1,720,974 research outputs found
Transcatheter Aortic Valve Replacement for Pure Aortic Regurgitation in a Large and Noncalcified Annulus
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Predicting and improving outcomes of transcatheter aortic valve replacement in older adults and the elderly
No full textIntroduction: Indications for transcatheter aortic valve replacement (TAVR) are progressively extending
to younger and lower risk patients. In this scenario, minimizing periprocedural complications and
optimizing procedural result are both crucial to achieve an excellent long-term outcome.
Areas covered: In this review, we summarize the main strategies that can be adopted before, during,
and after TAVR to predict and prevent complications, to optimize procedural results and ultimately
improve outcomes, with an emphasis on more recent evidence, new devices, and new techniques.
Expert opinion: In the next future TAVR will probably represent the first treatment option for patients
affected by aortic valve stenosis who are candidates to receive a biological valve. Continuous refinement
of TAVR devices has been key to allow safer and most effective procedures and further progress is
expected. Development of new techniques and devices, such as ultrasound-guided puncture and
intravascular lithotripsy, will expand safety and eligibility to transfemoral procedures. Effective preemptive
measures for coronary occlusion have been developed. Open issues include cerebral protection,
re-access to coronary arteries, post-procedural management, and therapy
Sino-tubular junction to sinuses of Valsalva ratio: An echocardiographic parameter to predict coronary artery ectasia in patients with aortic enlargement
No full textBACKGROUND: Coronary artery ectasia (CAE) is associated with ascending aortic (AA) ectasia. The purpose of this study is to evaluate the diagnostic performance of different echocardiographic parameters (EP) in predicting the presence of CAE. METHODS: Four hundred-eighteen patients with AA ectasia candidate to coronary angiography were identified and divided in two groups in respect of the presence of CAE. Receiver-operating characteristic curves areas (AUC) were used to assess the discrimination power of the following EP: aortic annulus diameter, sinuses of Valsalva (SV) diameter, sino-tubular junction (STJ) diameter, AA diameter, STJ to SV ratio (STJ-to-SV) and STJ to AA ratio (STJ-to-AA). All these parameters were indexed by body surface area. The relationship between the best EP and the presence of CAE was investigated by means of multivariable logistic regression. RESULTS: The rate of CAE in the study population was 32%. On univariable logistic regression, aortic annulus, STJ, STJ-to-SV and STJ-to-AA were associated with the presence of CAE after Bonferroni correction. STJ-to-SV emerged as the parameter with the best discrimination power (AUC = 0.81) compared to STJ (AUC = 0.69), STJ-to-AA (AUC = 0.68), aortic annulus (AUC = 0.59), AA (AUC = 0.56) and SV (AUC = 0.55); (p for comparison <0.01). An 89.6% value for STJ-to-SV ratio emerged as the best cut-off to diagnose CAE with a sensitivity = 75%, specificity = 82%, positive predictive value = 66% and negative predictive value = 88%. On multivariable analysis, STJ-to-SV was still associated with the presence of CAE (OR = 1.15;95%CI:1.11-1.19;p < 0.01). CONCLUSION: In patients with dilated aorta, STJ-to-SV sampled by transthoracic echocardiography shows a good diagnostic performance in predicting the presence of CAE
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
Off-label use of balloon-expandable transcatheter valves to treat pure aortic regurgitation
Full text linkBackground
Transcatheter aortic valve implantation (TAVI) in pure severe aortic regurgitation (AR) is challenging, as dedicated devices are not widely available. Off-label use of transcatheter heart valves (THVs) approved for the treatment of aortic stenosis has been reported. When balloon-expandable valves (BEV) are preferred, oversizing with respect to the annulus is necessary, but there is scant data regarding optimal oversizing. The study assesses BEV oversizing and outcomes of TAVI with BEV in pure AR.
Methods
Consecutive patients undergoing transfemoral TAVI in pure AR with Sapien BEV at our centre between 2019 and 2023 were included. Bicuspid (BAV) and tricuspid (TAV) aortic valves were analyzed separately. The aim was to implant a valve with 20-30% oversizing with respect to the annulus. TAV were divided into small annulus group (≤618mm2, SA) where ≥20% oversizing is achievable based on published data on BEV overexpansion and larger annulus group (LA, >618mm2). Overexpansion and oversizing were measured on post-procedural CT. Procedural and clinical outcomes were analyzed using the VARC-3 criteria.
Results
Seventeen patients were identified (76.5% males, mean age 79.2 years, STS 3.8%, TAV 13 patients). Mean aortic valvular calcium volume was: TAV=15.4mm3 and BAV=171.0mm3 (p=0.001). Technical success was 94.1% with one valve embolisation in TAV LA group. Mild paravalvular leak (PVL) was more frequent in BAV (p=0.0088). The post-procedural CT in TAV patients showed a mean 28.3% oversizing, significantly higher in SA (31.2%) then in LA group (19.4%), p= 0.0092. Oversizing ≥20% was achieved in 100% SA vs 33.3% LA patients (p=0.046). In LA patients the implanted BEVs were significantly more overexpanded than in SA group (10.8% vs 22.3%, p=0.0119)
In-hospital mortality was 5.9%. There was no difference in 1-year mortality between groups.
Conclusions
TAVI in pure AR with oversized Sapien BEV showed good procedural and short-term outcomes when ≥20% oversizing was predictably achievable
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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