1,721,021 research outputs found
A meta-analysis of minimally invasive versus conventional sternotomy for aortic valve replacement
Full text linkMinisternotomy or minithoracotomy for minimally invasive aortic valve replacement: a Bayesian network meta-analysis
Full text linkEstablishing the relative merits of ministernotomy (MS) and minithoracotomy (MT) approaches to minimally invasive aortic valve replacement (MIAVR) is difficult given the limited available direct evidence. Network meta-analysis is a Bayesian approach that can combine direct and indirect evidence to better define the benefits and risks of MS and MT
Early hemodynamic performance of the third generation St Jude Trifecta aortic prosthesis: A systematic review and meta-analysis
Full text linkThe Trifecta aortic prosthesis is a latest-generation trileaflet stented pericardial valve designed for supra-annular placement in the aortic position. Robust clinical evidence and long-term follow-up data for this new prosthesis are lacking; a systematic review was conducted to assess current evidence
Minimally invasive reoperative aortic valve replacement: a systematic review and meta-analysis
Full text linkWith prolonged life expectancy and more frequent use of biological prostheses, an increasingly higher proportion of patients are undergoing aortic valve replacement (AVR) after previous sternotomy. We critically appraised the quantity and quality of evidence to demonstrate the efficacy and safety of the minimally invasive (MIrAVR) versus conventional (CrAVR) approaches for reoperative AVR
Transcatheter aortic valve implantation (TAVI) versus sutureless aortic valve replacement (SUAVR) for aortic stenosis: a systematic review and meta-analysis of matched studies
No full textWith improving technologies and an increasingly elderly populations, there have been an increasing number of therapeutic options available for patients requiring aortic valve replacement. Recent evidence suggests that transcatheter aortic valve implantation (TAVI) is one suitable option for high risk inoperable patients, as well as high risk operable patients. Sutureless valve technology has also been developed concurrently, with facilitates surgical aortic valve replacement (SUAVR) by allow resection and replacement of the native aortic valve with minimal sutures and prosthesis anchoring required. For patients amenable for both TAVI and SUAVR, the evidence is unclear with regards to the benefits and risks of either approach. The objectives are to compare the perioperative outcomes and intermediate-term survival rates of TAVI and SUAVR in matched or propensity score matched studies
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
Transcatheter valve-in-valve implantation versus reoperative conventional aortic valve replacement : a systematic review
Full text linkTranscatheter valve-in-valve (VIV) implantation for degenerated aortic bioprostheses has emerged as a promising alternative to redo conventional aortic valve replacement (cAVR). However there are concerns surrounding the efficacy and safety of VIV. This systematic review aims to compare the outcomes and safety of transcatheter VIV implantation with redoes cAVR. Six databases were systematically searched. A total of 18 relevant studies (823 patients) were included. Pooled analysis demonstrated VIV achieved significant improvements in mean gradient (38 mmHg preoperatively to 15.2 mmHg postoperatively, P<0.001) and peak gradient (59.2 to 23.2 mmHg, P=0.0003). These improvements were similar to the outcomes achieved by cAVR. The incidence of moderate paravalvular leaks (PVL) were significantly higher for VIV compared to cAVR (3.3% vs. 0.4%, P=0.022). In terms of morbidity, VIV had a significantly lower incidence of stroke and bleeding compared to redo cAVR (1.9% vs. 8.8%, P=0.002 & 6.9% vs. 9.1%, P=0.014, respectively). Perioperative mortality rates were similar for VIV (7.9%) and redo cAVR (6.1%, P=0.35). In conclusion, transcatheter VIV implantation achieves similar haemodynamic outcomes, with lower risk of strokes and bleeding but higher PVL rates compared to redo cAVR. Future randomized studies and prospective registries are essential to compare the effectiveness of transcatheter VIV with cAVR, and clarify the rates of PVLs.11 page(s
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
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