Cardiovascular events, diabetes and guidelines: the virtue of simplicity.

Cardiovascular (CV) events or their minor syndromes, as various forms of ischemia, are medical emergencies that do not allow enough time for a guiding anamnesis or proper clinical examination, and lead to relying on Treatment Guidelines, but in many situations it is appropriate to deviate from them. Pathological studies have associated 75% of coronary artery events with atherosclerotic plaque rupture; it is now known that rupture alone is not enough for obstruction or occlusion of the vessel lumen. Concomitant conditions are required for the clinical manifestation of cardiovascular disease, including prothrombogenic and dysfunctional endothelium, less fibrinolytic capacity to protect it, increased platelet activation, increased adrenergic tone, microcirculation vasoconstriction, and other countless factors that contribute to thrombus formation, causing ischemia or infarction. But in most cases, repair of plaque rupture and re endothelization of the lesion are asymptomatic and silent. Atherosclerotic process is a chronic and progressive immune inflammation. Most of the therapeutic indications include statins, which cause side effects in 10% of patients, with a range varying between 7 and 21%, according to different authors. Many investigators have proved that statin use contribute to the genesis of diabetes, reports vary between 1 and 46%, where marked elevation of blood glucose fasting levels and glycosylated hemoglobin have been observed, be it by increased tissue resistance to insulin or by reduced ß-cell insulin secretion. Physicians should base their indications on the recommendations provided by Guidelines, but they should not forget that every patient is different, and they should not get confused due to lack of time in an emergency nor be influenced by the latest publications or techniques until they have been properly tested.

Endothelial dysfunction: a comprehensive appraisal.

The endothelium is a thin monocellular layer that covers all the inner surface of the blood vessels, separating the circulating blood from the tissues. It is not an inactive organ, quite the opposite. It works as a receptor-efector organ and responds to each physical or chemical stimulus with the release of the correct substance with which it may maintain vasomotor balance and vascular-tissue homeostasis. It has the property of producing, independently, both agonistic and antagonistic substances that help to keep homeostasis and its function is not only autocrine, but also paracrine and endocrine. In this way it modulates the vascular smooth muscle cells producing relaxation or contraction, and therefore vasodilatation or vasoconstriction. The endothelium regulating homeostasis by controlling the production of prothrombotic and antithrombotic components, and fibrynolitics and antifibrynolitics. Also intervenes in cell proliferation and migration, in leukocyte adhesion and activation and in immunological and inflammatory processes. Cardiovascular risk factors cause oxidative stress that alters the endothelial cells capacity and leads to the so called endothelial "dysfunction" reducing its capacity to maintain homeostasis and leads to the development of pathological inflammatory processes and vascular disease. There are different techniques to evaluate the endothelium functional capacity, that depend on the amount of NO produced and the vasodilatation effect. The percentage of vasodilatation with respect to the basal value represents the endothelial functional capacity. Taking into account that shear stress is one of the most important stimulants for the synthesis and release of NO, the non-invasive technique most often used is the transient flow-modulate "endothelium-dependent" post-ischemic vasodilatation, performed on conductance arteries such as the brachial, radial or femoral arteries. This vasodilatation is compared with the vasodilatation produced by drugs that are NO donors, such as nitroglycerine, called "endothelium independent". The vasodilatation is quantified by measuring the arterial diameter with high resolution ultrasonography. Laser-Doppler techniques are now starting to be used that also consider tissue perfusion. There is so much proof about endothelial dysfunction that it is reasonable to believe that there is diagnostic and prognostic value in its evaluation for the late outcome. There is no doubt that endothelial dysfunction contributes to the initiation and progression of atherosclerotic disease and could be considered an independent vascular risk factor. Although prolonged randomized clinical trials are needed for unequivocal evidence, the data already obtained allows the methods of evaluation of endothelial dysfunction to be considered useful in clinical practice and have overcome the experimental step, being non-invasive increases its value making it use full for follow-up of the progression of the disease and the effects of different treatments.

Distance correction in the electrocardiographic estimation of left ventricular mass.

Assessment of the left ventricular mass (LVM) from electrocardiograms may be improved by the addition of clinical variables into a multivariate equation. As the heart-thorax distance may affect the results, its relationships with electrocardiographic and clinical data have been evaluated in a group of 220 subjects (53 +/- 15 years, 126 female, 175 without demonstrated heart disease) who were assessed for echocardiographic LVM and heart-thorax distance. Sokolow, Cornell, and total QRS voltage indexes were obtained. Multiple regression equations with LVM as the dependent variable were fit, with an ECG index, body mass index (BMI), age, and gender as the independent predictors. Each of the 3 ECG indexes, BMI, age, and sex was shown to be independent predictors of LVM, with the ECG and BMI contributing with most of the explanatory power. When added to the model, the distance from the interventricular septum to the precordium (septal-LVD) was not a predictor of LVM, but when BMI was withdrawn, septal-LVD became an independent predictor of LVM (P < .001). This was not observed when septal-LVD was substituted for any other clinical or ECG variable, thus suggesting that septal-LVD accounts for information contained in BMI but not in the remaining variables. In addition, the distance from the center of LV to the precordium (mid-LVD) achieved significance as an independent LVM predictor, although the coefficient of multiple determination (R) practically did not change. Almost identical results are obtained when LVM is indexed for body surface area. Body mass index supplies virtually all the information contained in the heart-thorax distance.

Estimación ecocardiográfica visual de la función sistólica ventricular izquierda en la evaluación pronóstica de pacientes con un primer evento cardiovascular / Visual echocardiographic estimation of left ventricular systolic function in the prognostic assessment of patients with an initial cardiovascular event

Objetivo: Evaluar la estimación ecocardiográfica visual de la función sistólica ventricular izquierda (FSVI visual) en la predicción de nuevos eventos en una muestra aleatoria de pacientes internados por un evento cardiovascular inicial. Material y métodos: En 304 pacientes (66 ± 13 años, 114 mujeres) internados entre mayo de 2001 y agosto de 2002, la FSVI visual, a partir del eco 2D, se estimó: 1) normal, 2) deterioro leve, 3) leve a moderado, 4) moderado, 5) moderado a severo y 6) severo. Se midieron la fracción de acortamiento (FAC) y los diámetros de fin de diástole (DDVI) y de sístole (DSVI) del VI. La sobrevida libre de eventos se analizó mediante curvas de Kaplan-Meier y análisis multivariado (Cox). Resultados: Se registraron 79 eventos. Se distinguen tres estratos de FSVI visual: 1 (normal), 2 (deterioro leve) y 3-6 (mayor que leve) que predicen incrementos crecientes de nuevos eventos (17 por ciento, 31 por ciento y 41 por ciento respectivamente, p < 0,005: 1 versus 2, y p < 0,05: 2 versus 3-6). La FAC, el DDVI y el DSVI son asimismo predictores (41 por ciento, 39 por ciento y 42 por ciento, respectivamente). El análisis multivariado revela que la FSVI visual es un predictor independiente respecto de la FAC, el DDVI y el DSVI, que no aportan nueva información. De 89 pacientes con FSVI visual clase 2 (leve), 62 (70 por ciento) tienen una FAC > 28 por ciento y 74 (83 por ciento) tienen un DDVI < 57 mm. Conclusiones: Un deterioro leve de la FSVI visual predijo un aumento significativo de eventos y un deterioro mayor (3 a 6), un aumento significativo respecto del grupo con deterioro leve. La mayoría de los pacientes con deterioro leve de la FSVI visual aún no alteraron perceptiblemente la FAC ni los diámetros ventriculares.

Estimación ecocardiográfica visual de la función sistólica ventricular izquierda en la evaluación pronóstica de pacientes con un primer evento cardiovascular / Visual echocardiographic estimation of left ventricular systolic function in the prognostic assessment of patients with an initial cardiovascular event

Objetivo: Evaluar la estimación ecocardiográfica visual de la función sistólica ventricular izquierda (FSVI visual) en la predicción de nuevos eventos en una muestra aleatoria de pacientes internados por un evento cardiovascular inicial. Material y métodos: En 304 pacientes (66 ± 13 años, 114 mujeres) internados entre mayo de 2001 y agosto de 2002, la FSVI visual, a partir del eco 2D, se estimó: 1) normal, 2) deterioro leve, 3) leve a moderado, 4) moderado, 5) moderado a severo y 6) severo. Se midieron la fracción de acortamiento (FAC) y los diámetros de fin de diástole (DDVI) y de sístole (DSVI) del VI. La sobrevida libre de eventos se analizó mediante curvas de Kaplan-Meier y análisis multivariado (Cox). Resultados: Se registraron 79 eventos. Se distinguen tres estratos de FSVI visual: 1 (normal), 2 (deterioro leve) y 3-6 (mayor que leve) que predicen incrementos crecientes de nuevos eventos (17 por ciento, 31 por ciento y 41 por ciento respectivamente, p < 0,005: 1 versus 2, y p < 0,05: 2 versus 3-6). La FAC, el DDVI y el DSVI son asimismo predictores (41 por ciento, 39 por ciento y 42 por ciento, respectivamente). El análisis multivariado revela que la FSVI visual es un predictor independiente respecto de la FAC, el DDVI y el DSVI, que no aportan nueva información. De 89 pacientes con FSVI visual clase 2 (leve), 62 (70 por ciento) tienen una FAC > 28 por ciento y 74 (83 por ciento) tienen un DDVI < 57 mm. Conclusiones: Un deterioro leve de la FSVI visual predijo un aumento significativo de eventos y un deterioro mayor (3 a 6), un aumento significativo respecto del grupo con deterioro leve. La mayoría de los pacientes con deterioro leve de la FSVI visual aún no alteraron perceptiblemente la FAC ni los diámetros ventriculares. (AU)