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1.
《Journal of Children and Media》2013,7(4):316-330
Children's growing use of the Internet creates both opportunities and risks. Collecting and comparing empirical findings on risks and opportunities experienced across 20 different European countries shows significant differences between them. Using Qualitative Comparative Analysis (QCA), this article investigates which factors contribute towards a high degree of online risk experienced by children across these countries. The research shows that patterns of similarities and differences do not seem to coincide with regional, political, and historical divides across European Union countries. The findings seem to endorse the multilayered approach of multi-stakeholder governance, which stresses the co-responsibility in securing children's online safety. However, one of the most important country conditions explaining high risk appears to be the lack of positive online content provision. 相似文献
2.
John D. Biglands Montasir Ibraheem Derek R. Magee Aleksandra Radjenovic Sven Plein John P. Greenwood 《JACC: Cardiovascular Imaging》2018,11(5):711-718
Objectives
This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography.Background
Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion.Methods
This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis.Results
The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79).Conclusions
Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. 相似文献3.
《JACC: Cardiovascular Imaging》2014,7(11):1130-1148
Bioresorbable vascular scaffolds (BRS) represent a novel approach to provide transient vessel support to drug-delivery capability without the long-term limitations of metallic drug-eluting stents (DES). The technology has the potential to overcome many of the safety concerns associated with metallic DES and possibly even convey further clinical benefit. In particular, the BRS are designed to provide short-term lumen support, and after being completely bioresorbed, eliminate the permanent caging typical of metallic DES. However, this technology has required new imaging modalities and methodologies for its assessment because the design, degradation rate, loss of mechanical property, and drug deliverability may affect its safety and efficacy. We provide an overview of all existing methods for assessing bioresorbable devices, from noninvasive to invasive, from light to sound based, and from morphological to functional parameters. 相似文献
4.
《JACC: Cardiovascular Interventions》2014,7(10):1093-1102
ObjectivesThe aim of this study was to identify clinical, procedural, and angiographic correlates of late/very late drug-eluting stent (DES) thrombosis as well as to determine the clinical outcomes of these events.BackgroundLate/very late DES thromboses are a poorly studied phenomenon, partly due to the relative infrequency of these events, even in large cohort studies.MethodsIn the DESERT (International Drug-Eluting Stent Event Registry of Thrombosis), a retrospective, case-control registry, 492 cases of late/very late definite DES thrombosis from 21 international sites were matched in a 1:1 fashion with controls without stent thrombosis (ST). Controls were matched according to 2 criteria: same enrolling institution and date of initial DES implantation. Baseline and procedural variables were collected, and clinical follow-up was obtained for patients with ST as long as 1 year after the event. Offline quantitative coronary angiography was performed for a subset of 378 case-control pairs.ResultsThe majority of ST events occurred after 1 year (75%) and continued to occur for as long as 7.3 years. The clinical presentation of late/very late ST events was mainly myocardial infarction (66.7% ST-segment elevation myocardial infarction and 22.0% non–ST-segment elevation myocardial infarction); in-hospital mortality was 3.8%. A minority of patients (30%) with ST were receiving dual-antiplatelet therapy at the time of the event. Independent clinical correlates of late/very late ST were younger age, African-American race, current smoking, multivessel disease, longer stented length, overlapping stents, and percutaneous coronary intervention of vein graft lesions. Independent angiographic correlates for late/very late ST were lesions within the left anterior descending artery or a bypass graft, thrombus, and a larger residual diameter stenosis after the initial DES implantation. Despite the large sample of ST cases, all identified correlates of late/very late ST had weak associations with subsequent ST (all odds ratios <2.5).ConclusionsDespite a large sample of ST cases and use of limited matching to maximize the identification of predictive factors associated with late/very late ST, the variables associated with the development of late/very late ST were only weakly predictive of subsequent events. Additionally, a relatively low observed mortality rate of ST in this series may reflect a different pathophysiology of these late/very late events compared with acute/subacute ST. (Drug Eluting Stent Registry of Thrombosis [DESERT]; NCT00812552). 相似文献
5.
Yves Louvard MD Martyn Thomas MD Vladimir Dzavik MD David Hildick‐Smith MD Alfredo R. Galassi MD Manuel Pan MD Francisco Burzotta MD Michael Zelizko MD Darius Dudek MD Peter Ludman MD Imad Sheiban MD Jens F. Lassen MD Olivier Darremont MD Adnan Kastrati MD Josef Ludwig MD Ioannis Iakovou MD Philippe Brunel MD Alexandra Lansky MD David Meerkin MD Victor Legrand MD Alfonso Medina MD Thierry Lefèvre MD 《Catheterization and cardiovascular interventions》2008,71(2):175-183
6.
Nisharahmed I. Kherada Samantha SartoriMatthew I. Tomey Marco G. MennuniOmar A. Meelu Swathi RoyBibhu D. Mohanty Usman BaberRobert Pyo Jason C. KovacicJoseph Sweeny Pedro MorenoPrakash Krishnan George D. DangasRoxana Mehran Samin K. SharmaAnnapoorna S. Kini 《International journal of cardiology》2014
Objectives
To compare the outcomes of initial one-stent (1S) versus dedicated two-stent (2S) strategies in complex bifurcation percutaneous coronary intervention (PCI) using everolimus-eluting stents (EES).Background
PCI of true bifurcation lesions is technically challenging and historically associated with reduced procedural success and increased restenosis. Prior studies comparing initial one-stent (1S) versus dedicated two-stent (2S) strategies using first-generation drug-eluting stents have shown no reduction in ischemic events and more complications with a 2S strategy.Methods
We performed a retrospective study of 319 consecutive patients undergoing PCI at a single referral center with EES for true bifurcation lesions, defined by involvement of both the main vessel (MV) and side branch (SB). Baseline, procedural characteristics, quantitative coronary angiography and clinical outcomes in-hospital and at one year were compared for patients undergoing 1S (n = 175) and 2S (n = 144) strategies.Results
Baseline characteristics were well-matched. 2S strategy was associated with greater SB acute gain (0.65 ± 0.41 mm vs. 1.11 ± 0.47 mm, p < 0.0001). In-hospital serious adverse events were similar (9% with 2S vs. 8% with 1S, p = 0.58). At one year, patients treated by 2S strategy had non-significantly lower rates of target vessel revascularization (5.8% vs. 7.4%, p = 0.31), myocardial infarction (7.8% vs. 12.2%, p = 0.31) and major adverse cardiovascular events (16.6% vs. 21.8%, p = 0.21).Conclusion
In this study of patients undergoing PCI for true coronary bifurcation lesions using EES, 2S strategy was associated with superior SB angiographic outcomes without excess complications or ischemic events at one year. 相似文献7.
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9.
Moer R van Weert AW Myreng Y Mølstad P 《The international journal of cardiovascular imaging》2003,19(6):457-464
To assess the validity of locally performed off-line quantitative coronary angiography (QCA) measurement in clinical trials, we carried out a comparative study between on-site QCA analysis and analysis performed at an independent external core laboratory. One local operator analyzed the pre, post and follow-up angiograms of 116 patients participating in the Stenting in Small Coronary Arteries Study (SISCA) prior to final QCA analysis in the core laboratory. The mean values of the reference diameter (RD), minimal lumen diameter (MLD) and diameter stenosis (DS) showed acceptable agreement between study site and core laboratory. However, on the level of individuals the interobserver differences were large, affecting the outcome of restenosis rate significantly, and in a such way that the conclusions in the SISCA trial might have come out differently if a core laboratory had not been used. This emphasizes the importance of using independent core laboratories in coronary interventional trials. 相似文献
10.
Carlos Collet Bernard Chevalier Angel Cequier Jean Fajadet Marcello Dominici Steffen Helqvist Ad J. Van Boven Dariusz Dudek Dougal McClean Manuel Almeida Jan J. Piek Erhan Tenekecioglu Antonio Bartorelli Stephan Windecker Patrick W. Serruys Yoshinobu Onuma 《JACC: Cardiovascular Imaging》2018,11(5):722-732