36 research outputs found
Implementing the new European Regulations on medical devices-clinical responsibilities for evidence-based practice:a report from the Regulatory Affairs Committee of the European Society of Cardiology
The new European Union (EU) law governing the regulatory approval of medical devices that entered into force in May 2017 will now take effect from 26 May 2021. Here, we consider how it will change daily practice for cardiologists, cardiac surgeons, and healthcare professionals. Clinical evidence for any high-risk device must be reported by the manufacturer in a Summary of Safety and Clinical Performance (SSCP) that will be publicly available in the European Union Database on Medical Devices (Eudamed) maintained by the European Commission; this will facilitate evidence-based choices of which devices to recommend. Hospitals must record all device implantations, and each high-risk device will be trackable by Unique Device Identification (UDI). Important new roles are envisaged for clinicians, scientists, and engineers in EU Expert Panels-in particular to scrutinize clinical data submitted by manufacturers for certain high-risk devices and the evaluations of that data made by notified bodies. They will advise manufacturers on the design of their clinical studies and recommend to regulators when new technical specifications or guidance are needed. Physicians should support post-market surveillance by reporting adverse events and by contributing to comprehensive medical device registries. A second law on In Vitro Diagnostic Medical Devices will take effect from 2022. We encourage all healthcare professionals to contribute proactively to these new systems, in order to enhance the efficacy and safety of high-risk devices and to promote equitable access to effective innovations. The European Society of Cardiology will continue to advise EU regulators on appropriate clinical evaluation of high-risk devices
A new scoring system to determine thromboembolic risk after heart valve replacement
Objectiveâ To determine the most important inflammatory and hematologic predictors of thromboembolism (TE) in patients undergoing valve replacement (VR) to be used in conjunction with clinical risk factors for preoperative risk profiling.
Methods and Resultsâ Preoperative and immediately postoperative clinical, echocardiographic, hematologic, biochemical and microbiological parameters were examined prospectively in 370 patients undergoing VR (249 AVR, 93 MVR, 28 DVR). Mean follow-up was 4.4 years (max 6.6 years; total 1566 pt/yrs), and 96 TE events were documented (28 major and 68 minor). INR data were collected on all patients. Laboratory values were considered elevated if they exceeded the 80th percentile of those of 70 controls with the same distribution of age and gender. IgA antibody to Chlamydia pneumoniae (CP)â„1:64 was considered indicative of significant infection. Predictors of TE on multivariate analysis following AVR were (hazard ratios): CP infection (2.6), previous TE (2.5), raised eosinophils (2.4), cancer history (2.1), postoperative infection (2.0), hypertension (2.0), CABG Ă 3/4 (2.0), and diabetes (1.9). Predictors of TE following MVR/DVR were raised mean platelet volume (4.0), raised factor VII (3.1), CP infection (2.7), previous mitral valvotomy (2.5), raised fibrinogen (2.2), and raised reticulocytes (2.0). These risk factors were additive when present in the same patient, enabling a scoring system to be developed that accurately predicted risk of TE based on number of risk factors.
Conclusionsâ Selected blood tests and clinical risk factors provide a scoring system that accurately predicts TE risk and may guide prosthesis choice and antithrombotic management
Stratosphereâtroposphere coupling and annular mode variability in chemistryâclimate models
The internal variability and coupling between the stratosphere and troposphere in CCMValâ2 chemistryâclimate models are evaluated through analysis of the annular mode patterns of variability. Computation of the annular modes in long data sets with secular trends requires refinement of the standard definition of the annular mode, and a more robust procedure that allows for slowly varying trends is established and verified. The spatial and temporal structure of the modelsâ annular modes is then compared with that of reanalyses. As a whole, the models capture the key features of observed intraseasonal variability, including the sharp vertical gradients in structure between stratosphere and troposphere, the asymmetries in the seasonal cycle between the Northern and Southern hemispheres, and the coupling between the polar stratospheric vortices and tropospheric midlatitude jets. It is also found that the annular mode variability changes little in time throughout simulations of the 21st century. There are, however, both common biases and significant differences in performance in the models. In the troposphere, the annular mode in models is generally too persistent, particularly in the Southern Hemisphere summer, a bias similar to that found in CMIP3 coupled climate models. In the stratosphere, the periods of peak variance and coupling with the troposphere are delayed by about a month in both hemispheres. The relationship between increased variability of the stratosphere and increased persistence in the troposphere suggests that some tropospheric biases may be related to stratospheric biases and that a wellâsimulated stratosphere can improve simulation of tropospheric intraseasonal variability
An expert-assisted citizen science program involving agricultural high schools provides national patterns on bee species assemblages
The need for transparency of clinical evidence for medical devices in Europe
To use medical devices rationally, health-care professionals must base their choices of which devices to recommend for individual patients on an objective appraisal of their safety and clinical efficacy. The evidence submitted by manufacturers when seeking approval of their high-risk devices must be publicly available, including technical performance and premarket clinical studies. Giving physicians access to this information supplements the peer-reviewed scientific literature and might be essential for comparing alternative devices within any class. Interested patients should be encouraged to review the evidence for any device that has been recommended for them. The new EU law on medical devices states that the manufacturer is to prepare a summary of the evidence for any implantable or high-risk device. Defining its content, however, has been delegated to implementing legislation, which is now being considered. From a clinical perspective, it is imperative that all evidence reviewed by notified bodies and regulatory authorities is disclosedâwith the exception, if justified, only of technical specifications that are considered confidential or manufacturing details that are protected as intellectual propertyâand public access to this evidence must be guaranteed by EU law. From ethical and other perspectives, there are no grounds for less clinical evidence being available to health-care professionals about the medical devices that they use than is already available for new pharmaceutical products. Full transparency is needed; without it, informed decisions relating to the use of new medical devices will remain impossible
Morphologic analysis of a strand recovered from a prosthetic mitral valve: no evidence of fibrin
We report the first morphologic analysis of a linear mobile structure (strand) detected by transesophageal echocardiography on a bioprosthetic mitral valve and then recovered at surgery. Electron microscopy showed it to consist of a sparsely cellular component, with extracellular amorphous or fibrillary areas. Collagen was largely responsible for the fibrillary appearance