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.     

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.     

Very late stent fracture associated with a sirolimus-eluting stent

Late stent thrombosis (>1 year after implantation) is a recognised complication involving drug-eluting stents. Stent fracture is increasingly being reported as a complication of drug-eluting stent, and in particular sirolimus-eluting stent use. We report the case of very late sirolimus-eluting stent fracture resulting in an acute coronary syndrome. This case report highlights the need for greater awareness and post-marketing surveillance to detect a potential mechanism for late stent thrombosis in the drug-eluting stent era.     

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.     

Dark side of drug-eluting stent: multiple stent fractures and sudden death

Recently reported stent fractures after sirolimus-eluting stent (SES) implantation were found several months later during the follow-up of coronary angiogram (CAG) and single fracture mostly. The study reports a case of sequential, continuous, multiple coronary stent fracture and sudden death.     

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.     

Acute ST-elevation myocardial infarction 6 years following a sirolimus-eluting stent secondary to complete stent fracture

With increasing coronary interventions, coronary stent fracture following implantation of drug-eluting stents is being commonly recognized. Though isolated strut fractures are often only incidental findings, more severe forms of stent fracture with complete transection have adverse clinical outcomes. Most such cases are reported within several months following the index angioplasty. We report an unusual presentation of late stent fracture following a sirolimus-eluting stent, presenting with acute myocardial infarction 6 years after the initial stent implantation. The various mechanisms underlying fracture of drug-eluting stents are reviewed. Because no known mechanisms were noted in our case, unknown factors may also play a role in the genesis of stent fracture. Clinicians need to be aware that such complications may present rarely, extremely late after the index procedure as an acute myocardial infarction.     

Very late stent thrombosis in late stent malapposition after sirolimus-eluting stent implantation

Late stent malapposition (LSM) has been demonstrated to be more common after drug-eluting stent (DES) implantation than after bare-metal stent (BMS) implantation. To date, this unusual intravascular ultrasonic finding after DES implantation, however, has not received enough attention, because previous studies suggested few adverse clinical sequelae from LSM. We present a case of angiographically-confirmed very late stent thrombosis (ST) in LSM after elective implantation of sirolimus-eluting stents. In this 32-year-old male patient, very late ST occurred at 29 months after DES implantation and at 20 months after the identification of LSM. Although this patient had received sufficient dual antiplatelet therapy with aspirin and clopidogrel for more than 1 year, he suffered from ST shortly after the discontinuation of clopidogrel. Thus, patients with LSM may pose a significant risk for very late ST after discontinuation of dual antiplatelet therapy. The findings suggest that dual antiplatelet therapy should be further prolonged in patients with LSM.     

Sirolimus-eluting stent fractures leading to restenosis in cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is the most common cause of long-term graft failure after heart transplantation. In the absence of a specific treatment for this condition, percutaneous coronary revascularization (PCI) has been the main palliative treatment. Although long-term results are unknown, use of drug-eluting stents (DES) has been shown to have favorable outcome when used in heart transplant patients for treatment of focal lesions in CAV. We report the case of a 77-year-old male who presented with restenosis secondary to DES stent fracture (SF) after treatment of CAV with sirolimus-eluting stents (SES).     

Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

Background

This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial.

Methods

124 patients with definite ST were assessed by IVUS during the acute ST event. The study was conducted in 15 high-volume percutaneous coronary intervention -centers in the Nordic–Baltic countries.

Results

In early or late ST there were no differences in ISA between DES and BMS. In very late ST, ISA was a more frequent finding in DES than in BMS (52% vs.16%; p = 0.005) and the maximum ISA area was larger in DES compared to BMS (1.1 ± 2.3 mm² vs. 0.1 ± 0.5 mm²; p = 0.004). Further, ISA was more prevalent in sirolimus-eluting than in paclitaxel-eluting stents (58% vs. 37%; p = 0.02). Stent fractures were found both in DES (16%) and BMS (24%); p = 0.28, and not related to time of stent thrombosis occurrence. For stents with nominal diameters ≥ 2.75 mm, 38% of the DES and 22% of the BMS had a minimum stent area of less than 5 mm²; p = 0.14.

Conclusions

Very late stent thrombosis was more prevalent and associated with more extensive ISA in DES than in BMS treated patients. Stent fracture was a common finding in ST after DES and BMS implantation.     

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.     

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.     

Coronary stent fracture and restenosis in the drug-eluting stent era: do we have clues of management?

Despite the fact that the drug-eluting stents (DES) have markedly reduced neointimal proliferation, restenosis is still an open subject. Although DES fracture is very rare, it has been considered as one of the reasons for DES restenosis, however, the mechanism and proper management are not clearly elucidated yet. We describe two cases of sirolimus-eluting stent fracture combined with significant restenosis and suggest the possible revascularization strategies for successful management.     

药物洗脱支架断裂的影像认识

目的借助冠状动脉造影和血管内超声的影像资料,确定支架断裂的发生和类型。方法回顾性分析北京大学人民医院2 021例冠状动脉造影和183例血管内超声（IVUS）影像资料。结果共发现3例患者的6处支架断裂,其中2例经IVUS证实。3例支架断裂均发生在西罗莫司药物洗脱支架,且均发生在冠状动脉介入术后1年以内。冠状动脉造影证实4处支架断裂为完全断裂伴断裂处支架移位。IVUS证实3处支架断裂为完全断裂,2处为部分断裂;1处断裂靠近支架重叠处;1处支架断裂伴有血管瘤形成。结论冠状动脉造影和IVUS可以帮助确定支架断裂的诊断。     

Dislodged and mechanically distorted stent stuck within a previously implanted drug-eluting stent

Coronary stent loss during percutaneous coronary intervention is rare and is often associated with significant morbidity. Several retrieval techniques, overlying stent deployment and crushing, and surgical removal can be used to deal with a stent lost in the coronary system. We successfully treated a dislodged and mechanically distorted coil stent stuck within a previously implanted drug-eluting stent (DES) by stent-crush technique. This case might provide insight into the mechanisms responsible for the longitudinal fragility of cobalt alloy and coil-structure stents and stent fracture of DES. In the DES era, careful attention should be paid to such complications when attempting to deliver a stent to a distal vessel through a pre-existing DES.     

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.     

Late angiographic stent thrombosis (LAST) events with drug-eluting stents

OBJECTIVES: We sought to describe the incidence of late angiographic stent thrombosis (LAST) events in an unselected drug-eluting stent (DES) population. BACKGROUND: Concerns have been raised that LAST may be a potential limitation of DES. METHODS: We have previously reported the angiographic incidence of early stent thrombosis (1.0%) in this prospective cohort of 2,006 patients treated with either sirolimus-eluting stents (SES) (n = 1,017) or paclitaxel-eluting stents (PES) (n = 989). We continued long-term follow-up to determine the incidence of LAST events, defined as angiographically proven stent thrombosis associated with acute symptoms more than 30 days after DES implantation. All patients had at least 1 year of follow-up, mean duration 1.5 years. RESULTS: There were eight angiographically confirmed LAST events in seven patients: three with SES (at 2, 25, and 26 months) and five with PES (at 6, 7, 8, 11, and 14.5 months). Three cases were related to complete cessation of antiplatelet therapy, two cases occurred while patients were on aspirin therapy within one month of cessation of clopidogrel, and three cases occurred at a time when patients were apparently clinically stable on aspirin monotherapy. We observed no cases of LAST in patients who were on dual antiplatelet therapy. Two deaths occurred directly as a result of LAST. CONCLUSIONS: Angiographically proven late stent thrombosis occurs with an incidence of at least 0.35% (95% confidence limits 0.17% to 0.72%) in patients treated with DES. Importantly, it may also occur when patients are stable on antiplatelet monotherapy.     

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.     

Two cases of very late stent thrombosis after implantation of a sirolimus-eluting stent presenting as AMI

Stent thrombosis after sirolimus-eluting stent (SES) implantation has been reported to occur at 6 hours to 26 months after the procedure and usually within 2 weeks after discontinuation of antiplatelet medication. However, there are very few reports of stent thrombosis after 2 years. We report 2 cases of very late stent thrombosis after implantation of a sirolimus-eluting stent presenting as acute myocardial infarction (AMI). These late thromboses occurred about 2 years after SES implantation and over 1.5 years after discontinuation of ticlopidine.