0491: Extracardiac or chromosomal anomalies strongly influence parental treatment decision and postnatal survival of neonates with prenatally diagnosed congenital heart diseases

ObjectivesThis study was design to assess the influence of extracardiac or chromosomal anomalies on parental decision of termination of pregnancy and on survival rates in newborns with prenatally diagnosed congenital heart diseases.Methods and results2057 consecutive foetuses with congenital heart disease diagnosed from January 2002 to December 2011 were included: 1258 (61%) in-born neonates and 799 (39%) terminations of pregnancy (TOP). The overall prevalence of major extracardiac or chromosomal anomalies was 18,6%. Of the 1258 newborns, 121 had a major associated anomaly but only 55 were identified before birth. Prenatally identified associated anomalies were significantly lower in the newborn group in comparison with the TOP group (4% vs 31%, p<0,0001). They were also lower in the surviving group at one year of follow up (7,5% vs 20,7%, p<0,0001). A 4-fold increase of death rate was observed if an associated anomaly was identified (IC95%[2,5-6,7], p<0,0001). These associations remained significant after multiple logistic regression analysis including the severity of the heart defect (univentricular or biventricular physiology).ConclusionWomen are more likely to terminate pregnancy if extracardiac or chromosomal anomalies are associated. Post natal survival is strongly influenced by these associated anomalies

Off-pump replacement of the pulmonary valve in large right ventricular outflow tracts: A hybrid approach

BackgroundPercutaneous pulmonary valve replacement has recently been introduced and is under investigation in humans. This technique is, however, limited to patients with a right ventricular outflow tract that does not exceed 22 mm in diameter. We report our experience of off-pump pulmonary valve replacement using a hybrid approach in animals with large right ventricular outflow tracts.MethodsEight ewes were included in the protocol and were equally divided into 2 groups. A left thoracotomy was first performed, and the main pulmonary artery was banded by using 2 radiopaque rings with a diameter of 18 mm that allowed for further pulmonary valve replacement. We then intended to implant a valved stent either percutaneously (group 1) or through a transventricular approach (group 2). All animals were killed after valve implantation. The operation allowed the pulmonary diameter to be reduced from 30 to 17.6 mm.ResultsThe right ventricular pressure did not significantly increase after reduction of the pulmonary artery diameter (25 vs 36 mm Hg). Subsequent pulmonary valve replacement through a percutaneous or a transventricular approach was always possible without any requirement for extracorporeal circulation. All devices were successfully delivered inside the pulmonary artery banding and were functioning perfectly at early evaluation.ConclusionsImplantation of a pulmonary valve is possible in ewes through a hybrid approach when the right ventricular outflow tract exceeds 22 mm in diameter. This involves both surgeons and interventionists and allows for a staged procedure in which the valvulation is performed percutaneously or, for a combined hybrid approach, in which the valve is implanted off pump transventricularly during the same operation

275: Percutaneous insertion of a Melody valve in tricuspid position: technical aspects

Backgroundpercutaneous transcatheter heart valve replacement of aortic or pulmonary valve is established. Transcatheter atrioventricular valve replacement is been described. We report our experience focusing on the technical aspects.Methodswe retrospectively review the files of patients who received a transcatheter valve in tricuspid position between 2008 and 2012.ResultsFour patients were found. 3 had a heterograft (conduit of 14-mm, Sorin 33 et Edwards Perimount 33) and one had a connection between the RA and the RV infundibulum without a valve. Two patients had tricuspid regurgitation as a primary lesion, one had stenotic valve and the last one a mixted lesion. All successfully received a Melody valve from a femoral access. In patients with stenotic lesion, a predilatation using a high pressure balloon was performed before valve implant. In patients with regurgitation, the landing zone was calibrated using a low pressure balloon. These patients were presented to create a landing zone of adequate diameter. Melody valves were inserted using a 22-mm balloon catheter in 3 and a 24-mm in one. All but one were post-dilated. There was no significant regurgitation. The mean gradient across the tricuspid valve felt from 12 to 4.6-mmHg. One patient needed an epicardic pacemaker because of AV block following balloon dilatation. One patient required inotropic support and ventilation following the procedure but recovered after few days.ConclusionTranscatheter tricuspid valve insertion is feasible in patients with surgical hetero or homografts after a careful selection. The mechanism of dysfunction must be known. In case of stenosis or mixted lesions, the only question is to know if the stenosis could be relief. In case of regurgitation, it is very important to know the features of surgical substrats and to calibrate the tricuspid orifice. Finally, patients with inappropriate landing zone should be presented prior to valve insertion

0483: Cardiac magnetic resonance imaging and left ventricular diastolic function in children with hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) has a variety of causes in children. In adult, Cardiac Magnetic Resonance imaging (CMR) is emerging as a unique tool particularly suited to define myocardial anatomy and fibrosis. The purpose of the study is to define the feasibility and the role of CMR in children with HCM as well as the influence of myocardial fibrosis on left ventricular (LV) diastolic function in children.MethodsCMR protocol included T2 weighted sequence in short axis view, TRIPLE IR FSE sequence, cine SSFP in short axis, two-chamber, three and four chamber view without contrast and perfusion analysis and late enhancement after injection of contrast agent. If left ventricular wall thickness seemed asymmetric, the size and location of relatively thickened segments were noted. Echocardiography analyzed LV diastolic function.ResultsA total of 60 patients were included in the study. Age at diagnosis was 3 years (range 1 day to 16 years). Mean age at CMR was 11 years (range 1-18 years). CMR was successfully performed in all patients, revealing a better performance in comparison to echocardiography to define precisely the anatomy of LV hypertrophy. Mean LV mass was estimated at 94±41gr/m2. LV hypertrophy was concentric in 32 patients, asymmetric in 28 patients, with evidence of LV non-compaction aspect in 7 patients. The right ventricle was affected in 7 cases. Presence of LV fibrosis was detected in 6 patients in LV septum. Perfusion defects were present in 5 patients in papillary muscles. LV function was reduced (LV ejection fraction < 55%) in 7 patients. While LV fibrosis was rare, LV diastolic dysfunction was found in the majority of children.ConclusionCMR in children with HCM is feasible and it contributes to anatomic definition and tissue analysis. LV diastolic function in pediatric HCM is common but is not related to fibrosis or perfusion defects. Prognostic value of fibrosis and perfusion defects have to be evaluated

Efficacy and safety of tadalafil in a pediatric population with pulmonary arterial hypertension:phase 3 randomized, double-blind placebo-controlled study

This study evaluated the efficacy and safety of tadalafil in pediatric patients with pulmonary arterial hypertension. This phase-3, international, randomized, multicenter (24 weeks double-blind placebo-controlled period; two-year, open-labeled extension period), add-on (patient’s current endothelin receptor antagonist therapy) study included pediatric patients aged <18 years with pulmonary arterial hypertension. Patients received tadalafil 20 mg or 40 mg based on their weight (heavy-weight: ≥40 kg; middle-weight: ≥25 to <40 kg) or placebo orally once daily for 24 weeks. Primary endpoint was change from baseline in six-minute walk distance in patients aged ≥6 years at Week 24. Sample size was amended from 134 to ≥34 patients, due to serious recruitment challenges. Therefore, statistical significance testing was not performed between treatment groups. Results showed that patient demographics and baseline characteristics (N = 35; tadalafil = 17; placebo = 18) were comparable between treatment groups; median age was 14.2 years (6.2–17.9 years) and majority (71.4%, n = 25) of patients were in the heavy-weight cohort. Least square mean (standard error) changes from baseline in six-minute walk distance at Week 24 was numerically greater with tadalafil versus placebo (60.48 (20.41) vs 36.60 (20.78) meters; placebo-adjusted mean difference (standard deviation) 23.88 (29.11)). Safety of tadalafil treatment was as expected without any new safety concerns. During study Period 1, two patients (one in each group) discontinued due to investigator’s reported clinical worsening, and no deaths were reported. In conclusion, the statistical significance testing was not performed between the treatment groups due to low sample size; however, the study results show positive trend in improvement in non-invasive measurements, commonly utilized by clinicians to evaluate the disease status for children with pulmonary arterial hypertension. Safety of tadalafil treatment was as expected without any new safety signals

A fast BEM procedure using the Z-transform and high-frequency approximations for large-scale 3D transient wave problems

International audience3D rapid transient acoustic problems are difficult to solve numerically when dealing with large geometries, because numerical methods based on geometry discretisation (mesh), such as the boundary element method (BEM) or the finite element method (FEM), often require to solve a linear system (from the spacial discretisation) for each time step. We propose a numerical method to efficiently deal with 3D rapid transient acoustic problems set in large exterior domains. Using the Z-transform and the convolution quadrature method (CQM), we first present a straightforward way to reframe the problem to the solving of a large amount (the number of time steps, M) of frequency-domain BEMs. Then, taking advantage of a well-designed high-frequency approximation (HFA), we drastically reduce the number of frequency-domain BEMs to be solved, with little loss of accuracy. The complexity of the resulting numerical procedure turns out to be O(1) in regards to the time discretisation and O(N log N) for the spacial discretisation, the latter being prescribed by the complexity of the used fast BEM solver. Examples of applications are proposed to illustrate the efficiency of the procedure in the case of fluid-structure interaction: the radiation of an acoustic wave into a fluid by a deformable structure with prescribed velocity, and the scattering of an abrupt wave by simple and realistic geometries

Reconnaissance d'objets grâce à l'analyse des composantes couleur adaptées au changement d'éclairage entre deux images

Dans le domaine de l'indexation d'images, les méthodes de reconnaissance d'objets couleur ont tendance à échouer lorsque les conditions d'éclairage lors des acquisitions diffèrent d'une image à l'autre. Dans cet article, nous proposons une nouvelle approche pour la recherche d'objets dans des bases d'images couleur qui permet de s'affranchir des variations d'éclairage. Pour cela, nous considérons qu'un changement d'illuminant ne perturbe que très légèrement l'ordre des niveaux des composantes couleur des pixels d'une même image. Pour comparer deux images, nous transformons les composantes couleur de manière spécifique à chaque couple formé par une image-modèle et une image-requête. Les composantes couleur des pixels de chaque couple d'images considéré sont transformées par une analyse spécifique des mesures de rang des pixels. Des tests effectués sur une base publique d'images montrent l'amélioration obtenue par notre méthode en terme de reconnaissance d'objets