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Predictors of restenosis after percutaneous coronary intervention using bare-metal stents: a comparison between patients with and without dysglycemia

LIMA-FILHO, M.O.; FIGUEIREDO, G.L.; FOSS-FREITAS, M.C.; FOSS, M.C.; MARIN-NETO, J.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.36%
The objective of this study was to identify intravascular ultrasound (IVUS), angiographic and metabolic parameters related to restenosis in patients with dysglycemia. Seventy consecutive patients (77 lesions) selected according to inclusion and exclusion criteria were evaluated by the oral glucose tolerance test and the determination of insulinemia after a successful percutaneous coronary intervention (PCI) with a bare-metal stent. The degree of insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR). Six-month IVUS and angiogram follow-up were performed. Thirty-nine patients (55.7%) had dysglycemia. The restenosis rate in the dysglycemic group was 37.2 vs 23.5% in the euglycemic group (P = 0.299). The predictors of restenosis using bivariate analysis were reference vessel diameter (RVD): £2.93 mm (RR = 0.54; 95%CI = 0.05-0.78; P = 0.048), stent area (SA): <8.91 mm² (RR = 0.66; 95%CI = 0.24-0.85; P = 0.006), stent volume (SV): <119.75 mm³ (RR = 0.74; 95%CI = 0.38-0.89; P = 0.0005), HOMA-IR: >2.063 (RR = 0.44; 95%CI = 0.14-0.64; P = 0.027), and fasting plasma glucose (FPG): ≤108.8 mg/dL (RR = 0.53; 95%CI = 0.13-0.75; P = 0.046). SV was an independent predictor of restenosis by multivariable analysis. Dysglycemia is a common clinical condition in patients submitted to PCI. The degree of insulin resistance...

Long-term safety and efficacy of percutaneous coronary intervention with stenting and coronary artery bypass surgery for multivessel coronary artery disease - A meta-analysis with 5-year patient-level data from the ARTS, ERACI-II, MASS-II, and SoS trials

DAEMEN, Joost; BOERSMA, Eric; FLATHER, Marcus; BOOTH, Jean; STABLES, Rod; RODRIGUEZ, Alfredo; RODRIGUEZ-GRANILLO, Gaston; HUEB, Whady A.; LEMOS, Pedro A.; SERRUYS, Patrick W.
Fonte: LIPPINCOTT WILLIAMS & WILKINS Publicador: LIPPINCOTT WILLIAMS & WILKINS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.19%
Background-Randomized trials that studied clinical outcomes after percutaneous coronary intervention (PCI) with bare metal stenting versus coronary artery bypass grafting (CABG) are underpowered to properly assess safety end points like death, stroke, and myocardial infarction. Pooling data from randomized controlled trials increases the statistical power and allows better assessment of the treatment effect in high-risk subgroups. Methods and Results-We performed a pooled analysis of 3051 patients in 4 randomized trials evaluating the relative safety and efficacy of PCI with stenting and CABG at 5 years for the treatment of multivessel coronary artery disease. The primary end point was the composite end point of death, stroke, or myocardial infarction. The secondary end point was the occurrence of major adverse cardiac and cerebrovascular accidents, death, stroke, myocardial infarction, and repeat revascularization. We tested for heterogeneities in treatment effect in patient subgroups. At 5 years, the cumulative incidence of death, myocardial infarction, and stroke was similar in patients randomized to PCI with stenting versus CABG (16.7% versus 16.9%, respectively; hazard ratio, 1.04, 95% confidence interval, 0.86 to 1.27; P = 0.69). Repeat revascularization...

A quantitative coronary angiography-matched comparison between a prospective randomised multicentre cutting balloon angioplasty and bare metal stent trial (REDUCE III) and the Rapamycin-Eluting Stent Evaluation At Rotterdam Cardiology Hospital (RESEARCH) study

OZAKI, Yukio; LEMOS, Pedro A.; YAMAGUCHI, Tetsu; SUZUKI, Takahiko; NAKAMURA, Masato; ISMAIL, Tevfik F.; KITAYAMA, Michihiko; NISHIKAWA, Hideo; KATO, Osamu; SERRUYS, Patrick W.
Fonte: EUROPA EDITION Publicador: EUROPA EDITION
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.19%
Aims: There remains significant concern about the long-term safety of drug-eluting stents (DES). However, bare metal stents (BMS) have been used safely for over two decades. There is therefore a pressing need to explore alternative strategies for reducing restenosis with BMS. This study was designed to examine whether IVUS-guided cutting balloon angioplasty (CBA) with BMS could convey similar restenosis rates to DES. Methods and results: In the randomised REstenosis reDUction by Cutting balloon angioplasty Evaluation (REDUCE III) study, 521 patients were divided into four groups based on device and IVUS use before BMS (IVUS-CBA-BMS: 137 patients; Angio-CBA-BMS: 123; IVUS-BA-BMS: 142; and Angio-BA-BMS: 119). At follow-up, the IVUS-CBA-BMS group had a significantly lower restenosis rate (6.6%) than the other groups (p=0.016). We performed a quantitative coronary angiography (QCA) based matched comparison between an IVUS-guided CBA-BMS strategy (REDUCE III) and a DES strategy (Rapamycin-Eluting-Stent Evaluation At Rotterdam Cardiology. Hospital, the RESEARCH study). We matched the presence of diabetes, vessel size, and lesion severity by QCA. Restenosis (>50% diameter stenosis at follow-up) and target vessel revascularisation (TVR) were examined. QCA-matched comparison resulted in 120-paired lesions. While acute gain was significantly greater in IVUS-CBA-BMS than DES (1.65 +/- 0.41 mm vs. 1.28 +/- 0.57 mm...

Investigação das modificações na geometria vascular nas bordas de stents farmacológicos e não-farmacológicos e a correlação com a composição dos ateromas: estudo seriado com ultrassom intracoronário e Histologia Virtual®; Investigation of the modifications in vascular geometry at the edges of bare-metal and drug-eluting stents and the correlation of modifications in plaque composition: a serial with grey-scale intravascular ultrasound and Virtual Histology(TM)

Costa Junior, José de Ribamar
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/07/2011 PT
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Até o momento, pouco se sabe sobre a influência da modificação na composição do ateroma nas bordas dos stents e a ocorrência de alterações na geometria vascular. Este estudo objetiva correlacionar, utilizando de maneira seriada (pós-implante do stent e reestudo aos nove meses) o ultrassom monocromático e a Histologia Virtual®, as modificações na composição dos ateromas nas bordas proximais e distais de stents nãofarmacológicos e farmacológicos e as alterações ocorridas nas dimensões do vaso, luz e placa que possam explicar a ocorrência da reestenose nestes segmentos. Estudo prospectivo, de centro único, que randomizou (1:1) pacientes com síndrome coronária aguda para receberem stents nãofarmacológicos (Driver®, n=20 pacientes) ou farmacológicos (Cypher®, n=20 pacientes). Após a realização do procedimento, todos os pacientes submeteram-se a avaliação com ultrassom e Histologia Virtual®, que foi repetido ao final de nove meses de seguimento. O objetivo primário foi avaliar as modificações na área do vaso, luz e placa ao ultrassom e na composição do ateroma pela Histologia Virtual® no período entre o implante e o reestudo, buscando correlacionar as alterações no ateroma com as modificações na geometria vascular. Observou-se que na borda proximal...

Avaliação da eficácia tardia após o implante de um stent miniaturizado, farmacológico versus não-farmacológico, em artérias coronárias de pequeno calibre; Evaluating the effectiveness late after implantation of a miniaturized drug eluting stent versus a bare metal stent with the same platform in percutaneous coronary angioplasty of small vessels

Oliveira, Flavio Roberto Azevedo de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/05/2012 PT
Relevância na Pesquisa
46.56%
Os vasos de fino calibre apresentam maior risco para reestenose e revascularização da lesão alvo. Limitações relacionadas com a navegabilidade dos sistemas de dilatação por balão e menor capacidade de acomodação da neoíntima podem contribuir para isto. O stent autoexpansível de nitinol Sparrow® dedicado a vaso de calibre < 2,75 mm, resultou num conjunto com perfil de um fio-guia 0,014". Testado na forma de stent de metal puro no estudo CARE I, revelou-se seguro e eficaz em vasos de fino calibre. Este estudo avaliou, de forma pioneira, o despenho de um stent autoexpansível farmacológico neste cenário. O objetivo primário foi comparar a perda luminal tardia no vaso-alvo pela angiografia coronária quantitativa ao final de oito meses, entre os stents Sparrow® farmacológico e não farmacológico, em coronárias com diâmetro de referência < 2,75 mm. Casuística e métodos: Os pacientes foram randomizados de forma prospectiva em dois grupos para procedimento de angioplastia: um grupo com o emprego o stent Sparrow® farmacológico (sirolimus), e ou outro grupo com o stent Sparrow® na versão não farmacológica. Análise pela angiografia coronária quantitativa foi realizada imediatamente antes e após o procedimento e aos oito meses...

Long-term Outcomes of Drug-eluting versus Bare-metal stent for ST-elevation Myocardial Infarction

Wang,Liping; Wang,Hongyun; Dong,Pingshuan; Li,Zhuanzhen; Wang,Yanyu; Duan,Nana; Zhao,Yuwei; Wang,Shaoxin
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
66.46%
Background: Long-term outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remain uncertain. Objective: To investigate long-term outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI). Methods: We performed search of MEDLINE, EMBASE, the Cochrane library, and ISI Web of Science (until February 2013) for randomized trials comparing more than 12-month efficacy or safety of DES with BMS in patients with STEMI. Pooled estimate was presented with risk ratio (RR) and its 95% confidence interval (CI) using random-effects model. Results: Ten trials with 7,592 participants with STEMI were included. The overall results showed that there was no significant difference in the incidence of all-cause death and definite/probable stent thrombosis between DES and BMS at long-term follow-up. Patients receiving DES implantation appeared to have a lower 1-year incidence of recurrent myocardial infarction than those receiving BMS (RR = 0.75, 95% CI 0.56 to 1.00, p= 0.05). Moreover, the risk of target vessel revascularization (TVR) after receiving DES was consistently lowered during long-term observation (all p< 0.01). In subgroup analysis...

Spectral Analysis Related to Bare-Metal and Drug-Eluting Coronary Stent Implantation

Silva,Rose Mary Ferreira Lisboa da; Silva,Carlos Augusto Bueno; Greco,Otaviano José; Moreira,Maria da Consolação Vieira
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
46.36%
Background: The autonomic nervous system plays a central role in cardiovascular regulation; sympathetic activation occurs during myocardial ischemia. Objective: To assess the spectral analysis of heart rate variability during stent implantation, comparing the types of stent. Methods: This study assessed 61 patients (mean age, 64.0 years; 35 men) with ischemic heart disease and indication for stenting. Stent implantation was performed under Holter monitoring to record the spectral analysis of heart rate variability (Fourier transform), measuring the low-frequency (LF) and high-frequency (HF) components, and the LF/HF ratio before and during the procedure. Results: Bare-metal stent was implanted in 34 patients, while the others received drug-eluting stents. The right coronary artery was approached in 21 patients, the left anterior descending, in 28, and the circumflex, in 9. As compared with the pre-stenting period, all patients showed an increase in LF and HF during stent implantation (658 versus 185 ms2, p = 0.00; 322 versus 121, p = 0.00, respectively), with no change in LF/HF. During stent implantation, LF was 864 ms2 in patients with bare-metal stents, and 398 ms2 in those with drug-eluting stents (p = 0.00). The spectral analysis of heart rate variability showed no association with diabetes mellitus...

Predictors of restenosis after percutaneous coronary intervention using bare-metal stents: a comparison between patients with and without dysglycemia

Lima-Filho,M.O.; Figueiredo,G.L.; Foss-Freitas,M.C.; Foss,M.C.; Marin-Neto,J.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2010 EN
Relevância na Pesquisa
46.36%
The objective of this study was to identify intravascular ultrasound (IVUS), angiographic and metabolic parameters related to restenosis in patients with dysglycemia. Seventy consecutive patients (77 lesions) selected according to inclusion and exclusion criteria were evaluated by the oral glucose tolerance test and the determination of insulinemia after a successful percutaneous coronary intervention (PCI) with a bare-metal stent. The degree of insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR). Six-month IVUS and angiogram follow-up were performed. Thirty-nine patients (55.7%) had dysglycemia. The restenosis rate in the dysglycemic group was 37.2 vs 23.5% in the euglycemic group (P = 0.299). The predictors of restenosis using bivariate analysis were reference vessel diameter (RVD): £2.93 mm (RR = 0.54; 95%CI = 0.05-0.78; P = 0.048), stent area (SA): <8.91 mm² (RR = 0.66; 95%CI = 0.24-0.85; P = 0.006), stent volume (SV): <119.75 mm³ (RR = 0.74; 95%CI = 0.38-0.89; P = 0.0005), HOMA-IR: >2.063 (RR = 0.44; 95%CI = 0.14-0.64; P = 0.027), and fasting plasma glucose (FPG): ≤108.8 mg/dL (RR = 0.53; 95%CI = 0.13-0.75; P = 0.046). SV was an independent predictor of restenosis by multivariable analysis. Dysglycemia is a common clinical condition in patients submitted to PCI. The degree of insulin resistance...

Does the use of paclitaxel or rapamycin-eluting stent decrease further need for coronary-artery bypass grafting when compared with bare-metal stent?

Lemos Júnior,Hernani Pinto de; Atallah,Álvaro Nagib
Fonte: Associação Paulista de Medicina - APM Publicador: Associação Paulista de Medicina - APM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2007 EN
Relevância na Pesquisa
46.36%
CONTEXT AND OBJECTIVE: The safety and efficacy of drug-eluting stents reduce the need for surgical revascularization. The objective of the present study was to investigate whether paclitaxel or rapamycin-eluting stent are effective in avoiding the need for coronary-artery bypass grafting. METHODS: This was a systematic review of the literature using the methodology of the Cochrane Collaboration. The type of study considered was controlled randomized trials; the type of intervention was drug-eluting or bare-metal stents; and the main outcome investigated was coronary-artery bypass grafting. RESULTS: The ten studies included in this systematic review did not show any statistically significant difference between the drug-eluting stents and the bare-metal stents with regard to the outcome of coronary-artery bypass grafting (confidence interval: 0.31 to 1.42). CONCLUSION: The surgical revascularization rate was not reduced by the use of drug-eluting stents.

A novel method for endoluminal treatment of abdominal aortic aneurysms. With bare-metal Wallstent endoprostheses and endovascular coils.

Achari, A; Krajcer, Z
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //1998 EN
Relevância na Pesquisa
46.36%
The established therapy for symptomatic, expanding abdominal aortic aneurysms is open surgical replacement with an artificial graft. Over the last several years, there has been increasing enthusiasm for the use of endoluminal graft prostheses to exclude abdominal aortic aneurysms. However, even with rapid advances in stent graft technology, certain problems (i.e., large profile of the devices, risk of thromboembolism, poor flexibility, endoleak formation, and side-branch occlusion) have yet to be overcome. We present the case of an 85-year-old woman with multiple comorbid illnesses who underwent endoluminal repair of her expanding abdominal aortic aneurysms. We used bare-metal Wallstent endoprostheses (Schneider, Inc.; Minneapolis, Minn) in combination with endovascular coils (Cook, Inc.; Bloomington, Ind). The bare-metal Wallstent endoprostheses were used because the patient had severely narrowed iliac arteries and a large side branch originating from the aneurysm. The procedure was technically successful, and there was no significant morbidity. Follow-up angiographic evaluation at 6 months revealed no evidence of vascular enlargement; it also revealed preservation of important side branches, and spontaneous thrombosis of the aneurysms.

Very late thrombosis in a bare metal stent: An under-recognized problem

Fineschi, Massimo; Gori, Tommaso
Fonte: Pulsus Group Inc Publicador: Pulsus Group Inc
Tipo: Artigo de Revista Científica
Publicado em /02/2008 EN
Relevância na Pesquisa
46.46%
Recent publications have emphasized the concept that restenosis of a bare metal stent is not as clinically benign as previously believed. A case of very late (seven years) thrombosis after implantation of a bare metal stent is described. While doubts on the long-term safety of drug-eluting stents are debated, registry data and clinical reports suggest that the long-term safety of coronary bare metal stent implantation should also be reconsidered.

Repeat late instent-stenosis after an interval of four years in the same lesion after bare-metal and drug-eluting stent: a case report

Towae, Frank; Zahn, Ralf; Zeymer, Uwe
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 31/12/2009 EN
Relevância na Pesquisa
46.36%
In 2001, a 71-year old male was admitted to our hospital with unstable angina. The angiography revealed 2-vessel disease with a 90% stenosis of the proximal LAD. A bare-metal stent was implanted. Four years later the angiography showed a 80% instent-stenosis in the bare-metal stent but no progress at the other coronary arteries. A DES was implanted. Again, four years later, the patient presented with non-ST-elevation myocardial infarction. Angiography showed a 90% instent-restenosis, again without any progession of coronary artery disease in the other vessels. Again a DES implanted. Therefore the processes involved in the late instent-stenosis were not influenced by the antiproliferative agent sirolimus

Sirolimus-Eluting Stents versus Bare-Metal Stents in Routine Clinical Use: A Nonrandomized Comparison

Munir, Muhammad; Aliota, Jonathan; Ahmed, Amany; Mohammed, Anwarullah; Lee, Vei Vei; Elayda, MacArthur A.; Wilson, James M.
Fonte: Texas Heart Institute Publicador: Texas Heart Institute
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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46.36%
Conflicting patient outcomes have been reported after the use of sirolimus-eluting stents or bare-metal stents. In this nonrandomized study, we examine the outcomes after placement of sirolimus-eluting versus bare-metal stents in an unselected population of patients who underwent percutaneous coronary revascularization.

A Case of Successful Bare Metal Stenting for Aortic Coarctation in an Adult

Kook, Hyungdon; Rha, Seung-Woon; Kim, Woohyeun; Kim, Dong Hyeok; Lee, Sunki; Oh, Suk-Kyu; Ahn, Tae Hoon; Shim, Won Heum
Fonte: The Korean Society of Cardiology Publicador: The Korean Society of Cardiology
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.36%
Aortic coarctation is a correctable hypertensive disease. For safety reasons and due to the invasiveness of surgical techniques, percutaneous interventions have become drastically more popular in recent times. In elderly patients with aortic coarctation who are at risk of an aortic wall aneurysm and rupture, covered stents are preferred but in younger patients, bare metal stenting may be sufficient for long-term safety. Herein we present a 47-year-old typical aortic coarctation patient who was successfully treated with a bare metal stent.

Identification of independent risk factors for restenosis following bare-metal stent implantation: Role of bare-metal stents in the era of drug-eluting stents

PARK, CHANG-BUM; PARK, HOON-KI
Fonte: D.A. Spandidos Publicador: D.A. Spandidos
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.36%
In the era of drug-eluting stents (DESs), the ability of clinicians to predict which patients have a low risk of coronary restenosis following bare-metal stent (BMS) implantion is likely to be of benefit. The study population consisted of 2,711 patients who underwent BMS implantation in 3,770 lesions between 1995 and 2004. With clinical and 6 month follow-up angiographic data, we retrospectively sought to identify the independent risk predictors of restenosis, applied a previously proposed prediction model and assessed the characteristics of patients with a low likelihood of coronary restenosis within 6 months of BMS implantation. A 6-month follow-up coronary angiography was performed in 65.0% of the patients who had undergone the BMS implantation and the rate of restenosis was 26.6%. Using multivariate analysis, diabetes [odds ratio (OR), 1.294; 95% confidence interval (CI), 1.094–1.483; P=0.005], current smoking (OR, 1.294; 95% CI, 1.094–1.483; P=0.002), a reference vessel diameter of <3.25 mm (OR, 1.238; 95% CI, 1.021–1.501; P<0.001), a lesion length of >30 mm (OR, 1.645; 95% CI, 1.336–2.026; P<0.001), ostial lesion (OR, 1.858; 95% CI, 1.437–2.402; P<0.001), post-stenting minimal luminal diameter (OR, 0.576; 95% CI, 0.484–0.685; P<0.001) and bifurcation lesion (OR...

Very Late Bare Metal Stent Thrombosis

Soto Herrera, Mariana; Restrepo, José A.; Felipe Buitrago, Andrés; Gómez Mejía, Mabel; Díaz, Jesús H.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.36%
Very late stent thrombosis is a rare and not-well-understood complication after bare metal stent implantation. It usually presents as an ST elevation acute coronary syndrome and it is associated with high rates of morbidity and mortality. Pathophysiologic mechanisms are not well defined; nevertheless, recent studies have proposed a neoatherosclerotic process as the triggering mechanism. We present the case of a patient with bare metal very late stent thrombosis 12 years after implantation.

Clinical utility of platinum chromium bare-metal stents in coronary heart disease

Jorge, Claudia; Dubois, Christophe
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
Publicado em 27/08/2015 EN
Relevância na Pesquisa
46.36%
Coronary stents represent a key development for the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. While drug-eluting stents gained wide acceptance in contemporary percutaneous coronary intervention practice, further developments in bare-metal stents remain crucial for patients who are not candidates for drug-eluting stents, or to improve metallic platforms for drug elution. Initially, stent platforms used biologically inert stainless steel, restricting stent performance due to limitations in flexibility and strut thickness. Later, cobalt chromium stent alloys outperformed steel as the material of choice for stents, allowing latest generation stents to be designed with significantly thinner struts, while maintaining corrosion resistance and radial strength. Most recently, the introduction of the platinum chromium alloy refined stent architecture with thin struts, high radial strength, conformability, and improved radiopacity. This review will provide an overview of the novel platinum chromium bare-metal stent platforms available for coronary intervention. Mechanical properties, clinical utility, and device limitations will be summarized and put into perspective.

Vetorização termoinduzida de nanopartículas magnéticas biocompatíveis: uma aplicação no recobrimento de Stents nus por via líquida; Thermally induced vectorization of Biocompatible Magnetic Nanoparticles: an application to cover Bare Metal Stents by Dip Coating

RODRIGUES, Harley Fernandes
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Física; Ciências Exatas e da Terra Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Física; Ciências Exatas e da Terra
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.36%
In this work we developed a Dip Coating method that could control the temperature gradient between a substrate and the material that one wants to adsorb at its surface. In particular, the adsorption of biocompatible magnetic nanoparticles at the surface of bare metal Stents, under different experimental conditions, was investigated. The magnetic nanoparticles consisted of magnetite coated with tripoliphosphate (mean diameter 7.68 nm and standard deviation 1.88 nm) dispersed in water at physiological conditions, while the Stent was a CoCr based-one (Cronus stent from Scitech with 16 mm length). Nine series of experiments were performed where it was controlled parameters as: time of adsorption, stent temperature and magnetic fluid temperature. The stents coated with nanoparticles were magnetically characterized using a vibrating sample magnetometer (VSM), which allowed us to determine the number of nanoparticles at the stent surface. The increase of the magnetic moment of the stent with the increase of the adsorption time was theoretically modeled, with an excellent experimental agreement, as a transient diffusion process of nanoparticles at the interface stent-magnetic fluid, which clearly indicates an important diffusive contribution. Strong evidences of thermal diffusion (Soret effect)...

LOCAL-TAX Studie. Lokale intrakoronare Gabe von Paclitaxel nach Stentimplantation zur Verhinderung einer Restenose im Vergleich zu Stentimplantation alleine und zur Implantation eines Paclitaxel-beschichteten Stents; LOCAL-TAX trial. Local catheter-based delivery of fluid paclitaxel after bare metal stent implantation compared with the implantation of a bare metal stent alone and the implantation of a paclitaxel-eluting stent

Zulueta La Rosa, Graviel
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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46.53%
Einleitung: Medikamentenbeschichtete Stents (DES) haben die Inzidenz der Restenose nach perkutaner Koronarintervention (PCI) signifikant reduziert. Zweifel über die Wirksamkeit und vor allem über die Sicherheit dieser Stents kamen jedoch auf, als aktuelle Studien über späte In-Stent-Restenosen (ISR) nach DES-Implantation berichteten. Die LOCAL-TAX Studie bewertete die Sicherheit und Effizienz kathetergestützter Applikation von flüssigem Paclitaxel bei Patienten mit koronaren De-novo-Stenosen nach der Implantation von unbeschichteten Stents (BMS). Methode: LOCAL-TAX ist eine prospektive und randomisierte Studie, bei der anhand von 204 Patienten mit nativen De-novo-Koronarstenosen die antiproliferative Nachbehandlung mit gelöstem Paclitaxel nach BMS-Implantation (Gruppe I) verglichen wurde mit der Implantation konventioneller BMS-Stents alleine (Gruppe II) und mit der Implantation Paclitaxel-freisetzender Stents (Gruppe III). Der primäre Endpunkt wurde angiographisch definiert mit dem „late lumen loss“ (LLL) im Stent und im Segment. Sekundäre Endpunkte beinhalteten die Binäre Restenoserate > 50% (RR), den „minimal lumen diameter“ (MLD) und den „diameter of stenosis“ (DS). Desweiteren wurden klinische Endpunkte wie Myokardinfarkt und Tod (MACE) sowie perkutane oder operative Revaskularisationen der Zielläsion (TLR) 30 Tage und 6 Monate nach Intervention analysiert. Ergebnisse: Im angiographischen 6-monats-Follow-up zeigte sich mit einem In-Stent LLL von 0...

Acute and long-term clinical results of bare metal coronary stenting

García B., Sebastián; Frago M., Gabriel; Farías, Eric; Ibarra F., Mario; Ramírez N., Alfredo; Silva J., Ana María; Cumsille, Miguel Angel; Ugalde P., Héctor; Callejas R., Sonia; Dussaillant, Gastón
Fonte: Universidade do Chile Publicador: Universidade do Chile
Tipo: Artículo de revista
ES
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Publicación ISI; Background: Since the introduction of stents in 1994, improved clinical results have boosted the development of coronary angioplasty in Chile. Drug eluting stems, that have a reduced rate of restenosis, are being increasingly used. Aim: To assess the acute and long-term results of bare metal stent implantation. Patients and Methods: Acute and long-term clinical, procedural and angiographic results were assessed in non acute myocardial infarction patients undergoing coronary stent implantation between August 1996 and December 2003. Results: During the study period, 932 patients aged 30 to 87 years (194 women) had at least one stent implanted. Twenty two percent were diabetic, 33% had recent myocardial infarction, 53 unstable angina and 22% stable angina. Angiographic and clinical success were 99.6% and 98.2%, respectively. In hospital death was 0.5%. During a mean follow-up of 19.1 months, all cause mortality was 3.9%, cardiac death 1.9% and survival tee of major cardiac ischemic events was 85.3%. Only 64% of lesions underwent target vessel revascularization (TVR). Independent predictors of TVR were previous surgery, left anterior descending artery, small post stent minimum luminal diameter. Ostial location, in-stent restenosis...