To retrospectively quantify right ventricular dysfunction (RVD) and the pulmonary artery obstruction index at helical computed tomography (CT) on the basis of various criteria proposed in the ...literature and to assess the predictive value of these CT parameters for mortality within 3 months after the initial diagnosis of pulmonary embolism (PE).
Institutional review board approval was obtained, and informed consent was not required for retrospective study. In 120 consecutive patients (55 men, 65 women; mean age +/- standard deviation, 59 years +/- 18) with proved PE, two readers assessed the extent of RVD by quantifying the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV) and the pulmonary artery to ascending aorta diameters, the shape of the interventricular septum, and the extent of obstruction to the pulmonary artery circulation on helical CT images, which were blinded for clinical outcome in consensus reading. Regression analysis was used to correlate these parameters with patient outcome.
CT signs of RVD (RV/LV ratio, >1.0) were seen in 69 patients (57.5%). During follow-up, seven patients died of PE. Both the RV/LV ratio and the obstruction index were shown to be significant risk factors for mortality within 3 months (P = .04 and .01, respectively). No such relationship was found for the ratio of the pulmonary artery to ascending aorta diameters (P = .66) or for the shape of the interventricular septum (P = .20). The positive predictive value for PE-related mortality with an RV/LV ratio greater than 1.0 was 10.1% (95% confidence interval CI: 2.9%, 17.4%). The negative predictive value for an uneventful outcome with an RV/LV ratio of 1.0 or less was 100% (95% CI: 94.3%, 100%). There was a 11.2-fold increased risk of dying of PE for patients with an obstruction index of 40% or higher (95% CI: 1.3, 93.6).
Markers of RVD and pulmonary vascular obstruction, assessed with helical CT at baseline, help predict mortality during follow-up.
A computational model for mesolevel analysis of progressive laminate failure is presented. A previously developed discrete model for mesh independent representation of matrix cracks is combined with ...continuum descriptions for fiber failure and matrix nonlinearity. For fiber failure, a continuum damage model is introduced and a phenomenological damage/plasticity law is used for the shear nonlinearity. Special attention is paid to the application of the dissipation based arclength method to these models, where the presence of residual stresses is also taken into account. With the analysis of a notched cross-ply laminate the importance of the different components of the model to capture the complete failure process correctly is exemplified.
In a randomized trial, 5661 patients with acute myocardial infarction and a reduced left ventricular ejection fraction, pulmonary congestion, or both were assigned to receive either ...sacubitril–valsartan or ramipril. At a median of 22 months, there was no significant difference between the two groups in the incidence of death from cardiovascular causes or incident heart failure.
A combined experimental and numerical investigation is conducted on the anisotropic water diffusion behaviour of unidirectional glass/epoxy composites. Experimental diffusivity values are obtained by ...immersing thin material slices for each of its planes of orthotropy extracted from a thick composite panel and interphase measurements are performed using thermal analysis. In order to elucidate the observed anisotropy, the diffusion process is modelled at the microscale using a representative volume element (RVE) of the material with random fibre distribution. Water concentration gradients are applied to the micromodel and a homogenisation procedure is used to retrieve the macroscopic diffusivity coefficients. The influence of the interphase around the fibres on the diffusion process is modelled by making the matrix diffusivity a function of the distance to the nearest fibre using a level set field. The models are used to fit the experimental data and test a number of hypotheses that may explain the observed anisotropy. The effect of fibres acting as barriers for water movement is found to partially explain the observed transverse diffusivity. However, a fit is only obtained by allowing faster diffusivity at the interphase. In the longitudinal direction, a fit can only be found by allowing for orthotropic interphase diffusivity.
Background
Obese subjects have lower natriuretic peptide levels, but males and females have different anthropometric characteristics and fat distribution. Whether obesity‐associated lowering of ...natriuretic peptides differs among males and females is unknown. Therefore, we investigated sex‐specific associations of obesity and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) levels among adults in the general population.
Methods and results
Using 8260 participants (50.1% females) from the Prevention of REnal and Vascular ENd‐stage Disease (PREVEND) cohort, we evaluated the relationship of NT‐proBNP levels with obesity‐associated parameters, i.e. waist circumference (WC), body mass index (BMI) and body weight in the overall population, and in males and females separately. NT‐proBNP levels were higher in females (median, interquartile range: 50.5, 28.2–87.0 ng/L) than in males (24.3, 10.1–54.6 ng/L; P < 0.001). In the overall population, NT‐proBNP levels were significantly lower in heavier individuals and displayed a ‘U‐shaped’ relationship with increasing WC, but were not associated with BMI. After sex stratification, there was no significant association between NT‐proBNP concentrations and anthropometric measures in females. However, in males increasing WC and BMI were associated with higher NT‐proBNP levels (P < 0.05) while increasing body weight was associated with slightly lower NT‐proBNP levels (P < 0.05). Age strongly confounded the association of NT‐proBNP levels with obesity, and age‐associated increases in NT‐proBNP were significantly higher in males than in females (P < 0.001). In multivariable adjusted analyses, the inverse association of obesity and NT‐proBNP levels was also significantly modified by sex: NT‐proBNP levels were lower with increasing WC, BMI and body weight among females compared with males (Pinteraction < 0.05). After also accounting for BMI, abdominal obesity was associated with lower NT‐proBNP levels in females, but not in males (Pinteraction < 0.001).
Conclusions
Natriuretic peptide deficiency in obesity mostly pertains to females with abdominal obesity, whereas the relationship between obesity and natriuretic peptides appears to be more complex in males.
Serum selenium levels have been associated with the incidence of heart failure (HF) and signs of the metabolic syndrome. In addition, notable differences have been reported between males and females ...in food intake and micronutrient metabolism, possibly explaining different health outcomes.
Our objective was to elucidate sex-specific, cross-sectional phenotypic differences in the association of serum selenium concentrations with parameters of metabolic syndrome and HF.
We investigated data from individuals from a community-based cohort (PREVEND; N = 4288) and heart failure cohort (BIOSTAT-CHF; N = 1994). In both populations, cross-sectional analyses were performed for potential interaction (p < 0.1) between sex and serum selenium with overlapping signs and clinical parameters of the metabolic syndrome and HF.
Baseline selenium levels of the total cohort were similar between PREVEND (85.7 μg/L) and BIOSTAT-CHF (89.1 μg/L). Females with lower selenium levels had a higher BMI and increased prevalence of diabetes than females with higher selenium, in both PREVEND (p
< 0.001; p
= 0.040, resp.) and BIOSTAT-CHF (p
= 0.021; p
= 0.024, resp.), while opposite associations were observed for males. Additionally, in females, but not in males, lower selenium was associated with a higher prevalence of myocardial infarction (MI) in PREVEND (p
= 0.021) and BIOSTAT-CHF (p
= 0.084).
Lower selenium was associated with a higher BMI and increased prevalence of diabetes in females, opposite to males, and was also associated with more MI in females. Interventional studies are needed to validate this observation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work investigates hygrothermal aging degradation of unidirectional glass/epoxy composite specimens through a combination of experiments and numerical modeling. Aging is performed through ...immersion in demineralized water. Interlaminar shear testes are performed after multiple conditioning times and after single immersion/redrying cycles. Degradation of the fiber-matrix interface is estimated using single-fiber fragmentation tests and reverse modeling combining analytical and numerical models. A fractographic analysis of specimens aged at 50°C and 65°C is performed through X-ray computed tomography. The aging process is modeled using a numerical framework combining a diffusion analysis with a concurrent multiscale model with embedded hyper-reduced micromodels. At the microscale, a pressure-dependent viscoelastic/viscoplastic model with damage is used for the resin and fiber-matrix debonding is modeled with a cohesive-zone model including friction. A comparison between numerical and experimental results is performed.
•Experiments and numerical models are used to investigate hot/wet aging in composites.•ILSS tests and X-ray micro CT scans are conducted on both unaged and aged specimens.•A multiphysics/multiscale numerical framework is used to simulate the aging process.•The micromodels feature a VE/VP/D epoxy model and cohesive interfaces with friction.•A hyper-reduced micromodel is obtained by combining the POD and ECM techniques.
Low-dose colchicine reduces cardiovascular risk in patients with coronary artery disease (CAD), but absolute benefits may vary between individuals. This study aimed to assess the range of individual ...absolute benefits from low-dose colchicine according to patient risk profile.
The European Society of Cardiology (ESC) guideline-recommended SMART-REACH model was combined with the relative treatment effect of low-dose colchicine and applied to patients with CAD from the Low-Dose Colchicine 2 (LoDoCo2) trial and the Utrecht Cardiovascular Cohort-Second Manifestations of ARTerial disease (UCC-SMART) study (n = 10 830). Individual treatment benefits were expressed as 10-year absolute risk reductions (ARRs) for myocardial infarction, stroke, or cardiovascular death (MACE), and MACE-free life-years gained. Predictions were also performed for MACE plus coronary revascularization (MACE+), using a new lifetime model derived in the REduction of Atherothrombosis for Continued Health (REACH) registry. Colchicine was compared with other ESC guideline-recommended intensified (Step 2) prevention strategies, i.e. LDL cholesterol (LDL-c) reduction to 1.4 mmol/L and systolic blood pressure (SBP) reduction to 130 mmHg. The generalizability to other populations was assessed in patients with CAD from REACH North America and Western Europe (n = 25 812). The median 10-year ARR from low-dose colchicine was 4.6% interquartile range (IQR) 3.6-6.0% for MACE and 8.6% (IQR 7.6-9.8%) for MACE+. Lifetime benefit was 2.0 (IQR 1.6-2.5) MACE-free years, and 3.4 (IQR 2.6-4.2) MACE+-free life-years gained. For LDL-c and SBP reduction, respectively, the median 10-year ARR for MACE was 3.0% (IQR 1.5-5.1%) and 1.7% (IQR 0.0-5.7%), and the lifetime benefit was 1.2 (IQR 0.6-2.1) and 0.7 (IQR 0.0-2.3) MACE-free life-years gained. Similar results were obtained for MACE+ and in American and European patients from REACH.
The absolute benefits of low-dose colchicine vary between individual patients with chronic CAD. They may be expected to be of at least similar magnitude to those of intensified LDL-c and SBP reduction in a majority of patients already on conventional lipid-lowering and blood pressure-lowering therapy.
In this paper, a number of techniques used to accelerate the solution of finite element problems involving a large number of load cycles areexplored and applied to the micromechanical analysis of ...fiber-reinforced composites. The microscopic domain consists of unidirectional linear-elastic fibers embedded in a viscoelastic/viscoplastic polymeric matrix. Time homogenization is applied to divide the original equilibrium problem in macro- and microchronological parts. The size of the problem is further reduced by a combination of Proper Orthogonal Decomposition (POD) and the Empirical Cubature Method (ECM), resulting in a hyper-reduced model. A novel technique for history recovery combining Gappy Data reconstruction with a k-means clustering algorithm is proposed, as well as an adaptive strategy combining time homogenization and POD without an offline training phase. The performance of each acceleration technique is assessed and the resultant speed-ups obtained by combining them are presented.
•Plastic strain can be updated only once per load cycle using time homogenization.•Microchronological cycles may be skipped for further acceleration.•The combination of POD and ECM dramatically accelerates the analysis.•Clustering can be used to reduce the cost of stresses and history recovery.•Speed-ups higher than 1000 are obtained when combining all techniques.
The large, international, randomized controlled NeoPInS trial showed that procalcitonin (PCT)-guided decision making was superior to standard care in reducing the duration of antibiotic therapy and ...hospitalization in neonates suspected of early-onset sepsis (EOS), without increased adverse events. This study aimed to perform a cost-minimization study of the NeoPInS trial, comparing health care costs of standard care and PCT-guided decision making based on the NeoPInS algorithm, and to analyze subgroups based on country, risk category and gestational age.
Data from the NeoPInS trial in neonates born after 34 weeks of gestational age with suspected EOS in the first 72 h of life requiring antibiotic therapy were used. We performed a cost-minimization study of health care costs, comparing standard care to PCT-guided decision making.
In total, 1489 neonates were included in the study, of which 754 were treated according to PCT-guided decision making and 735 received standard care. Mean health care costs of PCT-guided decision making were not significantly different from costs of standard care (€3649 vs. €3616). Considering subgroups, we found a significant reduction in health care costs of PCT-guided decision making for risk category 'infection unlikely' and for gestational age ≥ 37 weeks in the Netherlands, Switzerland and the Czech Republic, and for gestational age < 37 weeks in the Czech Republic.
Health care costs of PCT-guided decision making of term and late-preterm neonates with suspected EOS are not significantly different from costs of standard care. Significant cost reduction was found for risk category 'infection unlikely,' and is affected by both the price of PCT-testing and (prolonged) hospitalization due to SAEs.
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