Dual weighted residual error estimation for the finite cell method

The paper presents a goal-oriented error control based on the dual weighted residual method (DWR) for the finite cell method (FCM), which is characterized by an enclosing domain covering the domain of the problem. The error identity derived by the DWR method allows for a combined treatment of the discretization and quadrature error introduced by the FCM. We present an adaptive strategy with the aim to balance these two error contributions. Its performance is demonstrated for some two-dimensional examples

Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and Europe

Background and aims: Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to identify cross-continental differences in utilization of primary prevention ICDs and survival free from sustained ventricular arrhythmia (VA) in ARVC. Methods: This was a retrospective analysis of ARVC patients without prior VA enrolled in clinical registries from 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe and were further stratified by baseline predicted VA risk into low- (25%/5 years) groups. Differences in ICD implantation and survival free from sustained VA events (including appropriate ICD therapy) were assessed. Results: One thousand ninety-eight patients were followed for a median of 5.1 years; 554 (50.5%) received a primary prevention ICD, and 286 (26.0%) experienced a first VA event. After adjusting for baseline risk factors, North Americans were more than three times as likely to receive ICDs {hazard ratio (HR) 3.1 [95% confidence interval (CI) 2.5, 3.8]} but had only mildly increased risk for incident sustained VA [HR 1.4 (95% CI 1.1, 1.8)]. North Americans without ICDs were at higher risk for incident sustained VA [HR 2.1 (95% CI 1.3, 3.4)] than Europeans. Conclusions: North American ARVC patients were substantially more likely than Europeans to receive primary prevention ICDs across all arrhythmic risk strata. A lower rate of ICD implantation in Europe was not associated with a higher rate of VA events in those without ICDs

Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and Europe

BACKGROUND AND AIMS: Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to identify cross-continental differences in utilization of primary prevention ICDs and survival free from sustained ventricular arrhythmia (VA) in ARVC. METHODS: This was a retrospective analysis of ARVC patients without prior VA enrolled in clinical registries from 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe and were further stratified by baseline predicted VA risk into low- (25%/5 years) groups. Differences in ICD implantation and survival free from sustained VA events (including appropriate ICD therapy) were assessed. RESULTS: One thousand ninety-eight patients were followed for a median of 5.1 years; 554 (50.5%) received a primary prevention ICD, and 286 (26.0%) experienced a first VA event. After adjusting for baseline risk factors, North Americans were more than three times as likely to receive ICDs {hazard ratio (HR) 3.1 [95% confidence interval (CI) 2.5, 3.8]} but had only mildly increased risk for incident sustained VA [HR 1.4 (95% CI 1.1, 1.8)]. North Americans without ICDs were at higher risk for incident sustained VA [HR 2.1 (95% CI 1.3, 3.4)] than Europeans. CONCLUSIONS: North American ARVC patients were substantially more likely than Europeans to receive primary prevention ICDs across all arrhythmic risk strata. A lower rate of ICD implantation in Europe was not associated with a higher rate of VA events in those without ICDs

Dual weighted residual error estimation for the finite cell method

The paper presents a goal-oriented error control based on the dual weighted residual method (DWR) for the finite cell method (FCM), which is characterized by an enclosing domain covering the domain of the problem. The error identity derived by the DWR method allows for a combined treatment of the discretization and quadrature error introduced by the FCM. We present an adaptive strategy with the aim to balance these two error contributions. Its performance is demonstrated for several two-dimensional examples(VLID)384486

Proceedings in Applied Mathematics & Mechanics / A posteriori error control for the finite cell method

The paper presents some concepts of the finite cell method and discusses a posteriori error control for this approach. The focus is on the application of the dual weighted residual approach (DWR), which enables the control of the error with respect to a userdefined quantity of interest. Since both the discretization error and the quadrature error are estimated, the application of the DWR approach provides an adaptive strategy which equilibrates the error contributions resulting from discretization and quadrature. The strategy consists in refining either the finite cell mesh or its associated quadrature mesh. Numerical experiments confirm the performance of the error control and the adaptive scheme for a nonlinear problem in 2D.(VLID)460562

Sacubitril/Valsartan Induces Global Cardiac Reverse Remodeling in Long-Lasting Heart Failure with Reduced Ejection Fraction: Standard and Advanced Echocardiographic Evidences

Sacubitril/valsartan reduces mortality in heart failure with reduced ejection fraction (HFrEF) patients, partially due to cardiac reverse remodeling (RR). Little is known about the RR rate in long-lasting HFrEF and the evolution of advanced echocardiographic parameters, despite their known prognostic impact in this setting. We sought to evaluate the rates of left ventricle (LV) and left atrial (LA) RR through standard and advanced echocardiographic imaging in a cohort of HFrEF patients, after the introduction of sacubitril/valsartan. A multi-parametric standard and advanced echocardiographic evaluation was performed at the moment of introduction of sacubitril/valsartan and at 3 to 18 months subsequent follow-up. LVRR was defined as an increase in the LV ejection fraction 6510 points associated with a decrease 6510% in indexed LV end-diastolic diameter; LARR was defined as a decrease >15% in the left atrium end-systolic volume. We analyzed 77 patients (65 \ub1 11 years old, 78% males, 40% ischemic etiology) with 76 (28-165) months since HFrEF diagnosis. After a median follow-up of 9 (interquartile range 6-14) months from the beginning of sacubitril/valsartan, LVRR occurred in 20 patients (26%) and LARR in 33 patients (43%). Moreover, left ventricular global longitudinal strain (LVGLS) improved from -8.3 \ub1 4% to -12 \ub1 4.7% (p 25% of cases, both at standard and advanced echocardiographic evaluations

Spline- and hp-basis functions of higher differentiability in the finite cell method

In this paper, the use of hpbasis functions with higher differentiability properties is discussed in the context of the finite cell method and numerical simulations on complex geometries. For this purpose, Ck hpbasis functions based on classical Bsplines and a new approach for the construction of C1 hpbasis functions with minimal local support are introduced. Both approaches allow for hanging nodes, whereas the new C1 approach also includes varying polynomial degrees. The properties of the hpbasis functions are studied in several numerical experiments, in which a linear elastic problem with some singularities is discretized with adaptive refinements. Furthermore, the application of the Ck hpbasis functions based on Bsplines is investigated in the context of nonlinear material models, namely hyperelasticity and elastoplasicity with finite strains.(VLID)439440

Spline- and hp-basis functions of higher differentiability in the finite cell method

In this paper, the use of hp-basis functions with higher differentiability properties is discussed in the context of the finite cell method and numerical simulations on complex geometries. For this purpose, Ck hp-basis functions based on classical B-splines and a new approach for the construction of C1 hp-basis functions with minimal local support are introduced. Both approaches allow for hanging nodes, whereas the new C1 approach also includes varying polynomial degrees. The properties of the hp-basis functions are studied in several numerical experiments, in which a linear elastic problem with some singularities is discretized with adaptive refinements. Furthermore, the application of the Ck hp-basis functions based on B-splines is investigated in the context of nonlinear material models, namely hyperelasticity and elastoplasicity with finite strains.Support by the Deutsche Forschungsgemeinschaft in the Priority Program 1748 “Reliable simulation techniques in solid mechanics. Development of non-standard discretization methods, mechanical and mathematical analysis” under the project DU 405/8-2, SCHR 1244/4-2, and RA 624/27-2

Contemporary survival trends and aetiological characterization in non-ischaemic dilated cardiomyopathy

Aim: Contemporary survival trends in dilated cardiomyopathy (DCM) are largely unknown. The aim of this study is to investigate clinical descriptors, survival trends and the prognostic impact of aetiological characterization in DCM patients. Methods and results: Dilated cardiomyopathy patients were consecutively enrolled and divided into four groups according to the period of enrolment (1978-1984; 1985-1994; 1995-2004; and 2005-2015). A subset of patients with DCM of specific aetiology, enrolled from 2005 to 2015, was also analysed. Over a mean follow-up of 12 \ub1 8 years, 1284 DCM patients (52 in the 1978-1984 group, 326 in the 1985-1994 group, 379 in the 1995-2004 group, and 527 in the 2005-2015 group) were evaluated. Despite older age (mean age 51 \ub1 15, 43 \ub1 15, 45 \ub1 14, and 52 \ub1 15 years for the 1978-1984, 1985-1994, 1995-2004, and 2005-2015 groups, respectively; P < 0.001), most of the baseline clinical characteristics improved in the 2005-2015 group, suggesting a less advanced disease stage at diagnosis. Similarly, at competing risk analysis, the annual incidence of all outcome parameters progressively decreased over time (global P < 0.001). At multivariable analysis, the last period of enrolment emerged as independently associated with a reduction in all-cause mortality/heart transplantation (HTx)/ventricular assist device (VAD) implantation (1.46 events/100 patients/year), cardiovascular death/HTx/VAD implantation (0.82 events/100 patients/year) and sudden cardiac death (0.15 events/100 patients/year). Lastly, in 287 patients with DCM of specific aetiology, patients with environmental, toxic, or removable factors appeared to have different phenotypes and prognosis compared to those with genetic, post-myocarditis, or idiopathic DCM (P < 0.001). Conclusions: Contemporary survival trends in DCM significantly improved, mainly due to a reduction of cardiovascular events. Appropriate aetiological characterization might help in prognostication of DCM patients

Performance of risk stratification scores and role of comorbidities in older vs younger patients with pulmonary arterial hypertension

Background: Risk scores are important tools for the prognostic stratification of pulmonary arterial hypertension (PAH). Their performance and the additional impact of comorbidities across age groups is unknown. Methods: Patients with PAH enrolled from 2001 to 2021 were divided in ≥65 years old vs <65 years old patients. Study outcome was 5-year all-cause mortality. French Pulmonary Hypertension Network (FPHN), FPHN noninvasive, Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) and Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL 2.0) risk scores were calculated and patients categorized at low, intermediate and high risk. Number of comorbidities was calculated. Results: Among 383 patients, 152 (40%) were ≥65 years old. They had more comorbidities (number of comorbidities 2, IQR 1-3, vs 1, IQR 0-2 in <65 years patients). Five-year survival was 63% in ≥65 vs 90% in <65 years. Risk scores correctly discriminated the different classes of risk in the overall cohort and in the older and younger groups. REVEAL 2.0 showed the best accuracy in the total cohort (C-index 0.74, standard error-SE- 0.03) and older (C-index 0.69, SE 0.03) patients, whereas COMPERA 2.0 performed better in younger patients (C-index 0.75, SE 0.08). Number of comorbidities was associated with higher 5-year mortality, and consistently increased the accuracy of risk scores, in younger but not in older patients. Conclusions: Risk scores have similar accuracy in the prognostic stratification of older vs younger PAH patients. REVEAL 2.0 had the best performance in older patients and COMPERA 2.0 had it in younger patients. Comorbidities increased the accuracy of risk scores only in younger patients