Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Thromb Thrombolysis ; 34(1): 91-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22350685

RESUMO

We previously found paclitaxel-eluting polymer-coated stents causing more human platelet-monocyte complex formation than bare metal stents in vitro. Presently, we examined patterns of platelet activation and adhesion after exposure to 6 nanofilm HAp-coated (HAp-nano) stents, 6 HAp-microporous-coated (HAp-micro) stents, 5 HAp sirolimus-eluting microporous-coated (HAp-SES) stents and 5 cobalt-chromium stents (BMS) deployed in an in vitro flow system. Blood obtained from healthy volunteers was circulated and sampled at 0, 10, 30 and 60 min. By flow cytometry, there were no significant differences in P-Selectin expression between the 4 stent types (HAp-nano = 32.5%; HAp-micro = 42.5%, HAp-SES = 10.23%, BMS = 7% change from baseline at 60 min, p = NS); PAC-1 antibody binding (HAp-nano = 11.8%; HAp-micro = 2.9%, HAp-SES = 18%, BMS = 6.4% change from baseline at 60 min, p = NS) or PMC formation (HAp-nano = 21.6%; HAp-micro = 4%, HAp-SES = 6.6%, BMS = 17.4% change from baseline at 60 min, p = NS). The 4 stent types did not differ in the average number of platelet clusters >10 µm in diameter by SEM (HAp-nano = 2.39 ± 5.75; HAp-micro = 2.26 ± 3.43; HAp-SES = 1.93 ± 3.24; BMS = 1.94 ± 2.41, p = NS). The majority of the struts in each stent group were only mildly covered by platelets, (HAp-nano = 80%, HAp-micro = 61%, HAp-SES = 78% and BMS = 52.1%, p = NS). The HAp-microporous-coated stents (ECD) attracted slightly more proteinaceous material than bare metal stents (HAp-micro = 35% struts with complete protein coverage, P < 0.0001 vs. other 3 stent types). In conclusion, biomimetic stent coating with nanofilm or microporous hydroxyapatite, even when eluting low-dose sirolimus, does not increase the platelet activation in circulating human blood, or platelet adhesion to stent surface when compared to bare metal stents in vitro.


Assuntos
Materiais Revestidos Biocompatíveis , Stents Farmacológicos , Durapatita , Imunossupressores/farmacologia , Teste de Materiais , Ativação Plaquetária/efeitos dos fármacos , Sirolimo/farmacologia , Adulto , Feminino , Humanos , Masculino , Fatores de Tempo
2.
Methodist Debakey Cardiovasc J ; 18(5): 74-76, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561079

RESUMO

Every physician encounters a barrage of direct-to-consumer and direct-to-physician advertising and is faced with the daunting task of deciding which drugs to add to their clinical armamentarium and how and when to add them. The purpose of this Points to Remember is to present a commonsense approach to incorporating newer drugs, or perhaps new indications for older drugs, into our clinical practice. To illustrate these points, this article focuses on a single drug, empagliflozin, a sodium-glucose cotransporter-2 (SGLT-2) inhibitor that has been highly marketed in lay and medical media and hence has been incorporated into professional society treatment guidelines.


Assuntos
Cardiologistas , Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Hipoglicemiantes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Glicemia
3.
J Am Coll Cardiol ; 77(5): 609-619, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33538259

RESUMO

Coenzyme Q10 (CoQ10) is a naturally occurring compound that is found in animals and all humans. It has a fundamental role in cellular energy production. Although it is produced in the body, tissue deficiency can occur due to medications such as statins, which inhibit the mevalonate pathway. The clinical syndromes of statin-associated muscle symptoms (SAMS) and some of the features observed in patients with heart failure (HF) may be related to blood and tissue deficiency of CoQ10. Numerous clinical trials of CoQ10 in SAMS have yielded conflicting results. Yet, the weight of evidence as reflected in meta-analyses supports the use of exogenous CoQ10 in SAMS. In patients with HF, large-scale randomized clinical trials are lacking, although one relatively contemporary trial, Q-SYMBIO, suggests an adjunctive role for CoQ10. The possibility that statin-related CoQ10 deficiency may play a role in patients with diastolic HF is an intriguing hypothesis that warrants further exploration.


Assuntos
Ataxia/tratamento farmacológico , Doenças Cardiovasculares/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Doenças Mitocondriais/tratamento farmacológico , Debilidade Muscular/tratamento farmacológico , Ubiquinona/análogos & derivados , Ubiquinona/deficiência , Suplementos Nutricionais , Humanos , Ubiquinona/uso terapêutico
4.
Methodist Debakey Cardiovasc J ; 15(3): 185-191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31687097

RESUMO

Coenzyme Q10 (CoQ10) is among the most widely used dietary and nutritional supplements on the market. CoQ10 has several fundamental properties that may be beneficial in several clinical situations. This article reviews the pertinent chemical, metabolic, and physiologic properties of CoQ10 and the scientific data and clinical trials that address its use in two common clinical settings: statin-associated myopathy syndrome (SAMS) and congestive heart failure (CHF). Although clinical trials of CoQ10 in SAMS have conflicting conclusions, the weight of the evidence, as seen in meta-analyses, supports the use of CoQ10 in SAMS overall. In CHF, there is a lack of large-scale randomized clinical trial data regarding the use of statins in patients receiving contemporary treatment. However, one relatively recent randomized clinical trial, Q-SYMBIO, suggests an adjunctive role for CoQ10 in CHF. Recommendations regarding the use of CoQ10 in these clinical situations are presented.


Assuntos
Antioxidantes/uso terapêutico , Suplementos Nutricionais , Insuficiência Cardíaca/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Miotoxicidade/tratamento farmacológico , Ubiquinona/análogos & derivados , Animais , Antioxidantes/efeitos adversos , Antioxidantes/farmacocinética , Suplementos Nutricionais/efeitos adversos , Metabolismo Energético/efeitos dos fármacos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/metabolismo , Humanos , Miotoxicidade/diagnóstico , Miotoxicidade/epidemiologia , Miotoxicidade/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fatores de Risco , Síndrome , Resultado do Tratamento , Ubiquinona/efeitos adversos , Ubiquinona/farmacocinética , Ubiquinona/uso terapêutico
5.
Arterioscler Thromb Vasc Biol ; 27(2): 387-93, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17138936

RESUMO

OBJECTIVE: To determine the accuracy of detection of different tissue types of intravascular ultrasound-virtual histology (IVUS-VH) in a porcine model of complex coronary lesions. METHODS AND RESULTS: Coronary lesions were induced by injecting liposomes containing human oxidized low-density lipoprotein into the adventitia of the arteries. IVUS-VH imaging was performed in vivo at 8.2+/-1.6 weeks after injection. A total of 60 vascular lesions were analyzed and compared with their correspondent IVUS-VH images. Correlation analysis was performed using linear regression models. Compared with histology, IVUS-VH correctly identified the presence of fibrous, fibro-fatty, and necrotic tissue in 58.33%, 38.33%, and 38.33% of lesions, respectively. The sensitivity of IVUS-VH for the detection of fibrous, fibro-fatty, and necrotic core tissue was 76.1%, 46%, and 41.1% respectively. A linear regression analysis performed for each individual plaque component did not show strong correlation that would allow significant prediction of individual values. CONCLUSIONS: In a porcine model of complex coronary lesions, IVUS-VH was not accurate in detecting the relative amount of specific plaque components within each individual corresponding histological specimen.


Assuntos
Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/patologia , Ultrassonografia de Intervenção/métodos , Interface Usuário-Computador , Animais , Estenose das Carótidas/etiologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Modelos Animais de Doenças , Técnicas Histológicas/métodos , Imuno-Histoquímica , Modelos Lineares , Lipossomos , Variações Dependentes do Observador , Sensibilidade e Especificidade , Suínos
6.
N Engl J Med ; 348(16): 1537-45, 2003 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-12700373

RESUMO

BACKGROUND: Intimal hyperplasia and resulting restenosis limit the efficacy of coronary stenting. We studied a coronary stent coated with the antiproliferative agent paclitaxel as a means of preventing restenosis. METHODS: We conducted a multicenter, randomized, controlled, triple-blind study to evaluate the ability of a paclitaxel-eluting stent to inhibit restenosis. At three centers, 177 patients with discrete coronary lesions (<15 mm in length, 2.25 to 3.5 mm in diameter) underwent implantation of paclitaxel-eluting stents (low dose, 1.3 microg per square millimeter, or high dose, 3.1 microg per square millimeter) or control stents. Antiplatelet therapies included aspirin with ticlopidine (120 patients), clopidogrel (18 patients), or cilostazol (37 patients). Clinical follow-up was performed at one month and four to six months, and angiographic follow-up at four to six months. RESULTS: Technical success was achieved in 99 percent of the patients (176 of 177). At follow-up, the high-dose group, as compared with the control group, had significantly better results for the degree of stenosis (mean [+/-SD], 14+/-21 percent vs. 39+/-27 percent; P<0.001), late loss of luminal diameter (0.29+/-0.72 mm vs. 1.04+/-0.83 mm, P<0.001), and restenosis of more than 50 percent (4 percent vs. 27 percent, P<0.001). Intravascular ultrasound analysis demonstrated a dose-dependent reduction in the volume of intimal hyperplasia (31, 18, and 13 mm3, in the high-dose, low-dose, and control groups, respectively). There was a higher rate of major cardiac events in patients receiving cilostazol than in those receiving ticlopidine or clopidogrel. Among patients receiving ticlopidine or clopidogrel, event-free survival was 98 percent and 100 percent in the high-dose and control groups, respectively, at one month, and 96 percent in both at four to six months. CONCLUSIONS: Paclitaxel-eluting stents used with conventional antiplatelet therapy effectively inhibit restenosis and neointimal hyperplasia, with a safety profile similar to that of standard stents.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Doença das Coronárias/terapia , Reestenose Coronária/prevenção & controle , Paclitaxel/uso terapêutico , Stents , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Angioplastia Coronária com Balão , Aspirina/efeitos adversos , Aspirina/uso terapêutico , Clopidogrel , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/patologia , Reestenose Coronária/diagnóstico por imagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Hiperplasia/diagnóstico por imagem , Hiperplasia/prevenção & controle , Masculino , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Ticlopidina/efeitos adversos , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico , Túnica Íntima/patologia , Ultrassonografia de Intervenção
7.
Am J Cardiol ; 99(8): 1044-50, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17437725

RESUMO

The SIRIUS study was a double-blinded, randomized trial of the sirolimus-eluting stent (SES) to evaluate its effect on the rate of restenosis. The present report is a retrospective analysis of short- and long-term outcomes of SESs compared with bare metal stents (BMSs) in a subgroup of patients with unstable angina enrolled in the trial. Of 1,058 patients randomized in SIRIUS, 533 (50.4%) had unstable angina pectoris and 490 had stable angina. In the unstable angina group, patients treated with SESs and BMSs had similar clinical and angiographic characteristics. The stenting procedure was highly successful in the 2 groups (95.9% and 97.4%, respectively) with similar immediate angiographic results and short-term (in-hospital) clinical event rates. At 1-year follow-up, compared with BMSs, patients with unstable angina treated with SESs had significantly lower rates of target lesion revascularization (5.5% vs 22.3%, p <0.0001), target vessel failure (10.9% vs 26.3%, p <0.0001), and major adverse cardiac events (8.4% vs 24.8%, p <0.0001). Stent thrombosis was a rare event, with only 1 patient (0.4%) in each group during the first 30 days. Late thrombosis occurred in 2 patients (0.7%) in the BMS group but in none of the SES group. In conclusion, in the higher risk subgroup of patients with unstable angina, SESs are as safe as BMSs in decreasing restenosis and the need for repeat revascularization. This is reflected by a significant decrease in major adverse cardiac events and target vessel failure. Patients with unstable angina undergoing percutaneous coronary intervention who meet the entry criteria of the SIRIUS study should be preferentially treated with SESs.


Assuntos
Angina Instável/terapia , Reestenose Coronária/etiologia , Fibrinolíticos/administração & dosagem , Sirolimo/administração & dosagem , Stents , Angioplastia Coronária com Balão , Aspirina/uso terapêutico , Clopidogrel , Angiografia Coronária , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/uso terapêutico , Retratamento , Estudos Retrospectivos , Segurança , Taxa de Sobrevida , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico , Fatores de Tempo , Resultado do Tratamento
9.
Am J Cardiol ; 98(11): 1464-7, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17126651

RESUMO

A direct coronary stenting technique using drug-eluting stents may decrease drug-eluting stent efficacy due to possible damage to the surface coating of the stent. The DIRECT is a multicenter, prospective, nonrandomized trial designed to evaluate the direct stenting strategy for the sirolimus-eluting Bx-Velocity stent compared with the historical control (SIRIUS trial, stenting with predilation). Volumetric and cross-sectional intravascular ultrasound analyses at 8-month follow-up were performed in 115 patients (DIRECT n= 64, control n = 51). Patient and lesion characteristics were comparable between groups. The DIRECT group achieved an equivalent uniform expansion index, defined as minimum stent area/maximum stent area x 100, compared with the control group (65.9 +/- 11.7 vs 63.1 +/- 12.7, p = NS). At 8-month follow-up, vessel, stent, lumen, and neointimal volume index (volume in cubic millimeters/length in millimeters) and percent neointimal volume were similar between the DIRECT and control groups (vessel volume index 13.9 +/- 4.40 vs 15.0 +/- 3.83; stent volume index 6.83 +/- 2.02 vs 6.94 +/- 2.04; lumen volume index 6.71 +/- 2.04 vs 6.81 +/- 2.07; neointimal volume index 0.14 +/- 0.24 vs 0.16 +/- 0.23; percent neointimal volume 3.73 +/- 6.97 vs 3.14 +/- 5.32, p = NS for all). In addition, in-stent neointimal hyperplasia distribution was significantly smaller near the distal stent edge (0.22 vs 0.098 mm(3)/mm, p = 0.01 for an average neointimal volume index within 3 mm from the distal stent edge). In conclusion, direct coronary stenting with the sirolimus-eluting Bx-Velocity stent is equally effective in terms of uniform stent expansion and long-term quantitative intravascular ultrasound results compared with conventional stenting using predilation. This strategy appears to be associated with less neointimal hyperplasia near the distal stent edge.


Assuntos
Estenose Coronária/terapia , Vasos Coronários/patologia , Dilatação/métodos , Sirolimo/administração & dosagem , Stents , Ultrassonografia de Intervenção , Feminino , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Arterioscler Thromb Vasc Biol ; 25(11): 2343-8, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16141400

RESUMO

OBJECTIVE: Mitomycin C (MMc) is an antibiotic that exerts a potent antiproliferative effect in tumor cells. Because the proliferation of vascular smooth muscle cells (VSMCs) plays a prominent role in the development of restenosis after percutaneous coronary interventions, the present study examined the effect of MMc on VSMC proliferation and on neointima formation after arterial balloon injury. METHODS AND RESULTS: Treatment of cultured rat aortic VSMCs with MMc (1 nmol to 30 micromol/L) inhibited VSMC proliferation in a concentration-dependent manner. Whereas high concentrations of MMc (1 to 30 micromol/L) induced VSMC apoptosis, as reflected by DNA laddering and caspase-3 activation, lower concentrations of MMc (1 to 300 nmol/L) directly inhibited VSMC growth by arresting cells in the G2/M phase of the cell cycle. The antiproliferative action of MMc was associated with a selective increase in the expression of the cyclin-dependent kinase inhibitor p21, and with a decrease in cyclin B1-cyclin-dependent kinase-1 complex activity. Finally, the local perivascular delivery of MMc immediately after balloon injury of rat carotid arteries induced p21 expression and markedly attenuated neointima formation. CONCLUSIONS: These studies demonstrate that MMc exerts a potent inhibitory effect on VSMC proliferation and neointima formation after arterial injury. MMc represents a potentially new therapeutic agent in treating and preventing vasculoproliferative disease.


Assuntos
Angioplastia com Balão/efeitos adversos , Antibióticos Antineoplásicos/farmacologia , Doenças da Aorta/tratamento farmacológico , Inibidor de Quinase Dependente de Ciclina p21/genética , Mitomicina/farmacologia , Animais , Aorta Torácica/lesões , Aorta Torácica/patologia , Doenças da Aorta/etiologia , Doenças da Aorta/patologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Relação Dose-Resposta a Droga , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Túnica Íntima/patologia
11.
Coron Artery Dis ; 17(4): 379-84, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16707962

RESUMO

BACKGROUND: The availability of drug-eluting stents was expected to expand the application of percutaneous coronary intervention to a wider group of patients and lesion types. We sought to determine whether drug-eluting stents' availability has changed the practices of operators performing percutaneous coronary intervention with regard to patient selection and procedural factors. METHODS: We compared the clinical and angiographic characteristics of patients who underwent percutaneous coronary intervention at the Methodist Hospital, Houston, Texas, during three periods: June 2002-March 2003, June 2003-March 2004 and June 2004-March 2005. Sirolimus-eluting stents were available during the latter two periods. Paclitaxel eluting stents became available during the third period. RESULTS: A greater proportion of patients undergoing diagnostic catheterization were referred for percutaneous coronary intervention during the latter two periods (26.8%, 30.4%, 30.4%, respectively, P<0.0001). Patients undergoing stent placement during the latter two periods were more likely to have hypertension, hyperlipidemia or to have undergone previous percutaneous coronary intervention. The average implanted stent length was greater during the latter periods (14.5+/-4.6, 16.4+/-5.2, 16.8+/-5.5 mm, respectively, P<0.0001) and the average stent diameter was smaller (3.23+/-1.22, 3.13+/-1.16, 3.02+/-0.6 mm, respectively, P<0.0001). The frequency of percutaneous coronary intervention involving long lesions (>20 mm) and Left Anterior Descending (LAD) lesions was higher in the latter two periods and the frequency of multivessel stenting was higher in the last period. CONCLUSIONS: The spectrum of patients and coronary lesions that have undergone stenting has changed, particularly in the third period when both drug-eluting stent types were available. We observed a gradual shift toward higher-risk clinical and lesion characteristics following the introduction of drug-eluting stents.


Assuntos
Angioplastia Coronária com Balão/estatística & dados numéricos , Sistemas de Liberação de Medicamentos/instrumentação , Stents , Idoso , Sistemas de Liberação de Medicamentos/métodos , Feminino , Humanos , Hiperlipidemias/tratamento farmacológico , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Texas
12.
Circulation ; 109(4): 487-93, 2004 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-14744971

RESUMO

BACKGROUND: The use of a stent to deliver a drug may reduce in-stent restenosis. Paclitaxel interrupts the smooth muscle cell cycle by stabilizing microtubules, thereby arresting mitosis. METHODS AND RESULTS: On the basis of prior animal studies, the European evaLUation of the pacliTaxel Eluting Stent (ELUTES) pilot clinical trial (n=190) investigated the safety and efficacy of V-Flex Plus coronary stents (Cook Inc) coated with escalating doses of paclitaxel (0.2, 0.7, 1.4, and 2.7 microg/mm2 stent surface area) applied directly to the abluminal surface of the stent in de novo lesions compared with bare stent alone. The primary efficacy end point was angiographic percent diameter stenosis at 6 months. At angiographic follow-up, percent diameter stenosis was 33.9+/-26.7% in controls (n=34) and 14.2+/-16.6% in the 2.7-microg/mm2 group (n=31; P=0.006). Late loss decreased from 0.73+/-0.73 to 0.11+/-0.50 mm (P=0.002). Binary restenosis (> or =50% at follow-up) decreased from 20.6% to 3.2% (P=0.056), with no significant benefit from intermediate paclitaxel doses. Freedom from major adverse cardiac events in the highest (effective) dose group was 92%, 89%, and 86% at 1, 6, and 12 months, respectively (P=NS versus control). No late stent thromboses were seen in any treated group despite clopidogrel treatment for 3 months only. CONCLUSIONS: Paclitaxel applied directly to the abluminal surface of a bare metal coronary stent, at a dose density of 2.7 microg/mm2, reduced angiographic indicators of in-stent restenosis without short- or medium-term side effects.


Assuntos
Reestenose Coronária/prevenção & controle , Sistemas de Liberação de Medicamentos , Paclitaxel/administração & dosagem , Stents , Angiografia Coronária , Reestenose Coronária/diagnóstico , Reestenose Coronária/diagnóstico por imagem , Relação Dose-Resposta a Droga , Europa (Continente) , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Paclitaxel/efeitos adversos , Paclitaxel/uso terapêutico
13.
Am J Cardiol ; 95(1): 107-9, 2005 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-15619404

RESUMO

Using data from the ASian Paclitaxel-Eluting Stent Clinical Trial, a 3-center, randomized, placebo-controlled trial of nonpolymeric paclitaxel-coated stents with a single center, 81-patient intravascular ultrasound (IVUS) substudy, the length of a stent that was free of IVUS-detectable intimal hyperplasia measured 3.2 +/- 4.8 mm in placebo stents, 6.1 +/- 5.6 mm in low-dose stents, and 8.7 +/- 6.1 mm in high-dose stents (p = 0.0029). IVUS percent neointima volume obstruction correlated with the length of this IVUS neointima-free segment (r = 0.785, p <0.0001); angiographic late lumen loss and follow-up diameter stenosis also correlated with the IVUS neointima-free length of the stents (r = 0.670, p <0.0001 and r = 0.679, p <0.0001, respectively.


Assuntos
Reestenose Coronária/diagnóstico por imagem , Reestenose Coronária/prevenção & controle , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Sistemas de Liberação de Medicamentos , Paclitaxel/administração & dosagem , Stents , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia , Ultrassonografia de Intervenção , Humanos , Hiperplasia/diagnóstico por imagem , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Am J Cardiol ; 95(1): 105-7, 2005 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-15619403

RESUMO

We used data from the ASian Paclitaxel-Eluting Stent Clinical Trial (a 3-center, randomized, placebo-controlled trial of nonpolymeric paclitaxel-coated stents with a single-center intravascular ultrasound substudy) to compare angiographic indexes of drug-eluting stent efficacy with the magnitude of intimal hyperplasia (IH) assessed by intravascular ultrasound. Overall, percent IH (IH volume divided by stent volume) was larger in restenotic lesions than in nonrestenotic lesions (46 +/- 19% vs 15 +/- 13%, p <0.0001); angiographic late loss and follow-up diameter stenoses correlated strongly with percent IH.


Assuntos
Angiografia Coronária , Reestenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Sistemas de Liberação de Medicamentos , Paclitaxel/administração & dosagem , Stents , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia , Ultrassonografia de Intervenção , Reestenose Coronária/prevenção & controle , Humanos , Hiperplasia/diagnóstico por imagem , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
Coron Artery Dis ; 16(4): 217-24, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15915073

RESUMO

BACKGROUND: We attempted to create a pig model of complex arterial lesions through the percutaneous injection of cholesteryl linoleate into the vessel wall. METHODS AND RESULTS: A total of 81 arterial segments (27 arteries) underwent percutaneous intramural injection of cholesteryl linoleate, in eight pigs. Intravascular ultrasound (IVUS) analysis and corresponding histology were obtained for analysis at 2 and 4 weeks after injection. Overall, 18 out of 27 (67%) of the injected arterial segments displayed lesions identifiable by IVUS as an eccentric echolucent zone present within the deeper layer of the lesion. Quantitative IVUS analysis demonstrated that these lesions were non-occlusive (36+/-8% area stenosis), eccentric (eccentricity index, 0.78+/-0.07) and located into positively remodeled vessels (remodeling index, 1.45+/-0.24). By histology, these lesions were eccentric and comprised less than a third of the vessel circumference. Medial thickening and a thickened intima containing lipid droplets and mononuclear cells were consistently found. The presence of lipids or local wall thickening seen by histology colocalized with the presence of echolucent structures seen by IVUS in 65% of the coronary segments and 70% of the iliac segments. CONCLUSIONS: The intramural deposition of cholesteryl linoleate results in the development of complex, lipid-containing inflammatory lesions in less than 4 weeks. These lesions are already identifiable by IVUS at 2 weeks and colocalize with histologic findings. Further development of this model may allow the validation of technologies designed to detect and treat high-risk atherosclerotic lesions.


Assuntos
Arteriosclerose/diagnóstico por imagem , Arteriosclerose/patologia , Vasos Coronários/patologia , Artéria Ilíaca/patologia , Ultrassonografia de Intervenção , Animais , Biópsia por Agulha , Ésteres do Colesterol , Vasos Coronários/diagnóstico por imagem , Modelos Animais de Doenças , Artéria Ilíaca/diagnóstico por imagem , Imuno-Histoquímica , Injeções Intra-Arteriais , Probabilidade , Sensibilidade e Especificidade , Sus scrofa , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia
16.
Int J Radiat Oncol Biol Phys ; 53(3): 714-9, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12062617

RESUMO

PURPOSE: Angioplasty effectively relieves coronary artery stenosis but is often followed by restenosis. Endovascular radiation (beta or gamma) at the time of angioplasty prevents restenosis in a large proportion of vessels in swine (short term) and humans (short and long term). Little information is available about the effects of this radiation exposure beyond the wall of the coronary arteries. METHODS AND MATERIALS: Samples were obtained from 76 minipigs in the course of several experiments designed to evaluate endovascular brachytherapy: 76 of 114 coronary arteries and 6 of 12 iliac arteries were exposed to endovascular radiation from 32P sources (35 Gy at 0.5 mm from the intima). Two-thirds of the vessels had angioplasty or stenting. The vessels were systematically examined either at 28 days or at 6 months after radiation. RESULTS: We found an unexpected lesion: acute necrotizing vasculitis in arterioles located < or =2.05 mm from the target artery. It was characterized by fibrinoid necrosis of the wall, often associated with lymphocytic exudates or thrombosis. Based on the review of perpendicular sections of tissue samples, the arterioles had received between 6 and 40 Gy. This arteriolar vasculitis occurred at 28 days in samples from 51% of irradiated coronary arteries and 100% of irradiated iliac arteries. By 6 months, the incidence of acute vasculitis decreased to 24% around the coronary arteries. However, at that time, healing vasculitis was evident, often with luminal narrowing, in 46% of samples. Vasculitis was not seen in any of 44 samples from unirradiated vessels (0%) and had no relation to angioplasty, stenting, or their sequelae. This radiation-associated vasculitis in the swine resembles the localized lymphocytic vasculitis that we have reported in tissues of humans exposed to external radiation. On the other hand, it is quite different from the various types of systemic vasculitis that occur in nonirradiated humans. CONCLUSION: Endoarterial brachytherapy using 32P results in vascular effects beyond the adventitia of the target vessel. This necrotizing vasculitis is causally related to radiation, but its mechanism is unclear and a dose effect is not evident. Quite possibly, local upregulation of inflammatory cytokines contributes to this radiation-associated vasculitis, which only involved some of the arterioles in each sample. It is likely that radiation-associated vasculitis also occurs around human coronary arteries and may result in foci of ischemia. To our knowledge, this lesion has not been previously recognized, either in experimental models or in human specimens examined after angioplasty/brachytherapy.


Assuntos
Arteríolas/efeitos da radiação , Arterite/etiologia , Braquiterapia/efeitos adversos , Doença das Coronárias/etiologia , Lesões Experimentais por Radiação/complicações , Porco Miniatura , Doença Aguda , Angioplastia com Balão/efeitos adversos , Animais , Arteríolas/patologia , Arterite/patologia , Doença das Coronárias/patologia , Feminino , Masculino , Lesões Experimentais por Radiação/patologia , Stents , Suínos
17.
Int J Radiat Oncol Biol Phys ; 52(1): 184-91, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11777637

RESUMO

PURPOSE: To compare by intravascular ultrasound (IVUS) the efficacy of delivering the prescribed dose to the adventitia between two commonly used dose prescriptions for intracoronary radiotherapy. METHODS AND MATERIALS: In 59 human postangioplasty coronary vessels, one IVUS cross-section (1 mm thick) with the highest plaque burden was used for creating dose-volume histograms with different hypothetical positions of the source. RESULTS: On average, prescription to 1 mm beyond lumen surface resulted in delivery of the prescribed dose (20 Gy +/- 20%) to a higher fraction of adventitial volume than with the prescription to 2 mm from the source, with source placed in vessel center, lumen center, or in the IVUS catheter position. Source placement in the lumen center resulted in a low dose heterogeneity to the adventitia and the least dose heterogeneity to the intima. CONCLUSIONS: Prescription to 1 mm beyond lumen surface appeared more effective in delivering the prescribed dose to the adventitia than the American Association of Physicists in Medicine (AAPM) recommended prescription to 2 mm from the source center. Moreover, centering the source in the lumen provides the better balance of effective adventitial targeting and intimal dose homogeneity. Modification of the current AAPM recommendation for dose prescription for intracoronary radiotherapy should be considered.


Assuntos
Reestenose Coronária/radioterapia , Vasos Coronários/efeitos da radiação , Endossonografia , Análise de Variância , Angioplastia Coronária com Balão , Reestenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Endotélio Vascular/efeitos da radiação , Feminino , Humanos , Masculino , Dosagem Radioterapêutica , Túnica Íntima/efeitos da radiação
18.
Am J Cardiol ; 94(2): 199-201, 2004 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-15246901

RESUMO

The investigators examined 326 pairs of angiograms from 2 randomized dose-finding (0.2 to 3.1 microg paclitaxel/mm(2) of stent surface area) clinical trials of polymer-free paclitaxel-eluting stents in de novo lesions (the ASian Paclitaxel-Eluting stent Clinical Trial [ASPECT] and the European evaLUation of Taxol Eluting Stent [ELUTES]). A dose-dependent effect was observed: the largest dose of paclitaxel in the 2 trials resulted in a significantly larger proportion of lesions at follow-up with <10% diameter stenosis (54% vs 16%, p = 0.00012 in ASPECT; 53% vs 21%, p = 0.013 in ELUTES) and with minimal luminal diameter located outside the stent compared with control stents (62% vs 20% in ASPECT, 48% vs 18% in ELUTES; p <0.05). Also, significantly shorter lesion lengths at 6-month follow-up were observed for the doses of 0.7 to 3.1 microg/mm(2) (p <0.03) relative to their respective lengths before the procedure compared with control stents.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Reestenose Coronária/prevenção & controle , Paclitaxel/administração & dosagem , Stents , Túnica Íntima/patologia , Angiografia Coronária , Relação Dose-Resposta a Droga , Humanos , Hiperplasia/prevenção & controle , Desenho de Prótese , Ensaios Clínicos Controlados Aleatórios como Assunto , Aço Inoxidável
20.
J Am Soc Echocardiogr ; 16(12): 1331-3, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14652616

RESUMO

This case report details a patient with a cardiac angiosarcoma who had an unusual presentation with hemodynamics consistent with mitral stenosis and constrictive-effusive pericarditis. It illustrates how transesophageal echocardiography adds to the information obtained from transthoracic imaging and hemodynamics in this unusual presentation of a cardiac tumor.


Assuntos
Ecocardiografia Transesofagiana , Neoplasias Cardíacas/diagnóstico , Hemangiossarcoma/diagnóstico , Estenose da Valva Mitral/diagnóstico , Pericardite Constritiva/diagnóstico , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA