Transcatheter aortic valve implantation in patients with rheumatic aortic stenosis.

BACKGROUND Rheumatic heart disease (RHD) accounts for the highest number of deaths from valvular heart disease globally. Yet, rheumatic aortic stenosis (AS) was excluded from landmark studies investigating the safety and efficacy of transcatheter aortic valve implantation (TAVI). We aimed to describe the clinical and anatomical characteristics of patients with rheumatic AS undergoing TAVI, and to compare procedural and clinical outcomes with patients undergoing TAVI for degenerative AS. METHODS In a prospective TAVI registry, patients with rheumatic AS were identified based on International Classification of Diseases version 10 codes and/or a documented history of acute rheumatic fever and/or the World Heart Federation criteria for echocardiographic diagnosis of RHD, and were propensity score-matched in a 1:4 ratio to patients with degenerative AS. RESULTS Among 2329 patients undergoing TAVI, 105 (4.5%) had rheumatic AS. Compared with patients with degenerative AS, patients with rheumatic AS were more commonly female, older, had higher surgical risk and more commonly suffered from multivalvular heart disease. In the unmatched cohort, both technical success (85.7% vs 85.9%, p=0.887) and 1-year cardiovascular mortality (10.0% vs 8.6%; HR 1.16, 95% CI 0.61 to 2.18, p=0.656) were comparable between patients with rheumatic and degenerative AS. In contrast, patients with rheumatic AS had lower rates of 30-day and 1-year cardiovascular mortality compared with matched patients with degenerative AS (1.9% vs 8.9%, adjusted HR (HRadj) 0.18, 95% CI 0.04 to 0.80, p=0.024; and 10.0% vs 20.3%, HRadj 0.44, 95% CI 0.24 to 0.84, p=0.012, respectively). CONCLUSION TAVI may be a safe and effective treatment strategy for selected elderly patients with rheumatic AS. TRIAL REGISTRATION NUMBER NCT01368250

Reproducibility of 4D cardiac computed tomography feature tracking myocardial strain and comparison against speckle-tracking echocardiography in patients with severe aortic stenosis.

BACKGROUND Myocardial strain is an established parameter for the assessment of cardiac function and routinely derived from speckle tracking echocardiography (STE). Novel post-processing tools allow deformation imaging also by 4D cardiac computed tomography angiography (CCT). This retrospective study aims to analyze the reproducibility of CCT strain and compare it to that of STE. METHODS Left (LV) and right ventricular (RV), and left atrial (LA) ejection fraction (EF), dimensions, global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) were determined by STE and CCT feature tracking in consecutive patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation. RESULTS 106 patients (mean age 79.9 ​± ​7.8, 44.3% females) underwent CCT at a median of 3 days (IQR 0-28 days) after STE. In CCT, strain measures showed good to excellent reproducibility (intra- and inter-reader intraclass correlation coefficient ≥0.75) consistently in the LV, RV and LA. In STE, only LV GLS and LA GLS yielded good reproducibility, whereas LV GCS and LV GRS showed moderate, and RV GLS and free wall longitudinal strain (FWLS) poor reproducibility. Agreement between CCT and STE was strong for LV GLS only, while other strain features displayed moderate (LV GCS, LA GLS) or weak (LV GRS, RV GLS and FWLS) inter-modality correlation. CONCLUSION LV, RV and LA CCT strain assessments were highly reproducible. While a strong agreement to STE was found for LV GLS, inter-modality correlation was moderate or weak for LV GCS, LV GRS, and RV and LA longitudinal strain, possibly related to poor reproducibility of STE measurements

LEGaTO: first steps towards energy-efficient toolset for heterogeneous computing

LEGaTO is a three-year EU H2020 project which started in December 2017. The LEGaTO project will leverage task-based programming models to provide a software ecosystem for Made-in-Europe heterogeneous hardware composed of CPUs, GPUs, FPGAs and dataflow engines. The aim is to attain one order of magnitude energy savings from the edge to the converged cloud/HPC.Peer ReviewedPostprint (author's final draft

Extractability of elements in sugar maple xylem along a gradient of soil acidity

Dendrochemistry has been used for the historical dating of pollution. Its reliability is questionable due primarily to the radial mobility of elements in sapwood. In the present study, the extractability of seven elements was characterized to assess their suitability for the monitoring of environmental conditions. Nine mature sugar maple trees (Acer saccharum Marsh.), a wide-ranging species in eastern North America that has suffered decline in past decades, were sampled in three Quebec watersheds along a soil acidity gradient. Five-year groups of annual tree rings were treated by sequential chemical extractions using extractants of varying strength (deionized H2O, 0.05 M HCl, and concentrated HNO3) to selectively solubilize the elements into three fractions (water-soluble, acid-soluble, and residual). Monovalent K; divalent Ba, Ca, Cd, Mg, Mn; and trivalent Al cations were found mostly in the water-soluble, acid-soluble, and residual fractions, respectively. Forms more likely to be mobile within the tree (water-soluble and acid-soluble) do not seem to be suitable for temporal monitoring because of potential lateral redistribution in sapwood rings. However, certain elements (Cd, Mn) were responsive to current soil acidity and could be used in spatial variation monitoring. Extractability of Al varied according to soil acidity; at less acidic sites, up to 90% of Al was contained in the residual form, whereas on very acidic soils, as much as 45% was found in the water-soluble and acid-soluble fractions. Sequential extractions can be useful for determining specific forms of metals as key indicators of soil acidification

LEGaTO: towards energy-efficient, secure, fault-tolerant toolset for heterogeneous computing

LEGaTO is a three-year EU H2020 project which started in December 2017. The LEGaTO project will leverage task-based programming models to provide a software ecosystem for Made-in-Europe heterogeneous hardware composed of CPUs, GPUs, FPGAs and dataflow engines. The aim is to attain one order of magnitude energy savings from the edge to the converged cloud/HPC.Peer ReviewedPostprint (author's final draft

Resource-efficient Reconfigurable Computer-on-Module for Embedded Vision Applications

Klimeck D, Meyer HG, Hagemeyer J, Porrmann M, Rückert U. Resource-efficient Reconfigurable Computer-on-Module for Embedded Vision Applications. In: 2018 IEEE 29th International Conference on Application-specific Systems, Architectures and Processors (ASAP). Piscataway, NJ: IEEE; 2018

Impact of Left Ventricular Outflow Tract Calcification on Procedural Outcomes After Transcatheter Aortic Valve Replacement.

OBJECTIVES This study aimed to systematically assess the importance of left ventricular outflow tract (LVOT) calcification on procedural outcomes and device performances with contemporary transcatheter heart valve (THV) systems. BACKGROUND LVOT calcification has been associated with adverse clinical outcomes after transcatheter aortic valve replacement (TAVR). However, the available evidence is limited to observational data with modest numbers and incomplete assessment of the effect of the different THV systems. METHODS In a retrospective analysis of a prospective single-center registry, LVOT calcification was assessed in a semiquantitative fashion. Moderate or severe LVOT calcification was documented in the presence of 2 nodules of calcification, or 1 extending >5 mm in any direction, or covering >10 % of the perimeter of the LVOT. RESULTS Among 1,635 patients undergoing TAVR between 2007 and 2018, moderate or severe LVOT calcification was found in 407 (24.9%). Patients with moderate or severe LVOT calcification had significantly higher incidences of annular rupture (2.3% vs. 0.2%; p < 0.001), bailout valve-in-valve implantation (2.9% vs. 0.8%; p = 0.004), and residual aortic regurgitation (11.1% vs. 6.3%; p = 0.002). Balloon-expandable valves conferred a higher risk of annular rupture in the presence of moderate or severe LVOT calcification (4.0% vs. 0.4%; p = 0.002) as compared with the other valve designs. There was no significant interaction of valve design or generation and LVOT calcification with regard to the occurrence of bailout valve-in-valve implantation and residual aortic regurgitation. CONCLUSIONS Moderate or severe LVOT calcification confers increased risks of annular rupture, residual aortic regurgitation, and implantation of a second valve. The risk of residual aortic regurgitation is consistent across valve designs and generations. (SWISS TAVI Registry; NCT01368250)

Triggered and Tunable Hydrogen Sulfide Release from Photogenerated Thiobenzaldehydes

International audienceHydrogen sulfide (H2 S) has been identified as an important cell-signaling mediator and has a number of biological functions, such as vascular smooth muscle relaxation, neurotransmission, and regulation of inflammation. A facile and versatile approach for H2 S production initiated by light irradiation and controlled by reaction with an amine or an amino acid was developed. The donor was synthesized in a one-pot reaction, and simple crystallization led to a yield of approximately 90 %. The synthetic strategy is scalable and versatile, and the H2 S donors can be expressed ina number of different molecular and macromolecular forms, including crystalline small-molecule compounds, water-soluble polymers, polystyrene films, and hydrogels. The H2 S donors based on polystyrene film and hydrogel were used as cell-culture scaffolds. The H2 S donor based on water-soluble polymer was applied in photocontrolled inhibition of P-selectin expression on human platelets and subsequent regulation of platelet aggregation. This study provides the simplest controllable H2 S source to study its biological functions. The developed materials are also new therapeutic platforms to deliver H2 S, as there is no accumulation of toxic byproducts, and the donor materials from polystyrene films and hydrogels can be readily removed after releasing H2 S

Bioavailable 87Sr/86Sr in different environmental samples — Effects of anthropogenic contamination and implications for isoscapes in past migration studies

87Sr/86Sr reference maps (isoscapes) are a key tool for investigating past human and animal migrations. However, there is little understanding of which biosphere samples are best proxies for local bioavailable Sr when dealing with movements of past populations. In this study, biological and geological samples (ground vegetation, tree leaves, rock leachates, water, soil extracts, as well as modern and archeological animal teeth and snail shells) were collected in the vicinity of two early medieval cemeteries (“Thuringians”, 5–6th century AD) in central Germany, in order to characterize 87Sr/86Sr of the local biosphere. Animal tooth enamel is not appropriate in this specific context to provide a reliable 87Sr/86Sr baseline for investigating past human migration. Archeological faunal teeth data (pig, sheep/goat, and cattle) indicates a different feeding area compared to that of the human population and modern deer teeth 87Sr/86Sr suggest the influence of chemical fertilizers. Soil leachates do not yield consistent 87Sr/86Sr, and 87Sr/86Sr of snail shells are biased towards values for soil carbonates. In contrast, water and vegetation samples seem to provide the most accurate estimates of bioavailable 87Sr/86Sr to generate Sr isoscapes in the study area. Long-term environmental archives of bioavailable 87Sr/86Sr such as freshwater bivalve shells and tree cores were examined in order to track potential historic anthropogenic contamination of the water and the vegetation. The data obtained from the archeological bivalve shells show that the modern rivers yield 87Sr/86Sr ratios which are similar to those of the past. However, the tree cores registered decreasing 87Sr/86Sr values over time towards present day likely mirroring anthropogenic activities such as forest liming, coal mining and/or soil acidification. The comparison of 87Sr/86Sr of the Thuringian skeletons excavated in the same area also shows that the vegetation samples are very likely anthropogenically influenced to some extent, affecting especially 87Sr/86Sr of the shallow rooted plants