1,721,351 research outputs found

    Feasibility and safety of transcaval transcatheter aortic valve implantation: a multicentre European registry

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    AIMS A transfemoral transarterial approach is considered the preferable access route for transcatheter aortic valve implantation (TAVI), followed by a transaxillary/subclavian TAVI approach. However, these approaches may not be an option in all patients. This study aimed to report the initial European experience with transfemoral transcaval TAVI. METHODS AND RESULTS Data on 50 patients treated by transcaval TAVI in five European centres were collected and analysed according to the Valve Academic Research Consortium (VARC)-2 definitions. The study population had a mean age of 78.7±8.0 years and a high surgical risk profile (median STS risk score 6.1%, interquartile range 3.0-11.2%). Transcaval access was successful in 49 out of 50 patients and device success was obtained in 94% of cases. Closure of the caval-aortic puncture site with a nitinol cardiac occluder was successful in all cases without need for emergent surgery. One patient received additional sealing of the aortic puncture site with a covered stent one day post TAVI due to a gradual haemoglobin drop of 3 g/dL. VARC-2-defined life-threatening bleeding and major vascular complications possibly related to transcaval access were 4% and 10%, respectively. There were no bleeding or vascular complications after discharge. At 30 days, the clinical efficacy endpoint was reached in 88% of patients. CONCLUSIONS Transfemoral transcaval access proved to be a feasible and safe TAVI approach for high-risk patients with severe aortic stenosis not suitable for transfemoral or transaxillary/subclavian transarterial access

    Redo-Transcatheter Aortic Valve Implantation Using the SAPIEN 3/Ultra Transcatheter Heart Valves—Expert Consensus on Procedural Planning and Techniques

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    Recent guidelines on valvular heart disease in Europe and the United States have expanded the indications for transcatheter aortic valve implantation (TAVI) to younger patients and those at lower surgical risk with severe symptomatic aortic stenosis. Consequently, the number of TAVI procedures will significantly increase worldwide. Patients with longer life expectancies will outlive their transcatheter heart valves (THVs) and require established treatment strategies for re-intervention. Current data have shown encouraging outcomes, including low mortality, with redo-TAVI; in contrast, surgical explantation of THVs is associated with high mortality. Redo-TAVI, therefore, is likely to be the treatment of choice for THV failure. The expected increase in the number of redo-TAVIs stands in contrast to the current lack of evidence on how this procedure should be planned and performed, including the risks and pitfalls operators need to consider. Preliminary reports stress the importance of preprocedural planning, understanding of THV skirt and leaflet characteristics, and implantation guidelines specific to different THVs. Currently, SAPIEN 3/Ultra is the only THV approved in Europe and the United States for redo-TAVI. Therefore, we gathered a panel of experts in TAVI procedures with the aim of providing operative guidance on redo-TAVI, using the SAPIEN 3/Ultra THV. This consensus article presents a step-by-step approach encompassing clinical, anatomical, and technical aspects in preprocedural planning, procedural techniques, and postprocedural care. In conclusion, the recommendations aim to improve the feasibility, safety, and long-term outcomes of redo-TAVI, including the durability of implanted THVs.</p

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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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