RESUMEN
Antecedentes: La hiperglicemia es habitual en los pacientes graves, tales como quienes cursan con un infarto al miocardio con supradesnivel del ST (IAMSDST). Los registros han demostrado que la hiperglicemia de ingreso es un marcador certero de mortalidad durante un IAM, especialmente en aquellos no diagnosticados previamente como diabéticos. Objetivos: El objetivo de este estudio fue establecer la relación entre los niveles de glicemia al ingreso y la mortalidad intrahospitalaria de pacientes cursando IAMSDST sometidos a angioplastía primaria. Métodos: Se analizaron 273 pacientes consecutivos sometidos a angioplastía primaria o de rescate (después de trombolisis fallida) entre junio de 2003 y mayo de 2005. En 234 de ellos se midió la glicemia dentro de las primeras 6 horas del ingreso. Se dividió a los pacientes en cuatro grupos según la glicemia: hasta 125 mg/dl, 126-150 mg/dl, 151-200 mg/dl y, mayor a200 mg/dl. Se registró la mortalidad intrahospitalaria y la ocurrencia de eventos cardíacos mayores (MACE: muerte, infarto no fatal, revascularización). Resultados: La mortalidad total fue de 9,4 por ciento y la ocurrencia de MACE fue 13,6 por ciento. La mortalidad aumentó significativamente conforme aumentaba la glicemia. Los pacientes con niveles altos de glicemia presentaron un riesgo mayor de shock cardiogénico. Los niveles de glicemia se correlacionaron con el tamaño del infarto medido como niveles de CK total (p<0.001). El análisis multivariado señaló como marcadores independientes de mortalidad intrahospitalaria a la disfunción ventricular (p=0,006) y a la glicemia mayor de 150 mg/dl (p=0,023)Conclusión: Los niveles de glicemia al ingreso se asocian a mayor mortalidad intrahospitalaria en pacientes con IAMSDST sometidos a angioplastía primaria.
Asunto(s)
Masculino , Humanos , Femenino , Persona de Mediana Edad , Angioplastia , Glucemia , Hiperglucemia/complicaciones , Hiperglucemia/mortalidad , Infarto del Miocardio/etiología , Infarto del Miocardio/mortalidad , Análisis de Varianza , Distribución de Chi-Cuadrado , Mortalidad Hospitalaria , Factores de RiesgoRESUMEN
BACKGROUND: Earlier angiographic studies have suggested that calcium antagonists may prevent the formation of new coronary lesions and the progression of minimal lesions. Conversely, a meta-analysis suggested that these drugs may increase cardiovascular mortality and morbidity in patients with coronary heart disease. OBJECTIVE: To investigate whether nisoldipine retards the progression of coronary atherosclerosis or reduces the occurrence of clinical events. DESIGN AND SETTING: The NICOLE study (NIsoldipine in COronary artery disease in LEuven) is a single centre, randomised, double blind, placebo controlled trial with coronary angiography at baseline, six months, and three years of follow up. PATIENTS: 826 patients who had undergone successful coronary angioplasty were randomised to nisoldipine 40 mg once daily or placebo. The intention to treat and per protocol population consisted of 819 and 578 patients, respectively. RESULTS: In the per protocol population, 625 of the nisoldipine treated and 655 of the placebo treated patients (NS) showed angiographic progression in at least one coronary arterial segment, defined as an increase in diameter stenosis of > or = 13%. The average minimum luminal diameter of the non-dilated lesions decreased by 0.163 mm and 0.167 mm in the nisoldipine and placebo groups, respectively (NS). The respective numbers of new lesions detected were 7 and 13 (NS). In the intention to treat population, the rates of death, stroke, and acute myocardial infarction were similar in both treatment groups. However, nisoldipine use was associated with fewer revascularisation procedures and thus the percentage of patients with any clinical event was lower (44.6% v 52.6%, p = 0.02). CONCLUSIONS: Nisoldipine has no demonstrable effect on the angiographic progression of coronary atherosclerosis or the risk of major cardiovascular events but its use is associated with fewer revascularisation procedures.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Nisoldipino/uso terapéutico , Bloqueadores de los Canales de Calcio/efectos adversos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estenosis Coronaria/prevención & control , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Nisoldipino/efectos adversos , Accidente Cerebrovascular/etiologíaRESUMEN
BACKGROUND: In 1994, a meta-analysis of 5 small randomized trials reported a 30% reduction in the odds of angiographic restenosis when calcium-channel blockers (CCB) were given after percutaneous coronary intervention. Recently, the results of 2 large similar trials (Nisoldipine In Coronary Artery Disease in Leuven [NICOLE], and Coronary AngioPlasty Amlodipine in REstenosis Study [CAPARES]) were published. An extended meta-analysis including the results of the latter trials was performed. METHODS: A total of 2380 patients were analyzed. Statistical analysis included calculation of odds ratios for each trial, common odds ratio, and homogeneity for treatment effects across trials. RESULTS: The incidence of angiographic restenosis was 36% in the CCB-treated group and 42% in the placebo group. The odds ratio of restenosis with CCB therapy was 0.78 (95% CI 0.64-0.95) compared with control patients (P =.01). Treatment effects were homogeneous across the trials. For the combined end point of death, coronary artery bypass grafting, repeat percutaneous transluminal coronary angioplasty, and myocardial infarction, 126 of 626 events occurred in the CCB group and 191 of 655 in the placebo group (odds ratio 0.61 [95% CI 0.47-0.80], P <.001). CONCLUSIONS: This extended meta-analysis confirmed a reduction in the odds of restenosis and clinical events when CCBs were added to standard therapy after percutaneous coronary intervention.
Asunto(s)
Angioplastia Coronaria con Balón/métodos , Bloqueadores de los Canales de Calcio/uso terapéutico , Enfermedad Coronaria/terapia , Reestenosis Coronaria/prevención & control , Amlodipino/uso terapéutico , Intervalos de Confianza , Reestenosis Coronaria/epidemiología , Humanos , Incidencia , Nisoldipino/uso terapéutico , Oportunidad Relativa , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricosRESUMEN
The NIsoldipine in COronary artery disease in LEuven (NICOLE) study investigates (1) whether nisoldipine, a dihydropyridine calcium antagonist, reduces the progression of minor coronary arterial lesions in the long term, and (2) whether it reduces the restenosis rate after successful percutaneous transluminal coronary angioplasty (PTCA). The NICOLE study is a single-center, randomized, double-blind trial in 826 patients, who underwent a successful PTCA. Nisoldipine 40 mg coat-core or placebo was started the morning after the procedure and continued for 3 years. All coronary arterial segments were measured on preprocedural angiogram and on the second follow-up angiogram at 3 years. On the first follow-up angiogram at 6 months only the dilated segments were measured. Although the study is still ongoing until the primary end point is reached, we report in this study the angiographic restenosis data as well as the clinical events observed at 6-month follow-up. The per-protocol population consisted of 646 patients. Restenosis, defined as a > or =50% loss of the initial gain (National Heart, Lung, and Blood Institute criterion IV) occurred in 49% and 55% of the 308 nisoldipine-treated and the 338 placebo-treated patients, respectively (p = NS). At follow-up, the rates of death and myocardial infarction were low and similar in both groups, but in the nisoldipine group, less patients required early coronary angiography (18% vs 26%, p = 0.006) and subsequent revascularization procedures (32% vs 41%, p = 0.057). Thus, nisoldipine did not significantly reduce the angiographic restenosis rate after PTCA, but reduced the number of repeat revascularization procedures, which may be due to its antianginal action.
Asunto(s)
Angioplastia Coronaria con Balón , Bloqueadores de los Canales de Calcio/uso terapéutico , Enfermedad Coronaria/terapia , Nisoldipino/uso terapéutico , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Preparaciones de Acción Retardada , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , RecurrenciaRESUMEN
Recent refinement in stent implantation technique and peri-procedural pharmacological treatment has lowered the incidence of stent thrombosis significantly. Still, all stent thromboses are associated with major adverse events. In previous studies it has been suggested that intravascular ultrasound fibrinolysis is safe and effective. In this report, ultrasound successfully reperfused thrombotically occluded stents. These observations suggest that ultrasound may dissolve occlusive platelet-rich thrombus effectively and safely. Cathet. Cardiovasc. Intervent. 51:332-334, 2000.
Asunto(s)
Stents , Trombosis/terapia , Terapia por Ultrasonido , Ultrasonografía Intervencional , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: The potential merits and disadvantages of the use of ionic or nonionic contrast media in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) have been the subjects of controversy. The present study was designed to evaluate the possible influence of both types of contrast media on major adverse cardiac events (MACE) in patients undergoing PTCA. METHODS AND RESULTS: In a randomized, parallel-group, double-blind study, 1411 patients received either iodixanol (a nonionic, iso-osmolar contrast medium) or ioxaglate (an ionic, low-osmolar contrast medium) during PTCA. A standardized anticoagulation regimen was followed. Patients were monitored in the hospital for 2 days and followed-up at 1 month. The primary end point, a composite of MACE (death, stroke, myocardial infarction, coronary artery bypass grafting, and re-PTCA) after 2 days, occurred in 4.3% of the total population, with no statistically significant difference between groups (iodixanol, 4.7%; ioxaglate, 3.9%; P=0.45). Further, between 2-day and 1-month follow-ups, no significant difference (P=0.27) existed between the groups in the rates of MACE. Hypersensitivity reactions (P=0.007) and adverse drug reactions (P=0.002) were significantly less frequent in the iodixanol group. The only significant predicting factors for the occurrence of MACE were dissection/abrupt closure and country. CONCLUSIONS: No significant differences were observed between the iodixanol and ioxaglate groups with regard to MACE, although hypersensitivity and adverse drug reactions were significantly less frequent in patients who received iodixanol.
Asunto(s)
Angioplastia Coronaria con Balón , Medios de Contraste/uso terapéutico , Cardiopatías/tratamiento farmacológico , Cardiopatías/terapia , Ácido Yoxáglico/uso terapéutico , Ácidos Triyodobenzoicos/uso terapéutico , Anciano , Medios de Contraste/efectos adversos , Puente de Arteria Coronaria , Método Doble Ciego , Femenino , Cardiopatías/mortalidad , Humanos , Cuidados Intraoperatorios , Ácido Yoxáglico/efectos adversos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Concentración Osmolar , Recurrencia , Accidente Cerebrovascular/etiología , Ácidos Triyodobenzoicos/efectos adversosRESUMEN
BACKGROUND: Recently, long (> or =20 mm) coronary stents were introduced for clinical use. They are intended as an alternative to multiple conventional stents to treat extensive dissections or suboptimal results of long lesions after balloon angioplasty. METHODS: In a total of 113 such consecutive vessels in 107 patients, the flexible Freedom stent was implanted. In 60 of these vessels, because of anatomic constraints, multiple overlapping short (16 mm) stents were implanted. The other 53 vessels were treated with a single long (> or =20 mm) stent. RESULTS: In the single stent group there were four implantation failures (8%) successfully managed by crossover to multiple overlapping short stents. During early follow-up, in-stent thrombosis was not observed, but three patients with a single long stent and two patients with multiple overlapping stents suffered myocardial infarction as a result of long lasting myocardial ischemia during a difficult angioplasty procedure. At 6-month follow-up, > or =50% restenosis was measured in 29% and 35% of the patients with a single long stent and in those with multiple overlapping stents, respectively (not significant). CONCLUSIONS: Compared with the alternative treatment modality (i.e., implantation of multiple short stents), no difference between in-hospital and 6-month outcome was observed. However, implantation of a single long stent, when technically feasible, reduces catheterization time, dye volume for the patient, and radiation exposure for both patient and operator during these embarrassing angioplasty procedures.
Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Disección Aórtica/terapia , Aneurisma Coronario/terapia , Enfermedad Coronaria/terapia , Stents , Adulto , Anciano , Disección Aórtica/diagnóstico por imagen , Aneurisma Coronario/diagnóstico por imagen , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Diseño de Equipo , Falla de Equipo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Retratamiento , Resultado del TratamientoRESUMEN
BACKGROUND: The functional significance of the anterograde and retrograde filling of coronaries on angiography is controversial. METHODS AND RESULTS: Eighteen patients with 27 severe lesions (> 85% diameter stenosis) after previous extensive myocardial infarction were selected. The left ventricle was divided into 33 segments for regional comparison of epicardial flow (as assessed by angiography) and tissue perfusion as well as metabolism (as measured by 13NH3- and 18FDG-PET). Viability was defined as normal perfusion (> 80% relative of maximum 13NH3 activity) or mismatch defect (> 1.2 metabolism/flow ratio). A method has been developed to register the 'lesion predicted region', determined on the basis of angiography, in the same polar map as derived from the positron emission tomography data. Distal to the lesion, the anterograde epicardial flow was evaluated by Thrombolysis in Myocardial Infarction (TIMI) criteria (TIMI flow 0-3), and retrograde filling was graded on a 0-3 scale (collateral grade 0-3). TIMI flow grade and retrograde collateral grade in every lesion predicted region segment were summed to indicate the total segmental epicardial flow. Out of the 594 segments, 369 were associated with a severe lesion. Among them, significantly higher average perfusion and metabolic activities were found in segments of good epicardial filling (summed epicardial flow > or = 3) than in the territories of limited epicardial flow (summed score < 3): 65.4 +/- 17% vs 45.6 +/- 10 (P = 0.001%) and 68.6 +/- 16% vs 47.4 +/- 11% (P = 0.0004), respectively. However, when we analysed the predictive value of angiographically detectable good epicardial flow for positron emission tomography viability criteria then the positive predictive value was found to be as low as 0.5, while the negative predictive value was considerably higher (0.82). CONCLUSION: After myocardial infarction, angiographically detectable limited epicardial flow reveals scarred segments while good epicardial contrast filling does not necessarily indicate maintenance of nutritive function.
Asunto(s)
Angiografía Coronaria , Circulación Coronaria/fisiología , Infarto del Miocardio/diagnóstico , Tomografía Computarizada de Emisión , Adulto , Anciano , Circulación Colateral/efectos de los fármacos , Circulación Colateral/fisiología , Angiografía Coronaria/efectos de los fármacos , Circulación Coronaria/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/fisiopatología , Pericardio/efectos de los fármacos , Pericardio/fisiopatología , Flujo Sanguíneo Regional/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Sensibilidad y Especificidad , Terapia TrombolíticaRESUMEN
To defray the escalating costs of coronary stenting, we handmade a balloon-expandable, stainless steel stent, which after experimental evaluation, was implanted in 156 patients undergoing PTCA complicated by a major dissection. The procedural success rate was 98%. The in-hospital course was characterized by a 1.3% cardiopulmonary mortality and a 4.5% nonfatal myocardial infarction rate, while emergency bypass surgery and early repeat PTCA were necessary in only one patient each (0.6%). Clinical 6-mo follow-up in 150 patients revealed no deaths and no myocardial infarctions, and the event-free survival rate was 82%. Six-month control angiography was performed in 93.3% of eligible patients and revealed a restenosis rate of 20%.
Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Stents , Disección Aórtica/etiología , Angioplastia Coronaria con Balón/efectos adversos , Constricción Patológica , Aneurisma Coronario/etiología , Angiografía Coronaria , Diseño de Equipo , Humanos , Recurrencia , Resultado del TratamientoRESUMEN
Distal coronary embolism of thrombotic material is quite common in the setting of primary coronary angioplasty for evolving acute myocardial infarction. Embolization to another coronary artery is, however, much more uncommon. We report on a case in which a large thrombus migrated from the proximal left anterior descending artery (LAD) to the proximal left circumflex artery (CX) during inflation of the dilatation balloon. The putative mechanism was retrograde expulsion of the thrombus by the deploying balloon.
Asunto(s)
Angioplastia Coronaria con Balón/efectos adversos , Trombosis Coronaria , Anciano , Resultado Fatal , Humanos , Masculino , Infarto del Miocardio/terapia , PresiónRESUMEN
We randomized 800 patients in a prospective study comparing the angiographic results, device usage and in-hospital outcome of balloon angioplasty of primary stenoses of native coronary vessels with low-compliant and highly compliant balloons. The cumulative incidence of prespecified clinical endpoints was 8.0% in both treatment groups. The primary angiographic success rates were 83.9% and 78.9% in the high- and low-compliance group, respectively (P = 0.05). For the lesions dilated with one study balloon only, the quantitative angiographic findings were virtually identical in the two treatment groups. The total number of dissections was slightly but not significantly higher in the lesions treated with a highly compliant balloon. The global usage of angioplasty balloons was similar in both treatment groups. We conclude that, in general, there is no objective reason to prefer one balloon material to another on the basis of its compliance characteristics.
Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Angiografía Coronaria , Enfermedad Coronaria/terapia , Adaptabilidad , Enfermedad Coronaria/diagnóstico por imagen , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Masculino , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Results of recent randomized clinical trials have revealed a significant reduction in angiographic restenosis rate when adjunctive stenting was performed after conventional coronary balloon angioplasty. The thrombogenicity of metal stents, however, remains a concern. In the present study, we compare the thrombogenicity of heparin-coated coronary stents with that of bare metallic coronary stents. METHODS AND RESULTS: Thrombogenicity of metallic coronary stents (four heparin-coated and eight bare stents) was studied in a rat arteriovenous shunt model with the use of 125I-labeled fibrinogen and 51Cr-labeled platelets. Total clot weight after 30-minute follow-up was significantly lower in the heparin-coated stents compared with the bare stents (8.1 +/- 3.7 versus 25.8 +/- 4.6 mg; P < .001). Relative 125I and 51Cr activities in the stents were significantly higher in the bare stents than in the heparin-coated stents (125I, 1.03 +/- 0.43 versus 0.18 +/- 0.04, P = .003; 51Cr, 17.5 +/- 6.8 versus 4.4 +/- 1.0, P = .004). Subsequently, heparin-coated and bare stents were randomly implanted in the right coronary artery of 20 domestic pigs. Angiographic parameters were similar between both groups at baseline and after 6-week follow-up. Morphometry also did not show a significant difference in lumen area (bare, 1.03 +/- 0.83 mm2; heparin-coated, 1.12 +/- 0.73 mm2; P = NS) or neointimal hyperplasia (bare, 1.01 +/- 0.81 mm2; heparin-coated, 1.21 +/- 0.57 mm2; P = NS). CONCLUSIONS: Heparin coating of metallic coronary stents decreases their thrombogenicity but does not improve late vessel patency and neointimal hyperplasia at follow-up in a porcine coronary model.
Asunto(s)
Vasos Coronarios , Reacción a Cuerpo Extraño/etiología , Heparina , Stents/efectos adversos , Trombosis/etiología , Animales , Derivación Arteriovenosa Quirúrgica , Arterias Carótidas/cirugía , Venas Yugulares/cirugía , Masculino , Ratas , Ratas Wistar , Propiedades de Superficie , Porcinos , Trombosis/prevención & controlRESUMEN
To defray the escalating cost of coronary stenting, we handmade a balloon expandable coil stent with stainless steel wire. Preliminary comparison with the Palmaz-Schatz stent showed that, when implanted in porcine iliac arteries, there was no difference in immediate angiographic results or in the degree of foreign body reaction at 6 wk. Subsequently, a total of 73 stents were implanted in 52 patients, either as a bailout device (54%) or for suboptimal angiographic results (46%). All but two implantations were successful. The postprocedural regimen consisted of heparin 1,000 IU/hr, aspirin 250 mg daily, and ticlopidine 500 mg daily. In-hospital complications were limited to two groin hematomas, one necessitating blood transfusion. Importantly, stent thrombosis was not observed. While 6-mo follow-up is pending, we already conclude that a balloon expandable coil stent can be handmade easily at low cost and implanted safely in patients.
Asunto(s)
Cateterismo/instrumentación , Enfermedad Coronaria/terapia , Seguridad de Equipos , Stents , Animales , Cateterismo/métodos , Angiografía Coronaria , Vasos Coronarios/patología , Vasos Coronarios/ultraestructura , Modelos Animales de Enfermedad , Diseño de Equipo , Estudios de Seguimiento , Humanos , Stents/economía , PorcinosRESUMEN
BACKGROUND: Systemic administration of angiopeptin has been shown to inhibit myointimal thickening after arterial injury in several animal species. METHODS AND RESULTS: To explore to what extent high and long-lasting local concentrations of angiopeptin influence the healing process after vascular injury, tantalum balloon-expandable stents were first coated with a polymer loaded with angiopeptin 250 µg. Implantation of these stents in porcine coronary arteries resulted in tissue concentrations of 10.7 pg/ml wet weight in the stented arterial segment 24 hours after stent implantation, gradually declining to 2.0 pg/ml wet weight at day 8. Finally, 20 pigs were randomly treated with either an angiopeptin-loaded or a blank-coated stent. At baseline, the angiographic parameters were similar between both groups but, after 6 weeks, the minimal luminal diameter of the stented arterial segment was larger in the angiopeptin-treated pigs when compared to controls (2.20 +/- 0.57 mm vs 1.57 +/- 0.68 mm, p < 0.01) This angiographic finding was confirmed by post-mortem morphometry where the respective lumen area values were 1.00 +/- 0.54 mm2 and 0.43 +/- 0.28 mm2 (p < 0.01). CONCLUSION: Polymer coated stents can be loaded with angiopeptin, which after implantation in porcine right coronary arteries result in high local tissue concentrations gradually declining over more than 8 days. These high local concentrations inhibit myointimal proliferation induced by poly(organo)phosphazene coated overstretched stents.
RESUMEN
PURPOSE: Comparison of the biocompatibility of self-expanding polyethylene terephthalate (PET) stents with self-expanding metallic stents (Wallstents). METHODS: Diameter- and length-matched PET stents and Wallstents were symmetrically implanted in the paired iliac arteries of 13 crossbred domestic swine. Stent deployment was studied angiographically and with intravascular ultrasound immediately after stent implantation. The angiographic stented lumen diameter was measured using quantitative vessel analysis before, immediately after stenting, and at 6-week follow-up. Cross-section histopathology and area morphometry were performed. RESULTS: Immediately poststenting, intravascular ultrasound revealed proximal dislocation of 5 of the 13 PET stents, whereas all metal stents were firmly embedded at the implantation site. At 6-week follow-up, three of the remaining PET stents were totally or subtotally occluded by organized thrombus, whereas all metal stents were patent. Compared with immediately poststenting, the angiographic lumen diameter within the five remaining PET stents was reduced by 30%, and that of the metallic stents was virtually unaltered (p < 0.02). This observation was confirmed by postmortem morphometry, wherein the PET-stented vessel segments a diameter stenosis of 40% was measured vs only 9% in the metallic stents (p < 0.0001). CONCLUSION: PET-stent deployment is difficult to control due to the lack of radiopacity of this stent. PET stents seem to be more thrombogenic and lead to significantly more neointimal proliferation than metallic stents.
Asunto(s)
Arteria Ilíaca , Stents , Animales , Cobalto , Diseño de Equipo , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/patología , Masculino , Tereftalatos Polietilenos , Radiografía , Stents/efectos adversos , Porcinos , Trombosis/etiología , Factores de Tiempo , Ultrasonografía IntervencionalRESUMEN
BACKGROUND: When poly(organo)phosphazene coated metallic stents are implanted into normal coronary arteries of pigs a severe histolymphocytic and fibromuscular reaction is induced. Corticosteroids possess potent anti-inflammatory and immunosuppressive effects, they have been shown to decrease migration and functional capability of the cells of inflammation and they may stabilize lysosomal cell membranes. This study aims to evaluates the feasibility and efficacy of local corticosteroid delivery by implantation of methylprednisolone loaded coronary stents into coronary arteries of pigs. METHODS: Tantalum balloon expandable coronary stents were coated with poly(organo)phosphazene impregnated with 5 wt% methylprednisolone. Methylprednisolone release was calculated in vitro and then randomly either a methylprednisolone loaded stent or a plain polymercoated stent was implanted into the right coronary artery of 20 pigs. Quantitative coronary artery analysis was done before, immediately after and 6 weeks after stent implantation. The pigs were then killed and the stented arteries processed for histopathological and morphometric evaluation. RESULTS: In-vitro testing revealed that the methylprednisolone loaded stents, when incubated in physiological saline, released 96% of the drug within 24 h. Quantitative angiography of the implanted stents showed similar angiographic parameters in both treatment groups immediately after implantation, but, after 6 weeks of follow-up study the minimal luminal diameter of the stented arterial segment was considerably larger in the methylprednisolone-treated pigs than it was in the control pigs (2.74 +/- 0.34 versus 1.36 +/- 0.72 mm, P < 0.005) This angiographic finding was confirmed at post-mortem morphometry where the respective values for neointimal thickness were 0.99 +/- 0.28 and 1.74 +/- 0.84 mm (P < 0.02). CONCLUSIONS: Polymer coated stents can be loaded with methylprednisolone which inhibits the severe foreign-body reaction induced by the combination of overstretch injury and the poly(organo)phosphazene polymer coating of metallic stents.
Asunto(s)
Prótesis Vascular/efectos adversos , Sistemas de Liberación de Medicamentos , Reacción a Cuerpo Extraño/prevención & control , Glucocorticoides/administración & dosificación , Metilprednisolona/administración & dosificación , Stents , Animales , Materiales Biocompatibles , Angiografía Coronaria , Vasos Coronarios/patología , Modelos Animales de Enfermedad , Femenino , Reacción a Cuerpo Extraño/etiología , Reacción a Cuerpo Extraño/patología , Histiocitos/efectos de los fármacos , Histiocitos/patología , Linfocitos/efectos de los fármacos , Linfocitos/patología , Masculino , Compuestos Organofosforados , Polímeros , PorcinosRESUMEN
PURPOSE: To investigate the neointimal response to poly(organo)phosphazene- and amphiphilic polyurethane-coated, oversized, stainless steel stents implanted in porcine peripheral arteries. METHODS: Nonarticulated, stainless steel, slotted-tube stents were coated with 1) a biodegradable poly-(organo)phosphazene with aminoacid ester side groups and 2) a biostable polyurethane prepared from an amphiphilic polyether, diphenyl methane-4,4'-diisocyanate and butane diol as chain extender. The stents were deployed in porcine peripheral arteries using an oversized balloon. RESULTS: The neonintimal response to amphiphilic polyurethane-coated stents was similar to the uncoated metallic stents. Poly(organo)phosphazene-coated stents, however, induced a severe histiolymphocytic and fibromuscular reaction resembling a foreign body reaction. CONCLUSIONS: Amphiphilic polyurethane is very promising as a biocompatible stent coating. Poly-(organo)phosphazene, however, appears unsuitable for this purpose.
Asunto(s)
Materiales Biocompatibles , Biodegradación Ambiental , Arteria Ilíaca/patología , Polímeros , Stents , Angioplastia de Balón , Animales , Materiales Biocompatibles/química , Butileno Glicoles/química , Femenino , Reacción a Cuerpo Extraño/patología , Histiocitos/patología , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/lesiones , Isocianatos/química , Linfocitos/patología , Masculino , Compuestos Organofosforados/química , Polímeros/química , Poliuretanos/química , Radiografía , Acero Inoxidable , Propiedades de Superficie , Porcinos , Túnica Íntima/patologíaRESUMEN
Polymer coatings have been suggested to decrease the thrombogenicity of metallic intravascular stents. The purpose of the present study was to investigate the intimal response to two different polymers when used as coatings for stents implanted in normal porcine coronary arteries. Non-articulated stainless steel-slotted tube stents were coated with either a biodegradable poly(organo)phosphazene with amino-acid ester side groups or a biostable polyurethane prepared from an amphiphilic polyether, dephenylmethane-4,4'-diisocyanate and butane diol as chain extender. In order to induce vascular wall injury, the stents were deployed using an oversized balloon. At 6 weeks follow-up, the angiographic luminal diameter measured in four polyurethane-coated stents and in six bare metallic stents was similar and 20% less than immediately post-stenting. However, in four polyphosphazene-coated stents the difference was 65% (P = 0.01 when compared to bare metal). At post-mortem morphometry the degree of luminal area stenosis was also similar in polyurethane-coated and in bare metallic stents (32 +/- 7.6% vs. 39 +/- 14%, NS) but reached 81 +/- 19% in polyphosphazene-coated stents (P < 0.03 when compared to bare metal). Thus, poly(organo)phosphazene induced a more pronounced histiolymphocytic and fibromuscular reaction than amphiphilic polyurethane, which appeared to be promising as biocompatible stent coating and, consequently, as a potential carrier for vasoactive drugs.
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Materiales Biocompatibles , Vasos Coronarios/patología , Polímeros , Stents , Túnica Íntima/patología , Animales , Animales Domésticos , Angiografía Coronaria , Vasos Coronarios/cirugía , Diseño de Equipo , Ensayo de Materiales/métodos , Metales , Poliuretanos , Porcinos , Túnica Íntima/cirugíaRESUMEN
BACKGROUND: Angiopeptin is a cyclic octapeptide analogue of somatostatin that has been shown to limit myointimal thickening of arteries in balloon injury models and to restore the vasodilating response to acetylcholine. A randomized, double-blind placebo controlled trial was conducted to assess the effect of angiopeptin in restenosis prevention after percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: Patients received a continuous infusion of either placebo or angiopeptin subcutaneously 6 to 24 hours before PTCA and for 4 days after PTCA (3 mg per 24 hours before PTCA followed by 6 mg per 24 hours after PTCA and for the remaining period). A 1.5-mg bolus dose of placebo or angiopeptin was given at PTCA. Aspirin (acetylsalicylic acid, 150 mg/d) was administered throughout the study period. Coronary angiograms obtained before and after PTCA and at 6-month follow-up were subjected to computerized quantification. Clinical follow-up was performed after 12 months. Primary clinical end points were death, myocardial infarction, coronary artery bypass surgery, or repeat PTCA. In total, 553 patients with 742 lesions were randomized. Clinical follow-up was available for all 553 patients. Angiopeptin decreased the clinical events during 12 months of follow-up from 36.4% in the placebo-treated group to 28.4% in the angiopeptin-treated patients (P = .046). Quantitative angiography after PTCA and at follow-up was available in 423 of 455 patients who underwent successful PTCA. The minimal lumen diameter at follow-up was 1.52 +/- 0.64 mm in the angiopeptin-treated group compared with 1.52 +/- 0.64 mm in the placebo-treated patients (P = .96). The late losses were 0.31 +/- 0.59 and 0.30 +/- 0.62 mm (P = .81) and the restenosis rates (> 50% diameter stenosis at follow-up) were 36% and 37% (P = .85) in the angiopeptin- and placebo-treated groups, respectively. CONCLUSIONS: In this study, angiopeptin significantly decreased the incidence of clinical events, principally the rate of revascularization procedures. In contrast, no significant effect was seen on angiographic variables.
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Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Oligopéptidos/uso terapéutico , Somatostatina/análogos & derivados , Anciano , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/mortalidad , Método Doble Ciego , Femenino , Estudios de Seguimiento , Enfermedades Gastrointestinales/inducido químicamente , Humanos , Masculino , Persona de Mediana Edad , Oligopéptidos/efectos adversos , Péptidos Cíclicos , Recurrencia , Somatostatina/efectos adversos , Somatostatina/uso terapéuticoRESUMEN
We studied the diagnostic value of exercise electrocardiographic (ECG) testing in 191 patients who were completely asymptomatic 6 months after a successful percutaneous transluminal coronary angioplasty procedure. With > 70%- and > 50%-diameter stenosis at follow-up as restenosis criteria, the sensitivities of exercise ECG testing were 29% and 21%; the specificities 89% and 91%; the positive predictive values 20% and 52%; the negative predictive values 93% and 70%; the accuracies 83% and 68%; and the risk ratios 2.8 and 1.7, for prevalences of 9% and 33%, respectively. There were no significant differences in the diagnostic value of exercise ECG testing between men and women, patients receiving or not receiving beta-blocking agents, and the presence or absence of pathologic Q waves. Significant differences in systolic blood pressure and the rate-pressure product at peak exercise were found between patients with and without restenosis. For individual patients, however, no practical conclusions can be drawn from these values. In conclusion, the diagnostic value of exercise ECG testing for silent restenosis is low, and supplementation with other techniques seems to be warranted.