1,720,974 research outputs found
Prognostic Relevance of Left Ventricular Myocardial Performance After Transcatheter Aortic Valve Replacement
Full text linkBACKGROUND:
The left-ventricular myocardial performance index Tei is an echocardiographic parameter that incorporates the information of systolic and diastolic time intervals. While the prognostic value of selected systolic and diastolic parameters is well established after transcatheter aortic valve replacement, the role of Tei has not been evaluated in this setting.
METHODS AND RESULTS:
Between August 2007 and December 2015, consecutive patients with symptomatic, severe aortic stenosis and transthoracic echocardiography pre- and post-transcatheter aortic valve replacement were considered eligible for this analysis. The primary end point was all-cause mortality at 1 year after transcatheter aortic valve replacement. Of 824 patients with echocardiographic images to calculate Tei, pre-Tei was normal (<0.45) in 639 and high (≥0.45) in 185, whereas post-Tei was normal in 602 and high in 120, respectively. After adjustment for confounding factors, high pre-Tei was associated with an increased risk of all-cause mortality at 30 days (adjusted hazard ratio [HRadj] 3.62; 95% CI, 1.89-6.91) and 1 year (HRadj 2.56; 95% CI, 1.78-3.69). Similarly, post-Tei was associated with an increased risk of mortality between 30 days and 1-year follow-up (HRadj 6.70; 95% CI, 4.22-10.63). At multivariable analysis Tei emerged as an independent predictor of early (pre-Tei index per 0.1-HRadj 1.40; 95% CI, 1.23-1.60) and late mortality (post-Tei index per 0.1-HRadj 1.40; 95% CI, 1.31-1.50), respectively.
CONCLUSIONS:
The left-ventricular myocardial performance index Tei is associated with impaired clinical outcomes during short- and longer-term follow-up after transcatheter aortic valve replacement
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
Surgical antegrade transcatheter mitral valve implantation for symptomatic mitral valve disease and heavily calcified annulus.
Full text linkSurgical techniques for the treatment of mitral valve disease (MVD) have continuously evolved; however, anatomical details like severe annular calcification remain challenging and require sophisticated surgical strategies. Among patients with symptomatic MVD referred for surgical valve repair or replacement, four presented with circumferential calcification of the mitral annulus precluding conventional surgical techniques. Successful treatment by implanting a balloon-expandable transcatheter aortic heart valve using an antegrade surgical access was performed. The perioperative course and follow-up assessment (19.3 ± 21 months) were uneventful. Echocardiographic assessment confirmed a well-seated valve with normal function (mean 4.5 ± 0.6 mmHg). Surgical mitral valve replacement using a balloon-expandable transcatheter aortic bioprosthesis can be a valuable and attractive bailout strategy in patients with a heavily calcified mitral annulus
Frequency, Timing, and Impact of Access-Site and NonâAccess-Site Bleeding on Mortality Among Patients Undergoing Transcatheter Aortic Valve Replacement
Full text linkOBJECTIVES
The aim of this study was to examine the frequency, timing, and association of access-site and non-access-site bleeding with mortality in the setting of transcatheter aortic valve replacement (TAVR) during long-term follow-up.
BACKGROUND
Bleeding is frequent and associated with impaired prognosis in patients undergoing TAVR. It is currently unknown whether the site of bleeding differentially influences the outcomes of TAVR patients.
METHODS
In total, 926 consecutive patients undergoing TAVR from 2007 through 2014 were evaluated. Bleeding was assessed according to the Valve Academic Research Consortium 2 criteria. The primary outcome of interest was all-cause mortality up to 5 years of follow-up.
RESULTS
A total of 285 patients (30.7%) experienced at least 1 (minor, major, or life-threatening) bleeding event up to 5 years. Compared with patients not experiencing bleeding, the adjusted risk for all-cause mortality was significantly increased among patients with access-site (hazard ratio: 1.34; 95% confidence interval: 1.01 to 1.76; p = 0.04) and non-access-site bleeding (hazard ratio: 2.08; 95% confidence interval: 1.60 to 2.71; p < 0.001). However, non-access-site bleeding conferred a significantly higher risk for mortality compared with access-site bleeding (hazard ratio: 1.56; 95% confidence interval: 1.12 to 2.18; p = 0.009). At multivariate analysis, female sex was a significant correlate of access-site bleeding, whereas chronic kidney disease and the Society of Thoracic Surgeons score were significantly associated with non-access-site bleeding.
CONCLUSIONS
Among patients with severe aortic stenosis undergoing TAVR, access-site and non-access-site bleeding were independently associated with an increased risk for mortality, with the greatest risk related to non-access-site bleeding during long-term follow-up
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
