Pedro Abreu González

Ritmo luz/oscuridad de las citocinas proinflamatorias en el infarto agudo de miocardio

Introduction and objectives. The concentration of certain proinflammatory cytokines has been found to be elevated in patients with acute coronary syndrome. Many studies have shown that coronary ischemic accidents do not show a uniform distribution throughout the day, but instead exhibit rhythmic variations. The objective of this study is to determine whether there is a circadian pattern of variation in the concentrations of proinflammatory cytokines in patients with acute myocardial infarction. Patients and method. The sample included 40 patients with acute myocardial infarction and 40 controls. Levels of interleukin 6 and 1β were determined in the first 24 hours after the acute coronary ischemic episode. Blood samples were extracted at 3:00 a.m. (period of darkness) and at 10:00 a.m. (period of daylight). Results. Both groups were similar in age, sex distribution, and coronary risk factors. Interleukin 6 levels showed a significant variation between daylight and nighttime concentrations in patients with acute myocardial infarction and controls (41.93 ± 5.90/100.39 ± 13.60 vs 25.76 ± 4.45/52.67 ± 7.73 pg/ml). However, interleukin 6 concentrations were higher in the acute myocardial infarction group than in the control group. Interleukin 1β concentrations did not vary between daylight and darkness. Conclusions. In both the control group and acute myocardial infarction group, interleukin 6 concentrations varied between daylight and darkness. Patients with acute myocardial infarction shown a higher concentration of interleukin 6 secondary to the physiological response to tissue damage. Circadian variations can affect the measurements obtained for different physiological and biochemical parameters.

[Effect of intravenous magnesium sulfate on chronic obstructive pulmonary disease exacerbations requiring hospitalization: a randomized placebo-controlled trial].

Objective Magnesium sulfate has been shown to have a bronchodilating effect in asthma, but this effect has not been clearly established in the context of chronic obstructive pulmonary disease (COPD). For this reason we investigated the possible bronchodilating effect of magnesium sulfate in COPD exacerbations. Patients and methods We studied 24 patients with exacerbated COPD who required admission to our hospitals pneumology department. All patients underwent baseline spirometry and were subsequently randomized to groups in a double-blind crossover design. Patients received 1.5 g of magnesium sulfate or placebo in an intravenous solution for 20 minutes. Those who received magnesium sulfate the first day were given placebo the second day, and vice versa. Spirometry was performed 15, 30, and 45 minutes after administration of magnesium sulfate or placebo. Finally, 400 μg of salbutamol were administered using a spacer and a final spirometry was performed 15 minutes later. All patients also received treatment with corticosteroids, intravenous antibiotics, oxygen, and regularly-scheduled bronchodilator therapy (salbutamol and ipratropium bromide every 6 hours). Results When we compared absolute increase in liters and percentage increase in forced expiratory volume in 1 second (FEV1) obtained with magnesium sulfate application to the increases obtained with placebo after 15, 30, and 45 minutes, no significant differences were found. When we compared absolute and percentage increases in FEV1 after administering salbutamol, we found significantly greater increases after magnesium sulfate administration. The mean (SD) absolute increase in FEV1 was 0.185 (0.42) L after magnesium sulfate administration and 0.081 (0.01) L after placebo (P=.004). The percentage increase in FEV1 was 17.11% (3.7%) after magnesium sulfate and 7.06% (1.8%) after placebo (P=.008). Conclusions Intravenous administration of magnesium sulfate has no bronchodilating effect in patients with COPD exacerbations. It does, however, enhance the bronchodilating effect of inhaled β2-agonists.

Efecto del sulfato de magnesio intravenoso en la exacerbación de la EPOC que precisa hospitalización: estudio aleatorizado controlado con placebo

Objetivo: El sulfato de magnesio (SM) ha demostrado tener en el asma bronquial un efecto broncodilatador, que resulta dudoso en el caso de la enfermedad pulmonar obstructiva cronica (EPOC). Por ello hemos llevado a cabo un estudio con el objetivo de investigar el posible efecto broncodilatador del SM intravenoso en la EPOC agudizada. Pacientes y metodos: Se estudio a 24 pacientes diagnosticados de EPOC agudizada que requirieron ingreso en la Unidad de Hospitalizacion de Neumologia. A cada uno se le realizo una espirometria basal. Posteriormente, se efectuo una aleatorizacion a doble ciego y cruzada de los pacientes para recibir 1,5 g de SM o placebo en solucion intravenosa (20 min). A quienes el primer dia recibieron SM se les administro placebo el segundo dia, y al reves. Se realizaron espirometrias a los 15, 30 y 45 min de la administracion de SM o placebo. Por ultimo, se administraron 400 µg de salbutamol inhalados mediante camara espaciadora y a los 15 min se realizo una ultima espirometria. Todos los enfermos recibieron ademas tratamiento con esteroides, antibioticos intravenosos, oxigeno y broncodilatadores pautados (salbutamol y bromuro de ipratropio cada 6 h). Resultados: Cuando se compararon los incrementos absolutos (en ml) y porcentuales del volumen espiratorio forzado en el primer segundo (FEV1) obtenidos con SM y placebo a los 15, 30 y 45 min, no se encontraron diferencias significativas. Al comparar los incrementos absolutos y porcentuales del FEV1 tras la administracion de salbutamol se observaron incrementos significativos con el SM (incrementos absolutos FEV1 SM/placebo: 0,185 ± 0,42 frente a 0,081 ± 0,01 l; p = 0,004. Incrementos porcentuales FEV1 SM/placebo: 17,11 ± 3,7% frente al 7,06 ± 1,8%; p = 0,008). Conclusiones: La administracion de SM intravenoso carece de efecto broncodilatador en pacientes con EPOC agudizada; sin embargo, si potencia dicho efecto de los betamimeticos inhalados.

Influencia de la diabetes mellitus en el tratamiento y el pronóstico del síndrome coronario agudo sin elevación del segmento ST

La diabetes mellitus condiciona un peor pronostico del sindrome coronario agudo. Presentamos un estudio retrospectivo cuyo objetivo fue analizar la influencia de la presencia de diabetes en el pronostico y el tratamiento de pacientes con sindrome coronario agudo sin elevacion del segmento ST. Se compararon las caracteristicas clinicas de 273 pacientes (93 pacientes diabeticos frente a 180 no diabeticos) ingresados en nuestro centro con el diagnostico de sindrome coronario agudo sin elevacion del segmento ST. Durante la hospitalizacion analizamos en ambos grupos el tratamiento medico y la realizacion de coronariografia, intervencionismo y cirugia coronaria. Finalmente, analizamos la incidencia acumulada de insuficiencia cardiaca intrahospitalaria y la mortalidad a los 28 dias y 6 meses en ambos grupos. El analisis multifactorial demostro que la diabetes fue un predictor independiente de mortalidad durante el periodo de seguimiento. Estos hallazgos no se acompanaron en nuestro registro de un tratamiento mas intervencionista en el grupo de pacientes diabeticos.

Variaciones diurnas de los biomarcadores en la medicina cardiovascular: importancia clínica

ciones II, III, aVF y precordiales derechas V2R-V6R. Las alteraciones del ECG que acompañan al infarto del ventrículo derecho muestran grandes variaciones y dependen del cociente de fuerzas eléctricas coexistentes entre la pared libre del ventrículo derecho isquémica y la pared inferior del ventrículo izquierdo. El infarto de miocardio (IM) ventricular derecho (VD) aislado da lugar a una elevación del segmento ST en las derivaciones precordiales, mientras que su combinación con un IM de cara diafragmática del ventrículo izquierdo elimina esta elevación del segmento ST en las derivaciones precordiales y produce una elevación del ST en las derivaciones II, III y aVF. La elevación masiva del segmento ST en las derivaciones precordiales e inferiores en el IM ventricular derecho se ha observado, pero es extraordinariamente infrecuente. Así pues, la elevación del ST en las derivaciones precordiales no descarta un infarto del ventrículo derecho que requiera un tratamiento diferente del de un infarto de cara anterior. En resumen, la oclusión aislada de la rama ventricular derecha puede acompañarse de una elevación del segmento ST en las derivaciones precordiales izquierdas. No debe darse por supuesto que esto indica un infarto de miocardio de la cara anterior en los pacientes que presentan un infarto agudo de miocardio de la cara diafragmática. Es importante que los médicos, y en especial los cardiólogos intervencionistas, tengan presente esta entidad y eviten intervenciones innecesarias a sus pacientes.

Association Between Serum Interleukin 10 Level and Development of Heart Failure in Acute Myocardial Infarction Patients Treated by Primary Angioplasty

Introduction and objectives. Interleukin 10 (IL-10) is an anti-inflammatory cytokine that inhibits the synthesis of proinflammatory cytokines. It has been shown that IL-10 is released into the circulation during post-ischemic myocardial reperfusion. The objective of this study was to determine whether the serum IL-10 concentration in patients with acute myocardial infarction who were undergoing primary angioplasty was related to the subsequent presence or absence of heart failure. Patients and method. The study included 65 patients who underwent successful primary angioplasty. During their subsequent stay in the coronary unit, their maximum degree of heart failure was recorded. Patients were then divided into 2 groups: group A patients were in Killip class I and group B patients in Killip classes II-IV. The serum IL-10 concentration was measured during the 24 hours following admission to the coronary unit. Results. The 2 groups were similar with regard to age, sex, and coronary risk factors. The IL-10 concentration was significantly higher in the group of patients with acute myocardial infarction without heart failure than in the group with heart failure (30.4±10.8 vs 19.8±7.9 pg/mL; P<.001). Conclusions. In patients with acute myocardial infarction who had undergone successful primary angioplasty, the serum IL-10 concentration measured during the following 24 hours was significantly higher in those who did not develop heart failure. These findings suggest that this anti-inflammatory cytokine has a protective effect on the myocardium during ischemia or reperfusion, or both.

Influence of Diabetes Mellitus on the Management and Prognosis of Non-ST-Elevation Acute Coronary Syndrome

The presence of diabetes mellitus worsens prognosis in acute coronary syndromes. The aim of our study was to analyze retrospectively the influence of diabetes mellitus on the management and prognosis of patients with non-ST-segment elevation acute coronary syndrome. We compared the baseline clinical characteristics of 273 patients (93 diabetic and 180 non-diabetic) admitted consecutively to our department with the diagnosis of non-ST-segment elevation acute coronary syndrome. In both groups, we assessed the medical treatment given during hospitalization and the use of coronary angiography, percutaneous coronary intervention, and coronary artery bypass grafting. Finally, we determined the incidence of heart failure during hospitalization and mortality at 28 days and 6 months in both groups. Multifactorial analysis revealed that diabetes was an independent risk factor for mortality during the study period. Data from our registry indicate that these findings were not associated with more extensive use of interventions in diabetic patients.

Light/Dark Cycle Variations in Proinflammatory Cytokines in Acute Coronary Syndromes

We have read with great interest the recent review by Angiolillo et al1 that provided an excellent overview of inflammation in acute coronary syndromes, but we were surprised that the authors did not mention light-dark cycles of proinflammatory cytokines. The implication or association of physiological rhythms with peak activity at a certain time of day or night might be suspected, given that the onset of cardiovascular accidents follows a circadian pattern.2 Several studies suggest that increased cardiovascular mortality in winter might be related to alterations in the biological clock controlled by the suprachiasmatic nucleus. This is regulated by day-night alternations, that is, by light-dark cycles.3,4 Other functions such as cortisol secretion,5 blood pressure variations,6 and vasomotor tone9 also depend on these rhythms. Our group has shown that interleukin 6 follows a lightdark cycle in patients with acute myocardial infarction.8 These variations can be attributed to the centrally controlled release of this compound by the neuroendocrine system. Such control would be exercised through synthesis and release of melatonin by the pineal gland, which, in turn, is regulated by light-dark variations.9 Although the study of the light-dark variations in proinflammatory cytokines in itself lacks clinical relevance, these findings point the way to new lines of investigation in the field of biological rhythms in humans. More studies will be needed to help clarify the mechanisms that underlie the cyclic nature of the presentation of some acute coronary syndromes. Such knowledge will undoubtedly lead to therapeutic interventions that provide better protection at times of greatest risk.

Homocisteína y enfermedad arterial coronaria

Hemos leído con gran interés el artículo titulado «Concentraciones totales de homocisteína plasmática en pacientes puertorriqueños con cardiopatía isquémica» de Rodríguez et al1 publicado en el número de diciembre de la Revista. Si bien es indudable la enorme trascendencia del tema, nos parece oportuno comentar algunos aspectos. En primer lugar, en la introducción se comenta que en España los estudios de cardiopatía isquémica se han enfocado más hacia la teoría del aumento en colesterol, y no hay estudios sobre los valores de homocisteína en esta población. A este respecto, existe un estudio español2 que ha comunicado que en el 26% de los pacientes con enfermedad coronaria se comprueba hiperhomocisteinemia. En segundo lugar, los autores no determinan los valores de vitamina B6, B12 y ácido fólico donde su déficit puede ser una causa nutricional de hiperhomocisteinemia. Se ha sugerido que aproximadamente el 60% de la hiperhomocisteinemia se debe a niveles inadecuados de una o más de estas vitaminas en la sangre3. Asimismo, no se comenta el estado dietético de la población de estudio, ya que es probable que el responsable de la incapacidad de encontrar una asociación entre la enfermedad coronaria y la concentración de homocisteína sea un efecto de la variación dietética a corto y largo plazo4. En diversos estudios retrospectivos y prospectivos se ha indicado la posibilidad de que una prueba de carga no metionina mejoraría la capacidad de discriminar el riesgo de enfermedad coronaria con respecto a la medición de homocisteína en ayunas5. En tercer lugar, los resultados están expuestos sin la suficiente claridad. En la tabla 2 se expone la distribución de

Interactions Between Environmental and Hormonal Oscillations Induce Plastic Changes in a Simple Neuroendocrine Transducer

Steroid hormones may affect, simultaneously, a wide variety of neuronal targets and influence the way neural networks interact and the way the brain reacts to the environment. Some of the neuronal effects of steroid hormones may be very fast and affect specific membrane conductances or second messenger cascades, while others may last a long time and exert profound influences on gene expression. The cross-talk between these forms of action may be crucial for the regulation of the way the brain develops and differentiates, changes with age, or remodels its synaptic circuitry during life. Here, we present some evidence of specific molecular changes brought about by gonadal steroids on a simple neuroendocrine transducer, the pineal gland.