Assessment of Left Ventricular Function in Cardiac MSCT Imaging by a 4D Hierarchical Surface-Volume Matching Process

Multislice computed tomography (MSCT) scanners offer new perspectives for cardiac kinetics evaluation with 4D dynamic sequences of high contrast and spatiotemporal resolutions. A new method is proposed for cardiac motion extraction in multislice CT. Based on a 4D hierarchical surface-volume matching process, it provides the detection of the heart left cavities along the acquired sequence and the estimation of their 3D surface velocity fields. A Markov random field model is defined to find, according to topological descriptors, the best correspondences between a 3D mesh describing the left endocardium at one time and the 3D acquired volume at the following time. The global optimization of the correspondences is realized with a multiresolution process. Results obtained on simulated and real data show the capabilities to extract clinically relevant global and local motion parameters and highlight new perspectives in cardiac computed tomography imaging

Review of patient-specific simulations of transcatheter aortic valve implantation

International audienceTranscatheter Aortic Valve Implantation (TAVI) accounts for one of the most promising new cardiovascular procedures. This minimally invasive technique is still at its early stage and is constantly developing thanks to imaging techniques, computer science, biomechanics and technologies of prosthesis and delivery tools. As a result, patient-specific simulation can find an exciting playground in TAVI. It canexpress its potential by providing the clinicians with powerful decision support, offering great assistance in their workflow. Through a review of the current scientific field, we try to identify the challenges and future evolutions of patient-specific simulation for TAVI. This review article is an attempt to summarize and coordinate data scattered across the literature about patient-specific biomechanical simulation for TAVI

Modélisation Markovienne pour l'estimation combinée de forme et de mouvement : Application au coeur en imagerie scanner multibarrette

Une méthode d'estimation conjointe de forme et de mouvement non rigide à partir de séquences temporelles tri-dimensionnelles est proposée. Basée sur une mise en correspondance surface-volume, elle permet, à partir d'une unique forme segmentée, d'estimer la forme et son mouvement sur toute la séquence. Une modélisation Markovienne combinée à un algorithme de recuit simulé estime les correspondances entre les noeuds du maillage modélisant l'objet à l'instant t et les voxels du volume à l'instant t + 1. La méthode a été appliquée à l'extraction de formes et de mouvements cardiaques en tomodensitométrie multibarrette. Les tests, réalisés sur données simulées et données réelles, ont donné des résultats prometteurs

Joint Shape and Motion Estimation using Markovian Fields : Application to Multislice Computed Tomography Cardiac Imaging

We propose a method for joint surface and non-rigid motion estimation from three-dimensional dynamic sequences. Based on a surface-volume matching, it provides, from one first segmented surface, both motion and deformations of the object of interest along the whole sequence. A Markovian model, combined with a simulated annealing process, estimates the correspondences between the nodes of the surface mesh modeling the object of interest at one time and the voxels of the volume representing the object at the following time. The method has been applied to cardiac surface and motion extraction in Multislice Computed Tomography. Tests realized with simulated motion and on real data have provided promising results.Une méthode d'estimation conjointe de forme et de mouvement non rigide à partir de séquences temporelles tridimensionnelles est proposée. Reposant sur une mise en correspondance surface-volume, elle permet, à partir d'une première segmentation de l'objet d'intérêt, d'estimer le mouvement de l'objet et ses déformations sur toute la séquence temporelle d'observation. Une modélisation markovienne combinée à un algorithme de recuit simulé estime les correspondances entre les noeuds du maillage de surface modélisant l'objet à un instant et les voxels du volume représentant l'objet à l'instant suivant. La méthode a été appliquée à l'extraction de formes et de mouvements cardiaques en tomodensitométrie multibarrette. Les tests, réalisés à la fois avec des mouvements simulés et sur des données réelles, ont donné des résultats prometteurs

Impact of post-procedural glycemic variability on cardiovascular morbidity and mortality after transcatheter aortic valve implantation : a post hoc cohort analysis

International audienceBackground : Glycemic variability is associated with worse outcomes after cardiac surgery, but the prognosis value of early glycemic variability after transcatheter aortic valve implantation is not known. This study was therefore designed to analyze the prognosis significance of post-procedural glycemic variability within 30 days after transcatheter aortic valve implantation.Methods : A post hoc analysis of patients from our center included in the FRANCE and FRANCE-2 registries was conducted. Post-procedural glycemic variability was assessed by calculating the mean daily δ blood glucose during the first 2 days after transcatheter aortic valve implantation. Major complications within 30 days were death, stroke, myocardial infarction, acute heart failure, and life-threatening cardiac arrhythmias.Results : We analyzed 160 patients (age (median [interquartile] = 84 [80–88] years; diabetes mellitus (n) = 41 (26%) patients; logistic Euroscore = 20 [12–32]). The median value of mean daily δ blood glucose was 4.3 mmol l−1. The rate of major complications within 30 days after procedure among patients with the lowest quartile of glycemic variability was 12%, increasing from 12 to 26%, and 39% in the second, third, and fourth quartiles, respectively. In multivariate analysis, glycemic variability was independently associated with an increased risk of major complications within 30 days after the procedure (odds ratio [95% CI] = 1.83 [1.19–2.83]; p = 0.006).Conclusions : This study showed that post-procedural glycemic variability was associated with an increased risk of major complications within 30 days after transcatheter aortic valve implantation

: Gender differences in STEMI

International audienceBACKGROUND: Gender differences in presentation, management and outcome in patients with ST-segment elevation myocardial infarction (STEMI) have been reported. AIM: To determine whether female gender is associated with higher inhospital mortality. METHODS: Data from ORBI, a regional STEMI registry of 5 years' standing, were analysed. The main data on presentation, management, inhospital outcome and prescription at discharge were compared between genders. Various adjusted hazard ratios were then calculated for inhospital mortality (women versus men). RESULTS: The analysis included 5000 patients (mean age 62.6±13 years), with 1174 women (23.5%). Women were on average 8 years older than men, with more frequent co-morbidities. Median ischaemia time was 215 minutes (26 minutes longer in women; P<0.05). Reperfusion strategies in women less frequently involved fibrinolysis, coronary angiography, radial access and thrombo-aspiration. Female gender, especially in patients aged<60 years, was associated with poorer inhospital prognosis (including higher inhospital mortality: 9% vs. 4% in men; P<0.0001), and underutilization of recommended treatments at discharge. Moreover, excess female inhospital mortality was independent of presentation, revascularization time and reperfusion strategy (hazard ratio for women 1.33, 95% confidence interval 1.01-1.76; P=0.04). CONCLUSIONS: One in four patients admitted for STEMI was female, with significant differences in presentation. Female gender was associated with less-optimal treatment, both in the acute-phase and at discharge. Efforts should be made to reduce these differences, especially as female gender was independently associated with an elevated risk of inhospital mortality

ACTIVATION (PercutAneous Coronary inTervention prIor to transcatheter aortic VAlve implantaTION): A Randomized Clinical Trial.

OBJECTIVES: This study sought to determine if percutaneous coronary intervention (PCI) prior to transcatheter aortic valve replacement (TAVR) in patients with significant coronary artery disease would produce noninferior clinical results when compared with no PCI (control arm). BACKGROUND: PCI in patients undergoing TAVR is not without risk, and there are no randomized data to inform clinical practice. METHODS: Patients with severe symptomatic aortic stenosis and significant coronary artery disease with Canadian Cardiovascular Society class ≤2 angina were randomly assigned to receive PCI or no PCI prior to TAVR. The primary endpoint was a composite of all-cause death or rehospitalization at 1 year. Noninferiority testing (prespecified margin of 7.5%) was performed in the intention-to-treat population. RESULTS: At 17 centers, 235 patients underwent randomization. At 1 year, the primary composite endpoint occurred in 48 (41.5%) of the PCI arm and 47 (44.0%) of the no-PCI arm. The requirement for noninferiority was not met (difference: -2.5%; 1-sided upper 95% confidence limit: 8.5%; 1-sided noninferiority test P = 0.067). On analysis of the as-treated population, the difference was -3.7% (1-sided upper 95% confidence limit: 7.5%; P = 0.050). Mortality was 16 (13.4%) in the PCI arm and 14 (12.1%) in the no-PCI arm. At 1 year, there was no evidence of a difference in the rates of stroke, myocardial infarction, or acute kidney injury, with higher rates of any bleed in the PCI arm (P = 0.021). CONCLUSIONS: Observed rates of death and rehospitalization at 1 year were similar between PCI and no PCI prior to TAVR; however, the noninferiority margin was not met, and PCI resulted in a higher incidence of bleeding. (Assessing the Effects of Stenting in Significant Coronary Artery Disease Prior to Transcatheter Aortic Valve Implantation; ISRCTN75836930)

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C