Association of HbA1c and utilization of internal mammary arteries with wound infections in CABG.

Background: Deep sternal wound infection (DSWI) remains a serious complication after coronary artery bypass grafting (CABG). We herein aimed to stratify diabetic patients who underwent CABG using bilateral internal mammary artery (BIMA) for levels of glycated hemoglobin A1C (HbA1c) and compare postoperative outcomes. Methods: Between January 2010 and August 2020, 4,186 consecutive patients underwent isolated CABG at our center. In 3,229 patients, preoperative HbA1c levels were available. Primary endpoints were wound healing disorder (WHD), DSWI, and 30-day mortality. Patients were stratified according to preoperative HbA1c levels. Patients were further divided into subgroups according to utilization of BIMA. Results: After adjustment, no differences in mortality and stroke rates were seen between group 1 (HbA1c < 6.5%) vs. group 2 (HbA1c ≥ 6.5%). WHD was more frequent in group 2 [2.8 vs. 5.6%; adjusted p = 0.002; adjusted odds ratio (OR), 1.853 (1.243-2.711)] but not DSWI [1.0 vs. 1.5%; adjusted p = 0.543; adjusted OR, 1.247 (0.612-2.5409)]. BIMA use showed a higher rate of WHD [no BIMA: 3.0%; BIMA: 7.7%; adjusted p = 0.002; adjusted OR, 4.766 (1.747-13.002)] but not DSWI [no BIMA: 1.1%; BIMA: 1.8%; adjusted p = 0.615; adjusted OR, 1.591 (0.260-9.749)] in patients with HbA1c ≥ 6.5%. Conclusions: Intraoperative utilization of BIMA is not connected with an increase of DSWI but higher rates of WHD in patients with poor diabetic status and HbA1c ≥ 6.5%. Therefore, application of BIMA should be taken into consideration even in patients with poor diabetic status, while identification of special subsets of patients who are at particular high risk for DSWI is of paramount importance to prevent this serious complication.

Cellulose modified to host functionalities via facile cation exchange approach.

Properties of cellulose are typically functionalized by organic chemistry means. We progress an alternative facile way to functionalize cellulose by functional group counter-cation exchange. While ion-exchange is established for cellulose, it is far from exploited and understood beyond the most common cation, sodium. We build on our work that established the cation exchange for go-to alkali metal cations. We expand and further demonstrate the introduction of functional cations, namely, lanthanides. We show that cellulose nanocrystals (CNCs) carrying sulfate-half ester groups can acquire properties through the counter-cation exchange. Trivalent lanthanide cations europium (Eu3+), dysprosium (Dy3+) and gadolinium (Gd3+) were employed. The respective ions showed distinct differences in their ability of being coordinated by the sulfate groups; with Eu3+ fully saturating the sulfate groups while for Gd3+ and Dy3+, values of 82 and 41 % were determined by compositional analysis. CNCs functionalized with Eu3+ displayed red emission, those containing Dy3+ exhibited no optical functionality, while those with Gd3+ revealed significantly altered magnetic relaxation times. Using cation exchange to alter cellulose properties in various ways is a tremendous opportunity for modification of the abundant cellulose raw materials for a renewable future.

Transcatheter aortic valve implantation in patients with significant septal hypertrophy.

BACKGROUND: Previous reports suggest septal hypertrophy with an interventricular septum depth (IVSD) ≥ 14 mm may adversely affect outcomes after transcatheter aortic valve implantation (TAVI) due to suboptimal valve placement, valve migration, or residual increased LVOT pressure gradients. AIMS: This analysis investigates the impact of interventricular septal hypertrophy on acute outcomes after TAVI. METHODS: Between 2009 and 2021, 1033 consecutive patients (55.8% male, 80.5 ± 6.7 years, EuroSCORE II 6.3 ± 6.5%) with documented IVSD underwent TAVI at our center and were included for analysis. Baseline, periprocedural, and 30-day outcome parameters of patients with normal IVSD (< 14 mm; group 1) and increased IVSD (≥ 14 mm; group 2) were compared. Data were retrospectively analyzed according to updated Valve Academic Research Consortium-3 (VARC-3) definitions. Comparison of outcome parameters was adjusted for baseline differences between groups using logistic and linear regression analyses. RESULTS: Of 1033 patients, 585 and 448 patients were allocated to groups 1 and 2, respectively. There was no significant difference between groups regarding transfemoral access rate (82.6% (n = 478) vs. 86.0% (n = 381), p = 0.157). Postprocedural mean transvalvular pressure gradient was significantly increased in group 2 (group 1, 7.8 ± 4.1 mmHg, vs. group 2, 8.9 ± 4.9 mmHg, p = 0.046). Despite this finding, there was no significant difference between groups regarding the rates of VARC-3 adjudicated composite endpoint device success (90.0% (n = 522) vs. 87.6% (n = 388), p = 0.538) or technical success (92.6% (n = 542) vs. 92.6% (n = 415), p = 0.639). Moreover, the groups showed no significant differences regarding the rates of paravalvular leakage ≥ moderate (3.1% (n = 14) vs. 2.6% (n = 9), p = 0.993), postprocedural permanent pacemaker implantation (13.4% (n = 77) vs. 13.8% (n = 61), p = 0.778), or 30-day mortality (5.1% (n = 30) vs. 4.5% (n = 20), p = 0.758). CONCLUSION: Although transvalvular mean pressure gradients were significantly higher in patients with increased IVSD after TAVI, acute outcomes were comparable between groups suggesting no early impact of adverse hemodynamics due to elevated IVSD. However, how these differences in hemodynamic findings may affect mid- and long-term outcomes, especially in terms of valve durability, needs to be evaluated in further investigations.

Coherent olfactory bulb gamma oscillations arise from coupling independent columnar oscillators.

Spike timing-based representations of sensory information depend on embedded dynamical frameworks within neuronal networks that establish the rules of local computation and interareal communication. Here, we investigated the dynamical properties of olfactory bulb circuitry in mice of both sexes using microelectrode array recordings from slice and in vivo preparations. Neurochemical activation or optogenetic stimulation of sensory afferents evoked persistent gamma oscillations in the local field potential. These oscillations arose from slower, GABA(A) receptor-independent intracolumnar oscillators coupled by GABA(A)-ergic synapses into a faster, broadly coherent network oscillation. Consistent with the theoretical properties of coupled-oscillator networks, the spatial extent of zero-phase coherence was bounded in slices by the reduced density of lateral interactions. The intact in vivo network, however, exhibited long-range lateral interactions that suffice in simulation to enable zero-phase gamma coherence across the olfactory bulb. The timing of action potentials in a subset of principal neurons was phase-constrained with respect to evoked gamma oscillations. Coupled-oscillator dynamics in olfactory bulb thereby enable a common clock, robust to biological heterogeneities, that is capable of supporting gamma-band spike synchronization and phase coding across the ensemble of activated principal neurons.NEW & NOTEWORTHY Odor stimulation evokes rhythmic gamma oscillations in the field potential of the olfactory bulb, but the dynamical mechanisms governing these oscillations have remained unclear. Establishing these mechanisms is important as they determine the biophysical capacities of the bulbar circuit to, for example, maintain zero-phase coherence across a spatially extended network, or coordinate the timing of action potentials in principal neurons. These properties in turn constrain and suggest hypotheses of sensory coding.

Features and outcomes of bailout repeat transcatheter aortic valve implantation (TAVI): the Bailout Acute TAVI-in-TAVI to Lessen Events (BATTLE) international registry.

AIM: Transcatheter aortic valve implantation (TAVI) is a mainstay in the management of severe aortic stenosis in patients with intermediate to prohibitive surgical risk. When a single TAVI device fails and cannot be retrieved, TAVI-in-TAVI must be performed acutely, but outcomes of bailout TAVI-in-TAVI have been incompletely appraised. We aimed at analyzing patient, procedural and outcome features of patients undergoing bailout TAVI-in-TAVI in a multicenter registry. METHODS: Details of patients undergoing bailout TAVI-in-TAVI, performed acutely or within 24 h of index TAVI, in 6 international high-volume institutions, were collected. For every case provided, 2 same-week consecutive controls (prior TAVI, and subsequent TAVI) were provided. Outcomes of interest were procedural and long-term events, including death, myocardial infarction, stroke, access site complication, major bleeding, and reintervention, and their composite (i.e. major adverse events [MAE]). RESULTS: A total of 106 patients undergoing bailout TAVI-in-TAVI were included, as well as 212 controls, for a total of 318 individuals. Bailout TAVI-in-TAVI was less common in younger patients, those with higher body mass index, or treated with Portico/Navitor or Sapien devices (all p < 0.05). Bailout TAVI-in-TAVI was associated with higher in-hospital rates of death, emergency surgery, MAE, and permanent pacemaker implantation (all p < 0.05). Long-term follow-up showed that bailout TAVI-in-TAVI was associated with higher rates of death and MAE (both < 0.05). Similar findings were obtained at adjusted analyses (all p < 0.05). However, censoring early events, outlook was not significantly different when comparing the two groups (p = 0.897 for death, and p = 0.645 for MAE). CONCLUSIONS: Bail-out TAVI-in-TAVI is associated with significant early and long-term mortality and morbidity. Thus, meticulous preprocedural planning and sophisticated intraprocedural techniques are of paramount importance to avoid these emergency procedures.

Long-term outcomes following transcatheter aortic valve implantation with the Portico self-expanding valve.

AIM: Transcatheter aortic valve implantation (TAVI) is a mainstay in the management of severe aortic valve stenosis in elderly patients, but there is uncertainty on their long-term effectiveness. We aimed to assess the long-term outcome of patients undergoing TAVI with the Portico valve. METHODS: We retrospectively collected the data on patients in whom TAVI with Portico was attempted from 7 high-volume centres. Only patients theoretically eligible for 3 or more years of follow-up were included. Clinical outcomes, including death, stroke, myocardial infarction, reintervention for valve degeneration and hemodynamic valve performance were systematically assessed. RESULTS: A total of 803 patients were included, with 504 (62.8%) women, mean age of 82 years, median EuroSCORE II of 3.1%, and 386 (48.1%) subjects at low/moderate risk. The median follow-up was 3.0 years (3.0; 4.0). The composite of death, stroke, myocardial infarction, and reintervention for valve degeneration occurred in 37.5% (95% confidence interval: 34.1-40.9%), with all-cause death in 35.1% (31.8-38.4%), stroke in 3.4% (1.3-3.4%), myocardial infarction in 1.0% (0.3-1.5%), and reintervention for valve degeneration in 1.1% (0.6-2.1%). The mean aortic valve gradient at follow-up was 8.1 ± 4.6 mmHg, and at least moderate aortic regurgitation was present in 9.1% (6.7-12.3%). Independent predictors of major adverse events or death were: peripheral artery disease, chronic obstructive pulmonary disease, estimated glomerular filtration rate, atrial fibrillation, prior pacemaker implantation, EuroSCORE II, and reduced left ventricular ejection fraction (all p < 0.05). CONCLUSIONS: Portico use is associated with favorable long-term clinical outcomes. Clinical outcomes were largely impacted by baseline risk factors and surgical risk.

Procedural success in transaxillary transcatheter aortic valve implantation according to type of transcatheter heart valve: results from the multicenter TAXI registry.

BACKGROUND: Transaxillary (TAx) transcatheter aortic valve implantation (TAVI) is a preferred alternative access in patients ineligible for transfemoral TAVI. AIMS: This study used the Trans-AXillary Intervention (TAXI) registry to compare procedural success according to different types of transcatheter heart valves (THV). METHODS: For the TAXI registry anonymized data of patients treated with TAx-TAVI were collected from 18 centers. Acute procedural, early and 1-month clinical outcomes were adjudicated in accordance with standardized VARC-3 definitions. RESULTS: From 432 patients, 368 patients (85.3%, SE group) received self-expanding (SE) THV and 64 patients (14.8%, BE group) received balloon-expandable (BE) THV. Imaging revealed lower axillary artery diameters in the SE group (max/min diameter in mm: 8.4/6.6 vs 9.4/6.8 mm; p < 0.001/p = 0.04) but a higher proportion of axillary tortuosity in BE group (62/368, 23.6% vs 26/64, 42.6%; p = 0.004) with steeper aorta-left ventricle (LV) inflow (55° vs 51°; p = 0.002) and left ventricular outflow tract (LVOT)-LV inflow angles (40.0° vs 24.5°; 0.002). TAx-TAVI was more often conducted by right sided axillary artery in the BE group (33/368, 9.0% vs 17/64, 26.6%; p < 0.001). Device success was higher in the SE group (317/368, 86.1% vs 44/64, 68.8%, p = 0.0015). In logistic regression analysis, BE THV were a risk factor for vascular complications and axillary stent implantation. CONCLUSIONS: Both, SE and BE THV can be safely used in TAx-TAVI. However, SE THV were more often used and were associated with a higher rate of device success. While SE THV were associated with lower rates of vascular complications, BE THV were more often used in cases with challenging anatomical circumstances.

Balloon-expandable transcatheter heart valves for treatment of aortic valve stenosis in patients with large aortic annuli: Evaluation of deployment balloon overfilling strategies.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) using balloon-expandable (BE) transcatheter heart valves (THV) in aortic annuli above 29 mm includes particular procedural steps, mainly involving overfilling of the deployment balloon. Data on overfilling strategies in clinical daily practice is scarce. We herein aimed for a retrospective description of utilized overfilling strategies in those patients. METHODS: Between January 2016 and December 2022, 45 patients (100% male, 76.9 ± 6.1 years) received TAVI in aortic annuli above 29 mm using a BE THV. Overfilling volumina of the deployment balloon were left to operators' discretion. Clinical and multislice computed tomography data were retrospectively collected. Clinical endpoints were adjudicated in accordance with the updated standardized VARC-3 definitions. RESULTS: Profound overfilling (+4/5 mL) was used in patients with a mild calcium burden (˂750 mm³) even in aortic annuli of 29.0-30.0 mm. Nominal/slight overfilling (+1 mL) was used in aortic annuli up to 32.5 mm but an intermediate to severe calcific burden (>750-3200 mm³). Accordingly, a low calcification group (˂750 mm³, n = 17) compared to a significant calcification group (≥750 mm³, n = 28), presented with higher overfilling volumina (2.1 ± 1.4 vs. 0.8 ± 1.0; p ˂ 0.001), although aortic annulus diameter was not different (29.8 ± 0.8 vs. 29.9 ± 0.9 mm; p = 0.7). All-cause 30-day mortality was 0%. Device success was 97.8%. Transvalvular mean pressure gradient at discharge was 9.5 ± 3.6 mmHg. No case of PVL >mild was documented. CONCLUSION: Extent of overfilling of the deployment balloon largely depends on calcification burden in addition to aortic annulus diameter with significant and profound overfilling particularly in patients with a calcification burden of the aortic valve complex ˂750 mm³.

Valve-in-valve procedures for degenerated surgical and transcatheter aortic valve bioprostheses using a latest-generation self-expanding intra-annular transcatheter heart valve.

Background: Valve-in-valve (ViV) transfemoral transcatheter aortic valve implantation (TAVI) for failing aortic surgical bioprostheses or transcatheter heart valves (THV) has demonstrated a reasonable clinical and hemodynamic efficacy. Traditionally, self-expanding (SE) supra-annular THV are considered to result in superior hemodynamics compared with balloon-expandable intra-annular THV after ViV. However, so far no data are found on latest-generation intra-annular SE THV for aortic ViV procedures which might be superior with regard to coronary access or subsequent valve reintervention. Aim: We herein aim to evaluate a latest-generation SE intra-annular THV for aortic ViV procedures. Materials and methods: Between May 2022 and November 2022, five consecutive patients (4/5 female with mean age of 76.2 years and mean Society of Thoracic Surgeons predicted risk of mortality score of 2.9%) received ViV TAVI using the Navitor system (Abbott, Chicago, IL, USA) for treatment of failing surgical bioprostheses or THV. Data were retrospectively analyzed according to updated Valve Academic Research Consortium 3 (VARC-3) definitions. Results: At 30 days, absence of mortality and VARC-3 adjudicated clinical endpoints were documented. Echocardiography at 30 days revealed complete absence of paravalvular leakage and single-digit mean transvalvular gradients (mean of 6.0 mmHg) in all patients. Conclusion: The investigated intra-annular SE THV results in excellent 30-day outcomes for aortic ViV procedures for failing surgical bioprostheses or THV. Despite the intra-annular design, hemodynamic results were excellent, even in small bioprostheses. Ease of use of this valve platform is reflected by only two cycles of resheathing in five ViV procedures with hemodynamic stability during all steps of valve deployment.

Prevention of LVOT Obstruction by Device-Mediated Laceration of the Anterior Mitral Valve Leaflet During TMVR.

Left ventricular outflow tract obstruction represents a life-threatening complication in patients undergoing transcatheter mitral valve replacement. Interventional approaches to prevent left ventricular outflow tract obstruction are complex and require exceptional procedural expertise. We demonstrate feasibility and safety of first-in-human device-mediated mechanical laceration of the anterior mitral valve leaflet prior to transapical transcatheter mitral valve replacement. (Level of Difficulty: Advanced.).

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Severely Reduced Left Ventricular Systolic Function in the Low Systolic Function and Transcatheter Aortic Valve Implantation (LOSTAVI) International Registry.

Transcatheter aortic valve replacement (TAVR) is an established therapy for severe, symptomatic aortic valve stenosis even in patients with impaired left ventricular systolic function. However, there is uncertainty on the clinical effectiveness of the currently available TAVR devices in patients with reduced left ventricular ejection fraction (LVEF). The LOSTAVI (Low Systolic function and Transcatheter Aortic Valve Implantation) registry is a retrospective observational study using baseline, procedural, discharge, and long-term follow-up details. A total of 3 groups of interest were distinguished: extremely reduced LVEF (<25%), severely reduced LVEF (25% to 30%), and reduced LVEF (31% to 35%). Unadjusted and adjusted analyses were carried out for in-hospital and follow-up outcomes. A total of 923 patients were included from 12 centers, with 146 patients (16%) with LVEF <25%, 425 (46%) with LVEF 25% to 30%, and 352 (38%) with LVEF 31% to 35%. Several baseline and procedural features were different across groups, including age, risk, functional class, and prevalence of bicuspid disease (all p <0.05). In-hospital mortality was similar in the 3 groups (7 [4.8%], 18 [4.2%], and 7 [2.0%], respectively, p = 0.661), but major adverse events were more common in those with extremely reduced and severely reduced LVEF (19 [13%], 53 [13%], and 25 [7.1%], respectively, p = 0.024). The 12-month follow-up confirmed the significant detrimental impact of reduced LVEF on both death (21 [14%], 49 [12%], and 25 [7.1%], respectively, p = 0.024) and major adverse events (37 [25%], 89 [21%], and 53 [15%], respectively, p = 0.016). The adjusted analysis confirmed the significant prognostic role of LVEF on both outcomes, whereas TAVR device type was not associated with death or major adverse events (all p >0.05). In conclusion, TAVR yields favorable early and 1-year results in patients with reduced LVEF, including those with extremely depressed systolic dysfunction. However, reduced LVEF still represents a major adverse prognostic factor for both short- and mid-term outcomes.

Fully Endoscopic Mitral Valve Repair with Percutaneous Cannulation of Groin Vessels.

Endoscopic mitral valve surgery (EMS) has become a standard of care at specialized heart centers, further reducing surgical trauma compared to a traditional minimally invasive, thoracotomy-based approach. Exposure of the groin vessels for the establishment of cardiopulmonary bypass (CPB) via surgical cutdown in minimally invasive surgery (MIS) may result in wound healing disorders or seroma formation. The avoidance of surgical exposure of the groin vessels by using fully percutaneous techniques for the insertion of a CPB cannula with the implementation of vascular pre-closure devices has the potential to reduce these complications and improve clinical results. Herein, we present the utilization of a novel plug based vacsular closure device with a resobable collagen plug and the absence of suture material for closure of the arterial access for CPB in MIS. While this device was initially predominantly used in transcatheter aortic valve implantation (TAVI) procedures, with its safety and feasibility shown, we herein show that it can be used in CPB cannulation, since it is capable of closing arterial access sites up to 25 French (Fr.) in size. This device may be suitable to significantly reduce groin complications in MIS and simplify the establishment of CPB. Here, we describe the fundamental steps of EMS, including percutaneous groin cannulation and decannulation using a vascular closure device.

Femtosecond laser preparation of resin embedded samples for correlative microscopy workflows in life sciences.

Correlative multimodal imaging is a useful approach to investigate complex structural relations in life sciences across multiple scales. For these experiments, sample preparation workflows that are compatible with multiple imaging techniques must be established. In one such implementation, a fluorescently labeled region of interest in a biological soft tissue sample can be imaged with light microscopy before staining the specimen with heavy metals, enabling follow-up higher resolution structural imaging at the targeted location, bringing context where it is required. Alternatively, or in addition to fluorescence imaging, other microscopy methods, such as synchrotron x-ray computed tomography with propagation-based phase contrast or serial blockface scanning electron microscopy, might also be applied. When combining imaging techniques across scales, it is common that a volumetric region of interest (ROI) needs to be carved from the total sample volume before high resolution imaging with a subsequent technique can be performed. In these situations, the overall success of the correlative workflow depends on the precise targeting of the ROI and the trimming of the sample down to a suitable dimension and geometry for downstream imaging. Here, we showcase the utility of a femtosecond laser (fs laser) device to prepare microscopic samples (1) of an optimized geometry for synchrotron x-ray tomography as well as (2) for volume electron microscopy applications and compatible with correlative multimodal imaging workflows that link both imaging modalities.

Differential effects of anaemia and iron deficiency on long-term outcomes following transcatheter edge-to-edge repair in degenerative vs. secondary mitral regurgitation: results from a large single-center study.

BACKGROUND: Anaemia and iron deficiency (ID) are independently associated with adverse outcomes in patients with cardiovascular diseases, especially in those with heart failure. Here, we aimed to clarify the long-term effect of anaemia and ID on outcomes in patients undergoing transcatheter mitral edge-to-edge repair (TEER) for relevant mitral regurgitation (MR) as well as to relate these to the underlying MR aetiology. METHODS: 833 patients (median age 77.1 years, 40.7% women, 63.3% secondary MR) treated by TEER between 09/2008 and 07/2019 were included and stratified according to baseline anaemia (hemoglobin < 12 g/dL in women and < 13 g/dL in men) or ID. RESULTS: Anaemia and ID were frequent with 61.6% and 68.1%, respectively. Anaemic patients had a lower functional status at baseline and were less likely to improve after TEER. In addition, anaemia was associated with all-cause mortality (hazard ratio [HR] = 1.68, 95% confidence interval [CI] 1.36-2.07, p < 0.001) and the composite endpoint of death or heart failure (HF) rehospitalization (HR = 1.30, 95% CI 1.10-1.54, p = 0.002). In contrast, ID was not associated with either all-cause mortality or the composite endpoint of death or HF rehospitalization. CONCLUSION: Patients undergoing TEER have high rates of both anaemia and ID. However, anaemia is associated with worse functional baseline status and post-interventional improvements compared to ID. Furthermore, anaemia is linked to higher rates of mortality and HF rehospitalization, particularly in those with secondary MR.

Cusp overlap versus standard three-cusp technique for self-expanding Evolut transcatheter aortic valves.

BACKGROUND: Reducing rates of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) is important for achieving the best procedural outcomes. The cusp overlap technique (COT) implements procedural steps including an overlap angulation of the right and left coronary cusp to mitigate this complication. AIMS: We investigated the incidence of PPI and complication rates following the COT compared to the standard three-cusp implantation technique (3CT) in an all-comers cohort. METHODS: A total of 2,209 patients underwent TAVI with the self-expanding Evolut platform from January 2016 to April 2022 at five sites. Baseline, procedural and in-hospital outcome characteristics were compared for both techniques before and after one-to-one propensity score matching. RESULTS: A total of 1,151 patients were implanted using the 3CT and 1,058 using the COT. At discharge, the rates of PPI (17.0 vs 12.3%; p=0.002) and moderate/severe paravalvular regurgitation (4.6% vs 2.4%; p=0.006) were significantly reduced with the COT compared with 3CT within the unmatched cohort. Overall procedural success and complication rates were similar; major bleeding was less common in the COT group (7.0% vs 4.6%; p=0.020). These results remained consistent after propensity score matching. In multivariable logistic regression analysis, right bundle branch block (odds ratio [OR] 7.19, 95% confidence interval [CI]: 5.18-10.0; p<0.001) and diabetes mellitus (OR 1.38, 95% CI: 1.05-1.80; p=0.021) emerged as predictors of PPI, whereas the COT (OR 0.63, 95% CI: 0.49-0.82; p<0.001) was protective. CONCLUSIONS: The introduction of the COT was associated with a significant and relevant reduction of PPI and paravalvular regurgitation rates without an increase in complication rates.

Polymer Brushes on Silica Nanostructures Prepared by Aminopropylsilatrane Click Chemistry: Superior Antifouling and Biofunctionality.

In nanobiotechnology, the importance of controlling interactions between biological molecules and surfaces is paramount. In recent years, many devices based on nanostructured silicon materials have been presented, such as nanopores and nanochannels. However, there is still a clear lack of simple, reliable, and efficient protocols for preventing and controlling biomolecule adsorption in such structures. In this work, we show a simple method for passivation or selective biofunctionalization of silica, without the need for polymerization reactions or vapor-phase deposition. The surface is simply exposed stepwise to three different chemicals over the course of ∼1 h. First, the use of aminopropylsilatrane is used to create a monolayer of amines, yielding more uniform layers than conventional silanization protocols. Second, a cross-linker layer and click chemistry are used to make the surface reactive toward thiols. In the third step, thick and dense poly(ethylene glycol) brushes are prepared by a grafting-to approach. The modified surfaces are shown to be superior to existing options for silica modification, exhibiting ultralow fouling (a few ng/cm2) after exposure to crude serum. In addition, by including a fraction of biotinylated polymer end groups, the surface can be functionalized further. We show that avidin can be detected label-free from a serum solution with a selectivity (compared to nonspecific binding) of more than 98% without the need for a reference channel. Furthermore, we show that our method can passivate the interior of 150 nm × 100 nm nanochannels in silica, showing complete elimination of adsorption of a sticky fluorescent protein. Additionally, our method is shown to be compatible with modifications of solid-state nanopores in 20 nm thin silicon nitride membranes and reduces the noise in the ion current. We consider these findings highly important for the broad field of nanobiotechnology, and we believe that our method will be very useful for a great variety of surface-based sensors and analytical devices.

Temporal changes of patient characteristics over 12 years in a single-center transcatheter aortic valve implantation cohort.

BACKGROUND: Beneficial results of transcatheter aortic valve implantation (TAVI) compared to surgical aortic valve replacement (SAVR) in patients at all risk strata have led to substantial changes in guideline recommendations for valvular heart disease. AIM: To examine influence of these guideline changes on a real-world TAVI cohort, we evaluated how risk profiles and outcomes of TAVI patients developed in our single-center patient cohort over a period of 12 years. METHODS: Baseline, procedural and 30-day outcome parameters of TAVI patients were retrospectively compared between three time periods (period 1: 2008-2012, period 2: 2013-2017, period 3: 2018-2020). RESULTS: Between 03/2008 and 12/2020, a total of 3678 patients underwent TAVI at our center. The median age was 81.1 years (25th, 75th percentile: 76.7, 84.9) with no significant change over time. The EuroSCORE II showed a continuous and significant decline from 5.3% (3.3, 8.6) in period 1 to 2.8% (1.7, 5.0) in period 3 (p < 0.001). Furthermore, rates of permanent pacemaker implantation, acute kidney injury, and paravalvular leakage ≥ moderate continuously declined over time. Accordingly, the 30-day mortality fell from 9.3% in period 1 to 4.3% in period 3 (p < 0.001). CONCLUSION: Despite substantial guideline alterations, median patient age remained largely unchanged in our TAVI cohort over the past 12 years. Therefore, increased age still appears to be the main reason to choose TAVI over SAVR. However, risk profiles declined substantially. Significant improvements in early outcomes suggest favorable influence of less invasive access routes, improved device platforms and growing user experience.

Prognostic impact and diagnostic value of invasively derived hemodynamic measures in patients with severe aortic stenosis undergoing TAVI.

BACKGROUND: Ejection time (ET), acceleration time (AT) and time between left ventricular and aortic systolic pressure peaks (T-LVAo) might be of diagnostic and prognostic use in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). AIM: We aimed to assess the diagnostic value and prognostic impact of invasively measured ET, AT, and T-LVAo in patients undergoing TAVI. METHODS: A total of 1274 patients received invasive measurement of ET, AT and T-LVAo prior to TAVI. Anatomic AS severity was assessed by CT-derived aortic valve calcification density (AVCd). Impact on all-cause mortality was retrospectively analyzed. RESULTS: In multivariable linear regression, T-LVAo showed the strongest correlation with AVCd. No prognostic impact of T-LVAo was found according to uni- and multivariable analyses. In contrast, using an individual C-statistic derived cutoff (CD), patients with ET or AT ≥ CD showed lower mortality rates compared to patients with ET or AT < CD (1-year mortality: ET ≥ vs. < CD: 15.01vs. 33.1%, AT ≥ vs < CD 16.3 vs. 26.5%, p < 0.001). Moreover, multivariable analysis identified ET ≥ CD (HR 0.61 [95% CI 0.43-0.87; p < 0.007]) to be associated with beneficial outcome after TAVI, independent from clinical risk factors and echocardiography-derived parameters. CONCLUSION: Among the studied hemodynamic parameters T-LVAo provides the highest diagnostic value, whereas ET is an outcome predictor beyond clinical risk factors and echocardiographic parameters in AS patients following TAVI. These parameters could be of considerable use in diagnostic evaluation and risk assessment of patients scheduled for TAVI. T-LVAo (yellow): defined as time between left ventricular and aortic systolic pressure peaks. ET (green): Ejection Time defined as time from the start to flow end. AT (orange): Acceleration time defined as time from the start to the peak flow. AOP: aortic pressure, AVC: aortic valve calcification, CI: confidence interval, HGAS: high-gradient aortic stenosis, LGAS: low-gradient aortic stenosis, LVP: left ventricular pressure, SD: standard deviation.

TAVI With or Without Predilation: Trends From a Large, Propensity-Score Weighted German Aortic Valve Registry (GARY) Population.

BACKGROUND AND AIMS: Currently, it is unclear whether transcatheter aortic valve implantation (TAVI) without predilation (direct TAVI; d-TAVI) or with preimplantation balloon valvuloplasty (b-TAVI) provides similar clinical safety and efficacy. Therefore, we analyzed patients undergoing d-TAVI or b-TAVI for severe aortic stenosis (AS) with either self-expanding or balloon-expandable transcatheter heart valves (THVs) from the German Aortic Valve Registry (GARY). METHODS: Between 2011 and 2017, a total of 44,783 TAVI patients were collected, with 25,717 (57.4%) receiving a balloon-expandable THV and 19,066 (42.6%) receiving a self-expanding THV. A propensity-score weighted model was used to compare d-TAVI vs b-TAVI regarding differences in outcome. RESULTS: B-TAVI was performed in 71% and d-TAVI was performed in 29% of patients. In the investigated time interval, frequency of b-TAVI declined from 88.4% to 58.2%, accompanied by a constant rate of postdilation. After propensity weighting of patients receiving balloon-expandable THV, d-TAVI vs b-TAVI was associated with more frequent postoperative transvalvular mean pressure gradients (mPG) >15 mm Hg (20.7% vs 18.4%; P<.001), similar rates of paravalvular leakage (PVL) ≥ moderate (18.0% vs 16.9%; P=.08), fewer postdilations (13.4% vs 15.5%; P<.001), and fewer complications (permanent pacemaker implantation, 10.2% vs 11.9% [P=.01]; vascular complications, 1.9% vs 2.6% [P<.01]; pericardial tamponade, 0.5% vs 0.9% [P<.01]; and stroke, 0.9% vs 1.3% [P=.02]). In patients receiving self-expanding THVs, d-TAVI vs b-TAVI was associated with more frequent postimplantation mean PG ≥ 15 mm Hg (12.7% vs 10.4%; P<.01), higher rates of PVL ≥ moderate (24.8% vs 16.5%; P<.001), and similar complication rates including permanent pacemaker implantation. CONCLUSIONS: The safety and efficacy of d-TAVI vs b-TAVI depends on the type of THV implanted. For balloon-expandable valves, d-TAVI provides an advantage, while self-expanding valves offer a similar safety profile for d-TAVI compared with b-TAVI. However, increased mPG post intervention with both valve types and more significant PVL in self-expanding THVs emphasize the importance of proper patient selection and evaluation of valve anatomy to identify suitable cases for d-TAVI.

Synthesis and Characterization of Catalytically Active Au Core─Pd Shell Nanoparticles Supported on Alumina.

A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al2O3 catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption-desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al2O3, and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O2 that is typically observed for noble metal catalysts.