668 research outputs found
Nuevas estrategias en prevención cardiovascular
Cardiovascular diseases, especially coronary heart disease, are the leading cause of mortality in Spain and western countries. The prevention of complications is based on a cardiovascular risk stratification that is based on the presence of classical cardiovascular risk factors. There are many scales for cardiovascular risk stratification that classify subjects into low, intermediate or high risk. Despite the fact that the impact and treatment of risk factors are well known, their control remains poor. Obesity, diabetes, and hypertension seems also seem to be increasing trends due to the changes in lifestyles and nutritional habits of our communities. In recent decades some new, or emerging, cardiovascular risk factors have been identified that can improve the stratification of cardiovascular risk: C-reactive protein, homocysteine, and lipoprotein a. The metabolic syndrome is an association of cardiovascular risk factors that cluster in the same subject because they share a physiopathologic link: insulin resistance. Its presence is related to most cardiovascular risk factors, classical or emerging, especially obesity, hypertension, and C-reactive protein. On the other hand, detection of subclinical or incipient atherosclerosis, especially with the measurement of intima-media thickness, offers indirect information closely related to coronary atherosclerosis that improves the stratification of subjects at intermediate risk
Influencia del grado de la severidad de la estenosis, del diámetro del vaso y del modelo de stent en el fenómeno del retroceso elástico en angioplastia coronaria. Evaluación angiográfica
Purpose: Stent recoil following stent deployment is still a very important outcome predictor after angiographic intervention. The aim of this study is to assess the influence of device model, angiographic characteristics of the lesion and vessel size on stent recoil. Methods: 61 consecutive patients were included in the study. 81 stents were successfully deployed. Maximal balloon diameter at peak pressure and maximal lumen diameter after stenting were measured by QCA (quantitative coronary angiography)
Results: There were no significant differences regarding either the model of device or length, symmetry or severity of the lesion. There were significant differences regarding the vessel size. Stent recoil was greater in small vessels (<2,75 mm).
Discussion: This finding is a paradox. The small size of the vessel has been always identified as an independent risk factor for the development of stenosis. The use of stents in small vessels remains controversial.Objetivos: El fenómeno de retroceso elástico, tras la implantación del stent, sigue siendo de gran importancia en el éxito del procedimiento angiográfico. El objetivo de este estudio es valorar la influencia que el tamaño del vaso, el modelo de stent y el modelo angiográfico de lesión, puedan tener en el retroceso elástico.
Material y métodos: Se incluyeron en el estudio 61 pacientes, en los que se implantaron con éxito 81 stents de diferentes modelos. Se valoró mediante angiografía coronaria cuantitativa los diámetros durante la implantación y tras la retirada del balón. Los resultados fueron analizados en función del modelo de stent, de las caracterís- ticas del vaso y de las características angiográficas de la lesión. Resultados: No se hallaron diferencias significativas en el fenómeno del retroceso elástico en relación a la longitud, simetría y severidad de la lesión. Tampoco en relación al modelo de stent empleado. Sí hubo diferencias si se tenía en cuenta el tamaño del vaso, siendo significativamente menor en los vasos pequeños (<2,75 mm). Discusión: El hallazgo de que el retroceso elástico sea menor en los vasos pequeños supone una paradoja. Tradicionalmente se ha con- siderado el pequeño tamaño del vaso como un factor de riesgo inde- pendiente para el desarrollo de reestenosis tras la implantación del stent. Este hallazgo mantiene la polémica sobre el empleo del stent en vasos pequeños
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
Reconstruction of inclined air showers detected with the Pierre Auger Observatory
We describe the method devised to reconstruct inclined cosmic-ray air showers
with zenith angles greater than detected with the surface array of
the Pierre Auger Observatory. The measured signals at the ground level are
fitted to muon density distributions predicted with atmospheric cascade models
to obtain the relative shower size as an overall normalization parameter. The
method is evaluated using simulated showers to test its performance. The energy
of the cosmic rays is calibrated using a sub-sample of events reconstructed
with both the fluorescence and surface array techniques. The reconstruction
method described here provides the basis of complementary analyses including an
independent measurement of the energy spectrum of ultra-high energy cosmic rays
using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of
Cosmology and Astroparticle Physics (JCAP
Risk of ischaemic heart disease and acute myocardial infarction in a Spanish population: observational prospective study in a primary-care setting
BACKGROUND: Ischaemic heart disease is a global priority of health-care policy, because of its social repercussions and its impact on the health-care system. Yet there is little information on coronary morbidity in Spain and on the effect of the principal risk factors on risk of coronary heart disease. The objective of this study is to describe the epidemiology of coronary disease (incidence, mortality and its association with cardiovascular risk factors) using the information gathered by primary care practitioners on cardiovascular health of their population. METHODS: A prospective study was designed. Eight primary-care centres participated, each contributing to the constitution of the cohort with the entire population covered by the centre. A total of 6124 men and women aged over 25 years and free of cardiovascular disease agreed to participate and were thus enrolled and followed-up, with all fatal and non-fatal coronary disease episodes being registered during a 5-year period. Repeated measurements were collected on smoking, blood pressure, weight and height, serum total cholesterol, high-density and low-density lipoproteins and fasting glucose. Rates were calculated for acute myocardial infarction and ischaemic heart disease. Associations between cardiovascular risk factors and coronary disease-free survival were evaluated using Kaplan-Meier and Cox regression analyses. RESULTS: Mean age at recruitment was 51.6 ± 15, with 24% of patients being over 65. At baseline, 74% of patients were overweight, serum cholesterol over 240 was present in 35% of patients, arterial hypertension in 37%, and basal glucose over 126 in 11%. Thirty-four percent of men and 13% of women were current smokers. During follow-up, 155 first episodes of coronary disease were detected, which yielded age-adjusted rates of 362 and 191 per 100,000 person-years in men and women respectively. Disease-free survival was associated with all risk factors in univariate analyses. After multivariate adjustments, age, male gender, smoking, high total cholesterol, high HDL/LDL ratio, diabetes and overweight remained strongly associated with risk. Relative risks for hypertension in women and for diabetes in men did not reach statistical significance. CONCLUSION: Despite high prevalence of vascular risk factors, incidence rates were lower than those reported for other countries and other periods, but similar to those reported in the few population-based studies in Spain. Effect measures of vascular risk factors were mainly as reported worldwide and support the hypothesis that protective factors not considered in this study must exist as to explain low rates. This study shows the feasibility of conducting epidemiological cohort studies in primary-care settings
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
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