470 research outputs found

    Myocardial stress perfusion scintigraphy for outcome prediction in patients with severe left ventricular systolic dysfunction

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    Abstract: Coronary angiography has been recommended in all patients with suspected chronic coronary syndrome and left ventricular ejection fraction (LVEF) ≤35%. The role of ischemia testing, for example, through stress-rest myocardial perfusion scintigraphy (MPS), for risk prediction is not well established. Methods: We evaluated 1576 consecutive patients referred to MPS and stratified into 3 LV ejection fraction (LVEF) categories: ≤35%, 36–49%, and ≥ 50%. Results: Patients with LVEF ≤35% were oldest, most often men, and with the highest likelihood of prior early (elective or urgent) coronary revascularization. They had also the highest values or summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS), as well as the highest frequency of significant coronary artery disease, and a greater number of diseased vessels. Follow-up: In this subgroup, 32 cardiovascular death or non-fatal myocardial infarction (MI) (21%), 35 all-cause deaths (22%), and 37 cardiovascular deaths, non-fatal MI, or late revascularizations (27%) were recorded with the shortest survival among all LVEF classes. SRS, SSS, and SDS had very low area under the curve values for the prediction of the 3 endpoints, with very high cut-offs, respectively. SRS and SSS cut-offs predicted a worse outcome in Cox regression models including the number of diseased vessels and early revascularization. Conclusions: In patients with LVEF ≤35%, SRS and SSS are less predictive of outcome than in patients with better preserved systolic dysfunction, but their cut-offs retain independent prognostic significance from the number of vessels with significant stenoses and from early revascularization

    Open TURNS: An industrial software for uncertainty quantification in simulation

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    The needs to assess robust performances for complex systems and to answer tighter regulatory processes (security, safety, environmental control, and health impacts, etc.) have led to the emergence of a new industrial simulation challenge: to take uncertainties into account when dealing with complex numerical simulation frameworks. Therefore, a generic methodology has emerged from the joint effort of several industrial companies and academic institutions. EDF R&D, Airbus Group and Phimeca Engineering started a collaboration at the beginning of 2005, joined by IMACS in 2014, for the development of an Open Source software platform dedicated to uncertainty propagation by probabilistic methods, named OpenTURNS for Open source Treatment of Uncertainty, Risk 'N Statistics. OpenTURNS addresses the specific industrial challenges attached to uncertainties, which are transparency, genericity, modularity and multi-accessibility. This paper focuses on OpenTURNS and presents its main features: openTURNS is an open source software under the LGPL license, that presents itself as a C++ library and a Python TUI, and which works under Linux and Windows environment. All the methodological tools are described in the different sections of this paper: uncertainty quantification, uncertainty propagation, sensitivity analysis and metamodeling. A section also explains the generic wrappers way to link openTURNS to any external code. The paper illustrates as much as possible the methodological tools on an educational example that simulates the height of a river and compares it to the height of a dyke that protects industrial facilities. At last, it gives an overview of the main developments planned for the next few years

    Differential effects of iron chelators on iron burden and long-term morbidity and mortality outcomes in a large cohort of transfusion-dependent β-thalassemia patients who remained on the same monotherapy over 10 years

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    We conducted a retrospective cohort study on 663 transfusion-dependent β-thalassemia patients receiving the same iron chelation monotherapy with deferoxamine, deferiprone, or deferasirox for up to 10 years (median age 31.8 years, 49.9 % females). Patients on all three iron chelators had a steady and significant decline in serum ferritin over the 10 years (median deferoxamine: -170.7 ng/mL, P = 0.049, deferiprone: -236.7 ng/mL, P = 0.001; deferasirox: -323.7 ng/mL, P < 0.001) yet had no significant change in liver iron concentration or cardiac T2*; while noting that patients generally had low hepatic and cardiac iron levels at study start. Median absolute, relative, and normalized changes were generally comparable between the three iron chelators. Patients receiving deferasirox had the highest morbidity and mortality-free survival probability among the three chelators, although the difference was only statistically significant when compared with deferoxamine (P = 0.037). On multivariate Cox regression analysis, there was no significant association between iron chelator type and the composite outcome of morbidity or mortality. In a real-world setting, there is comparable long-term iron chelation effectiveness between the three available iron chelators for patients with mild-to-moderate iron overload

    Molecular approaches in the diagnosis of sepsis in neutropenic patients with haematological malignances

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    Introduction. Sepsis is a major cause of significant morbidity and mortality in neutropenic patients. Blood culture remains the gold standard in the microbiological diagnosis of bacterial or fungal bloodstream infections, but it has clear limits of rapidity and sen- sitivity. The objective of the study was to compare the real-time polymerase chain reaction (RT-PCR) with automated blood cul- tures (BC) method in detection in whole blood of pathogens in febrile neutropenic patients with hematological malignancies. Methods. A total of 166 consecutive febrile neutropenic patients were enrolled. Blood samples for cultures and SeptiFast testing were obtained at the onset of fever, before the implementation of empirical antibiotic therapy. Results. Forty (24.1%) samples out of the 166 blood samples tested, were positive by at least one method. Twenty-three (13.9%) samples were positive by blood culture and 38 (22.9%) by multi- plex real-time PCR. The analysis of concordance evidenced a low correlation between the two methods (n = 21; 52.5%), mainly due to samples found negative by culture but positive with the Septi- Fast assay. Sensitivity, specificity, and positive and negative pre- dictive values of RT-PCR were 91.3%, 88.1%, 55.3%, and 98.4%, respectively, compared with BC. Discussion. Multiplex real-time PCR assay improved detection of the most bacteria associated with febrile neutropenia episodes. Fur- ther studies are needed to assess the real advantages and clinical benefits that molecular biology tests can add in diagnosis of sepsis. The full article is free available on www.jpmh.or

    Revisiting iron overload status and change thresholds as predictors of mortality in transfusion-dependent β-thalassemia: a 10-year cohort study

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    Data on iron overload status and change thresholds that can predict mortality in patients with transfusion-dependent β-thalassemia (TDT) are limited. This was a retrospective cohort study of 912 TDT patients followed for up to 10 years at treatment centers in Italy (median age 32 years, 51.6% female). The crude mortality rate was 2.9%. Following best-predictive threshold identification through receiver operating characteristic curve analyses, data from multivariate Cox-regression models showed that patients with Period Average Serum Ferritin (SF) > 2145 vs ≤ 2145 ng/mL were 7.1-fold (P < 0.001) or with Absolute Change SF > 1330 vs ≤ 1330 ng/mL increase were 21.5-fold (P < 0.001) more likely to die from any cause. Patients with Period Average Liver Iron Concentration (LIC) > 8 vs ≤ 8 mg/g were 20.2-fold (P < 0.001) or with Absolute Change LIC > 1.4 vs ≤ 1.4 mg/g increase were 27.6-fold (P < 0.001) more likely to die from any cause. Patients with Index (first) cardiac T2* (cT2*) < 27 vs ≥ 27 ms were 8.6-fold (P < 0.001) more likely to die from any cause. Similarly, results at varying thresholds were identified for death from cardiovascular disease. These findings should support decisions on iron chelation therapy by establishing treatment targets, including safe iron levels and clinically meaningful changes over time
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