1,720,966 research outputs found
Clinical and Hemodynamic Results after Transcatheter Aortic Valve implantation (TAVI): Early and Late (10-year) follow-up
Full text linkTranscatheter aortic valve implantation (TAVI) has become the treatment of choice in patients with severe symptomatic aortic stenosis (AS) considered inoperable or at high surgical risk. More recently, TAVI has been performed also to lower risk patients based on the Heart Team decision. Few studies have studied interaction between surgical risk categories and outcomes.
Aim of the study
To analyze safety and efficacy (VARC-2 defined) TAVI treated patients as function of different preoperative risk. To assess independent predictors of death.
Methods
Four-hundred-eighty-two patients who underwent TAVI in our center between 2007 and 2017 were included in the study. According to Society of Thoracic Surgeons (STS) score and to other parameters, all the patients were retrospectively stratified into 4 groups: prohibitive (contraindications to aortic valve replacement, n = 124), high (STS > 8, n = 131), intermediate (4 ≤ STS ≤ 8, n = 112) and low (STS < 4, n = 115) risk. Early, 1-year and long-term outcomes have been evaluated in those 4 groups according the VARC 2 criteria.
Results
The TAVI procedure resulted to be safe because of low mortality rate throughout all risk groups. The lowest 30-days mortality rate was observed in low and prohibitive-risk patients (p=0.048). In the low risk group, in-hospital mortality was 0%. The results were similar at 1-year of follow-up, with a mortality rate of 6% and 7% in low- and prohibitive-risk patients vs 21% and 19% in intermediate- and high-risk groups, (p<0.008). At 5-year of follow-up the mortality rate was 52% and it appeared to be lower only in low-risk patients at long-term follow-up. Independent predictors of mortality were pre-procedural congestive heart failure (CHF), neoplastic disease, pre-procedural-creatinine, post-procedural major or life threatening bleeding and post-procedural acute kidney injury (AKI). Implanted prosthesis performed well with stable hemodynamic results over time and rare dysfunction (2.1%).
Conclusions
In our study population, TAVI was safe and effective, with low rates of mortality and adverse events regardless of the surgical risk. At longer follow-up mortality rate was significantly lower in low-risk patients. Pre-procedural CHF, neoplastic diseases, pre-procedural creatinine, post-procedural severe bleedings and post-procedural AKI were independent predictors of mortality. Transcatheter heart valves (THV) performance after the procedure was excellent and stable over time with low rate of late prosthesis dysfunction. Further studies should be addressed to confirm the promising long-term results among low-risk patients and the long-term durability of THV
The SAPIEN 3 valve: lights and shadows.
No full textTranscatheter aortic valve implantation (TAVI) has become an accepted alternative treatment option for high-risk or inoperable patients with symptomatic severe aortic stenosis. The future challenge for TAVI devices is to ensure results in terms of safety and efficacy that may justify an eligibility extension for this procedure to patients at intermediate and low risk for surgery. The ideal aortic valve prosthesis should be durable, with optimal hemodynamic performance and able to reduce the current major complications of TAVI procedure, in particular vascular complications (not infrequent with the transfemoral access route), paravalvular leaks, stroke and atrioventricular block requiring a permanent pacemaker. The SAPIEN 3 (TM) (S3) (Edwards Lifesciences, Irvine, CA, USA) is the last Edwards family's transcatheter heart valves and incorporates a number of new and enhanced features intended to reduce the risk of vascular injury and paravalvular regurgitation, and to facilitate rapid and accurate positioning and implantation. The first data on S3 (SAPIEN3 trial) were presented at the EuroPCR 2014 and confirmed the advantage of the S3 compared with the previous Edwards valves (SAPIEN and SAPIEN XT) in terms of prevention of vascular complications and of moderate-severe paravalvular leaks, but showed an increase in the need of a permanent pacemaker post-TAVR. The S3 is certainly a promising evolution of transcatheter valves which may effectively reduce the risk of vascular complications and paravalvular leak. However, the S3 seems to be related to an increased risk of atrioventricular block, even if this complication could be due to the need to implant the valve in a higher position compared to previous models
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
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
Six-year clinical outcomes of first-generation drug-eluting stents: a propensity-matched analysis.
No full textOBJECTIVE:
Drug-eluting stents are more effective in reducing restenosis than bare-metal stents. Paclitaxel-eluting stents (PES) and sirolimus-eluting stents (SES) are the most widely used first-generation drug-eluting stents, but long-term comparative data on these are scant. The aim of the present report is to investigate the 6-year clinical outcomes of PES versus SES in a matched cohort of single-center registry patients.
MATERIALS AND METHODS:
Data were obtained from the observational, monocentric registry of 632 consecutive patients who underwent percutaneous coronary intervention between September 2002 and September 2005 with PES or SES. We assessed the composite and separate occurrence of the major adverse cardiac events (MACE), including death, nonfatal myocardial infarction, and target lesion revascularization (TLR).
RESULTS:
After a propensity 1 : 1 matching analysis, baseline clinical, procedural, and angiographic characteristics were well balanced between the two groups. Throughout the 6 years of follow-up, there were no significant differences between PES and SES in terms of MACE (P=0.52), all-cause death (P=0.24), myocardial infarction (P=0.25), stent thrombosis (P=0.38), and TLR (P=0.68). The sensitivity analysis on the total unmatched population confirmed this result, the stent type not being predictive of MACE (PES vs. SES group, hazard ratio 0.97, 95% confidence interval 0.66-1.41, P=0.87) or TLR (PES vs. the SES group, hazard ratio 1.35, 95% confidence interval 0.69-2.64, P=0.38).
CONCLUSION:
In this 'real-life' registry, PES and SES showed a comparable safety and efficacy profile throughout the 6 years of follow-up. The increase in the rate of TLR was slow and comparable between the two groups, even though the 'late catch-up' phenomenon showed a different temporal pattern between PES and SES
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
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