Diastolic delta best predicts paravalvular regurgitation after transcatheter aortic valve replacement as assessed by cardiac magnetic resonance: the APPOSE trial

Aims: Paravalvular regurgitation (PVR) is a common complication after transcatheter aortic valve replacement (TAVR) that poses an increased risk of rehospitalization for heart failure and mortality. The aim of this study was to assess the accuracy of haemodynamic indices to predict relevant PVR. Methods and results: In this prospective single-centre clinical trial, four haemodynamic indices of PVR measured during TAVR were assessed for their correlation with gold standard cardiac magnetic resonance (CMR)-derived regurgitant fraction (CMR-RF) at 1 month follow-up: diastolic delta (DD), heart rate-adjusted diastolic delta (HR-DD), aortic regurgitation index (ARI), and aortic regurgitation index ratio (ARI ratio). These haemodynamic indices were analysed for their ability to predict relevant PVR (defined as CMR-RF > 20%) using receiver operating characteristic (ROC) curves with corresponding area under the ROC curves (AUCs). A total of 77 patients were included and had CMR performed 41 ± 14 days after TAVR. Mean CMR-RF was 12.4 ± 9.3%. Fifteen (19.5%) patients had CMR-RF > 20%. DD had the best correlation with CMR-RF and the highest AUC to predict relevant PVR (0.82; 95% CI, 0.72-0.92), followed by HR-DD (AUC 0.78; 95% CI, 0.67-0.89), ARI (AUC 0.78; 95% CI, 0.66-0.89), and ARI ratio (AUC 0.65; 95% CI, 0.49-0.81). The optimal cut-off value for DD was 32 mmHg, with sensitivity of 69% and specificity of 77% in predicting relevant PVR. Conclusion: DD measured during TAVR best predicts relevant PVR. Correction for heart rate (HR-DD) or systolic blood pressure (ARI, ARI ratio) did not improve this predictive value

Fermentative production of isobutene

Isobutene (2-methylpropene) is one of those chemicals for which bio-based production might replace the petrochemical production in the future. Currently, more than 10 million metric tons of isobutene are produced on a yearly basis. Even though bio-based production might also be achieved through chemocatalytic or thermochemical methods, this review focuses on fermentative routes from sugars. Although biological isobutene formation is known since the 1970s, extensive metabolic engineering is required to achieve economically viable yields and productivities. Two recent metabolic engineering developments may enable anaerobic production close to the theoretical stoichiometry of 1isobutene + 2CO2 + 2H2O per mol of glucose. One relies on the conversion of 3-hydroxyisovalerate to isobutene as a side activity of mevalonate diphosphate decarboxylase and the other on isobutanol dehydration as a side activity of engineered oleate hydratase. The latter resembles the fermentative production of isobutanol followed by isobutanol recovery and chemocatalytic dehydration. The advantage of a completely biological route is that not isobutanol, but instead gaseous isobutene is recovered from the fermenter together with CO2. The low aqueous solubility of isobutene might also minimize product toxicity to the microorganisms. Although developments are at their infancy, the potential of a large scale fermentative isobutene production process is assessed. The production costs estimate is 0.9 € kg−1, which is reasonably competitive. About 70% of the production costs will be due to the costs of lignocellulose hydrolysate, which seems to be a preferred feedstock

Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

Development and testing of a composite index to monitor the continuum of maternal health service delivery at provincial and district level in South Africa

The continuum of care is a recommended framework for comprehensive health service delivery for maternal health, and it integrates health system and social determinants of health. There is a current lack of knowledge on a measurement approach to monitor performance on the framework. In this study we aim to develop and test a composite index for assessing the maternal health continuum in a province in South Africa with the possibility of nationwide use

Development of a supported self-management intervention for adults with type 2 diabetes and a learning disability

Background: Although supported self-management is a well-recognised part of chronic disease management, it has not been routinely used as part of healthcare for adults with a learning disability. We developed an intervention for adults with a mild or moderate learning disability and type 2 diabetes, building on the principles of supported self-management with reasonable adjustments made for the target population. Methods: In five steps, we: 1. Clarified the principles of supported self-management as reported in the published literature 2. Identified the barriers to effective self-management of type 2 diabetes in adults with a learning disability 3. Reviewed existing materials that aim to support self-management of diabetes for people with a learning disability 4. Synthesised the outputs from the first three phases and identified elements of supported self-management that were (a) most relevant to the needs of our target population and (b) most likely to be acceptable and useful to them 5. Implemented and field tested the intervention Results: The final intervention had four standardised components: (1) establishing the participant’s daily routines and lifestyle, (2) identifying supporters and their roles, (3) using this information to inform setting realistic goals and providing materials to the patient and supporter to help them be achieved and (4) monitoring progress against goals. Of 41 people randomised in a feasibility RCT, thirty five (85%) completed the intervention sessions, with over three quarters of all participants (78%) attending at least three sessions. Twenty-three out of 40 (58%) participants were deemed to be very engaged with the sessions and 12/40 (30%) with the materials; 30 (73%) participants had another person present with them during at least one of their sessions; 15/41 (37%) were reported to have a very engaged main supporter, and 18/41 (44%) had a different person who was not their main supporter but who was engaged in the intervention implementation. Conclusions: The intervention was feasible to deliver and, as judged by participation and engagement, acceptable to participants and those who supported them. Trial registration: Current Controlled Trials ISRCTN41897033 (registered 21/01/2013)

Transaxillary Transcatheter Aortic Valve Implantation: Preprocedural considerations and postprocedural outcomes

Contains fulltext : 222332.pdf (publisher's version ) (Open Access)Radboud University, 16 oktober 2020Promotores : Royen, N. van, Morshuis, W.J. Co-promotores : Kievit, P.C., Brouwer, M.A

Pre-hospital point-of-care troponin measurement: a clinical example of its additional value

In the majority of patients with chest pain, an acute coronary syndrome (ACS) can be ruled out. However, early recognition of an ACS is required in order to start treatment as soon as possible and reduce risks associated with myocardial ischaemia. Because of the lack of pre-hospital protocols to rule out an ACS, patients with a suspected ACS are transported to the emergency department, where the HEART score can be used to estimate the risk of major adverse cardiac events (MACE). Patients with a low HEART score have a low risk of MACE. A point-of-care (POC) troponin measurement enables ambulance paramedics to calculate the HEART score in the pre-hospital setting. POC troponin measurement and HEART score assessment have several potential advantages, including early recognition of an ACS and identification of high-risk patients before hospital arrival. Moreover, pre-hospital rule-out of an ACS could prevent unnecessary emergency department visits. The safety and cost-effectiveness of referring low-risk patients with a normal POC troponin value to the general practitioner are currently being investigated in the ARTICA randomised trial. This point-of-view article demonstrates one of the potential advantages of early detection of an ACS