1,721,003 research outputs found
Diagnostic testing to guide the management of chronic thromboembolic pulmonary hypertension: state of the art
No full textChronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening and debilitating disease affecting up to 5% of survivors of pulmonary embolism. Diagnostic testing is important to distinguish it from other forms of pulmonary hypertension and to assess the feasibility of pulmonary endarterectomy. This review provides an up-to-date perspective on the diagnosis and assessment of the disease. Patients with CTEPH often have a history of pulmonary embolism, deep-vein thrombosis, thrombophilia, splenectomy, ventriculo-atrial shunt, inflammatory bowel disease or malignancy. Chest radiography may reveal pulmonary infarcts. CTEPH is often diagnosed as a wedge-shaped perfusion defect with normal ventilation scan during ventilation–perfusion scintigraphy, but multi-slice computed tomography angiography may be needed for differential diagnosis. Right heart catheterisation is required for diagnostic confirmation. Suitability for surgery is assessed by evaluating the number of obstructed vessels which could be disobliterated in the context of the pulmonary vascular resistance. Pulmonary vascular resistance that is out of proportion to evident obstructions is indicative of distal disease. Conventional pulmonary angiography, multi-slice computed tomography angiography and, potentially, magnetic resonance imaging can aid the decision to operate, but risk stratification systems are needed. In conclusion, CTEPH can be cured surgically, providing that patients are diagnosed and assessed using the appropriate techniques
Bosentan effects in inoperable forms of chronic thromboembolic pulmonary hypertension Study Group. Bosentan for treatment of inoperable chronic thromboembolic pulmonary hypertension: BENEFiT (Bosentan Effects in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension), a randomized, placebo-controlled trial
No full textObjectives Our goal was to investigate the effect of treatment with the oral dual endothelin receptor antagonist bosentan on the
hemodynamics and exercise capacity of patients with chronic thromboembolic pulmonary hypertension (CTEPH).
Background CTEPH is characterized by vascular obstruction and remodeling, leading to increased pulmonary vascular resistance
(PVR). Although pulmonary endarterectomy (PEA) is potentially curative, medical therapy is needed in patients
with inoperable disease or persistent/recurrent pulmonary hypertension after PEA.
Methods The BENEFiT (Bosentan Effects in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension) study
was a double-blind, randomized, placebo-controlled study in CTEPH including patients with either inoperable
CTEPH or persistent/recurrent pulmonary hypertension after PEA (6 months after PEA). Independent coprimary
end points were change in PVR as a percentage of baseline and change from baseline in 6-min walk distance
after 16 weeks of treatment with bosentan or placebo. Secondary end points included change from baseline in
World Health Organization functional class and other hemodynamic parameters.
Results One hundred fifty-seven patients were enrolled and randomized: 80 to placebo, 77 to bosentan. A statistically
significant treatment effect (TE) of bosentan over placebo on PVR was demonstrated: 24.1% of baseline (95%
confidence interval [CI]: 31.5% to 16.0%; p 0.0001). Total pulmonary resistance (TE: 193 dyn·s·cm5;
95% CI: 283 to 104 dyn·s·cm5; p 0.0001) and cardiac index (TE: 0.3 l·min1·m2; 95% CI: 0.14 to 0.46
l·min1·m2; p 0.0007) improved. Mean TE on 6-min walk distance was 2.2 m (95% CI: 22.5 to 26.8 m;
p 0.5449). Bosentan treatment was well tolerated.
Conclusions This study demonstrated a positive TE of bosentan on hemodynamics in this patient population. No improvement was
observed in exercise capacity. Further trials are needed to define the role of medical therapy in patients with CTEPH
(Bosentan Effects in Inoperable Forms of Chronic Thromboembolic Pulmonary Hypertension; NCT00313222).
(J Am Coll Cardiol 2008;52:2127–34) © 2008 by the American College of Cardiology Foundatio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
S21 Objective and patient reported outcomes of long term management of patients with chronic thromboembolic pulmonary hypertension (CTEPH): a single centre experience
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
Pulmonary hypertension associated with lung diseases
Get PDFPulmonary hypertension (PH) associated with chronic lung disease (CLD) is both common and underrecognised. The presence of PH in the setting of lung disease has been consistently shown to be associated with worse outcomes. Recent epidemiological studies have advanced understanding of the heterogeneity of this patient population and shown that defining both the specific type of CLD as well as the severity of PH (i.e. deeper phenotyping) is necessary to inform natural history and prognosis. A systematic diagnostic approach to screening and confirmation of suspected PH in CLD is recommended. Numerous uncontrolled studies and one phase 3 randomised, controlled trial have suggested a benefit in treating PH in some patients with CLD, specifically those with fibrotic interstitial lung disease (ILD). However, other studies in diseases such as COPD-PH showed adverse outcomes with some therapies. Given the expanding list of approved pharmacological treatments for pulmonary arterial hypertension, developing a treatment algorithm for specific phenotypes of PH-CLD is required. This article will summarise existing data in COPD, ILD and other chronic lung diseases, and provide recommendations for classification of PH-CLD and approach to the diagnosis and management of these challenging patients
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