Parked II

A group outdoor exhibition curated by Emma Douglas in two public garden squares in Clerkenwell, London: St John's Garden and the Cloister Garden (part of the Museum of St John)

Device-dependent association between paravalvar aortic regurgitation and outcome after TAVI

Objective The aim of the current study was to identify predictors of paraprosthetic aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) and examine its influence on short/medium-term mortality using the UK TAVI Registry. TAVI is an effective treatment for high-risk patients with severe symptomatic aortic stenosis (AS), but paraprosthetic AR has been associated with increased in-hospital and mid-term mortality. Methods Between January 2007 and December 2011, 2584 TAVI procedures were performed in the UK. Patients undergoing 'valve-in-valve' procedures, patients with aortic regurgitation as the primary pathology and with no recorded severity of AR were excluded from this analysis (n=144). In total, therefore, 2440 patients were included. Balloon-expandable and self-expanding devices were implanted in 52.7 and 47.2%, respectively, using either transfemoral (67.7%) or non-transfemoral, surgical access (32.3%). Results Postprocedural AR was observed in 68%, mild AR in 57% and moderate-severe in 10%. A large aortic annulus, high preprocedural transaortic gradient, and use of self-expanding valve were independent predictors of moderate-severe AR. Moderate-severe (but not mild) AR was associated with increased mortality, and this relationship appeared significant for the balloon-expandable but not the self-expanding device. Conclusions Our data suggest that a large aortic annulus, high preprocedural transaortic gradient, and use of the self-expanding valve predict moderate-severe AR after TAVI. Such a degree of AR is associated with a significantly worse outcome with the balloon-expandable, but not with the self-expanding valve. Further studies are needed to verify this and explore potential mechanisms. © 2014 BMJ Publishing Group Ltd & British Cardiovascular Society

Global drivers of forest loss at 1 km resolution

Forests are in decline worldwide due to human activities such as agricultural expansion, urbanization, and mineral extraction. Forest loss due to generally temporary causes, such as wildfire and logging, is important to distinguish from permanent land use conversion due to the differing ecological and climate impacts of these disturbances and for the purposes of developing effective policies and management strategies. Existing global maps of the drivers of forest loss that are widely used are not spatially or thematically detailed enough for decision makers at local-to-regional scales, such as governments, land managers, or companies. Using publicly available satellite observations (Landsat, Sentinel) and ancillary biophysical and population data, we developed a 1 km resolution, global map of the dominant drivers of forest loss from 2001 to 2022 with seven classes: permanent agriculture (e.g. commodity crops or pasture), hard commodities (e.g. mining), shifting cultivation, logging, settlements and infrastructure, wildfire, and other natural disturbances. We interpreted nearly 7000 reference samples to train a global neural network model that classifies the driver of tree cover loss with an overall accuracy of 90.5%. Our results show that permanent agriculture was the leading driver of forest loss globally, representing 35% of loss from 2001 to 2022. The drivers of tree cover loss vary by region, with the leading driver identified as logging in Europe, permanent agriculture across the tropics, and wildfire in Russia, the Asian mainland, North America, and Oceania. Our results enable assessment of forest disturbance dynamics from local to global scales and can support tracking progress towards corporate and governmental zero-deforestation commitments, monitoring deforestation risks within jurisdictions and supply chains, and assessment of global biodiversity targets

Complications of transcatheter aortic valve implantation: avoidance and management

Transcatheter aortic valve implantation (TAVI) has taken the world of cardiovascular therapies by storm. The possibility of implanting aortic valves without recourse to sternotomy or cardiopulmonary bypass has been embraced by cardiologists, surgeons and patients alike as a revolution in management. First performed in 2002 by Alain Cribier(1), the technique has exploded into common use during the last three years, such that over 20,000 implants have now been undertaken worldwide. This article discusses complications of TAVI, their avoidance and management.</p