1,721,276 research outputs found
ST2 and prognosis in acutely decompensated heart failure. The international ST2 consensus panel
No full textST2 is a member of the interleukin (IL) 1 receptor family that exists in 2 forms, a transmembrane receptor (ST2L) and a soluble receptor (sST2). The ligand of ST2 is IL-33, known to be involved in reducing tissue fibrosis and myocyte hypertrophy in mechanically strained hearts. Through its ability to act as a decoy receptor, sST2 blocks the beneficial effects that occur when IL-33 attempts to bind to ST2L; experimentally, this leads to cardiac hypertrophy, fibrosis, and ventricular dysfunction. In patients with acutely decompensated heart failure, elevated concentrations of sST2 are strongly associated with the presence and severity of the diagnosis and powerfully predict increased risk of heart failure complications including arrhythmia, pump failure, or death, independent of natriuretic peptides and other established or emerging biomarkers. The role of sST2 measurement in acutely decompensated heart failure evaluation and management will be discussed
Left ventricular ejection fraction for risk stratification in chronic systolic heart failure
No full textBackground: Left ventricular ejection fraction (LVEF) represents the most used measure of cardiac systolic function. Different cut-offs have been proposed to classify patients with systolic dysfunction, and to inform therapy decision-making. Methods: Consecutive outpatients with systolic heart failure (HF; LVEF <50%) were prospectively enrolled and underwent a baseline characterization. The prognostic value of LVEF and LVEF cut-offs was made with regards to the prediction of all-cause and cardiovascular death. Results: Out of 2160 patients, 71% had LVEF <40%, and 61% had ≤35%. Over a 26-month median follow-up (interquartile interval 12–39), patients with LVEF ≤35% (log-rank 31.11 and 59.48, respectively; both p < 0.001) and <40% (log-rank 24.51 and 41.77, respectively; both p < 0.001) had a significantly worse prognosis for all-cause and cardiovascular death. LVEF independently predicted both endpoints in a strong prognostic model including age, sex, ischaemic aetiology, N-terminal fraction of pro-B-type natriuretic peptide, New York Heart Association class III–IV, several comorbidities and therapies. Receiver operating characteristics curves identified LVEF values 32% and 31% as the best cut-offs for the two endpoints. The 40% and lower cut-offs (35%, 32% or 31%) were independent predictors of all-cause and cardiovascular death (p < 0.001 in all cases). The 35% cut-off had a lower Akaike's Information Criterion value than 40%, denoting more accurate risk stratification. Conclusions: LVEF is an independent predictor of all-cause and cardiovascular mortality in chronic systolic HF. The 35% LVEF cut-off displays a better combination of sensitivity and specificity than the 40% cut-off for outcome prediction, although both hold independent prognostic value
Soluble ST2 in Heart Failure: A Clinical Role beyond B-Type Natriuretic Peptide
No full text: Soluble (s)ST2 has been proposed as a useful biomarker for heart failure (HF) patient management. Myocardial damage or mechanical stress stimulate sST2 release. ST2 competes with a membrane bound receptor (ST2 ligand, or ST2L) for interleukin-33 (IL-33) binding, inhibiting the effects induced by the ST2L/IL-33 interaction so that excessive sST2 may contribute to myocardial fibrosis and ventricular remodeling. Compared to natriuretic peptides (NPs), sST2 concentration is not substantially affected by age, sex, body mass index, kidney function, atrial fibrillation, anemia, or HF etiology, and has low intra-individual variation. Its prognostic role as an independent marker is well reported in the literature. However, there is a gap on its use in combination with NPs, currently the only biomarkers recommended by European and American guidelines for HF management. Reflecting the activation of two distinct biological systems, a benefit from the use of sST2 and NP in combination is advocated. The aim of this review is to report the current scientific knowledge on sST2 in the acute and chronic HF settings with a particular attention to its additive role to natriuretic peptides (NPs)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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