Commentary on a case report and literature review of acute carotid stent thrombosis

In this commentary on the article entitled“Acute carotid stent thrombosis:A case report and literature review”,the key points of the article are discussed.Acute carotid stent thrombosis(ACST)in the setting of carotid artery stenting(CAS)represents a rare but potentially catastrophic event.There is a wide range of treatment options available,including carotid endarterectomy,which is generally recommended for cases of refractory ACST.While there is no standard treatment regimen,dual antiplatelet therapy is typically recommended both before and after CAS to reduce risk of ACST.

Analysis of risk factors for early stent thrombosis in the Chinese population:A multicenter restrospective study

BACKGROUND:The predictive scoring systems for early stent thrombosis(EST)remains blank in China.The study aims to evaluate the risk factors and conduct a prediction model of EST in the Chinese population.METHODS:EST was defined as thrombosis that occurs within the first 30 days after primary percutaneous coronary intervention(PCI).Patients from ten Chinese hospitals diagnosed as stent thrombosis(ST)from January 2010 to December 2016 were retrospectively included as the study group.A control group(1 case:2 controls)was created by including patients without ST,major adverse cardiovascular events,or cerebrovascular events during follow-up.The present study evaluated 426 patients with single-vessel lesions and ultimately included 40 patients with EST and 80 control patients,who were included to identify factors that predicted EST and to develop a prediction scoring system.The other 171 patients without integrated 1:2 pair were used for external validation.RESULTS:EST was independently associated with a low hemoglobin concentration(adjusted odds ratio[OR]0.946,95%confi dence interval[95%CI]0.901-0.993,P=0.026),a high pre-PCI Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score(OR 1.166,95%CI 1.049-1.297,P=0.004),and a DAPT(DAPT)duration of<30 days(OR 28.033,95%CI 5.302-272.834,P<0.001).The simple EST prediction score provided an area under the curve(AUC)of 0.854(95%CI 0.777-0.932,P<0.001)with 70.0%sensitivity and 90.0%specifi city,and 0.742(95%CI 0.649-0.835,P<0.001)with 54.5%sensitivity and 81.0%specifi city for external validation dataset.CONCLUSIONS:EST may be independently associated with DAPT discontinuation within 30 days,a low hemoglobin concentration,and a high SYNTAX score.The scoring system also has a good ability to predict the risk of EST and may be useful in the clinical setting.

Acute carotid stent thrombosis:A case report and literature review

BACKGROUND Acute carotid stent thrombosis(ACST)is a rare but devastating complication in the carotid artery stenting(CAS)procedure.The aim of this article is to report a case and review cases of ACST reported in the literature,and investigate risk factors and management strategies for ACST.CASE SUMMARY We reviewed the treatment process of a patient with ACST after CAS.Then multiple databases were systematically searched to identify studies reporting ACST from 2005 to 2020.The demographic data,risk factors,treatment strategies,and prognosis were extracted and analyzed.CONCLUSION The reason for ACST is multifactorial.Proper patient selection,normative antiplatelet treatment,and perfect technical detail may decrease the incidence of ACST.Several treatment strategies such as thrombolysis,mechanical thrombectomy,and open surgery may be options for the treatment of ACST.Limited data have shown that carotid endarterectomy is effective with favorable results.

Acute coronary artery stent thrombosis caused by a spasm:A case report

BACKGROUND Acute stent thrombosis(AST)is a serious complication of percutaneous coronary intervention(PCI).The causes of AST include the use of stents of inappropriate diameters,multiple overlapping stents,or excessively long stents;incomplete stent expansion;poor stent adhesion;incomplete coverage of dissection;formation of thrombosis or intramural hematomas;vascular injury secondary to intraoperative mechanical manipulation;insufficient dose administration of postoperative antiplatelet medications;and resistance to antiplatelet drugs.Cases of AST secondary to coronary artery spasms are rare,with only a few reports in the literature.CASE SUMMARY A 55-year-old man was admitted to the hospital with a chief complaint of back pain for 2 d.He was diagnosed with coronary heart disease and acute myocardial infarction(AMI)based on electrocardiography results and creatinine kinase myocardial band,troponin I,and troponin T levels.A 2.5 mm×33.0 mm drugeluting stent was inserted into the occluded portion of the right coronary artery.Aspirin,clopidogrel,and atorvastatin were started.Six days later,the patient developed AST after taking a bath in the morning.Repeat coronary angiography showed occlusion of the proximal stent,and intravascular ultrasound showed severe coronary artery spasms.The patient’s AST was thought to be caused by coronary artery spasms and treated with percutaneous transluminal coronary angioplasty.Postoperatively,he was administered diltiazem to inhibit coronary artery spasms and prevent future episodes of AST.He survived and reported no discomfort at the 2-mo follow-up after the operation and initiation of drug treatment.CONCLUSION Coronary spasms can cause both AMI and AST.For patients who exhibit coronary spasms during PCI,diltiazem administration could reduce spasms and prevent future AST.

Sirolimus-eluting stent fractures associated with aneurysm and very late stent thrombosis in the right coronary artery

Although the occurrence of coronary stent fracture is rare,recent reports showed that stent fracture after sirolimus-eluting stent(SES)implantation may be associated with neointimal hyperplasia and restenosis.We report two cases of stent fracture that occurred late after elective SES implantation into the right coronary artery(RCA)that were related to the aneurysm,restenosis,thrombosis,and vessel occlusion.……

Acute Stent Thrombosis Following Concomitant Balloon Aortic Valvuloplasty and Percutaneous Coronary Intervention

Balloon aortic valvuloplasty is often used as a palliative measure or as a bridge to transcatheter aortic valve replacement in the management of aortic stenosis in high risk or inoperable patients. Severe aortic stenosis coexisting with coronary artery dis-ease is not uncommon. In these circumstances, adjuvant percutaneous coronary intervention may be warranted. The safety and efficacy of combined valve and coronary intervention strategies has been recently studied. An increased incidence of complications when both procedures are performed in the same setting may throw new challenges. We report a case of fatal acute stent thrombosis following balloon aortic valvuloplasty and percutaneous coronary intervention.

Predictive value of antiplatelet resistance on early stent thrombosis in patients with acute coronary syndrome

Background Despite outstanding antiplatelet properties of aspirin and clopidogrel, some patients taking these drugs continue to suffer complications. Antiplatelet resistance appears to be a new prognostic factor in acute coronary syndrome patients for clinical events associated with stent thrombosis （ST）. However, there is no optimal method to identify it and assess its correlation to clinical outcomes. This study sought to evaluate the predictive value of antiplatelet resistance assessed by whole blood impedance aggregometry for the risk of early ST in patients with acute coronary syndrome who underwent coronary stenting. Methods Platelet responses to aspirin and clopidogrel in 86 patients with acute coronary syndrome were measured by whole blood impedance aggregometry. Spontaneous platelet aggregation was defined as antiplatelet resistance identified by the increased electrical impedance. The clinical endpoint was early stent thrombosis during 30-day follow-up after coronary stenting. Results The prevalence of aspirin resistance, clopidogrel resistance and dual resistance of combined clopidogrel and aspirin resistance were 19.8%, 12.8% and 5.8% respectively. Diabetes, female and higher platelet counts were more frequently detected in clopidogrel-resistant and dual-resistant patients. During 30-day follow-up, the patients with clopidogrel resistance and dual resistance had higher incidence of early stent thrombosis （18.2% vs. 1.3%, 40.0% vs. 1.2%, P 〈0.05）. Binary Logistic Regression analysis indicated that dual resistance remained an independent predicator for early stent thrombosis （odds ratio 34.064, 95% CI 1.919-604.656, P=-0.016）. Conclusions Antiplatelet resistance assessed by whole blood impedance aggregometry is paralleled to clinical events, and dual antiplatelet resistance is an independent predicator for early stent thrombosis in patients with acute coronary syndrome. As a physiological assessment of platelet reactivity, whole blood impedance aggregometry is a convenient and accurate option for measurin.q antiplatelet resistance and hence predicting early stent thrombosis.

Very late stent thrombosis due to multiple stent fracture and stent malapposition

Coronary stent fracture （SF） is a rare but potentially serious complication of coronary arterystenting. Here we report a case of acute myocardial infarction as a consequence of very late in-stent thrombosis due to multiple stent fractures at 8 sites and multiple stent malapposition formation four years after a sirolimus-eluting stent implantation （Firebird, Microport, Shanghai, China）.

Comparison of the incidence of late stent thrombosis after implantation of different drug-eluting stents in the real world coronary heart disease patients： three-year follow-up results

Background Late stent thrombosis （LST） is still concerned by interventions cardiologists in daily clinical practice. This study aimed to compare the incidence of LST after implantation of different drug-eluting stents （DES） in coronary heart disease （CHD） patients in the real world.Methods From December 2001 to February 2009, a total of 11 875 consecutive CHD patients undergone DES implantation were enrolled in this single-center registery study. Patients with acute ST-segment elevation myocardial infarction, mixed DES implantation, restenosis lesions, and patients who could not take dual antiplatlet medication and those who were contraindicated for coronary interventional treatment were excluded. All patients were treated with completed dual antiplatelet medications for at least 9 months after DES deployment. The follow-up was completed by outpatient visits, letter correspondence, phone calls and coronary angiography. Definite LST was diagnosed auording to the Academic Research Consortium （ARC） definition.Results Cypher or Cypher Select stents were implanted in 4104 cases, Taxus or Taxus Liberty stents in 2271 cases and Firebird stents （Chinese rapamycin-eluting stents） in 5500 cases. One-year follow-up was completed in 9693 patients, including 3346 cases with Cypher or Cypher Select stents, 1529 cases with Taxus or Taxus Liberty stents and 4818 cases with Firebird stents. Two- and three-year follow-up results were obtained in 7133 and 4353 patients, respectively, including 2410 and 1760 cases with Cypher or Cypher Select stents, 1285 and 900 cases with Taxus or Taxus Liberty stents as well as 3438 and 1693 cases with Firebird stents. One-year follow-up results showed that the incidence of LST was 1.08% in patients with Cypher or Cypher Select stents, 1.24% in those with Taxus or Taxus Liberty stents and 0.71% in those with Firebird stents; there was no significant difference between those with Cypher or Cypher Select and Firebird stents, but there was significant difference between those with Taxus or Taxus Liberty and Firebird stents （P=0.044）. The incidence of LST at the 2- and 3-year follow-up was 1.33% and 1.70% in those with Cypher or Cypher Select stents, 1.40% and 1.70% in those with Taxus or Taxus Liberty stents, and 0.83% and 0.95% in those with Firebird stents, respectively. There were no significant differences among the three groups.Conclusions This study indicates that first-generation DES are acceptable to treat complex coronary lesions, and there is no significant difference of LST for three different DES.

Long-term Outcomes of Primary Percutaneous Coronary Intervention with Second-generation Drug-eluting Stents in ST-elevation Myocardial Infarction Patients Caused by Very Late Stent Thrombosis

Background： The ST-segment elevation myocardial inthrction （STEMI） patients due to stent thrombosis （ST） remain a therapeutic challenge for a clinician. Till date, very few researches have been conducted regarding the safety and effectiveness of primary percutaneous coronary intervention （PCI） with second-generation drug-eluting stents （DES） for STEMI caused by very late ST （VLST）. This retrospective study evaluated the safety, efficacy, and outcomes of primary PCI with second-generation DES for STEM1 due to VLST compared with primary PCI for STEM1 due to de novo lesion. Methods： Between January 2007 and December 2013, STEMI patients with primary PCI in Fuwai Hospital had only second-generation DES implanted for de novo lesion （558 patients） and VLST （50 patients） were included in this retrospective study. The primary end points included cardiac death and reinfarction. The secondary end points included cardiac death, reinfarction, and target lesion revascularization. Continuous variables were expressed as mean （standard deviation） or median （interquartile range） and compared by Student＇s t-test or Mann-Whitney U-test as appropriate. Categorical variables were expressed as counts and percentages, and comparison of these variables was performed with Chi-square or Fisher＇s exact test. A two-tailed value of P 〈 0.05 was considered statistically significant for all comparisons. Statistical analyses were performed by SAS software （version 9.4, SAS Institute Inc., Cary, USA） for Windows. Results： In-hospital primary end point and the secondary end point were no significant differences between two groups （P = 1.000 and P = 1.000, respectively）. No significant differences between two groups were observed according to the long-term primary end point and the secondary end point. Kaplan-Meier survival curves showed no significant difference between the two groups in the primary end point and the secondary end point at 2 years （P- 0.340 and P = 0,243, respectively）. According to Cox analysis, female, intra-aortic balloon pump support, and postprocedural thrombolysis in myocardial infarction flow 3 were found to be independent predictors fbr long-term follow-up. Conclusion： Primary PCI with second-generation DES is a reasonable choice for STEMI patients caused by VLST.

Incidence and predictors of definite stent thrombosis after coronary stent implantation

Background Coronary stents are widely used in percutaneous coronary intervention （PCI） procedures. We aimed to explore the incidence, predictors and characteristics of stent thrombosis （ST） after coronary stent implantation in routine clinical practice. Methods From data of 18 063 consecutive patients who underwent successful stent implantation in Shenyang Northern Hospital from 2004 to 2010, we identified patients with definite ST （n=140） and control patients （n=280） matched on age, diagnosis, sex, current antiplatelet medication and stent type. The incidence, predictors and characteristics of ST after coronary stent implantation were investigated.Results The incidence of angiographically confirmed ST was 0.78% （140/18 063）. The time distribution of ST was acute in 43 （30.7%）, subacute in 50 （35.7%）, and late in 47 （33.6%） patients. Binary Logistic regression analysis identi？ed the angiotensin-converting enzyme inhibitor （ACEI） （odds ratio （OR）=0.472, 95% CI： 0.276–0.807, P=0.006） and heparin （OR=0.477, 95% CI： 0.278–0.819, P=0.007） were associated with an reduced risk of cumulative ST. Stent length （OR=1.042, 95% CI： 1.026–1.058, P 〈0.001）, serum creatinine total （OR=1.020, 95% CI： 1.004–1.035, P=0.04）, cholesterol （OR=1.267, 95% CI： 1.021–1.573, P=0.032）, glucose （OR=1.086, 95% CI： 1.002–1.176, P=0.044）, and platelet aggregation （OR=1.113, 95% CI： 1.075–1.154, P 〈0.001） were associated with an increased risk of cumulative ST. Conclusion ST is associated with longer stent length and higher level of total cholesterol, glucose and platelet aggregation.

Acute myocardial infarction and sub-acute stent thrombosis associated with occult essential thrombocythemia

70-year-old female with no Aprevious cardiac history resented with complaints of severe chest and back pain lasting for 20 minutes. She had a past history of type 2 diabetes mellitus for five years and hypertension for twenty years, but denied a history of hyperlipidemia, smoking or hemorrhagic disorder. There was no family history of coronary artery or hematologic disease. On physical examination, the blood pressure was 145/90 mmHg and the heart rate was 102 beats/rain. Cardiac examination revealed normal S1 and $2 sounds. There were no murmors or clicks. The lungs were clear on auscultation. Hepatosplenomegaly or lymphadenopathy was not detected. Her electrocardiogram showed ST elevations in lead V1-V6, consistent with acute anterior MI and echocardiogram supported the diagnosis with a slight reduction in wall motion in the anterior region. Complete blood count revealed a white blood cell count of 9 000/mm3 with a normal differential, red blood cell count of 3.5×106/mm3, hematocrit of 40.2%, and platelet count of 238 000/mm3. Emergent coronary angiography demonstrated proximal thrombotic occlusion of the left anterior descending artery （LAD） （Figure 1A）. A loading dose of 600 mg clopidogrel and 300 mg acetylsalicylic asid （ASA） was given immediately. After administration of 10 000 U intravenous heparin, angioplasty was performed and a 3.0 mm×20.0 mm bare metal stent （BMS） was deployed to the LAD. Repeat angiogram revealed TIMI III flow in the LAD （Figure 1B）. Five days later, the patient was discharged without any bleeding or thrombotic complications. She was receiving dual antiplatelet therapy with ASA and clopidogrel 150 mg daily. However, she was admitted to our hospital again with severe chest pain just one day after dischargement. Her platelet count of 487 000/mm3 was remarkable in comparison with her previous complete blood count. Electrocardiogram showed ST elevations in leads V1-V6, suggestive of an acute anterior reinfarction. Coronary angiography revealed in- stent thrombosis in the LAD （Figure 1C）. After balloon angioplasty （Figure 1D）, TIMI III flow was achieved and no residual stenosis was seen. During her follow-up, complete blood cell counts showed gradually increasing platelets up to 818 000/ram3, on the fourth day of sub- acute stent thrombosis. Peripheral blood smear examination was performed and showed markedly increased large thrombocytes with anisothrombia, consistent with essential thrombocythemia （ET）. Soon after, platelet-loweringtherapy with hydroxyurea （500 mg/d） was initiated, One week after the initiation of hydroxyurea, the platelet count was decreased to 220 000/ram3. The patient remained on hydroxyurea and dual antiplatelet therapy. She was free of symptoms for three months during the follow-up period and her platelet counts remained within the normal range.

Hypersensitivity to drug-eluting stent and stent thrombosis- Kounis or not Kounis syndrome？

With the utilization of coronary-stents, coronary remodeling and restenosis were reduced compared with balloon angioplasty alone,t However, the risk of restenosis is still in the range of 15% to 20%. Drug-eluting stents （DES）, which could release antiproliferative pharmacological agents after deployment, were designed to inhibit the response to injury reaction after hare-metal stent （BMS） implantation.

Subacute coronary stent thrombosis in a patient with angina treated with double antiplatelet drugs for six days

Stent implantation has been a great advance in percutaneous coronary intervention （PCI）, decreasing the frequency of acute closure and restenosis. But stent thrombosis is a severe complication of this therapy regardless of the stent type： bare-metal stent （BMS） and drug-eluting stent （DES）. According to the timing after initial PCI, stent thrombosis is considered as acute when occurring between 0 hour and 24 hours after stent implantation, subacute between 24 hours and 30 days,

Coronary aneurysm and very late stent thrombosis formation associated with sirolimus-eluting stent implantation

Since drug-eluting stents （DES） can significantly reduce the risk of instant restenosis compared with bare-metal stents, they have been widely used in interventional therapy for coronary heart disease. With bare-metal stents being rapidly replaced by DES there is a great concern about the safety of DES due to stent thrombosis.Very late stent thrombosis （VLST） has been categorized as occurring beyond 1 year.3 Coronary aneurysm formation induced stent malapposition is a rare but potentially fatal cause of VLST. We report a case of coronary aneurysm with VLST formation 35 months after sirolimus-eluting stent （SES） implantation.

Very late coronary aneurysm formation with subsequent stent thrombosis secondary to drug-eluting stent

Drug-eluting stents have changed the practice in interventional cardiology. With the widespread use of these stents important safety concerns regarding stent thrombosis and formation of coronary artery aneurysm have been expressed. While the majority of attention was focused on stent thrombosis, the formation of coronary aneurysm was only described in anecdotal reports. We report on a patient who suffered from very late stent thrombosis in association with coronary artery aneurysm formation secondary to drug-eluting stent but not to bare-metal stent.

Intravascular ultrasound assessment of very late bare-metal stent thrombosis： a case report

Very late stent thrombosis （VLST） is increasingly being regarded as a complication of drug-eluting stents （DES）, and delayed endothelization, local hypersensitivity reactions, and late stent malapposition due to excessive positive remodeling have been postulated as mechanisms. Considering that stent endothelialization seems to be completed within 4 weeks following bare-metal stent （BMS） placement and that BMS do not possess antiproliferative coating, the mechanism of VLST may differ between patients with DES and those with BMS. We report a case of VLST 9 years after BMS implantation, in which thrombus from the ruptured neointima was confirmed by intravascular ultrasound. This finding suggests that de novo plaque rupture at the neointimal layer within the stent may be one of the explanations for VLST.

Late stent thrombosis:a not negligible issue after drug-eluting stent implantation

Drug-eluting stent （DES） has markedly reduced restenosis and the need for target lesion revascularization （TLR）. The safety profile of DES does not seem to differ from that of bare metal stent in the acute and subacute phases following coronary intervention. However, at World Congress of Cardiology 2006 a meta-analysis of randomized trials suggested that there was a small but significant increase in risk of death or Q-wave myocardial infarction throughout a period of 3 years after implantation of a Cypher stent possible due to late stent thrombosis） The study received wide attention and since then the long-term safety of DES has been questioned by the physicians, patients and societies.

Antiplatelet therapy resistance induced subacute coronary stent thrombosis in a patient with acute myocardial infarction

Stent implantation has greatly decreased the frequency of acute closure and restenosis after percutaneous coronary inter-vention (PCI) .But stent thrombosis continues to be observed in approximately 1% to 2% of unselected stent procedures and remains a devastating complication.Herein we present a case of subacute coronary stent thrombosis in a patient with anterior AMI treated with double antiplatelet drugs and low molecular weight heparin.

The role of endothelial progenitor cells in restenosis and stent thrombosis after percutaneous coronary intervention

Background After percutaneous coronary intervention （PCI）, some patients may suffer from restenosis and stent thrombosis. Many studies suggest that endothelial progenitor cell （EPC） has an important role in preventing restenosis and stent thrombosis. A novel stent which can attract EPC has been designed to provide a better outcome for these problems. Method The data of the present review was obtained by searching PUBMED and other databases （ 1994-2011 ） using the key terms of ＂endothelial progenitor cell＂, ＂reendothelialization＂, ＂restenosis＂, ＂stent thrombosis＂, and ＂percntaneous coronary intervention＂. Result Rapid reendothelialization is essential in preventing restenosis and stent thrombosis. EPC can differentiate into endothelial cell and accelerate the reendothelialization. After numerous preclinical and clinical researches, the correlation between circulating EPCs to restenosis still remains poorly understood. However, many studies have shown the important role of EPC in diminishing the risk of thrombosis following stent implantation. Some pharmacological agents have been reported can increase the number and/or functions of EPC. Recently, CD34＋ antibody coated stent has been developed to attract EPC to the healing endothelium, and has showed favorable results. Conclusion EPC has important role in rapid reendothelialization after vascular injury. EPC can prevent stent thrombosis after PCI, however the effects of EPC in preventing restenosis need further investigations. The capturing CD34＋ stent is safe and significantly decreases stent thrombosis.