Radioactive stents delay but do not prevent in-stent neointimal hyperplasia

BACKGROUND: Restenosis after conventional stenting is almost exclusively caused by neointimal hyperplasia. Beta-particle-emitting radioactive stents decrease in-stent neointimal hyperplasia at 6-month follow-up. The purpose of this study was to evaluate the 1-year outcome of (32)P radioactive stents with an initial activity of 6 to 12 microCi using serial quantitative coronary angiography and volumetric ECG-gated 3D intravascular ultrasound (IVUS). METHODS AND RESULTS: Of 40 patients undergoing initial stent implantation, 26 were event-free after the 6-month follow-up period and 22 underwent repeat catheterization and IVUS at 1 year; they comprised half of the study population. Significant luminal deterioration was observed within the stents between 6 months and 1 year, as evidenced by a decrease in the angiographic minimum lumen diameter (-0.43+/-0.56 mm; P:=0.028) and in the mean lumen diameter in the stent (-0.55+/-0. 63 mm; P:=0.001); a significant increase in in-stent neointimal hyperplasia by IVUS (18.16+/-12.59 mm(3) at 6 months to 27.75+/-11. 99 mm(3) at 1 year; P:=0.001) was also observed. Target vessel revascularization was performed in 5 patients (23%). No patient experienced late occlusion, myocardial infarction, or death. By 1 year, 21 of the initial 40 patients (65%) remained event-free. CONCLUSIONS: Neointimal proliferation is delayed rather than prevented by radioactive stent implantation. Clinical outcome 1 year after the implantation of stents with an initial activity of 6 to 12 microCi is not favorable when compared with conventional stenting

Informe de Economía e Instituciones

Resumen: El Informe de Economía e Instituciones cuenta con tres columnas que abordan cuestiones teóricas y de política económica relacionadas con la temática de la economía y las instituciones. En la primera columna “El gobierno del Poder Judicial: un campo de batalla” el autor expone el tema de la auto-organización del sistema judicial y el debate que existe en nuestro país acerca de cómo realizarla. Históricamente, la Corte Suprema asumió dicho rol, sin embargo con la reforma del 94 se buscó reformar la estructura del Poder Judicial. Para ello se quiso adoptar el modelo europeo en donde además de los jueces, los abogados, académicos y políticos desempeñarían un papel activo. Sin embargo, no se logró el consenso en temas relevantes y la discusión sobre dicha reforma se extiende hasta nuestros días En el segundo artículo: “Keynes, Röpke y Hayek: ¿Qué tan diferentes son sus ideas?”, El propósito del autor es mostrar las similitudes y diferencias entre estos pensadores sociales y económicos del siglo XX. Comienza planteándose hasta qué punto sería correcto ubicar el trabajo de Röpke entre el de Keynes y Hayek. Para ello, parte de la postura de Röpke en cuanto a que el mercado debe ser regulado mediante intervenciones conformes. Keynes por su parte defiende la intervención del Estado en la economía mientras que Hayek es un representante del laissez faire. A lo largo del artículo Ravier analiza las ideas de los tres economistas para mostrar que ninguno es un representante extremo de sus posturas, sino que hay relación entre ellos. En la última columna se presenta el artículo “Teoría General de los Contratos Administrativos” en donde la autora define el contrato administrativo como un acuerdo de voluntades generador de obligaciones. El Estado, con vista a sus fines administrativos, puede realizar dos tipos de estos contratos: contratos administrativos propiamente dichos, regidos por el derecho administrativo; o contratos administrativos de derecho común, regidos por el derecho privado. Por último la autora explica de manera detallada los elementos característicos del contrato administrativo, estos son: desigualdad de las partes; prerrogativas especiales y finalidad pública propia

Influence of a history of smoking on short term (six month) clinical and angiographic outcome after successful coronary angioplasty

OBJECTIVES—To assess the influence of smoking on restenosis after coronary angioplasty.
DESIGN AND PATIENTS—The incidence of smoking on restenosis was investigated in 2948 patients. They were prospectively enrolled in four major restenosis trials in which quantitative angiography was used before and immediately after successful angioplasty and again at six months.
RESULTS—Within the study population there were 530 current smokers, 1690 ex-smokers, and 728 non-smokers. Smokers were more likely to be men (85.9% v 87.5% v 65.3%, current v ex- v non-, p < 0.001), to be younger (54.0 (9.0) v 57.0 (9.1) v 59.9 (9.4) years, p < 0.001), to have peripheral vascular disease (7.2% v 5.5% v 2.3%, p < 0.001), and have sustained a previous myocardial infarction (42.9% v 43.9% v 37.9%, p = 0.022), but were less likely to be diabetic (9.1% v 9.5% v 12.6%, p = 0.043) or hypertensive (24.9% v 29.3% v 37.2, p < 0.001). There was no significant difference in the categorical restenosis rate (> 50% diameter stenosis) at six months (35.28% v 35.33% v 37.09%, current v ex- v non-), or the absolute loss (0.29 (0.54) v 0.33 (0.52) v 0.35 (0.55) mm, respectively; p = 0.172).
CONCLUSIONS—Although smokers have a lower incidence of known predisposing risk factors for atherosclerosis, they require coronary intervention almost six years earlier than non-smokers and three years earlier than ex-smokers. Once they undergo successful coronary angioplasty, there appears to be no evidence that smoking influences their short term (six month) outcome, but because of the known long term effects of smoking, patients should still be encouraged to discontinue the habit.


Keywords: coronary angioplasty; smoking; restenosis; quantitative angiograph