Acute thrombosis of drug eluting stent following protamine: a case report

Reversal of anticoagulant effect of heparin to treat coronary perforation after bare metal stent implantation is an accepted practice. However this practice may not be safe following drug eluting stent implantation. We report a case of acute stent thrombosis following protamine administration for coronary perforation after drug eluting stent implantation.     

雷帕酶素和巴曲酶复合药物涂层支架预防支架内再狭窄的实验研究

目的评价裸支架、巴曲酶支架、雷帕酶素支架、雷帕酶素和巴曲酶复合药物涂层支架（rapamycin-batroxobin eluting stent,RBES）抑制内膜增生的作用以及预防支架内再狭窄的效果。方法采用微喷法制备雷帕酶素和巴曲酶复合药物涂层支架,将裸支架、巴曲酶支架和雷帕酶素支架做为对照,复合药物组减少术后服用氯吡格雷的剂量和时间。于支架置入后3、7、28d截取支架段血管连同邻近的近端正常血管段,通过病理组织学分析和聚合酶链反应技术检测支架局部内膜增生情况。结果复合药物支架、雷帕酶素支架在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面与裸支架组、巴曲酶支架组有显著差异（P<0.05）。复合药物支架组与雷帕酶素组在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面无显著差异。裸支架组、巴曲酶支架组在再狭窄率、冠脉狭窄程度、管腔面积、新生内膜面积方面无显著差异。正常血管段在各个时间段增殖细胞核抗原（PCNA）mRNA均呈现无明显差异的低表达。裸支架、巴曲酶支架、雷帕酶素支架和复合药物支架置入后3d局部血管壁PCNA mRNA即呈现高表达,裸支架、巴曲酶支架显著高于正常血管段。雷帕酶素支架和复合药物支架略高于正常血管段,显著低于裸支架、巴曲酶支架,巴曲酶支架略低于裸支架;复合支架略低于雷帕酶素支架。结论复合药物支架置入可在一定程度上抑制内膜的增生反应,预防支架内再狭窄。     

OCT对于DES术后晚期或晚晚期血栓治疗的指导作用

目的 观察光学相干断层成像（OCT）技术对于药物洗脱支架（DES）术后发生晚期或晚晚期血栓治疗对策的指导作用.方法 选取2010年7月至2013年11月本院收治的行DES支架置入术后发生晚期或晚晚期支架内血栓患者22例,对患者行OCT检查,根据OCT结果采取进一步治疗措施.结果 DES术后晚期或晚晚期血栓的OCT表现为：支架内皮化不全6例、贴壁不良12例、支架内新生动脉粥样硬化斑块形成8例,支架内纤维过度增生较为少见2例,有些患者上述情况同时存在.治疗对策：单纯支架内皮化不全及支架贴壁不良者采取单纯球囊扩张术12例,新生动脉粥样硬化斑块形成或纤维过度增生者采取球囊扩张加支架置入术10例.结论 OCT可以准确了解DES术后晚期或晚晚期血栓的原因,提供更为合适的治疗方案.     

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.     

光学相干断层成像评价植入不同药物洗脱支架后的血管愈合情况

目的应用光学相干断层成像（OCT）比较急性心肌梗死（AMI）患者植入不同药物洗脱支架（DES）后的新生内膜覆盖和支架贴壁情况以评估血管愈合。方法 49例AMI患者植入不同DES后9个月时进行OCT检查。其中20个雷帕霉素药物洗脱支架（SES,Cypher）,12个紫杉醇药物洗脱支架（PES,Taxus）和17个雷帕霉素衍生物药物洗脱支架（ZES,Endeavor）。每隔1mm评估OCT横断面影像每个支架柱的新生内膜覆盖和贴壁情况,同时观察每个支架内的血栓发生情况。结果总计对12378个支架柱进行了分析。SES的新生内膜增生最少,新生内膜厚度：SES（77±60）μm、PES（153±82）μm、ZES（265±130）μm,且新生内膜增生面积百分比最低,SES（10±8）%、PES（19±8）%、ZES（28±9）%,但SES和PES有更多未被新生内膜覆盖的支架柱,SES（15.1±16）%、PES（7.1±10）%、ZES（0.6±1.5）%,且贴壁不良支架柱的发生率也高于ZES,SES（3.8±7.2）%、PES（2.1±4.4）%、ZES（0±0）%,而有完全新生内膜覆盖的支架比例以ZES为高,SES5%、PES33.3%、ZES82.4%。血栓的发生率SES和PES高于ZES,SES34%、PES33%、ZES6%。结论 AMI患者植入不同类型DES后,其支架的新生内膜覆盖程度和贴壁不良的发生率是显著不同的,因此DES的类型可能影响了AMI血栓性病变的血管愈合过程。     

Aneurysm formation after drug‐eluting balloon treatment of drug‐eluting in‐stent restenosis: First case report

A 55‐year‐old male underwent paclitaxel‐eluting stent implantation in a bifurcation lesion of his left anterior descending artery (LAD) during an episode of unstable angina in 2008. A late in‐stent restenosis developed 15 months after implantation of the drug‐eluting stent (DES) and was treated with paclitaxel eluting balloon. Two months later, during angiography for functional assessment of the significance of lesions in the circumflex artery, an aneurysm at the place of drug‐eluting balloon (DEB) inflation was observed. The patient was left on double antiplatelet therapy and scheduled for clinical observation after 3 months and control coronary angiography after 6 months for aneurysm progression follow‐up. © 2012 Wiley Periodicals, Inc.     

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.     

急性冠脉综合征患者药物洗脱支架雷帕霉素CypherTM植入后的不良反应分析

目的:分析雷帕霉素药物洗脱支架CypherTM植入后对急性冠脉综合征患者近、远期的不良反应.方法: 选择接受CypherTM治疗的冠心病患者83例,在支架植入术后9个月内全部接受门诊随访及冠脉造影,了解支架内急性和亚急性血栓、边缘效应、贴壁不良现象、支架处动脉瘤发生率及相应的不良心脏事件(MACE)发生情况.结果:83例患者共植入支架112个,植入成功率为98.8%(82/83).29例(34.9%)接受冠脉造影,MACE9例,发生率10.8%(9/83),其中,1例术中发生猝死,1例术后3d因亚急性血栓造成再发心肌梗死,其余7例在出院后1～3 月内发生心绞痛,皆经造影证实为血栓形成,再次成功靶血管血运重建8例;其余20例无症状患者造影发现支架边缘狭窄(无血栓)2例,总再狭窄为13.3%(11/83);无动脉瘤发生.9例MACE中,有弥漫病变5例,其中4例植入长支架,1例植入重叠支架,其余为简单病变;29例患者共发现贴壁不良现象5例,皆发生MACE,其中4例为弥漫病变植入长支架,1例为简单病变.结论:急性或亚急性血栓形成是药物支架CypheTM植入后出现的主要不良反应,可能与弥漫病变植入长、重叠支架引起贴壁不良有关.     

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。     

A current problem in cardiology: very late thrombosis after implantation of sirolimus eluting stent

Discontinuation of antiplatelet medications has been strongly associated with coronary stent thrombosis. The first reported cases have been documented at 6 h to 6 weeks after stent implantation. This article presents a case of very late stent thrombosis 24 months after sirolimus eluting stent implantation and 18 months after clopidogrel discontinuation, despite aspirin continuation, and argues in favor of prolonging dual antiplatelet medication including clopidogrel in this setting, at least until data from randomized trials address this important issue.     

Very late thrombosis after drug-eluting stents.

Stent thrombosis is a rare but potentially fatal complication of percutaneous treatment of coronary disease. Its occurrence after drug eluting stent (DES) placement has raised concerns, especially when it occurs late after the stent implantation. The mechanisms of late thrombosis after DES have yet to be completely understood. By means of serial angiography and intravascular (IVUS) images we described a relatively new and unusual vessel response to drug-eluting stents (e.g. huge positive remodeling in all vessel extension), leading to impressive late-acquired incomplete stent apposition and finally causing stent thrombosis and acute myocardial infarction. After describing the two cases, one after Cypher stent implantation and one after Taxus stent implantation, we briefly reviewed the literature available on stent thrombosis with special emphasis on its late occurrence.     

Extremely late drug-eluting stent thrombosis: 2037 days after deployment

Thrombosis of drug eluting stents has been documented up to four years after stent implantation, often in the setting of cessation of antiplatelet therapy. We present a case of drug-eluting stent thrombosis, 2037 days after initial implantation, which we believe is the latest reported case. Late stent thrombosis remains a rare but catastrophic complication of coronary intervention. We hypothesize that the procoagulant milieu of surgery, coupled with cessation of one or both antiplatelet agents preoperatively, compounds the risk of perioperative stent thrombosis.     

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.     

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.     

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.     

三氧化二砷洗脱支架防治兔血管损伤后再狭窄的实验研究

目的冠状动脉支架内再狭窄主要是由血管损伤后内膜增生引起,研究三氧化二砷(As2O3)多聚左旋乳糖酸(PLLA)涂层的药物洗脱支架在兔的损伤髂动脉内抑制内膜增生防治再狭窄的疗效、机制及As2O3释放的药物代谢动力学。方法45只雄性新西兰白兔,随机分三组,每组15只,分别将裸支架、PLLA涂层支架、As2O3洗脱支架置入兔髂动脉的近端,饲养28d后处死,组织病理学检测内膜厚度,TUNEL法测细胞凋亡。在体药代动力学研究:雄性新西兰白兔48只,按支架置入后饲养时间(2h、1d、3d、7d、14d、28d)分为6组,每组8只,检测血浆中及支架处组织中的As2O3浓度。结果As2O3洗脱支架释放As2O3达28d,第一天支架处组织中的As2O3浓度约是血浆中的55000倍,14d约为22000倍。As2O3洗脱支架较PLLA支架和裸支架分别减少内膜增生51%、31%。As2O3洗脱支架组较PLLA支架组和裸支架组血管平滑肌细胞凋亡面积明显增加(21·0±3·3比6·2±1·9,5·3±2·1)。结论As2O3洗脱支架在局部血管处释放As2O3达28d,在兔的髂动脉可有效抑制由支架和球囊损伤导致的兔血管内膜增生,其机制之一是促进平滑肌细胞凋亡。     

Diffuse coronary ectasia and intracoronary thrombus involving left circumflex coronary artery and presenting as acute coronary syndrome: report of two cases

Stent thrombosis is a feared complication of percutaneous coronary intervention. Promises and problems, late complications and early stent thrombosis have been reported after drug eluting stents implantation too. Moreover some patients with imperative cardiologic indications for combination therapy with aspirin and clopidogrel (stent placement and/or acute coronary syndrome) have a history of allergy to aspirin. We present a case of catastrophic early drug eluting stents thrombosis in a 79-year-old Italian woman with aspirin hypersensitivity.     

Late acquired stent malapposition detected by optical coherence tomography examination

Late stent malapposition may play a role in stent thrombosis, but the results of several intravascular ultrasound and few optical coherence tomography (OCT) studies are still controversial. We present a case of late acquired stent malapposition after drug eluting stent implantation, identified by follow-up OCT examination at 12 months, which was not related with any adverse clinical event.     

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).     

Prevalence and predictors of premature discontinuation of dual antiplatelet therapy after drug‐eluting stent implantation: importance of social factors in Asian patients

Aim: Premature discontinuation of antiplatelet therapy is an independent predictor of late stent thrombosis. We sought to determine the prevalence and predictors of premature discontinuation of antiplatelet therapy after drug‐eluting stent implantation among patients in Asia. Methods: A total of 207 consecutive patients who underwent drug‐eluting stent implantation at our institution was followed up after 1 year. Premature discontinuation of antiplatelet therapy was defined as omission of aspirin and/or clopidogrel for 1 week or more. Results: Four (1.9%) patients died and the remaining 203 patients formed the study population. Prevalence of premature discontinuation of antiplatelet therapy was 12.8% (n= 26, aspirin, n= 12; clopidogrel, n= 9; both, n= 5). The median duration between stent implantation and discontinuation of antiplatelet therapy was 2.8 months. Reasons for discontinuation included cost (n= 1), gastric discomfort (n= 1), allergy (n= 3), bleeding (n= 3), advice from doctors (n= 7) and no reason (n= 11). Logistic regression showed that living alone was the only independent predictor of premature discontinuation of dual antiplatelet therapy (50.0% vs 11.3%, P= 0.001). Conclusion: Among Asian patients who have undergone drug‐eluting stent implantation, 12.8% discontinued dual antiplatelet therapy within 12 months. Living alone is associated with a fivefold increase in risk of premature drug discontinuation.