Type 1 diabetes: Developing the first risk-estimation model for predicting silent myocardial ischemia. The potential role of insulin resistance.

OBJECTIVES: The aim of the study was to develop a novel risk estimation model for predicting silent myocardial ischemia (SMI) in patients with type 1 diabetes (T1DM) and no clinical cardiovascular disease, evaluating the potential role of insulin resistance in such a model. Additionally, the accuracy of this model was compared with currently available models for predicting clinical coronary artery disease (CAD) in general and diabetic populations. RESEARCH, DESIGN AND METHODS: Patients with T1DM (35-65years, >10-year duration) and no clinical cardiovascular disease were consecutively evaluated for: 1) clinical and anthropometric data (including classical cardiovascular risk factors), 2) insulin sensitivity (estimate of glucose disposal rate (eGDR)), and 3) SMI diagnosed by stress myocardial perfusion gated SPECTs. RESULTS: Eighty-four T1DM patients were evaluated [50.1±9.3 years, 50% men, 36.9% active smokers, T1DM duration: 19.0(15.9-27.5) years and eGDR 7.8(5.5-9.4)mg·kg-1·min-1]. Of these, ten were diagnosed with SMI (11.9%). Multivariate logistic regression models showed that only eGDR (OR = -0.593, p = 0.005) and active smoking (OR = 7.964, p = 0.018) were independently associated with SMI. The AUC of the ROC curve of this risk estimation model for predicting SMI was 0.833 (95%CI:0.692-0.974), higher than those obtained with the use of currently available models for predicting clinical CAD (Framingham Risk Equation: 0.833 vs. 0.688, p = 0.122; UKPDS Risk Engine (0.833 vs. 0.559; p = 0.001) and EDC equation: 0.833 vs. 0.558, p = 0.027). CONCLUSION: This study provides the first ever reported risk-estimation model for predicting SMI in T1DM. The model only includes insulin resistance and active smoking as main predictors of SMI.

Métodos diagnósticos de la enfermedad arterial periférica. Importancia del índice tobillo-brazo como técnica de criba / Diagnosis of peripheral vascular disease. Usefulness of the ankle-brachial index for screening

Debido a la elevada prevalencia de la enfermedad arterial periférica (EAP), que con frecuencia es asintomática, y sus graves repercusiones pronósticas, se recomienda la criba diagnóstica de los pacientes con alto riesgo de sufrirla: a) pacientes de edad > 70 años; b) pacientes de 50-69 años con historia de tabaquismo o diabetes mellitus; c) pacientes de 40-49 años con diabetes mellitus y al menos otro factor de riesgo de arteriosclerosis; d) síntomas compatibles con claudicación al esfuerzo o dolor isquémico en reposo; e) pulsos anormales en las extremidades inferiores; f) enfermedad arteriosclerosa en otros territorios, o g) pacientes con un score de Framingham entre el 10 y el 20%. Tanto la anamnesis como la exploración física tienen un valor para el diagnóstico de la enfermedad limitado porque, aunque son muy específicos, su sensibilidad es muy baja. Existen múltiples pruebas diagnósticas para valorar la presencia y la severidad de la enfermedad vascular periférica, entre las que cabe destacar el índice tobillo-brazo, las determinaciones de la presión segmentarias, los estudios de ecografía-Doppler y la angiografía mediante resonancia megnética, tomografía computarizada o de sustracción digital. En la actualidad se considera que el índice tobillo-brazo es el método no invasivo que presenta mejor rendimiento diagnóstico, ya que se trata de una prueba incruenta, fácil de realizar a la cabecera del paciente y con una elevada sensibilidad (superior al 90%) (AU)

Because peripheral arterial disease is highly prevalent, frequently silent, and has serious prognostic implications, it is recommended that diagnostic screening should be carried out in individuals at a high risk. This includes: a) those aged >70 years; b) those aged 50-69 years with a history of smoking or diabetes; c) those aged 40-49 years with diabetes mellitus and at least one other risk factor for atherosclerosis; d) those with symptoms indicating claudication on exercise or ischemic pain at rest; e) those with abnormal pulses in the lower extremities; f) those with atherosclerosis in other vascular territories; and g) those with a Framingham score of 10-20%. Neither anamnesis nor physical examination is of much value for disease diagnosis; although they are very specific, their sensitivity is very low. A large number of different diagnostic techniques are available for investigating the presence and severity of peripheral vascular disease, including ankle-brachial index measurement, segmental limb pressure measurement, Doppler ultrasonography, and various forms of angiography involving magnetic resonance imaging, computed tomography or digital subtraction imaging. At present, the ankle-brachial index is the non-invasive method that gives the best diagnostic performance. It is simple, inexpensive and has a high sensitivity (i.e. greater than 90%) (AU)

[Neointimal tissue proliferation after coronary stent implantation without predilatation]. / Proliferación neointimal después de la implantación coronaria de stent sin predilatación.

INTRODUCTION AND OBJECTIVES: Intravascular ultrasound (IVUS) studies in conventional stent angioplasty with predilatation have demonstrated that late luminal narrowing is caused by neointimal proliferation. In the present study, we analyzed the degree and distribution of in-stent neointimal proliferation after direct stent implantation and aimed to identify variables that predict a proliferative response. MATERIAL AND METHOD: We studied 45 patients who underwent successful stent implantation without predilatation and 23 patients with similar clinical and angiographic characteristics who underwent conventional stent angioplasty with predilatation. IVUS imaging was performed at 7.85+/-2.81 months. The cross-sectional area was measured at five predetermined points in the stented coronary segment. The inflation pressure used in patients who underwent direct stent implantation was higher than that employed in those who underwent conventional angioplasty with predilatation (13+/-3 atm vs 10+/-2 atm; P=.005). RESULTS: Luminal and stent cross-sectional areas were greater in the group that did not undergo predilatation than in the group that did. Neointimal proliferation in the 5 sections analyzed along the axis of the stent was similar in the 2 groups. There was a weak linear relationship between the amount of plaque outside the stent and neointimal proliferation in both the group that underwent predilatation (r=0.37; P=.005) and the group that did not (r=0.33; P=.005). CONCLUSIONS: As with conventional angioplasty, the neointimal proliferation that occurred after direct stent implantation showed a diffuse homogeneous pattern along the length of the stent. There was a weak correlation between this proliferative response and the amount of plaque outside the stent.

Proliferación neointimal después de la implantación coronaria de stent sin predilatación / Neointimal tissue proliferation after coronary stent implantation without predilatation

Introducción y objetivos. En la implantación de stent con predilatación la ecografía intracoronaria ha demostrado que la reducción luminal tardía se debe a la proliferación neointimal. En la presente serie analizamos el grado y la distribución de la proliferación neointimal intra-stent después de la implantación sin predilatación, así como las variables implicadas en esta respuesta proliferativa. Material y método. Se analizó a 45 pacientes después de la implantación exitosa de un stent sin predilatación y 23 pacientes con lesiones de características clínicas y angiográficas similares después de la implantación de un stent con predilatación. La ecografía intracoronaria en el seguimiento se realizó a los 7,85 ± 2,81 meses. Se midieron las áreas transversales (AT) en 5 segmentos predeterminados del segmento con stent. En el grupo de stent directo se empleó una presión de hinchado mayor que en el grupo con predilatación (13 ± 3 atm frente a 10 ± 2 atm; p = 0,005).Resultados. Los AT luminal y del stent fueron mayores en el grupo sin predilatación que en el grupo con predilatación. La proliferación neointimal en los 5 segmentos a lo largo del eje axial del stent fue similar en los dos grupos. Se observó una ligera relación lineal entre la placa fuera del stent y la proliferación neointimal en el grupo con predilatación (r = 0,37; p = 0,005) y sin predilatación (r = 0,33; p = 0,005). Conclusiones. De forma similar a la angioplastia convencional, en el stent directo la respuesta neointimal presenta un patrón difuso y homogéneo a lo largo del eje longitudinal del stent. Esta respuesta proliferativa se correlacionó ligeramente con la placa excluida por el stent (AU)

Introduction and objectives. Intravascular ultrasound (IVUS) studies in conventional stent angioplasty with predilatation have demonstrated that late luminal narrowing is caused by neointimal proliferation. In the present study, we analyzed the degree and distribution of in-stent neointimal proliferation after direct stent implantation and aimed to identify variables that predict a proliferative response. Material and method. We studied 45 patients who underwent successful stent implantation without predilatation and 23 patients with similar clinical and angiographic characteristics who underwent conventional stent angioplasty with predilatation. IVUS imaging was performed at 7.85±2.81 months. The cross-sectional area was measured at five predetermined points in the stented coronary segment. The inflation pressure used in patients who underwent direct stent implantation was higher than that employed in those who underwent conventional angioplasty with predilatation (13±3 atm vs 10±2 atm; P=.005). Results. Luminal and stent cross-sectional areas were greater in the group that did not undergo predilatation than in the group that did. Neointimal proliferation in the 5 sections analyzed along the axis of the stent was similar in the 2 groups. There was a weak linear relationship between the amount of plaque outside the stent and neointimal proliferation in both the group that underwent predilatation (r=0.37; P=.005) and the group that did not (r=0.33; P=.005). Conclusions. As with conventional angioplasty, the neointimal proliferation that occurred after direct stent implantation showed a diffuse homogeneous pattern along the length of the stent. There was a weak correlation between this proliferative response and the amount of plaque outside the stent (AU)