARC) were proposed to serve as standard criteria for stent thrombosis. According to these definitions, stent thrombosis was classified as acute (within 24 h post implantation), subacute (1-30 days), late (31 days to 1 year), and very late (later than 1 year). Furthermore, stent thrombosis was differentiated in definite with angiographic or autoptic verification, probable, and possible. In meta-analyses using the ARC criteria, the occurrence of subacute stent thrombosis did not differ between drug-eluting stents (DES; Cypher, Taxus) or bare-metal stents (BMS) with < 1%. Very late stent thrombosis occurred 0.4-0.6% more frequently with DES compared to BMS. Available follow-up periods are limited to 4 years. The occurrence of death and MI did not differ between DES and BMS within the total follow-up period. In the meta-analysis of the Taxus studies, the event rates (death and MI) were initially lower with DES compared to BMS based on the reduced need for target vessel revascularization. Nevertheless, this was compensated in the following period by a higher event rate due to very late stent thrombosis. In real-world registries, the event rates are higher than in the first randomized studies. With DES implantation as a routine strategy, the occurrence of angiographically documented stent thrombosis was 2.9% within a period of 3 years. Classic predictors for stent thrombosis with BMS remain relevant also in the DES era. The delayed endothelialization with DES in combination with suboptimally implanted DES takes the patients to a higher and longer risk for stent thrombosis. Several guidelines recommend dual antiplatelet therapy for 12 months after DES implantation in noncomplex lesions. In complex lesions combined antiplatelet treatment should be prescribed 24 months or longer (e.g., DES after brachytherapy). Patients scheduled for surgical procedures or patients with reduced compliance should not be treated with DES.     

Strategies for drug‐eluting stent treatment of bifurcation coronary artery disease in the United States: Insights from the e‐Cypher S.T.L.L.R.Trial

Objectives: Our goal is to report the first large multicenter data for percutaneous coronary intervention (PCI) of bifurcation disease with drug‐eluting stents (DES) in the United States. Background: Bifurcation PCI remains a challenge to this date. There are limited data on outcomes of patients treated with bifurcation DES implantation, particularly in the United States. Methods: There were 161 patients with bifurcation disease [side branch (SB) ≥2‐mm] treated with ≥1 sirolimus‐eluting stents at 41 centers participating in the Stent deployment Techniques on cLinicaL outcomes of patients treated with the cypheR?stent (STLLR) trial. There was no protocol mandated strategy for bifurcation PCI. One‐year outcome data were collected. Angiographic and clinical data were adjudicated independently. Results: There were 147 patients (91.3%) treated with single stent strategy. Only 14 (8.7%) patients received sirolimus‐eluting stents implantation in both branches. Among patients with single stent strategy, double wire strategy (DW) was selected in 27 (18.4%) patients whereas single wire strategy (SW) was selected in 120 (81.6%) patients. There were 48 (32.7%) Medina 1,1,1 bifurcations treated with SW (n = 34; 70.8%) and DW (n = 14; 29.2%). There were 26 procedures started with SW which had SB dilatation during the procedure, one as a bailout (TIMI‐1 grade flow in the SB). Overall 1‐year death, myocardial infarction, and target lesion revascularization occurred in 2.4, 4.0, and 5.6%, respectively. There was no significant difference in clinical outcomes between SW and DW. SB dilatation was associated with a high rate of stent thrombosis (8.6%). Conclusions: Main branch stenting without SB protection is the most common approach utilized in the STLLR study, which may reflect contemporary DES bifurcation strategies in the Unite States. This strategy was associated with an acceptable low incidence of adverse outcomes at 1‐year. © 2009 Wiley‐Liss, Inc.     

Late Stent Thrombosis: The Last Remaining Obstacle in Coronary Interventional Therapy

Drug-eluting stents (DES) represent an outstanding improvement in the interventional cardiology field. DES have markedly decreased stent restenosis and the clinical need for repeat revascularization, without increasing mortality, compared to bare-metal stents (BMS). However, the widespread use of DES has raised concerns regarding the occurrence of late stent thrombosis (ST), beyond the traditional 1-month timeframe in which thrombotic events were found to occur after BMS implantation. While early ST (events occurring within 1?month after stent placement) has been shown to be similar between DES and BMS, late (events occurring after 1?month following stent implantation) and very late (events occurring more than 1?year following stent implantation) ST have emerged as distinct major pitfalls of DES implantation. In this review we describe the current knowledge regarding late and very late ST after DES implantation.     

Multiple Stent Fractures After Everolimus-Eluting Stent Implantation Causing Acute Myocardial Infarction: A Case Report

Stent fracture is an uncommon complication of drug-eluting stent implantation, but it has a clinical significance because of its potential association with adverse cardiac events such as in-stent restenosis, target lesion revascularization, and stent thrombosis. Multiple stent fractures account for a small proportion, but they may lead to more serious complications. Newer generation drug-eluting stents are designed for improved safety and efficacy compared with early generation drug-eluting stents. Multiple stent fractures after newer generation drug-eluting stent implantation are a rare case.We report a case of 25-year-old male who presented with acute myocardial infarction caused by multiple stent fractures after everolimus-eluting stents implantation and was treated by balloon angioplasty.Physicians should be aware of the possibility of multiple stent fractures even after newer generation drug-eluting stent implantation.     

Stent thrombosis with an aneurysm 7 years after a drug eluting stent implantation

We report a case of very late stent thrombosis 7 years post sirolimus eluting stent implantation presenting as ST elevation MI while on dual antiplatelet therapy. Angiography revealed an aneurysm at the proximal end of the stent. The patient was managed successfully by primary percutaneous coronary intervention (PCI) with adjunct thrombus aspiration and intracoronary abciximab administration followed by deploying a mesh-covered stent MGuard. This very late complication is a rare presentation after a drug illuting stent (DES).     

采用光学相干断层成像技术评价国产雷帕霉素洗脱支架术内膜覆盖情况

Objective:Confirming complete neointimal coverage after implantation of drug-eluting stent(DES)is clinically important because incomplete stent coverage is maybe responsible for late thrombosis and sudden cardiac death.Optical coherence tomography(OCT)is a high-resolution(≈10 μm)imaging technique capable of detecting a thin layer of neointimal hyperplasia(NIH)inside DES.Helios stent system(KinheIy Bio-tech Co(Shenzhen).Ltd)is a new generation of sirolimus eluting stents.Methods:Motorized optical coherence t...     

Triple,simultaneous, very late coronary stent thrombosis

Coronary artery stent thrombosis is an uncommon but potentially catastrophic complication. The risk of very late stent thrombosis (VLST) raises important safety issues regarding the first generation of drug-eluting stents (DES). Although several complex mechanisms for VLST have been suggested and various predictors have been described, its pathophysiology is not completely understood and it is not known whether longer-term dual antiplatelet therapy reduces the risk. We present a rare case of simultaneous very late DES thrombosis in the three vascular territories, following discontinuation of antiplatelet therapy seven years after stent placement, presenting as cardiogenic shock.     

Risk Factors and Clinical Impacts of Peri‐Stent Contrast Staining After Second‐Generation Drug‐Eluting Stent Implantation

Background

Peri‐stent contrast staining (PSS) after sirolimus‐eluting stent implantation is associated with target lesion revascularization (TLR) and very late stent thrombosis. However, the risk factors and clinical sequelae of PSS after second‐generation DES implantation remain unclear.

Methods and Results

This study comprised 2,090 patients with 2,883 lesions treated with second‐generation DES from April 2009 to February 2013. Angiographic findings and clinical outcomes were compared between PSS and non‐PSS groups. Follow‐up angiography was available for 2,411 lesions. PSS was observed in 23 lesions: 4 in biolimus‐eluting stents, 4 in zotarolimus‐eluting stents (ZES), and 15 in everolimus‐eluting stents (EES). Right coronary artery lesions, chronic total occlusion (CTO), and lesions with severe angulation (>90°) were more frequent in the PSS group compared with the non‐PSS group. Lesions were longer and the cumulative TLR incidence at 3 years was higher in the PSS group than those in the non‐PSS group (27.9 mm vs. 19.4 mm, P < 0.0001; 27.4% vs. 8.6%, P = 0.0002). There was no significant difference in stent thrombosis between the two groups. Multivariable analysis identified CTO [odds ratio (OR) 3.75, 95%CI 1.52–8.88, P = 0.005] as an independent predictor of PSS.

Conclusions

PSS after second‐generation DES implantation was associated with an increased risk of subsequent TLR. CTO was the independent predictor of PSS. (J Interven Cardiol 2016;29:179–187)