Selection of the method to appraise and compare health systems using risk stratification: the ASSEHS approach.

To face the challenge of active and healthy ageing, European Health Systems and services should move towards proactive, anticipatory and integrated care. The comparison of methods to combine results across studies and to determine an overall effect was undertaken by the EU project ASSEHS (Activation of Stratification Strategies and Results of the interventions on frail patients of Healthcare Services, EU project (No. 2013 12 04). The questions raised in ASSEHS are broad and involve a complex body of literature. Thus, systematic reviews are not appropriate. The most appropriate method appears to be scoping studies. In this paper, an updated method of scoping studies has been used to determine the questions needed to appraise the health systems and services for frailty in the ageing population. Three objectives were set (i) to detect a relevant number of risk stratification tools for frailty and identify the best-in-class, (ii) to understand the feasibility of introducing stratification tools and identify the difficulties of the process and (iii) to find evidence on the impact of risk stratification in Health Services. This novel approach may provide greater clarity about scoping study methodology and help enhance the methodological rigor with which authors undertake and report scoping studies.

Clinical effects of an optimised care program with telehealth in heart failure patients in a community hospital in the Netherlands.

BACKGROUND: Our hypothesis was that telehealth in combination with an optimised care program coordinated amongst care professionals in primary, secondary and tertiary care can achieve beneficial outcomes in heart failure. The objective was to evaluate the clinical effects of introduction of telehealth in an optimised care program in a community hospital in the north of the Netherlands. METHODS: We compared the number of unplanned admissions for heart failure in the year before and after adding telehealth to the optimised care program. Furthermore, blood pressure and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were evaluated at baseline and 3, 6 and 12 months after telehealth. Quality of life and knowledge about the disease were regularly evaluated via surveys on the telehealth system. FINDINGS: The number of unplanned admissions for heart failure decreased from on average 1.29 to 0.31 admissions per year after telehealth introduction. Blood pressure decreased independent of medication and NT-proBNP levels improved as well. Quality of life increased during the telehealth intervention and disease knowledge remained high throughout the follow-up period. Unplanned admissions that remained after telehealth introduction could be accurately predicted at baseline by a multivariate regression model.

Early cardiac dysfunction is rescued by upregulation of SERCA2a pump activity in a rat model of metabolic syndrome.

AIM: Various components of metabolic syndrome associate with cardiac intracellular calcium (Cai 2+) mishandling, a precipitating factor in the development of heart failure. We aimed to provide a thorough description of early stage Cai 2+-cycling alterations in the fructose-fed rat, an experimental model of the disorder, where insulin resistance, hypertension and dyslipidaemia act cooperatively on the heart. METHOD: Rats were fed with fructose-rich chow. After 6 weeks, echocardiography was performed, which was followed by measurements of myocardial Cai 2+ transients recorded by Indo-1 surface fluorometry in isolated perfused hearts. Sarcoplasmic reticulum (SR) Ca(2+) -ATPase (SERCA2a) activity was assessed by administration of its inhibitor cyclopiazonic acid (CPA). Mathematical model analysis of Cai 2+ transients was used to estimate kinetic properties of SR Ca(2+) transporters. Protein levels of key Ca(2+) handling proteins were also measured. RESULTS: Echocardiography showed signs of cardiac hypertrophy, but in vivo and ex vivo haemodynamic performance of fructose-fed rat hearts were unaltered. However, a decline in Ca(2+) sequestration capacity (-dCai 2+/dt and decay time of Cai 2+ transients) was observed. Model estimation showed decreased affinity for Ca(2+) (higher K(m) ) and elevated V(max) for SERCA2a. Diseased hearts were more vulnerable to CPA application. Fructose feeding caused elevation in SERCA2a and phosphorylated phospholamban (PLB) expression, while total PLB level remained unchanged. CONCLUSION: In early stage, metabolic syndrome primarily disturbs SERCA2a function in the heart, but consequential haemodynamic dysfunction is prevented by upregulation of SERCA2a protein level and phosphorylation pathways regulating PLB. However, this compensated state is very vulnerable to a further decline in SERCA2a function.

Mathematical modelling of the calcium-left ventricular pressure relationship in the intact diabetic rat heart.

AIM: The objective was to characterize cross-bridge kinetics from the cytoplasmic calcium ion concentration ([Ca2+](i)) and the left ventricular pressure (LVP) in the early-stage diabetic rat heart under baseline conditions and upon beta-adrenergic stimulation. METHODS: Four weeks after the induction of diabetes in rats by the injection of streptozotocin, the hearts were perfused according to Langendorff, and [Ca2+](i) was obtained by epifluorescence measurements using Indo-1 AM. [Ca2+](i) and LVP were measured simultaneously at a temporal resolution of 200 Hz. The input/output relationship between the Ca2+ and the pressure transients was described by a mathematical model representing the chemical binding of Ca2+ to troponin C on the actin myofilament (TnCA), and the subsequent cooperative force-producing cross-bridge formation of the Ca2+-TnCA complex with myosin. The kinetic parameters of this model were evaluated using a numerical optimization algorithm to fit the model equations to the experimental data. beta-adrenergic stimulation of the hearts with increasing doses of isoproterenol allowed quantification of the model parameters over an extended dynamic range, because isoproterenol administration increased developed pressure, heart rate, as well as [Ca2+](i) amplitude in a dose-dependent manner. RESULTS: Model analysis of the experimental data indicates that beta-adrenergic stimulation of healthy hearts resulted in a decreased sensitivity of TnCA for Ca2+, increased rates of cross-bridge cycling and decreased cooperativity. By contrast, the responses in cross-bridge kinetic parameters to isoproterenol stimulation were blunted in the 4-week diabetic heart. CONCLUSION: We conclude from our modelling results that myocardial cross-bridge cycling is impaired at the early stage of diabetes.

Identification of a switching model of calcium cycling in isolated rat hearts.

So far, the processes involved in regulation of intracellular calcium (Ca/sub i//sup 2+/) in cardiomyocytes have been mainly studied through biochemical and isolated cell analysis. Here, we present a novel technique to model and identify cardiac Ca/sub i//sup 2+/-cycling under physiologically relevant conditions in the intact beating heart. Ca/sub i//sup 2+/ was measured using fluorescence techniques in ex vivo perfused rat hearts. For analysis, we developed a parametric mathematical model, switching between active and inactive calcium release. The kinetic parameters of the two submodes of the model were computed using a recently developed technique from hybrid system identification. Application of the method to control and isoproterenol-stimulated hearts resulted in parameter values within a physiologically reliable range.