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761 results on '"Simoni, G"'

1. Tunable Thermoelectric Superconducting Heat Pipe and Diode

Author

Antola, F., Braggio, A., De Simoni, G., and Giazotto, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Superconductivity
Abstract

Efficient heat management at cryogenic temperatures is crucial for superconducting quantum technologies. This study demonstrates the controlled manipulation of the heat flow and heat rectification through an asymmetric superconducting tunnel junction. The system exhibits a non-reciprocal behavior, developing a thermoelectric regime exclusively when the electrode with the larger gap is heated. This feature significantly boosts thermal rectification effectively classifying the device as a heat diode. At the same time when operating as a thermoelectric engine, the same device also functions as a heat pipe, expelling heat from the cryogenic environment, minimizing losses at the cold terminal. This dual functionality is inherently passive, and the performance of the heat pipe and the heat diode can be finely adjusted by modifying the external electrical load., Comment: 6 pages, 4 color figures

Published
2024
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2. Demonstration of high-impedance superconducting NbRe Dayem bridges

Author

Battisti, S., Koch, J., Paghi, A., Ruf, L., Gulian, A., Teknowijoyo, S., Cirillo, C., Kakhaki, Z. Makhdoumi, Attanasio, C., Scheer, E., Di Bernardo, A., De Simoni, G., and Giazotto, F.

Subjects
Condensed Matter - Superconductivity
Abstract

Here we demonstrate superconducting Dayem-bridge weak-links made of different stoichiometric compositions of NbRe. Our devices possess a relatively high critical temperature, normal-state resistance, and kinetic inductance. In particular, the high kinetic inductance makes this material a good alternative to more conventional niobium-based superconductors (e.g., NbN or NbTiN) for the realization of superinductors and high-quality factor resonators, whereas the high normal-state resistance yields a large output voltage in superconducting switches and logic elements realized upon this compound. Moreover, out-of-plane critical magnetic fields exceeding 2 T ensure that possible applications requiring high magnetic fields can also be envisaged. Altogether, these features make this material appealing for a number of applications in the framework of quantum technologies., Comment: 10 pages, 4 figures

Published
2023
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3. Estimation of the FR4 Microwave Dielectric Properties at Cryogenic Temperature for Quantum-Chip-Interface PCBs Design

Author

Paghi, A., Trupiano, G., Puglia, C., Burgaud, H., De Simoni, G., Greco, A., and Giazotto, F.

Subjects
Physics - Instrumentation and Detectors, Physics - Applied Physics
Abstract

Ad-hoc interface PCBs are today the standard connection between cryogenic cabling and quantum chips. Besides low-loss and low-temperature-dependent-dielectric-permittivity materials, FR4 provides a low-cost solution for fabrication of cryogenic PCBs. Here, we report on an effective way to evaluate the dielectric performance of a FR4 laminate used as substrate for cryogenic microwave PCBs. We designed a coplanar waveguide {\lambda}/2 open-circuit series resonator and we fabricated the PCB using a low-cost manufacturing process. Such a geometry allows to exploit the resonance peak of the resonator to measure the variation of the complex dielectric permittivity as a function of the temperature. Resonance peak frequency and magnitude were used as sensing parameters for the real part of dielectric permittivity and dielectric loss tangent, respectively. We estimated a 9 % reduction of the real part of the dielectric permittivity and a 70 % reduction of the dielectric loss tangent in the temperature range from 300 to 4 K. The proposed approach can be immediately extended to the detection of cryogenic temperature-dependent dielectric performance of any kind on substrate., Comment: 5 pages, 6 figures, supporting information at the end of the paper

Published
2023
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4. Gate-controlled Suspended Titanium Nanobridge Supercurrent Transistor

Author

Rocci, M., De Simoni, G., Puglia, C., Esposti, D. Degli, Strambini, E., Zannier, V., Sorba, L., and Giazotto, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Condensed Matter - Superconductivity
Abstract

In a family of experiments carried on all-metallic supercurrent nano-transistors a surprising gating effect has been recently shown. These include the full suppression of the critical supercurrent, the increase of quasiparticle population, the manipulation of the superconducting phase, and the broadening of the switching current distributions. Aside from the high potential for future applications, these findings raised fundamental questions on the origin of these phenomena. To date, two complementary hypotheses are under debate: an electrostatically-triggered orbital polarization at the superconductor surface, or the injection of highly-energetic quasiparticles extracted from the gate. Here, we tackle this crucial issue via a fully suspended gate-controlled Ti nano-transistor. Our geometry allows to eliminate any direct injection of quasiparticles through the substrate thereby making cold electron field emission through the vacuum the only possible charge transport mechanism. With the aid of a fully numerical 3D model in combination with the observed phenomenology and thermal considerations we can rule out, with any realistic likelihood, the occurrence of cold electron field emission. Excluding these two trivial phenomena is pivotal in light of understanding the microscopic nature of gating effect in superconducting nanostructures, which represents an unsolved puzzle in contemporary superconductivity. Yet, from the technological point of view, our suspended fabrication technique provides the enabling technology to implement a variety of applications and fundamental studies combining, for instance, superconductivity with nano-mechanics., Comment: 7 pages, 4 color figures

Published
2020
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5. Vanadium gate-controlled Josephson half-wave nanorectifier

Author

Puglia, C., De Simoni, G., Ligato, N., and Giazotto, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Superconductivity
Abstract

Recently, the possibility to tune the critical current of conventional metallic superconductors via electrostatic gating was shown in wires, Josephson weak-links and superconductor-normal metal-superconductor junctions. Here we exploit such a technique to demonstrate a gate-controlled vanadium-based Dayem nano-bridge operated as a \emph{half-wave} rectifier at $3$ K. Our devices exploit the gate-driven modulation of the critical current of the Josephson junction, and the resulting steep variation of its normal-state resistance, to convert an AC signal applied to the gate electrode into a DC one across the junction. All-metallic superconducting gated rectifiers could provide the enabling technology to realize tunable photon detectors and diodes useful for superconducting electronics circuitry., Comment: 5 pages, 4 figures

Published
2020
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6. Electrostatic control of phase slips in Ti Josephson nanotransistors

Author

Puglia, C., De Simoni, G., and Giazotto, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Superconductivity
Abstract

The investigation of the switching current probability distribution of a Josephson junction is a conventional tool to gain information on the phase slips dynamics as a function of the temperature. Here we adopt this well-established technique to probe the impact of an external static electric field on the occurrence of phase slips in gated all-metallic titanium (Ti) Josephson weak links. We show, in a temperature range between 20 mK and 420 mK, that the evolution of the phase slips dynamics as a function of the electrostatic field starkly differs from that observed as a function of the temperature. This fact demonstrates, on the one hand, that the electric field suppression of the critical current is not simply related to a conventional thermal-like quasiparticle overheating in the weak-link region. On the other hand, our results may open the way to operate an electrostatic-driven manipulation of phase slips in metallic Josephson nanojunctions, which can be pivotal for the control of decoherence in superconducting nanostructures., Comment: 9 pages, 7 color figures, 1 table

Published
2019
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8. A superconducting absolute spin valve

Author

De Simoni, G., Strambini, E., Moodera, J. S., Bergeret, F. S., and Giazotto, F.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

A superconductor with a spin-split excitation spectrum behaves as an ideal ferromagnetic spin-injector in a tunneling junction. It was theoretical predicted that the combination of two such spin-split superconductors with independently tunable magnetizations, may be used as an ideal $absolute$ spin-valve. Here we report on the first switchable superconducting spin-valve based on two EuS/Al bilayers coupled through an aluminum oxide tunnel barrier. The spin-valve shows a relative resistance change between the parallel and antiparallel configuration of the EuS layers up to 900% that demonstrates a highly spin-polarized currents through the junction. Our device may be pivotal for realization of thermoelectric radiation detectors, logical element for a memory cell in cryogenics superconductor-based computers and superconducting spintronics in general., Comment: 6 pages, 4 color figures, 1 table

Published
2018
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9. Metallic supercurrent field-effect transistor

Author

De Simoni, G., Paolucci, F., Solinas, P., Strambini, E., and Giazotto, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Superconductivity
Abstract

In their original formulation of superconductivity, the London brothers predicted the exponential suppression of an $electrostatic$ field inside a superconductor over the so-called London penetration depth, $\lambda_L$. Despite a few experiments indicating hints of perturbation induced by electrostatic fields, no clue has been provided so far on the possibility to manipulate metallic superconductors via field-effect. Here we report field-effect control of the supercurrent in $all$-metallic transistors made of different Bardeen-Cooper-Schrieffer (BCS) superconducting thin films. At low temperature, our field-effect transistors (FETs) show a monotonic decay of the critical current under increasing electrostatic field up to total quenching for gate voltage values as large as $\pm 40$V in titanium-based devices. This $bipolar$ field effect persists up to $\sim 85\%$ of the critical temperature ($\sim 0.41$K), and in the presence of sizable magnetic fields. A similar behavior was observed in aluminum thin film FETs. A phenomenological theory accounts for our observations, and points towards the interpretation in terms of an electric-field-induced perturbation propagating inside the superconducting film. In our understanding, this affects the pairing potential and quenches the supercurrent. These results could represent a groundbreaking asset for the realization of an $all$-metallic superconducting field-effect electronics and leading-edge quantum information architectures., Comment: 9 pages, 7 color figures, revised text version

Published
2017
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10. Revealing the magnetic proximity effect in EuS/Al bilayers through superconducting tunneling spectroscopy

Author

Strambini, E., Golovach, V. N., De Simoni, G., Moodera, J. S., Bergeret, F. S., and Giazotto, F.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

A ferromagnetic insulator attached to a superconductor is known to induce an exchange splitting of the Bardeen-Cooper-Schrieffer (BCS) singularity by a magnitude proportional to the magnetization, and penetrating into the superconductor to a depth comparable with the superconducting coherence length. We study this long-range magnetic proximity effect in EuS/Al bilayers and find that the exchange splitting of the BCS peaks is present already in the unpolarized state of the ferromagnetic insulator (EuS), and is being further enhanced when magnetizing the sample by a magnetic field. The measurement data taken at the lowest temperatures feature a high contrast which has allowed us to relate the line shape of the split BCS conductance peaks to the characteristic magnetic domain structure of the EuS layer in the unpolarized state. These results pave the way to engineering triplet superconducting correlations at domain walls in EuS/Al bilayers. Furthermore, the hard gap and clear splitting observed in our tunneling spectroscopy measurements indicate that EuS/Al bilayers are excellent candidates for substituting strong magnetic fields in experiments studying Majorana bound states., Comment: 9 pages, 4 color figures

Published
2017
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11. Delocalized-localized transition in a semiconductor two-dimensional honeycomb lattice

Author

De Simoni, G., Singha, A., Gibertini, M., Karmakar, B., Polini, M., Piazza, V., Pfeiffer, L. N., West, K. W., Beltram, F., and Pellegrini, V.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report the magneto-transport properties of a two-dimensional electron gas in a modulation-doped AlGaAs/GaAs heterostructure subjected to a lateral potential with honeycomb geometry. Periodic oscillations of the magneto-resistance and a delocalized-localized transition are shown by applying a gate voltage. We argue that electrons in such artificial-graphene lattices offer a promising approach for the simulation of quantum phases dictated by Coulomb interactions.

Published
2010
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12. Demonstration of high-impedance superconducting NbRe Dayem bridges.

Author

Battisti, S., Koch, J., Paghi, A., Ruf, L., Gulian, A., Teknowijoyo, S., Cirillo, C., Kakhaki, Z. Makhdoumi, Attanasio, C., Scheer, E., Di Bernardo, A., De Simoni, G., and Giazotto, F.

Subjects
CRITICAL temperature, MAGNETIC fields, ELECTRIC inductance, SUPERCONDUCTORS, RESONATORS, BRIDGES
Abstract

Here, we demonstrate superconducting Dayem-bridge weak-links made of different stoichiometric compositions of NbRe. Our devices possess a relatively high critical temperature, normal-state resistance, and kinetic inductance. In particular, the high kinetic inductance makes this material a good alternative to more conventional niobium-based superconductors (e.g., NbN or NbTiN) for the realization of superinductors and high-quality factor resonators, whereas the high normal-state resistance yields a large output voltage in superconducting switches and logic elements realized upon this compound. Moreover, out-of-plane critical magnetic fields exceeding 2 T ensure that possible applications requiring high magnetic fields can also be envisaged. Altogether, these features make this material appealing for a number of applications in the framework of quantum technologies. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Effects of fabrication routes and material parameters on the control of superconducting currents by gate voltage

Author

Ruf, L., primary, Elalaily, T., additional, Puglia, C., additional, Ivanov, Yu. P., additional, Joint, F., additional, Berke, M., additional, Iorio, A., additional, Makk, P., additional, De Simoni, G., additional, Gasparinetti, S., additional, Divitini, G., additional, Csonka, S., additional, Giazotto, F., additional, Scheer, E., additional, and Di Bernardo, A., additional

Published
2023
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17. Superconductors with a spin-splitting field: fundamentals and applications

Author

Bergeret, F. S., Golovach, V. N., Hijano, Alberto, Ilić, Stefan, Rouco, Mikel, Rogero, Celia, Ilin, M., Orellana, Pedro A., Giazotto, F., Strambini, E., Spies, M., De Simoni, G., Heikkilä, T. T., Virtanen, P., Silaev, M. A., and Moodera, J. S.

Abstract

Resumen del trabajo presentado a la Conference Low dimensional superconducting hybrids for novel quantum functionalities, celebrada en Paris (Francia) del 12 al 14 de octubre de 2021.

Published
2021

18. Gate Control of the Current-Flux Relation of a Josephson Quantum Interferometer Based on Proximitized Metallic Nanojuntions

Author

De Simoni G., Battisti S., Ligato N., Mercaldo M.T., Cuoco M., and Giazotto F.

Subjects
Josephson Effect, Superonducting Magnetometer, Condensed Matter::Superconductivity, Gated Metallic Superconductor, SNS, SQUID, Proximity Effect
Abstract

We demonstrate an Al superconducting quantum interference device in which the Josephson junctions are implemented through gate-controlled proximity Cu mesoscopic weak links. This specific kind of metallic weak links behaves analogously to genuine superconducting metals in terms of the response to electrostatic gating and provides a good performance in terms of current-modulation visibility. We show that through the application of a static gate voltage we can modify the interferometer current-flux relation in a fashion that seems compatible with the introduction of ?-channels within the gated weak link. Our results suggest that the microscopic mechanism at the origin of the suppression of the switching current in the interferometer is apparently phase coherent, resulting in an overall damping of the superconducting phase rigidity. We finally tackle the performance of the interferometer in terms of responsivity to magnetic flux variations in the dissipative regime and discuss the practical relevance of gated proximity-based all-metallic SQUIDs for magnetometry at the nanoscale.

Published
2021

20. Niobium Dayem nano-bridge Josephson gate-controlled transistors

Author

De Simoni, G., Puglia, C., and Giazotto, F.

Subjects
Computer Science::Hardware Architecture, Computer Science::Emerging Technologies, Condensed Matter::Superconductivity, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Abstract

We report on the realization of Nb-based all-metallic Dayem nano-bridge gate-controlled transistors (Nb-GCTs). These Josephson devices operate up to a temperature of ~ 3 K and exhibit full suppression of the supercurrent thanks to the application of a control gate voltage. The dependence of the kinetic inductance and of the transconductance on gate voltage promises a performance already on par with so far realized metallic Josephson transistors and leads us to foresee the implementation of a superconducting digital logic based on the Nb-GCT. We conclude by showing the practical realization of a scheme implementing an all-metallic gate-tunable half-wave rectifier to be used for either superconducting electronics or photon detection applications.

Published
2020

22. Reply

Author

Novelli, A., Grati, F. R., Ballarati, L., Bernardini, L., Bizzoco, D., Camurri, L., Casalone, R., Cardarelli, L., Cavalli, P., Ciccone, R., Clementi, M., Dalprà, L., Gentile, M., Gelli, G., Grammatico, P., Malacarne, M., Nardone, A. M., Pecile, V., Simoni, G., Zuffardi, O., and Giardino, D.

Published
2012
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23. Microarray application in prenatal diagnosis: a position statement from the cytogenetics working group of the Italian Society of Human Genetics (SIGU), November 2011

Author

Novelli, A., Grati, F. R., Ballarati, L., Bernardini, L., Bizzoco, D., Camurri, L., Casalone, R., Cardarelli, L., Cavalli, P., Ciccone, R., Clementi, M., Dalprà, L., Gentile, M., Gelli, G., Grammatico, P., Malacarne, M., Nardone, A. M., Pecile, V., Simoni, G., Zuffardi, O., and Giardino, D.

Published
2012
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31. Science Software 2019

Author

Muzzini V.G., Mattioni M., Calandrelli R., De Simoni G., Leonardi L., Rullo G., Menardi M.T., Canu S., Peruzzi E., and Ianniello L.

Subjects
Science Software
Abstract

IRET e? un Istituto che si occupa di ricerca sugli ecosistemi terrestri. Qualsiasi ricerca si basa su alcuni passi fondamentali per arrivare a produrre conclusioni scientificamente accettabili, ossia raccolta e produzione di dati, loro analisi e discussione dei risultati. Relativamente all'analisi dati, con l'aumento delle informazioni e dei dati raccolti (Big Data), per svolgere i calcoli necessari ed effettuare operazioni anche semplici su un gruppo di dati, e? necessario utilizzare un computer ed un software di analisi. Sono nati nel corso del tempo numerosi programmi scientifici per questo scopo, da quelli piu? semplici come Excel a quelli piu? complessi come Mathematica e Matlab, da quelli proprietari a quelli gratuiti e/o opensource come R. Questi ultimi, utilizzabili da chiunque in modo gratuito, vengono mantenuti e sviluppati dalla comunita? di ricercatori e sviluppatori. Per cercare di promuovere l'uso di programmi scientifici opensource nel nostro istituto, si e? deciso di procedere con una ricerca e selezionare i piu? "intuitivi" e diffusi programmi di analisi dati messi a disposizione per la comunita? scientifica. I criteri utilizzati per questa selezione di software scientifici sono essenzialmente due: - programmi open source o in alternativa gratuiti; - programmi multipiattaforma ovvero programmi che possano essere eseguiti sui tre maggiori sistemi operativi: windows, macintosh e linux

Published
2019

33. Meeting abstracts

Author

Agnifili A., Gola P., Guadagni S., Verzaro R., Carducci G., Gianfelice F., Ibi I., Marino M., Mancini E., De Bernardinis G., Allegri C., Spoletini F., Mariotti V., Vari A., Polinari U., Altomare D. F., Brienza E., Rinaldi M., Vicente-Prieta R., Memeo V., Bertolino F., Ceccopieri B., Nasi P. G., Porcellana V., Mattio R., Forconi S., Dellepiane M., Biccari V., Tedesco M., Matrone A. M., Sirovich I., Nicolanti V., Stipa S., Bonalumi U., Galleano R., Baiardi A., Balbi P., Simoni G., Calleri G., Casaldi, V., Cosimelli, M., Giannarelli, D., Botti, C., Mannella, E., Wappner, G., Cavaliere, R., Casale, V., Fracasso, P., Grassi, A., Lapenta, R., Stigliano, V., Nasi P. G., Cianciulli A. M., Antonaci S., Casale V., Greco C., Gandolfo G. M., Coco, C., Giordano, A., Roncolini, G., Mattana, C., Coppola, R., Magistrelli, P., Crespi C., De Giorgio A. M., Giuliani A., Galasso V., Truglia S., De Ligio F., De Ligio S., Serafino L., Limiti R., Arrabito G., Guadagni S., Palumbo G., Pantaleoni G., D'Alessandro V., Agnifili A., Carducci G., Mancini E., Marino M., Gola P., Gianfelice F., Verzaro R., Ibi I., Ranalletta D., Fanini R., De Bernardinis G., Huscher, C., Chiodini, S., Zamboni, F., Montorsi, M., Marchese C., Bertolino F., Ceccopieri B., Locatelli L., Mareni C., Mattio R., Scaglione D., Vanzetti M., Mascagni, D., Di Matteo, G., Hojo, K., Moriya, Y., Sugihara, K., Massidda, B., Nicolosi, A., Tarquini, A., Natalini, G., Borgognoni, F., Ranieri, S., Menculini, M., Carioni, G., Botti C., Cosimelli M., Casaldi V., Cavaliere R., Caporossi M., Huguet C., Chiavellati L., Cavallaro A., Pietroletti, R., Cianca, G., Barnabei, R., Simi, M., Romano G., Di Carlo A., Mariano A., D'Alessandro V., Rotondano G., Macchia V., Secco, G. B., Fardelli, R., Zoli, S., Lapini, C., Cariati, A., Prior, C., Sironi, I., Mietti, G., Arisi, B. A., Ferrari, G. C., Gasbacortat, M., Brusamolino, R., Bauer, D., Russo, A., Spinelli C., Berti P., Gori L., Materazzi G., Mucci M., Pierallini S., Miccoli P., Cosimeili M., Mannella E., Valabrega, S., Pozzi, G., De Angelis, R., D'Angelo, F., Indinnimeo, M., Aurello, P., Tabbi, P., Fegiz, G., Venezia, P., Colella, R., Pitzalis, M. V., Pitzalis, M., Vuolo, G., Di Cosmo, L., Grimaldi, L., Maglio, C., Masellis, D., and Carli, A.

Published
1994
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34. Miscellaneous II

Author

Farkas, J. -C., Lecompte, Th., Combe, S., Laurian, C., Samama, M. M., Cormier, J-M., Romo, H., Maldonado, A., Montenegro, C., Rubio, J. J., Chamorro, C., Romera, M. A., Nieto, M., Estecha, M. A., Molina, J. M., Lendinez, M. Jimenez, Pascual, C., Cerdeno, V., Yus, S., Lopez, J., Denia, R., Anon, J., Minuto, A., Sicignano, A., Vesconi, S., Foroni, C., Riboni, A., Altemir, F. Hernández, Voß, E., Strauß, R., Hahn, E. G., Schneider, M. U., Gianotti, A., Simoni, G., Ardia, A., de Lassence, A., Beaune, J., Fleury, J., Escudier, E., Cordonnier, C., Roche, N., Verdière, B., Moret, G., Boule, D., Ngwintin, L., Bazin, C., Fraisse, F., Klementaviĉienê, J., Lukoŝeviĉiutê, A., Xirgu, J., Torrabadella, P., Klamburg, J., Payá, J. M., Galan, A., Velasco, P., Challiner, A. J., Smith, G. B., Redke, Finn, Björkman, Sven, Vernersson, Einar, Ferrer, P., Tormo, C., Albiñana, G., Vega, E., Sesma, R., Pérez, C., Arroyo, J., García, I., Sánchez, A., Santman, F. W., Grootendorst, A. F., Hulstaert, P. F., and Wigant, C.

Published
1992
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40. Revealing the magnetic proximity effect in EuS/Al bilayers through superconducting tunneling spectroscopy

Author

Massachusetts Institute of Technology. Department of Physics, Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology), Moodera, Jagadeesh, Strambini, E., Golovach, V. N., De Simoni, G., Bergeret, F. S., Giazotto, F., Massachusetts Institute of Technology. Department of Physics, Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology), Moodera, Jagadeesh, Strambini, E., Golovach, V. N., De Simoni, G., Bergeret, F. S., and Giazotto, F.

Abstract

A ferromagnetic insulator in contact with a superconductor is known to induce an exchange splitting of the singularity in the Bardeen-Cooper-Schrieffer (BCS) density of states (DoS). The magnitude of the splitting is proportional to the exchange field that penetrates into the superconductor to a depth comparable with the superconducting coherence length and which ranges in magnitude from a few to a few tens of tesla. We study this magnetic proximity effect in EuS/Al bilayers and show that the domain structure of the EuS affects the positions and the line shapes of the exchange-split BCS peaks. Remarkably, a clear exchange splitting is observed even in the unmagnetized state of the EuS layer, suggesting that the domain size of the EuS is comparable with the superconducting coherence length. Upon magnetizing the EuS layer, the splitting increases while the peaks change shape. Conductance measurements as a function of bias voltage at the lowest temperatures allowed us to relate the line shape of the split BCS DoS to the characteristic domain structure in the ultrathin EuS layer. These results pave the way to engineering triplet superconducting correlations at domain walls in EuS/Al bilayers. Furthermore, the hard gap and large splitting observed in our tunneling spectroscopy measurements make EuS/Al an excellent candidate for substituting strong magnetic fields in experiments studying Majorana bound states.

Published
2018

42. P20.10: Risk of fetal loss in pregnancies undergoing mid-trimester amniocentesis after inconclusive chorionic villus sampling

Author

Salsi, G., primary, Grati, F., additional, Bellussi, F., additional, Pompilii, E., additional, Maggi, F., additional, Simoni, G., additional, D'Ambrosi, F., additional, Orsi, M., additional, Fanelli, T., additional, Rembouskos, G., additional, Volpe, P., additional, Gentile, M., additional, Persico, N., additional, and Pilu, G., additional

Published
2018
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43. Severity of Asymptomatic Carotid Stenosis and Risk of Ipsilateral Hemispheric Ischaemic Events: Results from the ACSRS Study

Author

Nicolaides, A, Kakkos, S, Griffin, M, Sabetai, M, Dhanjil, S, Tegos, T, Thomas, D, Giannoukas, A, Geroulakos, G, Georgiou, N, Francis, S, Ioannidou, E, Doré, C, Adovasio, R, Ziani, B, Aló, E, Cicilioni, C, Ambrosio, G, Andreev, A, Andreozzi, G, Verlato, F, Camporese, G, Arosio, E, Barkauskas, E, Barros D'Sa, A, Brannigan, P, Batchvarova, V, Dramov, A, Belardi, P, Novelli, G, Simoni, G, Bell, P, Bornstein, N, Bouchier Hayes, D, Fitzgerald, P, Cairols, M, Cao, P, DeRango, P, Carboni, G, Geoffredo, C, Catalano, M, Chambers, B, Goetzmann, M, Dickinson, A, Clement, D, Bobelyn, M, Coccheri, S, Conti, E, Diamantopolous, E, Andreadis, E, Middleton, L, Pantziaris, M, Tyllis, T, Minar, E, Willfort, A, Moggi, L, Nenci, G, Radicchia, S, Norgren, L, Ribbie, E, Novo, S, Tantillo, R, Olinic, D, Paaske, W, Pagnan, A, Pauletto, P, Pagliara, V, Pettina, G, Pratesi, C, Matticari, S, Polivka, J, Sevcik, P, Poredos, P, Blinc, A, Videcnik, V, Pujia, A, Raso, A, Rispoli, P, Conforti, M, Robinson, T, Dennis, M, Rosfors, S, Rudofsky, G, Schroeder, T, Gronholdt, M, Finocchi, C, Rodriguez, G, Dimakakos, P, Kotsis, T, Eikelboom, B, Entz, L, Ferrari Bardilleas, n, Aloi, T, Salerno, M, Fernandes, J., BIASI, GIORGIO MARIA, MINGAZZINI, PAOLO, Nicolaides, A, Kakkos, S, Griffin, M, Sabetai, M, Dhanjil, S, Tegos, T, Thomas, D, Giannoukas, A, Geroulakos, G, Georgiou, N, Francis, S, Ioannidou, E, Doré, C, Adovasio, R, Ziani, B, Aló, E, Cicilioni, C, Ambrosio, G, Andreev, A, Andreozzi, G, Verlato, F, Camporese, G, Arosio, E, Barkauskas, E, Barros D'Sa, A, Brannigan, P, Batchvarova, V, Dramov, A, Belardi, P, Novelli, G, Simoni, G, Bell, P, Biasi, G, Mingazzini, P, Bornstein, N, Bouchier Hayes, D, Fitzgerald, P, Cairols, M, Cao, P, Derango, P, Carboni, G, Geoffredo, C, Catalano, M, Chambers, B, Goetzmann, M, Dickinson, A, Clement, D, Bobelyn, M, Coccheri, S, Conti, E, Diamantopolous, E, Andreadis, E, Middleton, L, Pantziaris, M, Tyllis, T, Minar, E, Willfort, A, Moggi, L, Nenci, G, Radicchia, S, Norgren, L, Ribbie, E, Novo, S, Tantillo, R, Olinic, D, Paaske, W, Pagnan, A, Pauletto, P, Pagliara, V, Pettina, G, Pratesi, C, Matticari, S, Polivka, J, Sevcik, P, Poredos, P, Blinc, A, Videcnik, V, Pujia, A, Raso, A, Rispoli, P, Conforti, M, Robinson, T, Dennis, M, Rosfors, S, Rudofsky, G, Schroeder, T, Gronholdt, M, Finocchi, C, Rodriguez, G, Dimakakos, P, Kotsis, T, Eikelboom, B, Entz, L, Ferrari Bardilleas, N, Aloi, T, Salerno, M, Fernandes, J, NICOLAIDES A N, KAKKOS S K, GRIFFIN M, SABETAI M, DHANJIL S, TEGOS T, THOMAS D J, GIANNOUKAS A, GEROULAKOS G, GEORGIOU N, FRANCIS S, IOANNIDOU E, and NOVO S

Subjects
Risk, medicine.medical_specialty, medicine.medical_treatment, Carotid Stenosi, Predictive Value of Test, Carotid endarterectomy, Severity of Illness Index, Asymptomatic, Brain Ischemia, chemistry.chemical_compound, Cerebrovascular Accident, medicine.artery, Internal medicine, Severity of illness, NASCET, MED/22 - CHIRURGIA VASCOLARE, medicine, Carotid, Stenosis, Medicine(all), Ultrasonography, Doppler, Duplex, Creatinine, business.industry, Risk Factor, Incidence (epidemiology), medicine.disease, major clinical study, Ultrasonography, Duplex, Doppler, chemistry, Predictive value of tests, Cardiology, Surgery, ECST, Radiology, Internal carotid artery, medicine.symptom, Cardiology and Cardiovascular Medicine, business, Human
Abstract

Objectives. This study determines the risk of ipsilateral ischaemic neurological events in relation to the degree of asymptomatic carotid stenosis and other risk factors. Methods. Patients (n = 1115) with asymptomatic internal carotid artery (ICA) stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6-84 (mean 37.1) months. Stenosis was graded using duplex, and clinical and biochemical risk factors were recorded. Results. The relationship between ICA stenosis and event rate is linear when stenosis is expressed by the ECST method, but S-shaped if expressed by the NASCET method. In addition to the ECST grade of stenosis (RR 1.6; 95% CI 1.21-2.15), history of contralateral TIAs (RR 3.0; 95% CI 1.90-4.73) and creatinine in excess of 85 μmol/L (RR 2.1; 95% CI 1.23-3.65) were independent risk predictors. The combination of these three risk factors can identify a high-risk group (7.3% annual event rate and 4.3% annual stroke rate) and a low risk group (2.3% annual event rate and 0.7% annual stroke rate). Conclusions. Linearity between ECST percent stenosis and risk makes this method for grading stenosis more amenable to risk prediction without any transformation not only in clinical practice but also when multivariable analysis is to be used. Identification of additional risk factors provides a new approach to risk stratification and should help refine the indications for carotid endarterectomy. © 2005 Elsevier Ltd. All rights reserved.

Published
2005

47. Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

Author

Nicolaides, Andrew N, Kakkos, Stavros K., Kyriacou, Efthyvoulos, Griffin, Maura, Sabetai, Michael, Thomas, Dafydd J., Tegos, Thomas, Geroulakos, George, Labropoulos, Nicos, Dor, Caroline J., Morris, Tim P., Naylor, Ross, Abbott, Anne L., Adovasio, Roberto, Ziani, B., Alò, F. P., Cicilioni, C. G., Ambrosio, G., Andreev, A., Andreozzi, G. M., Verlato, F., Camporese, G., Arosio, E., Barkauskas, E., Barros D'Sa, A. A. B., Brannigan, P., Batchvarova, V., Dramov, A., Belardi, P., Novelli, Gp, Simoni, G., Bell, P., Biasi, G. M., Mingazzini, P., Bornstein, N. M., Bouchier Hayes, D., Fitzgerald, P., Cairols, M. A., Cao, P. G., Derango, P., Carboni, G. P., Geoffredo, C., Catalano, M., Chambers, B., Goetzmann, M., Dickinson, A., Clement, D., Bobelyn, M., Coccheri, S., Conti, E., Diamantopoulos, E., Andreadis, E. A., Dimakakos, P. B., Kotsis, T., Eikelboom, B., Entz, L., Ferrari Bardile, Null, Aloi, T., Salerno, M., Fernandes e. Fernandes, J., Pedro, L., Fitzgerald, D. E., O'Shaunnersy, Anne, Fletcher, J., Forconi, S., Cappeli, R., Bicchi, M., Arrigucci, S., Gallai, V., Cardaiolli, G., Geroulakos, G., Kakkos, S., Gomez Isaza, L. F., Gorgoyannis, G., Liasis, N., Graf, M., Guarini, P., Hardy, S., Harris, P., Aston, S., Iosa, G., Katsamouris, A., Giannoukas, A., Krzanowski, M., Ladurner, G., Leal Monedero, J., Lee, B. B., Liapis, C., Galanis, P., Liboni, W., Pavanelli, E., Mannarino, E., Vaudo, G., Mccollum, P., Levison, R., Micieli, G., Bosone, D., Middleton, L., Pantziaris, M., Tyllis, T., Minar, E., Willfort, A., Moggi, L., Nenci, G., Radicchia, S., Nicolaides, A., Thomas, D, Norgren, L., Ribbe, E., Novo, S., Tantillo, R., Olinic, D., Paaske, W., Pagnan, A., Pauletto, P., Pagliara, V., Pettina, G., Pratesi, C., Matticari, S., Polivka, J., Sevcik, P., Poredos, P., Blinc, A., Videcnik, V., Pujia, A., Raso, A., Rispoli, P., Conforti, M., Robinson, T., Dennis, M. S. J., Rosfors, S., Rudofsky, G., Schroeder, T., Gronholdt, M. L., Finocchi, C., Rodriguez, G., Spartera, C., Ventura, M., Scarpelli, P., Sprynger, M., Sadzot, B., Hottermans, C., Moonen, Null, Taylor, P. R., Tovar Pardo, A., Negreira, J., Vayssairat, M., Faintuch, J. M., Valaikiené, J., Walker, M. G., Wilkinson, A. R., Nicolaides, A, Kakkos, S, Kyriacou, E, Griffin, M, Sabetai, M, Thomas, D, Tegos, T, Geroulakos, G, Labropoulos, N, Dor, C, Morris, T, Naylor, R, Abbott, A, Adovasio, R, Ziani, B, Alò, F, Cicilioni, C, Ambrosio, G, Andreev, A, Andreozzi, G, Verlato, F, Camporese, G, Arosio, E, Barkauskas, E, Barros D'Sa, A, Brannigan, P, Batchvarova, V, Dramov, A, Belardi, P, Novelli, G, Simoni, G, Bell, P, Biasi, G, Mingazzini, P, Bornstein, N, Bouchier Hayes, D, Fitzgerald, P, Cairols, M, Cao, P, Derango, P, Carboni, G, Geoffredo, C, Catalano, M, Chambers, B, Goetzmann, M, Dickinson, A, Clement, D, Bobelyn, M, Coccheri, S, Conti, E, Diamantopoulos, E, Andreadis, E, Dimakakos, P, Kotsis, T, Eikelboom, B, Entz, L, Ferrari Bardileah, N, Aloi, T, Salerno, M, Fernandes, J, Pedro, L, Fitzgerald, D, O'Shaunnersy, A, Fletcher, J, Forconi, S, Cappeli, R, Bicchi, M, Arrigucci, S, Gallai, V, Cardaiolli, G, Gomez Isaza, L, Gorgoyannis, G, Liasis, N, Graf, M, Guarini, P, Hardy, S, Harris, P, Aston, S, Iosa, G, Katsamouris, A, Giannoukas, A, Krzanowski, M, Ladurner, G, Leal Monedero, J, Lee, B, Liapis, C, Galanis, P, Liboni, W, Pavanelli, E, Mannarino, E, Vaudo, G, Mccollum, P, Levison, R, Micieli, G, Bosone, D, Middleton, L, Pantziaris, M, Tyllis, T, Minar, E, Willfort, A, Moggi, L, Nenci, G, Radicchia, S, Norgren, L, Ribbe, E, Novo, S, Tantillo, R, Olinic, D, Paaske, W, Pagnan, A, Pauletto, P, Pagliara, V, Pettina, G, Pratesi, C, Matticari, S, Polivka, J, Sevcik, P, Poredos, P, Blinc, A, Videcnik, V, Pujia, A, Raso, A, Rispoli, P, Conforti, M, Robinson, T, Dennis, M, Rosfors, S, Rudofsky, G, Schroeder, T, Gronholdt, M, Finocchi, C, Rodriguez, G, Spartera, C, Ventura, M, Scarpelli, P, Sprynger, M, Sadzot, B, Hottermans, C, Moonenbp, N, Taylor, P, Tovar Pardo, A, Negreira, J, Vayssairat, M, Faintuch, J, Valaikiené, J, Walker, M, Wilkinson, A, Nicolaides, Andrew N, Kakkos, Stavros K., Kyriacou, Efthyvoulo, Griffin, Maura, Sabetai, Michael, Thomas, Dafydd J., Tegos, Thoma, Geroulakos, George, Labropoulos, Nico, Dor, Caroline J., Morris, Tim P., Naylor, Ro, Abbott, Anne L., Adovasio, Roberto, Ziani, B., Alò, F. P., Cicilioni, C. G., Ambrosio, G., Andreev, A., Andreozzi, G. M., Verlato, F., Camporese, G., Arosio, E., Barkauskas, E., Barros D'Sa, A. A. B., Brannigan, P., Batchvarova, V., Dramov, A., Belardi, P., Novelli, Gp, Simoni, G., Bell, P., Biasi, G. M., Mingazzini, P., Bornstein, N. M., Bouchier Hayes, D., Fitzgerald, P., Cairols, M. A., Cao, P. G., Derango, P., Carboni, G. P., Geoffredo, C., Catalano, M., Chambers, B., Goetzmann, M., Dickinson, A., Clement, D., Bobelyn, M., Coccheri, S., Conti, E., Diamantopoulos, E., Andreadis, E. A., Dimakakos, P. B., Kotsis, T., Eikelboom, B., Entz, L., Ferrari Bardile, Null, Aloi, T., Salerno, M., Fernandes e. Fernandes, J., Pedro, L., Fitzgerald, D. E., O'Shaunnersy, Anne, Fletcher, J., Forconi, S., Cappeli, R., Bicchi, M., Arrigucci, S., Gallai, V., Cardaiolli, G., Geroulakos, G., Kakkos, S., Gomez Isaza, L. F., Gorgoyannis, G., Liasis, N., Graf, M., Guarini, P., Hardy, S., Harris, P., Aston, S., Iosa, G., Katsamouris, A., Giannoukas, A., Krzanowski, M., Ladurner, G., Leal Monedero, J., Lee, B. B., Liapis, C., Galanis, P., Liboni, W., Pavanelli, E., Mannarino, E., Vaudo, G., Mccollum, P., Levison, R., Micieli, G., Bosone, D., Middleton, L., Pantziaris, M., Tyllis, T., Minar, E., Willfort, A., Moggi, L., Nenci, G., Radicchia, S., Nicolaides, A., Norgren, L., Ribbe, E., Novo, S., Tantillo, R., Olinic, D., Paaske, W., Pagnan, A., Pauletto, P., Pagliara, V., Pettina, G., Pratesi, C., Matticari, S., Polivka, J., Sevcik, P., Poredos, P., Blinc, A., Videcnik, V., Pujia, A., Raso, A., Rispoli, P., Conforti, M., Robinson, T., Dennis, M. S. J., Rosfors, S., Rudofsky, G., Schroeder, T., Gronholdt, M. L., Finocchi, C., Rodriguez, G., Spartera, C., Ventura, M., Scarpelli, P., Sprynger, M., Sadzot, B., Hottermans, C., Moonen, Null, Taylor, P. R., Tovar Pardo, A., Negreira, J., Vayssairat, M., Faintuch, J. M., Valaikiené, J., Walker, M. G., and Wilkinson, A. R.

Subjects
Male, Carotid Stenosi, carotid artery stenosis, Brain Ischemia, 80 and over, MED/22 - CHIRURGIA VASCOLARE, Carotid Stenosis, Cerebrovascular disease, cerebrovascular risk, Stroke, Ultrasonography, Aged, 80 and over, Middle Aged, cardiovascular system, Female, Radiology, Internal carotid artery, medicine.symptom, Cardiology and Cardiovascular Medicine, Carotid Artery, Internal, Adult, Aged, Amaurosis Fugax, Humans, ROC Curve, Risk Assessment, Surgery, Human, medicine.medical_specialty, Asymptomatic, Central nervous system disease, medicine.artery, medicine, Asymtomatic carotid stenosis, cardiovascular diseases, Risk factor, carotid surgery, Vascular disease, business.industry, Amaurosis fugax, medicine.disease, Internal, Stenosis, atherosclerosis, Carotid Artery, business
Abstract

Background: The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods: This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. Results: A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with

Published
2010

48. Predictors and clinical significance of progression or regression of asymptomatic carotid stenosis

Author

Kakkos, Sk, Nicolaides, An, Charalambous, I, Thomas, D, Giannopoulos, A, Naylor, Ar, Geroulakos, G, Abbott, Al, Asymptomatic Carotid Stenosis, Risk of Stroke Study Group Adovasio, R, Ziani, B, Alò, F, Cicilioni, C, Ambrosio, G, Andreev, A, Andreozzi, G, Verlato, F, Camporese, G, Arosio, E, Barkauskas, E, D'Sa, A, Brannigan, P, Batchvarova, V, Dramov, A, Belardi, P, Novelli, G, Simoni, G, Bell, P, Biasi, G, Mingazzini, P, Bornstein, N, Bouchier Hayes, D, Fitzgerald, P, Cairols, M, Cao, P, Derango, P, Carboni, G, Geoffredo, C, Catalano, M, Chambers, B, Goetzmann, M, Dickinson, A, Clement, D, Bobelyn, M, Coccheri, S, Conti, E, Diamantopoulos, E, Andreadis, E, Dimakakos, P, Kotsis, T, Eikelboom, B, Entz, L, Ferrari Bardile, A, Aloi, T, Salerno, M, Fernandes J, Fernandes e., Pedro, L, Fitzgerald, D, O'Shaughnessy, A, Fletcher, J, Forconi, S, Cappeli, R, Bicchi, M, Arrigucci, S, Gallai, V, Cardaiolli, G, Kakkos, S, Gomez Isaza, L, Gorgoyannis, G, Liasis, N, Graf, M, Guarini, P, Hardy, S, Harris, P, Aston, S, Iosa, G, Katsamouris, A, Giannoukas, A, Krzanowski, M, Ladurner, G, Leal Monedero, J, Lee, B, Liapis, C, Galanis, P, Liboni, W, Pavanelli, E, Mannarino, E, Vaudo, G, Mccollum, P, Levison, R, Micieli, G, Bosone, D, Middleton, L, Pantziaris, M, Tyllis, T, Minar, E, Willfort, A, Moggi, L, Nenci, G, Radicchia, S, Nicolaides, A, Norgren, L, Ribbe, E, Novo, S, Tantillo, R, Olinic, D, Paaske, W, Pagnan, A, Pauletto, P, Pagliara, V, Pettina, G, Pratesi, C, Matticari, S, Polivka, J, Sevcik, P, Poredos, P, Blinc, A, Videcnik, V, Pujia, A, Raso, A, Rispoli, Pietro, Conforti, M, Robinson, T, Dennis, M, Rosfors, S, Rudofsky, G, Schroeder, T, Gronholdt, M, Finocchi, C, Rodriguez, G, Spartera, C, Ventura, M, Scarpelli, P, Sprynger, M, Sadzot, B, Hottermans, C, Moonen, M, Taylor, P, Tovar Pardo, A, Negreira, J, Vayssairat, M, Faintuch, J, Valaikiené, J, Walker, M, Wilkinson, A. R., Kakkos, Stavros K., Nicolaides, Andrew N., Charalambous, Ioanna, Thomas, Dafydd, Giannopoulos, Argyrio, Naylor, A. Ro, Geroulakos, George, Abbott, Anne L., Adovasio, Roberto, Ziani, B., Alò, F. P., Cicilioni, C. G., Ambrosio, G., Andreev, A., Andreozzi, G. M., Verlato, F., Camporese, G., Arosio, E., Barkauskas, E., Barros D'Sa, A. A. B., Brannigan, P., Batchvarova, V., Dramov, A., Belardi, P., Novelli, G. P., Simoni, G., Bell, P., Biasi, G. M., Mingazzini, P., Bornstein, N. M., Bouchier Hayes, D., Fitzgerald, P., Cairols, M. A., Cao, P. G., Derango, P., Carboni, G. P., Geoffredo, C., Catalano, M., Chambers, B., Goetzmann, M., Dickinson, A., Clement, D., Bobelyn, M., Coccheri, S., Conti, E., Diamantopoulos, E., Andreadis, E. A., Dimakakos, P. B., Kotsis, T., Eikelboom, B., Entz, L., Ferrari Bardile, A., Aloi, T., Salerno, M., Fernandes E. Fernandes, J., Pedro, L., Fitzgerald, D. E., O'Shaughnessy, A. M., Fletcher, J., Forconi, S., Cappeli, R., Bicchi, M., Arrigucci, S., Gallai, V., Cardaiolli, G., Gomez Isaza, L. F., Gorgoyannis, G., Liasis, N., Graf, M., Guarini, P., Hardy, S., Harris, P., Aston, S., Iosa, G., Katsamouris, A., Giannoukas, A., Krzanowski, M., Ladurner, G., Leal Monedero, J., Lee, B. B., Liapis, C., Galanis, P., Liboni, W., Pavanelli, E., Mannarino, E., Vaudo, G., Mccollum, P., Levison, R., Micieli, G., Bosone, D., Middleton, L., Pantziaris, M., Tyllis, T., Minar, E., Willfort, A., Moggi, L., Nenci, G., Radicchia, S., Norgren, L., Ribbe, E., Novo, S., Tantillo, R., Olinic, D., Paaske, W., Pagnan, A., Pauletto, P., Pagliara, V., Pettina, G., Pratesi, C., Matticari, S., Polivka, J., Sevcik, P., Poredos, P., Blinc, A., Videcnik, V., Pujia, A., Raso, A., Rispoli, P., Conforti, M., Robinson, T., Dennis, M. S. J., Rosfors, S., Rudofsky, G., Schroeder, T., Gronholdt, M. L., Finocchi, C., Rodriguez, G., Spartera, C., Ventura, M., Scarpelli, P., Sprynger, M., Sadzot, B., Hottermans, C., Moonen, M., Taylor, P. R., Tovar Pardo, A., Negreira, J., Vayssairat, M., Faintuch, J. M., Valaikiené, J., Walker, M. G., and Wilkinson, A. R.

Subjects
Male, Time Factors, Cost effectiveness, medicine.medical_treatment, Carotid Stenosi, Predictive Value of Test, Kaplan-Meier Estimate, Carotid endarterectomy, Retinal Disease, Risk Factors, 80 and over, Carotid Stenosis, Plaque, Atherosclerotic, Ultrasonography, Aged, 80 and over, Ultrasonography, Doppler, Duplex, Incidence, Remission Induction, Doppler, Middle Aged, Prognosis, Plaque, Atherosclerotic, Duplex, Europe, Stroke, Predictive value of tests, Disease Progression, Cardiology, Female, medicine.symptom, Cardiology and Cardiovascular Medicine, Carotid Artery, Internal, Human, Adult, medicine.medical_specialty, Time Factor, Victoria, Prognosi, Asymptomatic, Retinal Diseases, Predictive Value of Tests, Internal medicine, medicine, Humans, Clinical significance, Aged, Asymptomatic Disease, business.industry, Risk Factor, medicine.disease, Internal, Confidence interval, Surgery, Stenosis, Asymptomatic Diseases, Relative risk, asymptomatic carotid artery stenosis, Carotid Artery, business
Abstract

OBJECTIVE: To determine baseline clinical and ultrasonographic plaque factors predictive of progression or regression of asymptomatic carotid stenosis and the predictive value of changes in stenosis severity on risk of first ipsilateral cerebral or retinal ischemic events (including stroke).METHODS: A total of 1121 patients with asymptomatic carotid stenosis of 50% to 99% in relation to the bulb diameter (European Carotid Surgery Trial [ECST] method) underwent six monthly clinical assessments and carotid duplexes for up to 8 years (mean follow-up, 4 years). Progression or regression was considered present if there was a change of at least one grade higher or lower, respectively, persisting for at least two consecutive examinations.RESULTS: Regression occurred in 43 (3.8%), no change in 856 (76.4%), and progression in 222 (19.8%) patients. Younger age, high grades of stenosis, absence of discrete white areas in the plaque, and taking lipid lowering therapy were independent baseline predictors of increased incidence of regression. High serum creatinine, male gender, not taking lipid lowering therapy, low grades of stenosis, and increased plaque area were independent baseline predictors of progression. One hundred and thirty first ipsilateral cerebral or retinal ischemic events, including 59 strokes, occurred. Forty (67.8%) of the strokes occurred in patients whose stenosis was unchanged, 19 (32.2%) in those with progression, and zero in those with regression. For the entire cohort, the 8-year cumulative ipsilateral cerebral ischemic stroke rate was zero in patients with regression, 9% if the stenosis was unchanged, and 16% if there was progression (average annual stroke rates of 0%, 1.1%, and 2.0%, respectively; log-rank, P = .05; relative risk in patients with progression, 1.92; 95% confidence interval, 1.14-3.25). For patients with baseline stenosis 70% to 99% in relation to the distal internal carotid (North American Symptomatic Carotid Endarterectomy Trial [NASCET] method), in the absence of progression (n = 349), the 8-year cumulative ipsilateral cerebral ischemic stroke rate was 12%. In the presence of progression (n = 77), it was 21% (average annual stroke rates of 1.5% and 2.6%, respectively; log-rank, P = .34). Only nine (30%) of the 30 strokes occurred in the progression group.CONCLUSIONS: Progressive asymptomatic carotid stenosis identified a subgroup with about twice the risk of ipsilateral stroke compared with those without progression. However, the clinical value of screening for progression simply for selecting patients for carotid procedures is limited because of the low frequency of progression and its relatively low associated stroke rate. The cost effectiveness of screening for change in stenosis severity to better direct current optimal medical treatment needs testing.

Published
2014

49. 10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial

Author

Halliday, A, Harrison, M, Hayter, E, Kong, X, Mansfield, A, Marro, J, Pan, H, Peto, R, Potter, J, Rahimi, K, Rau, A, Robertson, S, Streifler, J, Thomas, D, Fraedrich G, Asymptomatic Carotid Surgery Trial Collaborative G. r. o. u. p., Schmidauer, C, Hölzenbein, Th, Huk, I, Haumer, M, Kretschmer, G, Metz, V, Polterauer, P, Teufelsbauer, H, Cras, P, Hendriks, J, Lauwers, P, Van Schil, P, de Souza EB, Dourado, Me, Gurgel, G, Rocha, Gm, Petrov, V, Slabakov, G, Cooper, Me, Gubitz, G, Holness, R, Howes, W, Langille, R, Legg, K, Nearing, S, Mackean, G, Mackay, M, Phillips, Sj, Sullivan, J, Wood, J, Erdelez, L, Sosa, T, Angelides, Ns, Christopoulos, G, Malikidou, A, Pesta, A, Ambler, Z, Mracek, J, Polivka, J, Rohan, V, Sevcik, P, Simaná, J, Benes, V, Kramár, F, Kaste, M, Lepäntalo, M, Soinne, L, Cardon, Jm, Legalou, A, Gengenbach, B, Pfadenhauer, K, Wölfl, Kd, Flessenkämper, I, Klumpp, Bf, Marsch, J, Kolvenbach, R, Pfeiff, T, Sandmann, W, Beyersdorf, F, Hetzel, A, Sarai, K, Schöllhorn, J, Spillner, G, Lutz, Hj, Böckler, D, Maeder, N, Busse, O, Grönniger, J, Haukamp, F, Balzer, K, Knoob, Hg, Roedig, G, Virreira, L, Franke, S, Moll, R, Schneider, J, Dayantas, J, Sechas, Mn, Tsiaza, S, Kiskinis, D, Apor, A, Dzinich, C, Entz, L, Hüttl, K, Jàrànyi, Z, Mogan, I, Nagy, Z, Szabo, A, Varga, D, Juhász, G, Mátyás, L, Hutchinson, M, Mehigan, D, Aladjem, Z, Harah, E, Elmakias, S, Gurvich, D, Yoffe, B, Ben Meir, H, Dagan, L, Karmeli, R, Keren, G, Shimony, A, Weller, B, Avrahami, R, Koren, R, Streifler, Jy, Tabachnik, S, Zelikovski, A, Angiletta, D, Federico, F, Impedovo, G, Marotta, V, Pascazio, L, Regina, G, Andreoli, A, Pozzati, E, Bonardelli, S, Giulini, Sm, Guarneri, B, Caiazzo, P, Mascoli, F, Becchi, G, Masini, R, Santoro, E, Simoni, G, Ventura, M, Scarpelli, P, Spartera, C, Arena, O, Collice, M, Puttini, M, Romani, F, Santilli, I, Segramora, V, Sterzi, R, Deriu, G, Verlato, F, Cao, Pg, Cieri, Enrico, De Rango, P, Moggi, L, Ricci, S, Antico, A, Spigonardo, F, Malferrari, G, Tusini, N, Vecchiati, E, Cavallaro, A, Kasemi, H, Marino, M, Sbarigia, E, Speziale, F, Zinicola, N, Alò, Fp, Bartolini, M, Carbonari, L, Caporelli, S, Grili Cicilioni, C, Lagalla, G, Ioannidis, G, Pagliariccio, G, Silvestrini, M, Palombo, D, Peinetti, F, Adovasio, R, Chiodo Grandi, F, Mase, G, Zamolo, F, Fregonese, V, Gonano, N, Mozzon, L, Blair, R, Chuen, J, Ferrar, D, Garbowski, M, Hamilton, Mj, Holdaway, C, Muthu, S, Shakibaie, F, Vasudevan, Tm, Kroese, A, Slagsvold, Ce, Dahl, T, Johnsen, Hj, Lange, C, Myhre, Ho, Gniadek, J, Andziak, P, Elwertowski, M, Leszczynski, J, Malek, Ak, Mieszkowski, J, Noszczyk, W, Szostek, M, Toutounchi, S, Correia, C, Pereira, Mc, Akchurin, Rs, Flis, V, Miksic, K, Stirn, B, Tetickovic, E, Cairols, M, Capdevila, Jm, Iborra Ortega, E, Obach, V, Riambau, V, Vidal Barraquer, F, Vila Coll, R, Diaz Vidal, E, Iglesias Negreia JI, Tovar Pardo, A, Iglesias, Rj, Alfageme, Af, Barba Velez, A, Estallo Laliena, L, Garcia Monco JC, Gonzalez, Lr, Corominas, C, Julia, J, Lozano, P, Marti Masso JF, Porta, Rm, Carrera, Ar, Gomez, J, Blomstrand, C, Gelin, J, Holm, J, Karlström, L, Mattsson, E, Bornhov, S, Dahlstrom, J, De Pedis, G, Jensen, Sm, Pärsson, H, Plate, G, Qvarfordt, P, Arvidsson, B, Brattström, L, Forssell, C, Potemkowski, A, Skiöldebrand, C, Stoor, P, Blomqvist, M, Calander, M, Lundgren, F, Almqvist, H, Norgren, L, Norrving, B, Ribbe, E, Thörne, J, Gottsäter, A, Mätzsch, T, Nilsson, Me, Lonsson, M, Stahre, B, Stenberg, B, Konrad, P, Jarl, L, Lundqvist, L, Olofsson, P, Rosfors, S, Swedenborg, J, Takolander, R, Bergqvist, D, Ljungman, C, Kniemeyer, Hw, Widmer, Mk, Kuster, R, Kaiser, R, Nagel, W, Sege, D, Weder, B, De Nie, J, Doelman, J, Yilmaz, N, Buth, J, Stultiens, G, Boiten, J, Boon, A, van der Linden, F, Busman, Dc, Sinnige, Ha, Yo, Ti, de Borst GJ, Eikelboom, Bc, Kappelle, Lj, Moll, F, Dortland, Rw, Westra, Te, Jaber, H, Manaa, J, Meftah, Rb, Nabil, Br, Sraieb, T, Bateman, D, Budd, J, Horrocks, M, Kivela, M, Shaw, L, Walker, R, D'Sa, Aa, Fullerton, K, Hannon, R, Hood, Jm, Lee, B, Mcguigan, K, Morrow, J, Reid, J, Soong, Cv, Simms, M, Baird, R, Campbell, M, Cole, S, Ferguson, It, Lamont, P, Mitchell, D, Sassano, A, Smith, Fc, Blake, K, Kirkpatrick, Pj, Martin, P, Turner, C, Clegg, Jf, Crosley, M, Hall, J, De Cossart, L, Edwards, P, Fletcher, D, Rosser, S, Mccollum, Pt, Davidson, D, Levison, R, Bradbury, Aw, Chalmers, Rt, Dennis, M, Murie, J, Ruckley, Cv, Sandercock, P, Campbell, Wb, Frankel, T, Gardner Thorpe, C, Gutowski, N, Hardie, R, Honan, W, Niblett, P, Peters, A, Ridler, B, Thompson, Jf, Bone, I, Welch, G, Grocott, Ec, Overstall, P, Aldoori, Mi, Dafalla, Be, Bryce, J, Clarke, C, Ming, A, Wilkinson, Ar, Bamford, J, Berridge, D, Scott, J, Abbott, Rj, Naylor, R, Harris, P, Humphrey, P, Adiseshiah, M, Aukett, M, Baker, D, Bishop, Cc, Boutin, A, Brown, M, Burke, P, Burnand, Kg, Colchester, A, Coward, L, Davies, Ah, Espasandin, M, Giddings, Ae, Hamilton, G, Judge, C, Kakkos, S, Mcguiness, C, Morris Vincent, P, Nicolaides, A, Padayachee, Ts, Riordan, H, Sullivan, E, Taylor, P, Thompson, M, Wolfe, Jh, Mccollum, Cn, O'Neill, Pa, Welsh, S, Barnes, J, Cleland, P, Davis, M, Gholkar, A, Jones, R, Jaykishnam, V, Mendelow, Ad, O'Connell, Je, Siddique, Ms, Stansby, G, Vivar, R, Ashley, S, Cosgrove, C, Gibson, J, Wilkins, Dc, Chant, Ad, Frankel, J, Shearman, Cp, Williams, J, Hall, G, Holdsworth, R, Davies, Jn, Mclean, B, Woodburn, Kr, Brown, G, Curley, P, Loizou, L, Chaturvedi, S, Diaz, F, Radak, D, Todorovic, Pr, Kamugasha, D, Baxter, A, Berry, C, Burrett, J, Collins, R, Crowther, J, Davies, C, Farrell, B, Godwin, J, Gray, R, Harwood, C, Hirt, L, Hope, C, Knight, S, Lay, M, Munday, A, Murawska, A, Peto, Cg, Radley, A, Richards, S., Cras, Patrick, van Schil, Paul, et al., Asymptomatic Carotid Surgery Trial (ACST) Collaborative Group, Halliday, A, Harrison, M, Hayter, E, Kong, X, Mansfield, A, Marro, J, Pan, H, Peto, R, Potter, J, Rahimi, K, Rau, A, Robertson, S, Streifler, J, Thomas, D, Adovasio, Roberto, and Asymptomatic Carotid Surgery Trial Collaborative, Group

Subjects
Male, Time Factors, medicine.medical_treatment, Kaplan-Meier Estimate, Carotid endarterectomy, Aged, 80 and over, Carotid Stenosis, Endarterectomy, Carotid, Female, Humans, Incidence, Middle Aged, Primary Prevention, Stroke, Treatment Outcome, Stroke/epidemiology, law.invention, Randomized controlled trial, law, Aged, 80 and over, Endarterectomy, Carotid, endarterectomy, Carotid Stenosis/mortality, Incidence (epidemiology), Carotid*/mortality, General Medicine, Carotid Stenosis | Internal Carotid Artery | Endarterectomy, medicine.symptom, medicine.medical_specialty, Asymptomatic, Internal medicine, asymptomatic carotid artery stenosi, medicine, asymptomatic carotid artery stenosis, business.industry, Carotid Stenosis/complications, Stroke/prevention & control, Perioperative, medicine.disease, Surgery, Stenosis, Human medicine, business
Abstract

SummaryBackgroundIf carotid artery narrowing remains asymptomatic (ie, has caused no recent stroke or other neurological symptoms), successful carotid endarterectomy (CEA) reduces stroke incidence for some years. We assessed the long-term effects of successful CEA.MethodsBetween 1993 and 2003, 3120 asymptomatic patients from 126 centres in 30 countries were allocated equally, by blinded minimised randomisation, to immediate CEA (median delay 1 month, IQR 0·3–2·5) or to indefinite deferral of any carotid procedure, and were followed up until death or for a median among survivors of 9 years (IQR 6–11). The primary outcomes were perioperative mortality and morbidity (death or stroke within 30 days) and non-perioperative stroke. Kaplan-Meier percentages and logrank p values are from intention-to-treat analyses. This study is registered, number ISRCTN26156392.Findings1560 patients were allocated immediate CEA versus 1560 allocated deferral of any carotid procedure. The proportions operated on while still asymptomatic were 89·7% versus 4·8% at 1 year (and 92·1% vs 16·5% at 5 years). Perioperative risk of stroke or death within 30 days was 3·0% (95% CI 2·4–3·9; 26 non-disabling strokes plus 34 disabling or fatal perioperative events in 1979 CEAs). Excluding perioperative events and non-stroke mortality, stroke risks (immediate vs deferred CEA) were 4·1% versus 10·0% at 5 years (gain 5·9%, 95% CI 4·0–7·8) and 10·8% versus 16·9% at 10 years (gain 6·1%, 2·7–9·4); ratio of stroke incidence rates 0·54, 95% CI 0·43–0·68, p

Published
2010

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