A case of early drug-eluting stent fracture

Although stent fracture following femoro-popliteal intervention is well recognized, coronary stent fracture represents an underrecognized entity. Its incidence is low but it represents an important clinical entity as it may complicate with stent thrombosis causing acute coronary syndromes, or may predispose to instent restenosis. Although coronary stent fracture may involve both bare metal stents (BMS) and drug-eluting stents (DES), a recent analysis of the literature indicates that reports of stent fracture have increased since DES was introduced. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture. We present the case of a patient with a non-ST-segment elevation acute coronary syndrome caused by the early fracture of an everolimus-eluting stent (Xience?) implanted only three days before.     

Late stent thrombosis thirteen months after drug-eluting stent implantation

We present a case of a very late stent thrombosis which occurred 13 months after drug-eluting stent (DES) implantation. The DES was off-label used in a high-risk patient and was followed by 12-month clopidogrel administration. One month after the drug discontinuation the stent thrombosis occurred, resulting in acute myocardial infarction. The patient was successfully treated with balloon coronary angioplasty and was advised to use clopidogrel indefinitely.     

Percutaneous treatment of a coronary aneurysm by stent graft and drug-eluting stent implantation: a potential method to reduce stent graft restenosis

Coronary artery aneurysms (CAAs) can occur congenitally or secondary to specific disorders such as Kawasaki disease or atherosclerosis. Apart from a surgical approach, CAA can be treated by coronary stent graft (CSG) implantation. However, restenosis is frequent after CSG placement, precluding a wider use of this technique. We hypothesized that implantation of a drug-eluting stent (DES) within a CSG could be of use to avoid CSG restenosis. We report the case of a patient with a large aneurysm of the right coronary artery who underwent CSG implantation followed by DES placement. The immediate angiographic result showed complete exclusion of the aneurysm. Intravascular ultrasound confirmed good apposition of both the CSG and DES. Follow-up angiography after 23 weeks demonstrated a good long-term result without restenosis. The patient has remained asymptomatic during 12 months of follow-up. In conclusion, the present case suggests that CSG placement followed by DES implantation is a safe and effective approach to treat coronary aneurysms interventionally.     

Simultaneous subacute stent thrombosis after implantation of sirolimus-eluting stent and bare-metal stent

Simultaneous multivessel stent thrombosis is a rare, but can cause catastrophic clinical results. We report a case occurred ST simultaneously in DES and BMS. Our case demonstrated that the use of multiple stents, irrespective of stent type, in multiple coronary artery lesions should be undertaken with great attention in the patient who has multiple adverse clinical predictors such as AMI.     

Simultaneous late stent thrombosis in two coronary arteries following drug-eluting stent implantation

Late stent thrombosis has emerged as an infrequent but serious complication of drug-eluting stent (DES) implantation. Premature cessation of dual antiplatelet therapy is the most common risk factor for its occurrence. In the era of multivessel stenting with DES, there is a potential for multivessel late stent thrombosis following cessation of dual antiplatelet therapy. We present a rare case of a patient who sustained simultaneous late stent thromboses in DESs implanted in two coronary arteries as a result of premature cessation of dual antiplatelet therapy.     

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.     

Two-year clinical outcomes after large coronary stent (4.0 mm) placement: comparison of bare-metal stent versus drug-eluting stent

Background:

The absolute benefit of drug‐eluting stents (DES) in low‐risk patients and lesions is not well established.

Hypothesis:

The long term clinical outcomes after percutaneous coronary intervention in a single coronary artery disease may not be affected by the type of stent.

Methods:

This study assessed and compared 2‐year clinical outcomes of 304 consecutive patients (147 BMS patients and 157 DES patients) treated with a single coronary stent (4.0 mm) for single de novo large coronary artery disease in 3 referral cardiac centers. The primary outcome was a composite of major adverse cardiac events at 2 years after the index procedure.

Results:

The reference vessel diameter was similar in both groups (3.92 ± 0.29 mm in BMS vs 3.95 ± 0.24 mm in DES, P = 0.50). Late loss was larger in the BMS group (1.04 ± 0.83 mm vs 0.73 ± 0.91 mm in DES, P = 0.03). The incidence of major adverse cardiac events at the 2‐year clinical follow‐up was very low, 24 of 304 patients (7.9%), regardless of stent type deployed (7.5% in BMS vs 8.3% in DES, P = 0.83). The rate of target vessel revascularization was also similar in both groups (4.8% in BMS vs 5.7% in DES, P = 0.80).

Conclusions:

Two‐year clinical outcomes after PCI with a single large coronary stent (4.0 mm) were excellent. The clinical outcomes were not affected by the type of stent used. Copyright © 2010 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

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。     

Late stent thrombosis associated with coronary aneurysm formation after sirolimus-eluting stent implantation

Stent thrombosis is a rare but potentially fatal complication of coronary stent implantation. Its occurrence late after drug-eluting stent (DES) deployment has led to concerns regarding their long-term safety. We report a case of late stent thrombosis 26 months after sirolimus-eluting stent (SES) (Cypher, Cordis Corp., Miami, Florida) implantation. This was associated with marked positive vessel remodeling and coronary aneurysm formation involving the stented segment of the coronary artery. The patient was on dual antiplatelet therapy at the time.     

药物洗脱支架置人术后断裂导致支架内再狭窄的临床分析

目的 探讨药物洗脱支架(DES)置入术后支架断裂与再狭窄的关系及支架断裂的特点.方法 回顾性分析冠状动脉支架置人术后行冠状动脉造影复查的536例患者,实验分为DES组(N=397)和裸金属支架(BMS)组(n=139).分析支架置入术前、术后及复查时的冠状动脉造影图像,找出支架内再狭窄和支架断裂的病例,分析支架断裂和再狭窄的关系以及支架断裂的病变特征及形态特征.结果 DES组和BMS组再狭窄分别为31例和30例(P＜0.01),其中5例发生支架断裂,断裂的支架均为DES,BMS组未见支架断裂,两组差异有统计学意义(P＜0.05).发生支架断裂的5例靶病变均为扭曲病变,支架断裂均发生在血管扭曲成角处.结论 支架断裂是DES置入术后发生再狭窄的原因之一,扭曲病变置入长的DES后可能容易发生支架断裂.     

In-stent restenosis in the drug-eluting stent era

The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing rates of restenosis and target lesion revascularization after percutaneous coronary intervention. However, the rapid implementation of DES in standard practice and expansion of the indications for percutaneous coronary intervention to high-risk patients and complex lesions also introduced a new problem: DES in-stent restenosis (ISR), which occurs in 3% to 20% of patients, depending on patient and lesion characteristics and DES type. The clinical presentation of DES ISR is usually recurrent angina, but some patients present with acute coronary syndrome. Mechanisms of DES ISR can be biological, mechanical, and technical, and its pattern is predominantly focal. Intravascular imaging can assist in defining the mechanism and selecting treatment modalities. Based upon the current available evidence, an algorithm for the treatment approaches to DES restenosis is proposed.     

Coexistent in-stent restenosis, late incomplete stent apposition and mural thrombus in a zotarolimus-eluting stent

Drug-eluting stents (DES) have been demonstrated to dramatically reduce the rate of in-stent restenosis (ISR). However, some studies found an increased rate of late incomplete stent apposition (ISA) and late stent thrombosis (ST) in DES compared to traditional bare-metal stents (BMS). Endeavor stent, a new cobalt-alloy DES coated with phosphorylcholine and zotarolimus, has been reported to have a very favorable safety profile with few documented late-acquired ISA and late ST. In the present report, we described an interesting case with coexistent ISR, late ISA and mural thrombus in an Endeavor zotarolimus-eluting stent 8 months after primary percutaneous coronary intervention.     

Recurrent coronary stent thromboses and myocardial infarctions

Although stent thrombosis is a recognized complication of coronary intervention, recurrent stent thrombosis is rarely reported. We present a patient who suffered 3 ST-segment elevation myocardial infarctions associated with repeated stent thromboses within a month and a half. Although a potentially mechanical cause of thrombosis was identified in the only baremetal stent implanted in this case, no predisposing factors were seen for the 2 drug-eluting stents (DES). While recent worrisome data have suggested a slight increase in the incidence of late angiographic stent thrombosis (defined as occurring beyond 30 days) with drug-eluting stents (DES), their risk of subacute thrombosis (from 1 to 30 days) is reported to be equivalent to that of BMS. Therefore, this rare occurrence serves as a sobering reminder of the risks of subacute thrombosis with both BMS and DES. Marked neointimal inhibition, allergic reactions, as well as thienopyridine resistance, may all contribute to the pathophysiology of DES thrombosis. The Food and Drug Administration advisory panel has concluded that when these devices are used for "on-label" indications, the counterbalance of dramatic target lesion revascularization reduction versus rare incidence of late angiographic stent thrombosis results in no overall increase in DES myocardial infarction or mortality risk. Furthermore, a minimum of 1 year of dual antiplatelet therapy is recommended for all recipients of DES at low risk of bleeding.     

Drug-eluting stent thrombosis after cilostazol withdrawal in a patient previously treated with triple antiplatelet therapy

Antiplatelet therapy has been shown to reduce cardiac events after coronary stenting. However, despite aggressive antiplatelet therapy, stent thrombosis remains a serious complication of coronary stenting with drug-eluting stent (DES). Although several predictors for DES thrombosis have been suggested by investigators, this serious condition is still not completely preventable now. In particular, patients undergoing non-cardiac surgery or invasive procedures with bleeding risk may interrupt antiplatelet therapy and occasionally experience stent thrombosis. We report a case of DES thrombosis after cilostazol withdrawal for colonoscopic polypectomy in a patient previously treated with triple antiplatelet therapy. The patient presented with acute myocardial infarction but survived after successful emergency coronary revascularization. We discuss a plausible mechanism for DES thrombosis in the described case.     

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.     

Thrombosis and acute myocardial infarction as consequences of very late stent malapposition after implantation of a drug-eluting stent

The use of drug-eluting stents (DES) provides early and late benefits demonstrated by angiographic and clinical outcomes. Here we report a case of late stent thrombosis and acute myocardial infarction caused by late stent malapposition (LSM) of a DES at 16 months after the procedure. We successfully treated the patient with balloon angioplasty after intravenous thrombolytic therapy. This case illustrates that a LSM can develop at any time after DES implantation and can result in acute coronary syndrome. Therefore, clinicians should be aware of the possibility of late cardiac events after implantation of DES.     

Spontaneous coronary artery perforation secondary to a sirolimus-eluting stent infection

Coronary stent infection is exceedingly rare despite the widespread use of percutaneous coronary intervention (PCI). The utilization of drug-eluting stents (DES) may have a higher theoretical risk of infection due to their local immunosuppressant effect. Vigilance in suspecting stent infection is important, as the associated mortality rate is approximately 50%. We discuss the case of a patient who presented with an infected DES 2 weeks after implantation which led to spontaneous Type II coronary perforation. The perforation was sealed with prolonged balloon inflation, and the patient was treated with intravenous antibiotics. This is the first reported case of a patient with a stent infection who presented with a spontaneous coronary perforation.     

Drug-eluting stent fracture and acute coronary syndrome

BackgroundCoronary stent fracture is an underrecognized entity but has been reported more frequently in the drug-eluting stent (DES) era. Nevertheless, the clinical implications of coronary stent fracture remain unclear.Methods and MaterialsA literature search for reports of DES fracture was conducted via MEDLINE, and the US Food and Drug Administration Manufacturer and User facility Device Experience (MAUDE) database was accessed via the internet and interrogated for reports of stent fracture between January 1, 2003, and April 30, 2008. Each report was reviewed, and clinical information was extracted for analysis.ResultsThe MEDLINE search identified 202 cases of coronary DES fracture, with 95% of cases involving Cypher sirolimus-eluting stents. Clinical information regarding patient presentation was available in 96 cases. Patients presented with ST-elevation myocardial infarction (STEMI) or stent thrombosis in six cases (6%) and with unstable angina or non-STEMI (NSTEMI) in 40 cases (42%). The MAUDE database search identified 337 stent fracture reports, with 97% of cases involving Cypher stents. Clinical information regarding patient presentation was available 193 cases. Patients presented with STEMI or stent thrombosis in 24 cases (12%) and with unstable angina or NSTEMI in 36 cases (19%).ConclusionsMost reports of drug-eluting stent fracture involve Cypher stents. DES fracture can be associated with stent thrombosis, myocardial infarction and angina. However, whether the incidence of such events reported in the literature and in the MAUDE database is representative of all patients experiencing stent fracture remains unclear.     

Antiplatelet therapy in the era of late stent thrombosis

Opinion statement Drug-eluting stents (DES) are the treatment of choice for obstructive coronary artery disease when percutaneous intervention is feasible. Although there are concerns regarding increased incidence of stent thrombosis, subsequent myocardial infarction, and death in patients receiving DES, careful analysis of large randomized trials has shown that risk of stent thrombosis with both bare metal stents (BMS) and DES is small. However, late stent thrombosis seems to occur more frequently with DES and seems to be closely associated with the discontinuation of dual antiplatelet therapy with aspirin and a thienopyridine derivative (usually clopidogrel). Before placing a DES in a patient, the interventional cardiologist must ensure that there are no conditions under which a patient or physician may have to discontinue dual antiplatelet therapy within a year after stent placement. If the cardiologist anticipates premature discontinuation of thienopyridine and aspirin therapy, his or her alternative is to place a BMS or recommend bypass surgery. If a situation arises in which dual antiplatelet therapy may have to be interrupted (eg, emergency or semi-elective surgery), it is strongly recommended that the treating physician consult a cardiologist and follow published guidelines.     

Longitudinal stent compression of everolimus-eluting stent: A report of 2 cases

Second generation drug eluting stents(DES) have shown better safety and efficacy in comparison to first generation DES,because of thinner struts,nondurable polymers and coating with better anti-proliferative drugs.The newer DES with cobalt alloy base have demonstrated a greater trackability,deliverability,conformability,flexibility and radio-opacity.However,these thin strut stents have a downside of poor longitudinal axial strength,and therefore get easily deformed/ compressed at their end with a slight trauma during exchange of various catheters.We hereby report two cases of "longitudinal stent compression(LSC)" of everolimus-eluting stent,which happened during percutaneous coronary intervention of right coronary artery.Both the cases were successfully managed with non-compliant balloon dilatation.Various reasons for LSC and its management are discussed in the article.