Aims: Aortic regurgitation (AR) after Medtronic CoreValve System (MCS) implantation may be explained by patient-, operator- and procedure-related factors. We sought to explore if frame geometry, as a result of a specific device-host interaction, contributes to AR.
Methods And Results: Using rotational angiography with dedicated motion compensation, we assessed valve frame geometry in 84 patients who underwent TAVI with the MCS. Aortic regurgitation was assessed by angiography (n=84, Sellers) and echocardiography at discharge (n=72, VARC-2). Twenty-two patients (26%) had AR grade ≥2 using contrast angiography, and 17 (24%) by echocardiography. Balloon predilatation and sizing and depth of implantation did not differ between the two groups. Despite more frequent balloon post-dilatation in patients with AR (40.9 vs. 9.7%, p=0.001), the frame was more elliptical at its nadir relative to the patient's annulus (6±13 vs. -1±11%, p=0.046) and occurred in a larger proportion of patients (61.9 vs. 26.8%, p=0.004). Although the Agatston score and the eccentricity of the MCS frame relative to the annulus were independent determinants of AR (odds ratio: 1.635 [1.151-2.324], p=0.006, and 4.204 [1.237-14.290], p=0.021), there was a weak association between the Agatston score and the adjusted eccentricity (Spearman's rank correlation coefficient =-0.24, p=0.046).
Conclusions: These findings indicate that AR can be explained by a specific device-host interaction which can only partially be explained by the calcium load of the aortic root.
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http://dx.doi.org/10.4244/EIJY15M08_02 | DOI Listing |
Polymers (Basel)
January 2025
Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, 16500 Prague, Czech Republic.
This article is a numerical and experimental study of the mechanical properties of different glass, flax and hybrid composites. By utilizing hybrid composites consisting of natural fibers, the aim is to eventually reduce the percentage usage of synthetic or man-made fibers in composites and obtain similar levels of mechanical properties that are offered by composites using synthetic fibers. This in turn would lead to greener composites being utilized.
View Article and Find Full Text PDFPediatr Cardiol
January 2025
School of Medicine, Children's Hospital Colorado, The Heart Institute, University of Colorado Denver|Anschutz Medical Campus, 13123 E 16Th Ave, Box 100, Aurora, CO, 80045-2560, USA.
Though major complications during transcutaneous pulmonary valve replacement (TPVR) are rare, clinically-significant ventricular arrythmia (CSVA) has been reported following self-expanding valve placement. We assess whether alterations in valve frame dimensions and geometry within the right ventricular outflow tract (RVOT) post-implantation in patients who underwent TPVR with Harmony TPV25 or Alterra contribute to CSVA risk. A single center review was performed of patients who underwent TPVR with either Harmony TPV25 or Alterra Pre-stent between August 2019 and April 2023.
View Article and Find Full Text PDFBiol Cybern
January 2025
CIAMS, Université Paris-Saclay, Orsay & Université d'Orléans, Orléans, France.
According to the Projective Consciousness Model (PCM), in human spatial awareness, 3-dimensional projective geometry structures information integration and action planning through perspective taking within an internal representation space. The way different perspectives are related to and transform a world model defines a specific perception and imagination scheme. In mathematics, such a collection of transformations corresponds to a 'group', whose 'actions' characterize the geometry of a space.
View Article and Find Full Text PDFHeliyon
January 2025
Civil Engineering Department, University of Technology, Baghdad, Iraq.
The foundation of the turbo-generator comprises a generator, turbine, and associated equipment situated on the top of the frame foundation, which consists of a bottom raft, top deck, and columns. The current study examines how the geometrical characteristics of the frame foundation, such as slab thickness, column dimensions, and length, affect the dynamic displacement response and the natural frequencies of the frame foundation. The work is done through 3-D dynamic modal and harmonic analyses using Ansys Workbench finite element software.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Industrial Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates.
Despite the extensive literature revealing various core structures that can enhance the impact resistance of composite panels, a comparative study illustrating the difference in performance of the various cores under same loading conditions is missing. The aim of this study is to determine the optimal core structure and design in terms of energy absorption under low-velocity impact using both numerical simulations and experimental testing for validation. Response surface analysis was used to design the experiments and analyse the panel's behaviour.
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