Stent thrombosis: an overview

Stent thrombosis is a challenging problem following percutaneous coronary intervention that can lead to serious clinical consequences, such as death and acute myocardial infarction. Its pathophysiology is not yet completely known, and there are several causes suggested, such as incomplete stent endothelization, presence of polymers and late incomplete stent apposition. One of the main predictors is the early discontinuation of dual antiplatelet therapy. Stent improvements related to their design, with more friendly metallic platforms, thinner biocompatible or biodegradable polymers, absence of polymers, and even stents manufactured with bioabsorbable materials, could make the percutaneous procedure much safer and effective, allowing its application in increasingly complex anatomic and clinical scenarios, with low thrombosis rates.     

Long-term care after percutaneous coronary intervention: focus on the role of antiplatelet therapy

Arterial wall injury caused by percutaneous coronary intervention (PCI) triggers transient platelet activation and mural thrombosis; these effects are superimposed on the preexisting platelet hyperreactivity associated with underlying atherothrombosis. Platelet activation has been implicated in the major complications of PCI: acute and subacute thrombosis and restenosis. Antithrombotic and anticoagulant therapy minimizes thrombotic complications after PCI. Aspirin plus a thienopyridine (ticlopidine or clopidogrel) is more effective than aspirin plus heparin and extended warfarin therapy in preventing periprocedural ischemic events and subsequent stent thrombosis and results in less major and minor bleeding. Dual antiplatelet therapy with aspirin and clopidogrel (the preferred thienopyridine because of its superior hematologic safety) is recommended for at least 4 weeks to prevent subacute stent thrombosis with bare-metal stents and 3 to 6 months to prevent late-stent thrombosis with drug-eluting stents. Coronary atherothrombosis is a diffuse vascular disease, and reduction of the risk of future ischemic events requires strategies that extend beyond the focal treatment of stenotic lesions. Optimal long-term care after PCI requires aggressive systemic pharmacotherapy (antiplatelet agents, statins, beta-blockers, and angiotensin-converting enzyme Inhibitors) in conjunction with therapeutic lifestyle changes (smoking cessation, weight reduction, dietary measures, and exercise). In this context, dual antiplatelet therapy (aspirin plus clopidogrel) is recommended for at least 12 months after PCI for prophylaxis of future atherothrombotic events.     

Is stent thrombosis the new Achilles heel of interventional cardiology? State of the Art clinical trials, causes and approaches for prevention

Coronary stents are the mainstay of percutaneous coronary intervention. Stent thrombosis is a potentially catastrophic and often life-threatening complication. If it occurs it presents in up to 80% as myocardial infarction, about half of the affected patients die from this complication. The dual antiplatelet therapy has markedly reduced its occurrence. Today, stent thrombosis occurs in <1%, usually as a delayed event; but compared to bare metal stents the overall incidence has not increased in meta-analyses of randomized trials. The advent of drug-eluting stents (DES) has raised concerns regarding the occurrence of delayed stent thrombosis. Delayed arterial wall healing as well as prothrombotic characteristics of the drug eluting stent itself may contribute to stent thrombosis. In order to prevent stent thrombosis a standardized fixed dose antiplatelet therapy with ASA and clopidogrel is recommended. But, their efficacy depends on patient's individual characteristics such drug metabolism. Therefore, individual determination of platelet function in each patient undergoing stent implantation may help to avoid prothrombotic as well as bleeding complications.     

Cardiac magnetic resonance imaging safety following percutaneous coronary intervention

In the first 8 weeks after percutaneous coronary intervention (PCI), possible negative interactions exist between the cardiac magnetic resonance (CMR) imaging environment and the weakly ferromagnetic material in coronary stents. There are circumstances when CMR would be indicated shortly following PCI, such as acute myocardial infarction (AMI). The purpose of this study is to demonstrate CMR safety shortly following stent PCI in AMI patients. We performed a retrospective analysis of safety data in AMI patients with recently placed coronary artery stents enrolled in a multi-center phase II trial for gadoversetamide. Patients underwent 1.5T CMR within 16 days of PCI. Vital signs (blood pressure, heart rate, respiratory rate, and body temperature) and ECGs were taken pre-CMR, 1, 2, and 24 h post-CMR. Any major adverse cardiac event (MACE) or other serious adverse events in the first 24 h after MRI were recorded. There were 258 stents in 211 AMI patients. The mean delay to CMR following PCI was 6.5 ± 4 days, with 62 patients (29 %) receiving CMR within 3 days and 132 patients (63 %) within 1 week. Patients showed no significant vital sign changes following CMR. Ten patients (4.7 %) showed mild, transient ECG changes. Within the 24-h follow-up group, 4 patients (1.9 %) had moderate to severe events, including chest pain (1) and elevated cardiac enzymes (1), resolving in 24 h; heart failure (1) and ischemic stroke (1). There were no deaths. This study demonstrates fewer MACE in AMI patients undergoing 1.5T CMR within 16 days of stent placement in comparison to post-stent event rate reported in the literature. This study adds to the CMR after stent PCI safety profile suggested by previous studies and is the largest and first study that uses multicenter data to assess stent safety following CMR examination.     

Benefits of and safety concerns associated with drug-eluting coronary stents

Drug-eluting coronary stents are being used with increasing frequency in patients undergoing percutaneous coronary intervention. Although these stents have shown remarkably low rates of restenosis compared with their predecessors, there have been increasing concerns lately regarding their safety. Extensive data have been published that demonstrate a higher risk of very late stent thrombosis with drug-eluting stents; however, this has not had any impact on long-term mortality or the risk of myocardial infarction when compared with bare-metal stents. Their overall net clinical benefit therefore still favors their use. Recent research has led to a greater understanding of the multifactorial cause of stent thrombosis, which has enabled measures to be taken to reduce an individual patient’s risk. In the future, new stent designs and new antiplatelet agents may help to reduce this risk further.     

国产Firebird支架在急性冠状动脉综合征急诊介入治疗中的作用

目的:探讨国产雷帕霉素药物洗脱支架(Firebird)在急性冠状动脉综合征(ACS)急诊经皮冠状动脉介入治疗(PCI)中应用的安全性和有效性。方法:选择2004年1月至2007年9月间的ACS患者118例,于发病12h内行急诊PCI治疗,于梗死相关血管的靶病变处置入Firebird支架。记录1个月和6个月随访终点时的主要心脏不良事件(包括死亡、再发心肌梗死、靶血管再成形等)发生率、支架内血栓发生率、支架内再狭窄发生率。结果:118例患者急诊PCI治疗均获得成功。118支梗死相关血管的125处罪犯病变共置入140枚Firebird支架,12例患者出现无复流现象,1例应用主动脉内气囊反搏术,6例出现心室颤动,18例出现一过性室性心动过速。10例出现一过性低血压,术后2例发生穿刺部位血肿。仅1例患者于术后第3天因再发急性心肌梗死死亡,1个月随访终点时主要心脏不良事件为0.8%。6个月随访终点时有28例接受了冠状动脉造影复查(造影随访率23.9%),无支架内再狭窄发生,无主要心脏不良事件。结论:Firebird支架在ACS急诊PCI中应用与普通支架一样有较高的安全性和有效性,并可以明显降低再狭窄率。     

药物洗脱支架治疗急性心肌梗死的远期疗效观察

目的观察药物洗脱支架用于急性心肌梗死的安全性及远期临床疗效。方法97例发病3周以内的急性心肌梗死患者,其梗塞相关动脉行经皮冠状动脉介入治疗时使用药物洗脱支架(包括雷帕霉素及紫杉醇药物洗脱支架),并于术后(26.5±10.6)个月进行门诊及电话随访,必要时复查冠状动脉造影,观察住院及随访期间心血管事件发生率(死亡、再发急性心肌梗死及血管重建术)。结果125枚药物洗脱支架(雷帕霉素药物支架90枚,紫杉醇药物支架35枚)植入97个梗塞相关动脉,支架长度(24.4±6.1)mm,支架直径(3.0±0.4)mm;支架植入成功率100%。5例(5.2%)死亡,其中3例死于慢性心力衰竭,1例死于脑梗死,1例于术后1月死于可能的血栓形成;1例(1.0%)术后1周发生支架内急性血栓形成,而行靶血管再次血管重建术;1例因非靶血管病变致心绞痛于术后3月转外院行CABG术;无一例发生晚期支架内血栓形成及非致死性再梗。结论药物洗脱支架应用于急性心肌梗死治疗安全、有效,并可以明显降低再狭窄率,具有良好的远期效果。     

Acute multi-vessel coronary stent thrombosis

Background: Coronary artery stent thrombosis is a rare but often fatal complication associated with percutaneous coronary intervention (PCI) using both bare-metal stents and drug-eluting stents. Although strict adherence to dual anti-platelet therapy (aspirin plus clopidogrel) minimizes this risk, stent thrombosis will still occur in rare patients, leading to acute, subacute, or late life-threatening acute coronary syndromes. Objectives: To present a rare case of acute stent thrombosis involving multiple vessels to increase awareness of this life-threatening condition among emergency physicians, and to review the current guidelines for anti-platelet therapy in this patient population. Case Report: A 52-year-old man who underwent PCI using drug-eluting stents in two separate coronary vessels presented to the Emergency Department within 2 h of discharge from the hospital with chest pain, dynamic electrocardiogram changes, and elevated cardiac markers. Despite compliance with the current recommendations for post-PCI anti-platelet therapy, urgent repeat catheterization revealed total thrombotic occlusion of both stents, requiring urgent repeat intervention. Conclusion: Despite patient compliance with the currently recommended anti-platelet regimen after stent therapy for coronary artery disease, acute stent thrombosis remains a rare but life-threatening risk in both the immediate and delayed post-intervention period. In addition, premature cessation of this anti-platelet therapy stands as the greatest risk factor for such thrombotic events. This case is presented to inform emergency physicians of the current post-PCI anticoagulation recommendations to help mitigate the risk of such complications.     

Stent thrombosis in a clopidogrel nonresponder

Stent thrombosis is a known complication of percutaneous coronary intervention (PCI) following coronary stent deployment. Dual antiplatelet therapy is standard of care following PCI, however, recent studies demonstrate marked variability in platelet response to clopidogrel. This case study explores the management of a clopidogrel nonresponder who presented with recurrent stent thrombosis despite traditional pharmacologic management.     

Bivalirudin in ST-segment-elevation myocardial infarction: for better or worse?

Bivalirudin and heparin are the major available parenteral anticoagulants for percutaneous coronary intervention (PCI) in ST-segment-elevation myocardial infarction. Even though hard clinical outcomes are comparable with both drugs, bivalirudin appears to be safer (less bleeding events) at the expense of lower short-term efficacy (more acute stent thrombosis events). The selection of anticoagulation during PCI in ST-segment-elevation myocardial infarction should be individualized, taking into account the patient’s ischemic and bleeding risk. In patients with increased bleeding risk, bivalirudin might be preferable to heparin, whereas in complex PCI with increased risk for stent thrombosis, heparin is preferable. Further clinical studies are needed to elucidate the role of these drugs in PCI for ST-segment-elevation myocardial infarction in the era of radial approaches, new potent antiplatelet agents and the use of glycoprotein IIb/IIIa inhibitors.     

国产药物洗脱支架联合替罗非班治疗急性心肌梗死近中期疗效的临床观察

目的评价国产药物洗脱支架（乐普支架）联合替罗非班在急性心肌梗死急诊介入治疗中的安全性、有效性及近中期疗效。方法2009年9月～2011年8月,共62例急性心肌梗死患者行急诊介入治疗,随机分为替罗非班组和对照组,替罗非班组在对病变血管经皮冠状动脉介入治疗（PCI）过程中置人乐普支架。所有患者术前均口服负荷量阿司匹林300mg、氯吡格雷300mg。术中推注肝素8000-10000U。球囊预扩张病变血管后,冠脉内注射10—15ml替罗非班,PCI术后0．15g／（kg·min）静脉滴注维持24—48h,术后皮下注射低分子肝素5～7d,对照组患者未冠脉内注射替罗非班。结果两组患者一般资料比较,差异无统计学意义（P〉0．05）。两组患者的梗死相关动脉PCI术后全部即刻再通,且梗死相关动脉即刻再灌注率。两者差异无统计学意义（P〉0．05）。PCI术后替罗非班组梗死相关血管TIMI3级血流获得率96．7％,高于对照组83．9％,差异有统计学意义（P〈0．05）,校正TIMI计桢数显示替罗非班组血流速度高于对照组,差异有统计学意义（P〈0．05）。所有患者住院期间均未发生急性、亚急性血栓,均未发生心源性死亡、再发急性心肌梗死、急诊CABG和重复PCI等主要不良心脏事件。所有患者均接受了临床随访,均无不良心血管事件：再发心绞痛、心肌梗死、心力衰竭及猝死等发生。其中,32例患者术后6个月复查了冠状动脉造影,无一例发生支架内再狭窄。结论国产药物洗脱支架（乐普支架）联合替罗非班治疗用于急性心肌梗死急诊介入治疗,是安全、有效的方法,近中期效果良好。     

Increased incidence of in-stent thrombosis related to cocaine use: case series and review of literature

The purpose of this article was to determine the incidence of in-stent thrombosis (IST) after coronary stent implantation in patients with cocaine abuse. A retrospective review was done of medical records of consecutive patients who underwent coronary stent implantation for obstructive coronary artery disease at a single inner-city institution from January 1997 to October 2006. Patients with temporal cocaine use were identified by positive urine drug screen. IST was confirmed angiographically. Of the 81 patients with active cocaine use that underwent coronary stent implantation, 4 (5%) suffered IST (mean period from stent implantation, 28.5 +/- 14 days). All procedures were performed successfully and received intravenous IIb/IIIa antagonist intraprocedurally. All patients were prescribed dual antiplatelet therapy with aspirin and clopidogrel at discharge; however, all 4 patients that suffered from IST continued cocaine abuse were noncompliant with the prescribed dual antiplatelet therapy. Of these 4 patients, 2 presented with ST segment elevation myocardial infarction (50%), whereas 2 presented with non-ST-segment elevation myocardial infarction (50%). One was managed medically. Two received repeat percutaneous coronary intervention, and 1 underwent coronary artery bypass surgery. The patient that underwent surgery died in the postoperative period. The remaining 3 patients survived. Patients with active cocaine abuse who undergo successful coronary stent revascularization have a high (5%) incidence of stent thrombosis. A majority of patients that suffer stent thrombosis continue cocaine abuse and are noncompliant with antiplatelet therapy.     

单中心62例无保护左主干病变支架植入的1年临床疗效

目的观察62饲无保护左主干病变并行介入治疗的患者,分析其临床特点,随访1年临床疗效。方法非随机入选符合标准的患者,术前常规给予阿司匹林和氯吡格雷（波立维）治疗,术中根据病变分布、血管直径选择单支架和T支架、V支架、对吻（kissing）支架、挤压（crush）支架和裤裙（clotte）支架双支架术,6个月和1年时电话或门诊随访死亡、心肌梗死、靶血管血运重建和外科搭桥等不良心血管事件。结果病变分布开口、体部和末端分叉所占比例分别是24．2％、20．1％和54．8％,其中56．5％（35例）的患者使用单支架,43．5％（27例）的患者使用双支架。1年随访,猝死1例,急性心肌梗死2例,靶血管重建2例,冠状动脉搭桥（CABG）3例,1年总不良心血管事件发生率12．9％。结论无保护左主干病变患者行药物洗脱支架治疗临床疗效可靠,不良事件发生率与CABG相当,时其有选择性地行介入治疗安全可行。     

早期支架血栓形成住院患者22例临床分析

目的分析冠状动脉药物洗脱支架（DES）植入术后住院患者早期支架内血栓形成（stent thrombosis,ST）临床特点并探讨其原因。方法对6 036例经皮冠状动脉介入治疗（percutaneous coronary intervention,PCI）中的22例早期ST患者临床资料、冠状动脉造影结果以及围手术期抗血栓治疗等相关因素进行回顾性研究。结果 2005年1月至2011年3月,我院资料库登记成功实施PCI治疗的6 036例住院患者,术后发生急性ST 2例,亚急性ST 20例,院内早期ST发生率0.36%。ST时间相对集中于术后较早期,20例亚急性ST形成时间为1～7天,平均（3.6±1.5）天;ST后所有患者均出现典型的临床表现及心电图改变。其中多支病变20例,急性心肌梗死（AMI）11例,血栓形成于前降支13例,21例经冠状动脉造影证实ST,13例紧急PCI治疗行球囊扩张后血栓消失,5例再次支架植入后血管再通,患者发生心室颤动5例,低血压状态6例。行急诊PCI治疗,18例患者治愈存活出院,4例患者死亡（病死率18.2%）。结论 ST是介入术后严重的并发症,与患者临床病变特点、介入操作因素、支架本身、抗血小板治疗不充分等因素有关,多发生在AMI,合并心功能不全,多支血管病变、前降支病变等患者。支架内血栓一旦形成,再次介入治疗是有效的抢救手段。     

Percutaneous coronary intervention and stent thrombosis

Despite improved stent implantation technologies and effective antiplatelet regimens, stent thrombosis has been one of the most important problem in percutaneous coronary intervention. Stent thrombosis is a rare but usually catastrophic event, frequently associated with large MI or death. Stent thrombosis is generally categorized according to the timing of the event as early (0 to 30 days), late (31 days to 1 year), very late (> 1 year). Late and very late stent thrombosis after stent implantation has not yet been adequately characterized, mainly because of its low incidence. And the optimal duration of dual antiplatelet therapy remains uncertain for patients receiving drug-eluting stents.     

Stent thrombosis during COVID‐19 pandemic: A case series

The coronavirus disease 2019 (COVID‐19) pandemic originated from Wuhan, China, in late 2019. In addition to the respiratory system, COVID‐19 also affects other organ systems. The disease can lead to cardiovascular complications such as myocarditis, acute myocardial infarction, acute heart failure, and venous thromboembolism; patients with COVID‐19 experience more thrombotic events than non‐COVID‐19 patients. A 50‐year‐old male cigarette smoker presented to the emergency department (ED) with typical chest pain. His electrocardiography (ECG) showed an anterior STEMI. He developed multiple episodes of ventricular fibrillation (VF) and received defibrillator shocks. His angiogram showed thrombotic severe in‐stent restenosis (ISR) of the left anterior descending (LAD) artery stents. A 70‐year‐old diabetic hypertensive woman presented to the ED with dyspnea and chest pain. The patient had undergone angioplasty two times beforehand, and a fresh angiogram revealed severe thrombotic ISR of LAD stents and another far midpart lesion after the stents. She underwent successful percutaneous coronary intervention (PCI). A 54‐year‐old man presented to the ED with typical chest pain commencing an hour beforehand. He had undergone angioplasty about 10 years earlier. The patient received the Oxford/AstraZeneca COVID‐19 vaccine 36 h before developing chest pain. The ECG revealed an infero‐posterior STEMI, and the angiogram depicted thrombotic occluded ISR in the RCA. The patient underwent successful PCI. Patients with COVID‐19 or even with COVID‐19 vaccination experience stent thrombosis due to a hypercoagulable state. Hence, we need standard guidelines to prevent stent thrombosis.     

ZEEK血栓抽吸导管在急性心肌梗死介入治疗中的应用

目的 观察一种新型的操作简便的冠脉内血栓抽吸导管在经桡动脉急性心肌梗死(AMI)急诊介入治疗中的临床应用效果.方法 本研究为单中心回顾性研究,入选北京友谊医院心血管中心2006年3月至2008年6月进行急诊经皮冠脉介入治疗(PCI)的AMI患者,冠脉造影发现病变高血栓负荷50例,支架置入前进行冠状动脉内血栓抽吸.术后造影观察梗死相关血管心肌梗死溶栓治疗试验(TIMI)血流、校正的TIMI帧数(cTFC)、TIMI心肌灌注显像分级(TMPG)、无复流发生率,住院期间支架内急性血栓及亚急性血栓的发生率,随访6～24个月期间的心脏缺血事件、再血管化及死亡率.手术前后的TIMI血流和TMPG比较采用配对t检验.结果 抽吸组即刻血栓消失35例,血栓减少15例.术后梗死部位前向血流TIMI分级显著好转(0 vs.2.7±0.5,P<0.01),TMPG显著提高(0 vs.2.6±0.8,P<0.01),术后的cTFC为20.2±16.8.术中及术后无严重并发症.结论 急诊经桡动脉进行冠状动脉内血柃抽吸安全可行,ZEEK吸栓导管足治疗冠状动脉狭窄合并血栓病变的简单有效的方法,可提高经皮冠状动脉介入治疗的成功率、减少无复流等并发症的发生及改善长期预后.     

Acute and subacute stent thrombosis after primary percutaneous coronary intervention for ST‐segment elevation myocardial infarction: incidence,predictors and clinical outcome

Summary. Background: Early coronary stent thrombosis occurs most frequent after primary percutaneous coronary intervention (PCI) for ST‐segment elevation myocardial infarction (STEMI). Objectives: To identify the specific predictors of, respectively, acute and subacute stent thrombosis in patients after primary PCI for STEMI. Patients/Methods: Consecutive STEMI patients with angiographically confirmed early stent thrombosis were enrolled and compared in a 2 : 1 ratio with a matched control group. Clinical outcome was collected up to 1 year. Results: Of 5842 STEMI patients treated with primary PCI, 201 (3.5%) presented with a definite early stent thrombosis. Of these, 97 (1.7%) had acute stent thromboses and 104 (1.8%) had subacute stent thromboses. Postprocedurally discovered dissection, undersizing and smaller stent diameter were the strongest predictors for acute stent thrombosis. No glycoprotein IIb/IIIa therapy and the use of drug‐eluting stents were also associated with acute stent thrombosis. Lack of clopidogrel therapy in the first 30 days after the index PCI was the strongest predictor for subacute stent thrombosis. Mortality rates at 1‐year follow‐up were lower for acute stent thrombosis than for subacute stent thrombosis (8.3% vs. 13.2%, P = 0.294). The incidence of definite recurrent stent thrombosis at 1‐year follow up was significantly lower after a first definite acute stent thrombosis than after a first definite subacute stent thrombosis (6.4% vs. 19.3%, P = 0.007 at 1 year). Conclusions: The specific risk factors for, respectively, acute and subacute stent thrombosis after primary PCI vary greatly. Mortality rates are high for both categories of stent thrombosis. However, recurrent stent thrombosis occurs more frequently after subacute stent thrombosis.     

药物洗脱支架在急性ST段抬高型心肌梗死中的应用

目的:探讨药物洗脱支架(DES)在急性ST段抬高型心肌梗死(AMI)直接经皮冠状动脉介入治疗(PCI)中应用的安全性和有效性。方法:选择2005年5月—2005年10月间的ST段抬高型AMI患者67例,在发病12h内行急诊PCI治疗,于梗死相关血管(IRA)的靶病变植入DES。术后前瞻性随访300d,观察主要心血管不良事件(MACE)(包括死亡、非致死性再梗和靶血管血运重建)的发生情况。结果:67例患者中,伴糖尿病者占20．9%,多支病变者占71．6%。67例患者共植入84枚DES,64例(95．5%)术终血流达到TIMI-3级。住院期间4例(6．0%)患者死亡,1例(1．5%)术后当天发生早期支架内血栓形成引起非致死性再梗而行靶血管再次血运重建。出院至术后300d随访期间,2例(3．0%)死亡,无一例发生晚期支架内血栓形成、非致死性再梗或因造影或临床再狭窄需行靶血管再次血运重建。结论:DES应用于ST段抬高型AMI患者具有良好的安全性,而且可以明显降低靶血管血运重建的发生率,改善患者远期预后。     

急性ST段抬高心肌梗死小血管病变急诊经皮冠状动脉介入治疗应用雷帕霉素药物洗脱支架的疗效分析

目的探讨雷帕霉素药物洗脱支架在急性ST段抬高心肌梗死(STEMI)小血管病变患者急诊经皮冠状动脉介入治疗(PCI)中应用的安全性和有效性。方法对121例STEMI小血管病变患者128处罪犯病变行PCI治疗,共置入了136枚雷帕霉素药物洗脱支架。结果121例PCI均成功,未发生与PCI有关的并发症。1例术后第2天死于心脏破裂,未发生主要不良心血管事件。进行12个月临床随访,有2例术后5个月再次行冠状动脉血运重建术,无其他主要不良心血管事件发生。结论雷帕霉素药物洗脱支架在STEMI小血管病变患者急诊PCI中应用有较高的安全性和有效性。