药物洗脱支架术后血栓致急性冠状动脉综合征病因分析及处理评价

目的:分析药物洗脱支架术(DES)后支架内血栓形成导致急性冠状动脉综合征的影响因素。方法:分析38例DES术后形成支架内血栓形成患者的临床特点、冠状动脉病变特点、手术相关资料及患者发生急性冠状动脉综合征后的临床表现,处理措施和预后情况。结果:患者冠状动脉造影显示病变特点比较复杂,其中B2/C型病变占到了71%,分叉病变、慢性完全闭塞(CTO)病变、弥散长病变以及小血管病变也占到了相当大的比例,反映了真实的临床情况;38例患者中52.6%表现为急性ST段抬高心肌梗死,29%的患者表现为急性非ST段抬高心肌梗死;支架内血栓中急性、亚急性血栓形成占63%,晚期及迟发晚期血栓形成占37%;绝大多数患者成功接受了再次血运重建治疗,其中有31.6%的患者死亡;2例患者血小板聚集率≥50%,发生率为8.3%;4例接受冠脉内超声(IVUS)检查的患者结果显示:支架近端贴壁不良1例,支架远端残余夹层1例,支架内膜增生不完全1例,支架两端动脉瘤形成1例。结论:DES术后支架内血栓形成与患者的冠状动脉病变复杂程度、术后抗血小板治疗不充分、支架贴壁不良、夹层形成、内膜增生不完全以及动脉瘤的发生等因素相关,支架内血栓形成(ST)后多数表现为ST段抬高心肌梗死(STEMI),尽管大部分能成功再次血运重建治疗,但死亡率仍然较高(31.6%)。     

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.     

“Procedural trauma risks longitudinal shortening of the promus element™ stent platform”

This case series raises further awareness of the potential for longitudinal shortening with the Promus Element? (Boston Scientific, MN) drug‐eluting stent (DES) platform. With safety at the forefront of DES development, newer generation systems are utilizing thinner platforms with little or no polymer. Although these contemporary, ultrathin platforms also improve conformability and deliverability, specific design characteristics might inadvertently reduce longitudinal strength. To date, there are no randomized data addressing this issue in vivo for any stent platform, with opinion based on individual experience and bench testing. We report five cases of longitudinal shortening with the Promus Element stent occurring in our institution over a 15‐month period. During the same period, we experienced only isolated cases with other second generation DES platforms. Our experience supports recently published bench‐top data correlating the two‐link design of this platform with the risk of compression. © 2012 Wiley Periodicals, Inc.     

Stent thrombosis is a major concern in clinical practice: A single Saudi center experience

BackgroundDrug-eluting stents (DES) are used in the majority of patients who undergo percutaneous coronary intervention (PCI), and have reduced the rate of in-stent restenosis and repeated revascularization in comparison to bare metal stents. However, stent thrombosis (ST) is an uncommon but serious complication of coronary artery stents that is mostly fatal or presents as a large non-fatal myocardial infarction (MI), usually with ST elevation.ObjectiveTo study the incidence of stent thrombosis in Middle Eastern Saudi patients who underwent PCI using both drug-eluting stents (DES) and bare metal stents (BMS). ST can occur acutely (within 24 h), sub acutely (within 30 days), or as late as one year (late) or even more than one year (very late).MethodsIn an observational, single center study in catheterization (cath) lab a total of 1386 patients underwent PCI between January 2008 and September 2010. The study included all patients in that period who had acute coronary syndrome and stable coronary artery disease (CAD).ResultsA total of 1386 patients had PCI and stent deployments; 19 (1.3%) patients had stent thrombosis, four patients (21%) received BMS and 15 patients (79%) received DES. Four patients had acute ST; five had subacute ST; eight patients had late ST; while two patients had very late ST. Nine patients (47%) had DM and eight patients (42%) had hypertension.ConclusionThe incidence of ST in Saudi patients who received DES at our center is similar to internationally reported numbers. Almost half of ST patients are diabetics and there is increasing concern that the risk for late stent thrombosis is slightly higher with DES than BMS.     

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.     

Neo-atherosclerosis in very late stent thrombosis of drug eluting stent

Background

Recent studies have described neo-atherosclerosis, developing inside the stent, as cause of very late stent thrombosis.

Case report

A 59-year-old man, with family history of coronary artery disease, presented to our Department because of anterior ST-segment elevation myocardial infarction. Two years before he had underwent percutaneous coronary intervention with multiple drug-eluting stents (DES) implantation on proximal-mid left anterior descending artery (LAD), and mid-right coronary artery (RCA), respectively. The angiogram revealed stent thrombosis with total occlusion of proximal LAD. Multiple passages with manual thrombus-aspiration catheter were successfully performed with improvement in TIMI flow. Optical Coherence Tomography (OCT) imaging revealed fully expanded stents without areas of inappropriate apposition to vessel wall; and mild to moderate intimal hyperplasia throughout the stented segment, with full covered stent struts; areas of ulcerated and ruptured plaque within the proximal struts of stented segment was depicted with intraluminal protruding material. Thus, an additional bare metal stent (BMS) was deployed inside and overlapping the previous in order to seal this plaque. OCT post procedure revealed optimal stent expansion and apposition, without residual protruding material. At 9-month follow-up patient was alive and free from symptoms. Coronary angiogram revealed patency of implanted stents without significant restenosis.

Conclusions

Neo-atherosclerosis with thrombosis on top of ruptured necrotic plaque core may play a role in the pathophysiology of very late stent thrombosis in both BMS and DES. Our report highlights the role OCT to assess the mechanism of VLST.     

Longitudinal deformation – Price we pay for better deliverability of coronary stent platforms

Coronary stents, especially drug eluting stents (DES), have revolutionized the practice of interventional cardiology. Newer stents are manufactured by altering basic design characteristics to tackle complex coronary morphologies more effectively. Alteration in one particular attribute might affect other attributes adversely. Even though, reduction in the number and alteration of the orientation of the connectors improves the stent flexibility and deliverability, it adversely decreases the axial strength of the stent with resulting longitudinal stent deformation. A 67 year old female underwent percutaneous coronary intervention for a mid left anterior descending artery stenosis with a 2.75 × 16 mm Promus Element stent (Boston Scientific, Natick, Massachusetts). The stent got longitudinally distorted during post-stent balloon dilatation which was effectively managed with further dilatation with non-compliant balloon.     

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.     

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.     

Influence of stent design on the immediate and long-term outcome after coronary stent implantation: a comparison of sinusoidal-ring and tube stents

To evaluate the influence of stent design on the immediate and long-term outcome after coronary stent implantation, we retrospectively reviewed 151 patients (170 lesions) who underwent coronary stent implantation. The patients were divided into two groups according to the stent design, namely, the sinusoidal-ring group (GFX stent and AVE S670 stent; 64 patients, 66 lesions) and the tube group (Multi-Link stent and NIR stent; 87 patients, 104 lesions). The indication for coronary stent implantation was only provisional and additional stenting was considered in the presence of suboptimal results (residual stenosis >30%) or of a large dissection after balloon angioplasty. Angiographically confirmed success was achieved in all patients. No major adverse cardiac events were documented in either group during the hospitalization period. There were no cases of death nor of Q-wave myocardial infarction in either group during the follow-up period. The restenosis and target lesion revascularization (TLR) rates were 24.1% and 15.3% in the sinusoidal-ring group, and 20.2% and 12.6% in the tube group, respectively. The restenosis and TLR rates were similar in both groups. In conclusion, an influence of stent design on the immediate and long-term outcome after coronary stent implantation was not observed using sinusoidal-ring and tube stents. Received: September 12, 2000 / Accepted: April 14, 2001     

Safety and efficacy of the Yukon Choice Flex sirolimus-eluting coronary stent in an all-comers population cohort

Aims

The use of biodegradable-polymer drug-eluting stents has been shown to provide favorable results when compared with durable polymer drug-eluting stents and long-term follow up data have recently shown significant reductions in terms of very late stent thrombosis.Aim of the present study was to assess the safety and efficacy profile of a novel biodegradable polymer DES, the Yukon Choice Flex sirolimus-eluting stent.

Methods

We report here the one-year clinical outcomes associated with the use of the Yukon Choice Flex sirolimus-eluting stent in an all-comers patient population. The present stent represents a further refinement of the stent platform tested in the ISAR TEST 3 and 4 randomized clinical trials. A total of 778 consecutive patients undergoing implantation of this stent were enrolled in the present observational study and prospectively followed for one year.

Results

The use of the Yukon Choice Flex stent in a patient population with complex coronary lesion morphology was associated with optimal immediate angiographic results. At one year follow up the rates of death, myocardial infarction, definite stent thrombosis and ischemia-driven target lesion revascularization were respectively 2.4%, 1.9%, 0.3% and 11.3%.

Conclusions

The use of the sirolimus-eluting biodegradable polymer Yukon Choice Flex stent in an all-comers population of patients with complex coronary artery disease is associated with a favorable safety and efficacy profile up to one year follow up.     

Very delayed coronary stent fracture: A case report

A stent fracture is an emerging complication of the coronary stents. There are numerous risk factors for stent fractures; which include forceful exaggerated motion in the atrioventricular groove seen in right coronary artery, long stent, an ostial lesion at the point of maximum curvature in a tortuous vessel, stent over-expansion, stent overlapping with different size stents, complex lesion after stenting of a totally occluded vessel, Cypher stent and a highly mobile segment causing high mechanical stress. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture.Here we report a case of 40-year-old male who had two overlapping Cypher stents (3.0 × 13 mm and 2.75 × 18 mm) deployed at mid left anterior descending artery 2 years earlier presented with progressive chest pain.     

小直径肾动脉狭窄应用西罗莫司洗脱支架的安全性和有效性

目的评估小直径肾动脉粥样硬化性狭窄患者应用冠状动脉西罗莫司洗脱支架的安全性和有效性。方法两年内入选15例患者,平均年龄67·7岁。双侧肾动脉狭窄或闭塞和单侧肾动脉狭窄各6例,副肾动脉狭窄3例。应用2种国产西罗莫司洗脱(火鸟和同心)冠状动脉支架。研究主要终点包括术后1、3和6个月靶病变直径狭窄程度(再狭窄率)和肾功能状态。结果在15例患者19处病变共成功置入22个支架,其中西罗莫司洗脱支架19个,肾动脉金属裸支架3个。全部患者完成了1个月肾动脉Doppler超声随访和血清肌酐随访,其中5例和7例分别完成了3个月和6个月的前述随访,还有3例进行了6个月血管造影随访。随访结果均未显示靶血管再狭窄,并且肾功能较术前没有明显变化。结论冠状动脉西罗莫司洗脱支架可以安全和有效应用于治疗小直径肾动脉粥样硬化性狭窄患者。     

Titanium-nitride-oxide-coated Titan-2 bioactive coronary stent: a new breakthrough in interventional cardiology

The introduction of drug-eluting stents (DES) has revolutionized the field of interventional cardiology, since it has reduced the incidence of restenosis by 50% to 70%. However, recent worrisome data from registries and meta-analyses emphasized higher rates of late and very late stent thrombosis associated with DES. The recently introduced titanium-nitride-oxide-coated stent bioactive stent (Titan-2) was manufactured by a proprietary process to coat titanium-nitride-oxide on the surface of the stainless steel stent, based on a plasma technology using the nano-synthesis of gas and metal. This late-breaking stent has demonstrated an excellent biocompatibility, as reflected by lower rates of platelet aggregation and fibrin deposition, and better endothelialization. Preclinical and clinical trials and registries involving real-life unselected populations have shown a low rate of major adverse cardiac events at long-term follow-up. Restenosis rates were comparable with those of DES, with very rare stent thrombosis. Equally favorable results have been obtained in patients at high-risk of in-stent restenosis, such as diabetics and those with small coronary arteries. Results in patients presenting with acute coronary syndrome have been again comparable to those of DES, with tendency to lower rates of myocardial infarction and stent thrombosis. Comparisons with second generation drug-eluting stents have also been promising.     

One-year clinical outcomes of BioMatrix™-Biolimus A9™ eluting stent: The e-BioMatrix multicenter post marketing surveillance registry in India

Objective

The e-BioMatrix is a post marketing multicenter registry with an objective to evaluate the 2 year clinical safety and efficacy outcomes in patients treated with BioMatrix™ - Biolimus A9™ (BA9™) drug eluting stents (DES).

Background

Drug-eluting stents still have late-stage disadvantages that might be attributable to the permanent polymer. BioMatrix a new generation DES containing anti-proliferative drug Biolimus A9™ incorporating a biodegradable abluminal coating that leaves a polymer-free stent after drug release enhancing strut coverage while preventing neointimal hyperplasia.

Methods

This interim analysis consists of a total of 1189 patients with 1418 lesions treated with BioMatrix stent who entered this multicenter registry in India. We analyzed the incidence of major adverse cardiac events (MACE) and stent thrombosis (ST) at 1, 6, and 12 months with an extended follow-up of 2 years. Recommended antiplatelet regimen included clopidogrel and aspirin for 12 months.

Results

The mean age was 57.6 ± 10.9 years, 81.8% were males, comorbidity index was 1.20 ± 1.33, 68% presented with acute coronary syndrome, 49% had hypertension and 40.8% had diabetes mellitus. One-year clinical follow-up was completed in 987 patients at the time of interim analysis. The incidence of MACE is 0.45 for 1544 person-year follow-up. There were only 03 cases of ST (01 late ST) reported during this time.

Conclusion

This registry demonstrates excellent one-year clinical safety and efficacy of BioMatrix stents. The 1-year result shows that BioMatrix stent may be a suitable alternative as compared to contemporary DESs which are currently available in the market for simple as well complex disease.     

Decreased risk of stent fracture‐related restenosis between paclitaxel‐eluting stents and sirolimus eluting stents: Results of long‐term follow‐up

Objective: To compare the outcomes between paclitaxel‐eluting stents (PES) and sirolimus‐eluting stents (SES) for the treatment of drug‐eluting stent (DES) fracture. Background: DES fracture is considered as an important predictor of in‐stent restenosis (ISR). However, little data are available evaluating the optimal treatment for this complication of coronary stenting. Methods: From January 1, 2004 to December 31, 2008, patients with DES ISR treated with a second DES were identified and evaluated for stent fracture. Stent fracture was defined by the presence of strut separation in multiple angiographic projections, assessed by two independent reviewers. Target lesion revascularization (TLR) at 6 and 12 months were the primary end points. Results: Of 131 lesions with DES ISR treated with a second DES, we found 24 patients (24 lesions, 18.2%) with angiographically confirmed stent fracture. Of these, 20 patients (20 lesions) treated with either PES (n = 11/55%) or SES (n = 9/45%) were included in the study. TLR at 6 months occurred in 9% of patients treated with PES and 22% of those treated with SES (P = 0.41). After 12 months, TLR was 9% and 55.5%, respectively (P = 0.024). Conclusions: This study demonstrates a high incidence of stent fracture in patients presenting with DES ISR in need of further treatment with another DES. The suggested association between treatment of stent fracture‐associated DES ISR with PES as compared with SES, and better long‐term outcomes, is in need of confirmation by larger prospective registries and randomized trials. © 2011 Wiley Periodicals, Inc.     

Double jeopardy: balance between bleeding and stent thrombosis with prolonged dual antiplatelet therapy after drug-eluting stent implantation

Prolonged dual antiplatelet therapy with aspirin and clopidogrel is mandatory after drug-eluting stent (DES) implantation because of potential increase risk of stent thrombosis compared to bare-metal stents. As more DES are being implanted, many of these patients will undergo non-cardiac surgery whilst on antiplatelet therapy. The optimal management of perioperative antiplatelet therapy is not well established. The risk of excessive bleeding associated with antiplatelet therapy needs to be balanced against the risk of stent thrombosis with interruption of antiplatelet therapy on a case-to-case basis.     

Future stent drug delivery systems

Drug-eluting stents (DES) with antiproliferative drugs attached via polymers on the stent surface have reduced in-stent restenosis and repeat revascularization compared with bare metal stent (BMS) across nearly all lesion and patient subsets. However, the small number of patients with in-stent restenosis after DES treatment still exists. Furthermore, concerns about long-term safety of DES are raised, particularly regarding the higher-than-expected late-event thrombosis. There is no doubt that the DES will continue to play a pivotal role in the treatment of coronary artery disease, yet future designs need to incorporate features that reduce thrombosis and promote endothelialization along with maintaining the efficacy. This review focuses on novel generation of DES, discussing new programs, including new antiproliferative agents, novel polymeric and non polymeric stents.     

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.     

Stent thrombosis of drug eluting stent: pathological perspective

Although, the first-generation drug eluting stents (DES) have significantly reduced rates of restenosis compared to bare metal stents (BMS), an increased risk of late stent thrombosis (LST) has emerged as a major concern. Pathologic studies of patients dying from late DES thrombosis demonstrates delayed arterial healing characterized by persistent fibrin deposition and poor endothelialization as the primary substrate. However, recent thorough investigations revealed additional mechanisms of stent thrombosis such as hypersensitivity reaction, excessive fibrin deposit with malapposition, or neoatherosclerosis, which are associated with device-specific components and the majority of very late stent thrombosis is likely associated with these abnormal vascular responses. Therefore, although the incidence of stent thrombosis following DES implantation is similar in each period, the underlying mechanisms of this complication may vary. In the current review, the mechanisms of stent thrombosis in the DES era will be discussed using the data from autopsy studies that have been published.