Comparison of Elicitation Approaches in Early Stage HTA Applied on Artificial Thymus for Patients with DiGeorge Syndrome.

This paper focuses on research in expert elicitation as a part of the early stage health technology assessment (eHTA). The current state of affairs is analysed and two elicitation approaches are compared-the four fixed intervals method and the histogram method-as applied to an example of early assessment of clinical effectiveness of artificial thymus for patients with DiGeorge syndrome. A survey was carried out consisting of four questions concerning the topic, with the aim to apply the elicitation methods. Eight experts answered the questions using both elicitation methods. Based on their answers, the methods were compared visually and by means of statistical tests. In order to compare the perception of the two elicitation methods, the survey also included questions regarding the experts' subjective preferences. The results of the comparison of the two elicitation approaches did not clearly confirm which method was more beneficial and better; however, it was possible to indicate which of the two methods is better suited for different types of experts. Before selecting an elicitation method as a part of eHTA, it is advisable to effectively consider the technology to be assessed and the type of experts to be invited to share their opinion.

Vascular Remodeling of Clinically Used Patches and Decellularized Pericardial Matrices Recellularized with Autologous or Allogeneic Cells in a Porcine Carotid Artery Model.

Background: Cardiovascular surgery is confronted by a lack of suitable materials for patch repair. Acellular animal tissues serve as an abundant source of promising biomaterials. The aim of our study was to explore the bio-integration of decellularized or recellularized pericardial matrices in vivo. Methods: Porcine (allograft) and ovine (heterograft, xenograft) pericardia were decellularized using 1% sodium dodecyl sulfate ((1) Allo-decel and (2) Xeno-decel). We used two cell types for pressure-stimulated recellularization in a bioreactor: autologous adipose tissue-derived stromal cells (ASCs) isolated from subcutaneous fat of pigs ((3) Allo-ASC and (4) Xeno-ASC) and allogeneic Wharton's jelly mesenchymal stem cells (WJCs) ((5) Allo-WJC and (6) Xeno-WJC). These six experimental patches were implanted in porcine carotid arteries for one month. For comparison, we also implanted six types of control patches, namely, arterial or venous autografts, expanded polytetrafluoroethylene (ePTFE Propaten® Gore®), polyethylene terephthalate (PET Vascutek®), chemically stabilized bovine pericardium (XenoSure®), and detoxified porcine pericardium (BioIntegral® NoReact®). The grafts were evaluated through the use of flowmetry, angiography, and histological examination. Results: All grafts were well-integrated and patent with no signs of thrombosis, stenosis, or aneurysm. A histological analysis revealed that the arterial autograft resembled a native artery. All other control and experimental patches developed neo-adventitial inflammation (NAI) and neo-intimal hyperplasia (NIH), and the endothelial lining was present. NAI and NIH were most prominent on XenoSure® and Xeno-decel and least prominent on NoReact®. In xenografts, the degree of NIH developed in the following order: Xeno-decel > Xeno-ASC > Xeno-WJC. NAI and patch resorption increased in Allo-ASC and Xeno-ASC and decreased in Allo-WJC and Xeno-WJC. Conclusions: In our setting, pre-implant seeding with ASC or WJC had a modest impact on vascular patch remodeling. However, ASC increased the neo-adventitial inflammatory reaction and patch resorption, suggesting accelerated remodeling. WJC mitigated this response, as well as neo-intimal hyperplasia on xenografts, suggesting immunomodulatory properties.

Multi-lead vs single-lead Tpeak -T end interval measurements for prediction of reperfusion ventricular tachyarrhythmias.

INTRODUCTION: Electrocardiographic Tpeak -Tend interval (Tp-Te) is a promising marker for the prediction of ventricular tachycardia and/or ventricular fibrillation (VT/VF). The study was aimed to compare single-lead vs multilead Tp-Te variables as VT/VF predictors in experimental ischemia/reperfusion model. METHODS AND RESULTS: Computer simulations were done using the ECGSIM model with an ischemic region set in anterior left ventricular apex. In 18 anesthetized cats, myocardial ischemia was induced by 30-minute ligation of left anterior descending coronary artery followed by reperfusion. Body surface ECGs in limb leads and modified precordial leads were recorded. Tp-Te was detected automatically in individual leads with a custom-designed parametric algorithm. Tp-Te dispersion and total Tp-Te were calculated as a difference between the maximal and minimal value of individual Tp-Te(s) and an interval between the earliest Tpeak and the latest Tend throughout all leads, respectively. Simulations showed that the increase of local, but not total, dispersion of repolarization characteristic for ischemic damage led to nonuniform shortening of T-peak times across 12 standard leads, which in turn resulted in the increase of single-lead Tp-Te(s), total Tp-Te and Tp-Te dispersion. Animals experienced VT/VF showed increased Tp-Te dispersion and total Tp-Te during reperfusion. In univariate logistic regression analysis, only the Tp-Te dispersion at the beginning of reperfusion was associated with the VT/VF incidence. According to ROC curve analysis, the optimal cut-off value of the Tp-Te dispersion was 17 ms (sensitivity 0.71, specificity 0.80). CONCLUSIONS: The reperfusion VT/VFs were independently predicted by increased Tp-Te dispersion, which suggests the importance of multi-lead evaluation of Tp-Te intervals.

Electrocardiographic diagnosis of left ventricular hypertrophy on the basis of dipole electrocardiotopography method.

PURPOSE: The aim of this study was to verify a new criterion of hypertension-related left ventricular hypertrophy (LVH) on the basis of the dipole electrocardiotopographic technique, which provides intelligible pictorial patterns and efficient quantitative parameters for recognition of pathologic states of the heart. METHODS: Standard 12-lead and vectorcardiographic measurements with the McFee-Parungao lead system were carried out for 289 echocardiographically accessed healthy subjects and hypertensive patients with LVH. The proposed parameter index of left ventricular hypertrophy for recognition of LVH is a product of the following 3 characteristics: maximum magnitude of depolarization vector, total duration of ventricular depolarization, and local spatial integral of activation duration. This parameter was compared with several other parameters commonly used for LVH diagnosis. The diagnostic efficiencies of these parameters were statistically estimated and compared using the receiver operating characteristics (ROC curves), area under the ROC curve, and partial areas under the ROC curve (pAUC). The area under the ROC curve values were compared by the standard nonparametric method, and pAUC comparison was performed by bootstrap methodology. RESULTS: The ROC curves display the definite advantage of the proposed criterion, especially for the specificities greater than 0.7. Statistical comparative analysis showed that the corresponding pAUC for the index of left ventricular hypertrophy is greater than for R(x) + S(z), Cornell product, and Sokolow-Lyon criteria at confidence level > or = .95. CONCLUSION: The dipole electrocardiotopography-based diagnostic criterion of LVH is demonstrated to be statistically more accurate as compared to other criteria studied. The advantage of this criterion suggests that with the use of decartograms, it is possible to reveal some additional information not accessible for other diagnostic tools. Decartograms help to visualize and quantify the redistribution of activation duration over the myocardium, thus providing a valuable instrument for heuristic analysis and dynamic observation of the heart state affected by LVH.

Modular measuring system for assessment of the thyroid gland functional state.

Distributed modular system BioLab for biophysical examinations enabling assessment of the thyroid gland functional state is presented. Two smart sensors modules measuring 4 different biosignals are connected to an Ethernet based network and enable to obtain peripheral indicators of human cardiovascular and neuromuscular functions. Personal notebook or desktop computer with a network interface controls the sensors and performs processing and evaluation of measured biosignals.