Hypoalbuminaemia predicts outcome in adult patients with congenital heart disease

Background In patients with acquired heart failure, hypoalbuminaemia is associated with increased risk of death. The prevalence of hypoproteinaemia and hypoalbuminaemia and their relation to outcome in adult patients with congenital heart disease (ACHD) remains, however, unknown. Methods Data on patients with ACHD who underwent blood testing in our centre within the last 14 years were collected. The relation between laboratory, clinical or demographic parameters at baseline and mortality was assessed using Cox proportional hazards regression analysis. Results A total of 2886 patients with ACHD were included. Mean age was 33.3 years (23.6–44.7) and 50.1% patients were men. Median plasma albumin concentration was 41.0 g/L (38.0–44.0), whereas hypoalbuminaemia (<35 g/L) was present in 13.9% of patients. The prevalence of hypoalbuminaemia was significantly higher in patients with great complexity ACHD (18.2%) compared with patients with moderate (11.3%) or simple ACHD lesions (12.1%, p<0.001). During a median follow-up of 5.7 years (3.3–9.6), 327 (11.3%) patients died. On univariable Cox regression analysis, hypoalbuminaemia was a strong predictor of outcome (HR 3.37, 95% CI 2.67 to 4.25, p<0.0001). On multivariable Cox regression, after adjusting for age, sodium and creatinine concentration, liver dysfunction, functional class and disease complexity, hypoalbuminaemia remained a significant predictor of death. Conclusions Hypoalbuminaemia is common in patients with ACHD and is associated with a threefold increased risk of risk of death. Hypoalbuminaemia, therefore, should be included in risk-stratification algorithms as it may assist management decisions and timing of interventions in the growing ACHD population

Non-Arrhenius Behavior of Surface Diffusion Near a Phase Transition Boundary

We study the non-Arrhenius behavior of surface diffusion near the second-order phase transition boundary of an adsorbate layer. In contrast to expectations based on macroscopic thermodynamic effects, we show that this behavior can be related to the average microscopic jump rate which in turn is determined by the waiting-time distribution W(t) of single-particle jumps at short times. At long times, W(t) yields a barrier that corresponds to the rate-limiting step in diffusion. The microscopic information in W(t) should be accessible by STM measurements.Comment: 4 pages, Latex with RevTeX macro

Right atrial area and right ventricular outflow tract akinetic length predict sustained tachyarrhythmia in repaired tetralogy of Fallot

AIMS: Repaired tetralogy of Fallot (rtoF) patients are at risk of atrial or ventricular tachyarrhythmia and sudden cardiac death. Risk stratification for arrhythmia remains difficult. We investigated whether cardiac anatomy and function predict arrhythmia. METHODS: One-hundred-and-fifty-four adults with rtoF, median age 30.8 (21.9–40.2) years, were studied with a standardised protocol including cardiovascular magnetic resonance (CMR) and prospectively followed up over median 5.6 (4.6–7.0) years for the pre-specified endpoints of new-onset atrial or ventricular tachyarrhythmia (sustained ventricular tachycardia/ventricular fibrillation). RESULTS: Atrial tachyarrhythmia (n = 11) was predicted by maximal right atrial area indexed to body surface area (RAAi) on four-chamber cine-CMR (Hazard ratio 1.17, 95% Confidence Interval 1.07–1.28 per cm(2)/m(2); p = 0.0005, survival receiver operating curve; ROC analysis, area under curve; AUC 0.74 [0.66–0.81]; cut-off value 16 cm(2)/m(2)). Atrial arrhythmia-free survival was reduced in patients with RAAi ≥ 16 cm(2)/m(2) (logrank p = 0.0001). Right ventricular (RV) restrictive physiology on echocardiography (n = 38) related to higher RAAi (p = 0.02) and had similar RV dilatation compared with remaining patients. Ventricular arrhythmia (n = 9) was predicted by CMR RV outflow tract (RVOT) akinetic area length (Hazard ratio 1.05, 95% Confidence Interval 1.01–1.09 per mm; p = 0.003, survival ROC analysis, AUC 0.77 [0.83–0.61]; cut-off value 30 mm) and decreased RV ejection fraction (Hazard ratio 0.93, 95% Confidence Interval 0.87–0.99 per %; p = 0.03). Ventricular arrhythmia-free survival was reduced in patients with RVOT akinetic region length > 30 mm (logrank p = 0.02). CONCLUSION: RAAi predicts atrial arrhythmia and RVOT akinetic region length predicts ventricular arrhythmia in late follow-up of rtoF. These are simple, feasible measurements for inclusion in serial surveillance and risk stratification of rtoF patients

Dietary protein restriction throughout intrauterine and postnatal life results in potentially beneficial myocardial tissue remodeling in the adult mouse heart

Diet composition impacts metabolic and cardiovascular health with high caloric diets contributing to obesity related disorders. Dietary interventions such as caloric restriction exert beneficial effects in the cardiovascular system, but alteration of which specific nutrient is responsible is less clear. This study investigates the effects of a low protein diet (LPD) on morphology, tissue composition and function of the neonatal and adult mouse heart. Mice were subjected to LPD (8.8% protein) or standard protein diet (SPD, 22% protein) throughout intrauterine and postnatal life. At birth LPD female but not male offspring exhibit reduced body weight whereas heart weight was unchanged in both sexes. Cardiomyocyte cross sectional area was increased in newborn LPD females compared to SPD, whereas proliferation, cellular tissue composition and vascularization were unaffected. Adult female mice on LPD exhibit reduced body weight but normal heart weight compared to SPD controls. Echocardiography revealed normal left ventricular contractility in LPD animals. Histology showed reduced interstitial fibrosis, lower cardiomyocyte volume and elevated numbers of cardiomyocyte and non-myocyte nuclei per tissue area in adult LPD versus SPD myocardium. Furthermore, capillary density was increased in LPD hearts. In conclusion, pre- and postnatal dietary protein restriction in mice causes a potentially beneficial myocardial remodeling

He Scattering from Compact Clusters and from Diffusion-Limited Aggregates on Surfaces: Observable Signatures of Structure

The angular intensity distribution of He beams scattered from compact clusters and from diffusion limited aggregates, epitaxially grown on metal surfaces, is investigated theoretically. The purpose is twofold: to distinguish compact cluster structures from diffusion limited aggregates, and to find observable {\em signatures} that can characterize the compact clusters at the atomic level of detail. To simplify the collision dynamics, the study is carried out in the framework of the sudden approximation, which assumes that momentum changes perpendicular to the surface are large compared with momentum transfer due to surface corrugation. The diffusion limited aggregates on which the scattering calculations were done, were generated by kinetic Monte Carlo simulations. It is demonstrated, by focusing on the example of compact Pt Heptamers, that signatures of structure of compact clusters may indeed be extracted from the scattering distribution. These signatures enable both an experimental distinction between diffusion limited aggregates and compact clusters, and a determination of the cluster structure. The characteristics comprising the signatures are, to varying degrees, the Rainbow, Fraunhofer, specular and constructive interference peaks, all seen in the intensity distribution. It is also shown, how the distribution of adsorbate heights above the metal surface can be obtained by an analysis of the specular peak attenuation. The results contribute to establishing He scattering as a powerful tool in the investigation of surface disorder and epitaxial growth on surfaces, alongside with STM.Comment: 41 pages, 16 postscript figures. For more details see http://www.fh.huji.ac.il/~dan

Percutaneous Pulmonary Valve Implantation in Small Conduits: A Multicenter Experience

BACKGROUND: Guidelines allow percutaneous pulmonary valve implantation (PPVI) in conduits above 16mm diameter. Balloon dilatation of a conduit to a diameter>110% of the original implant size is also not recommended. We analyzed patients undergoing PPVI in such conditions. METHODS AND RESULTS: Nine patients (May 2008-July 2016) from 8 institutions underwent PPVI in conduits 110%. Mean age and weight of the 14 patients was 12.1 (7.7 to 16) years and 44.9 (19 to 83) kg. Median conduit diameter at PPVI was 12 (10 to 17) mm. Median systolic right ventricular pressure was 70 (40 to 94) mmHg. Procedure was successful in all cases. A confined conduit rupture occurred in 7 patients (50%) and was treated with covered stent in 6. One patient experienced dislocation of 2 pulmonary artery stents that were parked distally. The post-implantation median systolic right ventricular pressure was 36 (28 to 51) mmHg. A fistula between right-ventricle outflow and aorta was found in one patient, secondary to undiagnosed conduit rupture. This was closed surgically. After a median follow-up of 20.16 (6.95 to 103.61) months, all the patients are asymptomatic with no significant RVOT stenosis. CONCLUSIONS: PPVI is feasible in small conduits but rate of ruptures is high. Although such ruptures remain contained and can be managed with covered stents in our experience, careful selection of patients and high level of expertise are necessary. More studies are needed to better assess the risk of PPVI in this population.info:eu-repo/semantics/publishedVersio

Near-infrared spectroscopy as a predictor of clinical deterioration: a case report of two infants with duct-dependent congenital heart disease

Background: Some infants with congenital heart disease are at risk of in-hospital cardiac arrest. To better foresee cardiac arrest in infants with congenital heart disease, it might be useful to continuously assess end-organ perfusion. Near-infrared spectroscopy is a non-invasive method to continuously assess multisite regional tissue oxygen saturation. Case presentation: We report on two infants with duct-dependent congenital heart disease who demonstrated a gradual change in cerebral and/or renal tissue oxygen saturation before cardiopulmonary resuscitation was required. In both cases, other clinical parameters such as heart rate, arterial oxygen saturation and blood pressure did not indicate that deterioration was imminent. Conclusions: These two cases demonstrate that near-infrared spectroscopy might contribute to detecting a deteriorating clinical condition and might therefore be helpful in averting cardiopulmonary collapse and need for resuscitation in infants with congenital heart disease

Three-dimensional late gadolinium enhancement cardiovascular magnetic resonance predicts inducibility of ventricular tachycardia in adults with repaired tetralogy of Fallot

Background - Adults with repaired tetralogy of Fallot (rTOF) die prematurely from ventricular tachycardia (VT) and sudden cardiac death. Inducible VT predicts mortality. Ventricular scar, the key substrate for VT, can be non-invasively defined with late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) but whether this relates to inducible VT is unknown. Methods - Sixty-nine consecutive rTOF patients (43 male, mean 40{plus minus}15 years) clinically scheduled for invasive programmed VT-stimulation were prospectively recruited for prior 3D LGE CMR. Ventricular LGE was segmented and merged with reconstructed cardiac chambers and LGE volume measured. Results - VT was induced in 22(31%) patients. Univariable predictors of inducible VT included increased RV LGE (OR 1.15;p=0.001 per cm3), increased non-apical vent LV LGE (OR 1.09;p=0.008 per cm3), older age (OR 1.6;p=0.01 per decile), QRS duration ≥180ms (OR 3.5;p=0.02), history of non-sustained VT (OR 3.5; p=0.02) and previous clinical sustained VT (OR 12.8;p=0.003); only prior sustained VT (OR 8.02;p=0.02) remained independent in bivariable analyses after controlling for RV LGE volume (OR 1.14;p=0.003). An RV LGE volume of 25cm3 had 72% sensitivity and 81% specificity for predicting inducible VT (AUC 0.81;p10cm3 was 100% sensitive and >36cm3 was 100% specific for predicting inducible VT. Conclusions - 3D LGE CMR-defined scar burden is independently associated with inducible VT and may help refine patient selection for programmed VT-stimulation when applied to an at least intermediate clinical risk cohort

Tracer diffusion and correlations in ordered adsorption systems with defect-controlled transport mechanisms

In this study we develop a theory of tracer diffusion in 2D lattice-gas systems with strongly repulsive nearest neighbor interactions. The study is performed for a square lattice in the vicinity of half monolayer coverage. In this case the lattice gas forms a highly-ordered c$(2\times 2)$ phase. The adatom kinetics is reduced to the problem of random walks of long-living structural defects. The correlated motion of tracer-defect pairs is considered. Equations for correlation functions of tracer-vacancy, tracer-excessive adatoms and tracer-dimer pairs are derived and solved in terms of microscopic jump probabilities of defects. The solutions are exact in the case of dominant single defect transport mechanisms. In the case of dimer transport we applied the approximation of short-range correlation length. The values obtained for the correlation factor are in good agreement with the results of computer simulations in the over-stoichiometric range, while for sub-stoichiometric coverages the agreement is not very good