Bioinspired Design and Experimental Validation of an Aquatic Snake Robot.

This article presents the design, simulation, and experimental validation of a novel modular aquatic snake robot capable of surface locomotion. The modular structure allows each unit to function independently, facilitating ease of maintenance and adaptability to diverse aquatic environments. Employing the material point method with the moving least squares (MPM-MLS) simulation technique, the robot's dynamic behavior was analyzed, yielding reliable results. The control algorithm, integral to the robot's autonomous navigation, was implemented to enable forward propulsion at high speed, steering, and obstacle detection and avoidance. Extensive testing of the aquatic snake robot was conducted, demonstrating its practical viability. The robot showcased promising swimming capabilities, achieving high speeds and maneuverability. Furthermore, the obstacle detection and avoidance mechanisms were proven effective, showing the robot's ability to navigate through dynamic environments. The presented aquatic snake robot represents an advancement in the field of underwater robotics, offering a modular and versatile solution for tasks ranging from environmental monitoring to search and rescue operations.

A Bioinspired Cownose Ray Robot for Seabed Exploration.

This article presents the design and the experimental tests of a bioinspired robot mimicking the cownose ray. These fish swim by moving their large and flat pectoral fins, creating a wave that pushes backward the surrounding water so that the fish is propelled forward due to momentum conservation. The robot inspired by these animals has a rigid central body, housing motors, batteries, and electronics, and flexible pectoral fins made of silicone rubber. Each of them is actuated by a servomotor driving a link inside the leading edge, and the traveling wave is reproduced thanks to the flexibility of the fin itself. In addition to the pectoral fins, two small rigid caudal fins are present to improve the robot's maneuverability. The robot has been designed, built, and tested underwater, and the experiments have shown that the locomotion principle is valid and that the robot is able to swim forward, perform left and right turns, and do floating or diving maneuvers.

In-Hospital Outcomes and Predictors of Paravalvular Leak and Deep Implantation With the Evolut R 34-mm Device: A Comparison With Smaller Evolut R Sizes.

PURPOSE: To compare in-hospital outcome of Evolut-R 34 mm vs. smaller Evolut-R devices and to identify predictors of paravalvular leak (PVL) and deep implantation specific for Evolut-R 34 mm. METHODS: This single-center retrospective study included 359 consecutive patients undergoing transcatheter aortic valve replacement (TAVR) with Evolut-R 34 mm (N = 84,23.4%) and Evolut-R 23/26/29 mm (N = 275,76.6%) between 2016 and 2019. RESULTS: Patients in Evolut-R 34 mm group were more frequently males, had lower STS score, ejection fraction, and mean aortic gradient compared to the Evolut-R 23/26/29 mm group. Horizontal aorta and large LVOT were more frequent findings in the Evolut-R 34 mm group, whereas calcium volume was comparable among the groups. During TAVR, mean implantation depth and contrast volume were greater in the Evolut-R 34 mm group, compared to the Evolut 23/26/29 mm group. Post-procedurally, 30-day mortality, ≥moderate PVL, device success and pacemaker implantation (PM) rates were comparable between groups. Among independent predictors of ≥moderate PVL, calcium volume (OR:1.04; p < 0.001) was predictive with different thresholds in both groups, whereas aortic angulation (OR:1.40; p = 0.005) was predictive only in Evolut-R 34 mm group at a cutoff of 60° (AUC:0.73; p = 0.043). Body weight (OR:1.03; p = 0.027), left ventricular outflow tract (LVOT) diameter (OR:1.34; p = 0.001), and mean aortic gradient (OR:0.96; p = 0.006) were independent predictors of deep implantation (mean depth ≥ 6 mm), with LVOT>27 mm being predictive specifically for Evolut-R 34 mm (AUC:0.66; p = 0.024). CONCLUSIONS: TAVR with Evolut-R 34 mm and Evolut-R 23/26/29 mm showed comparable in-hospital outcome. Aortic angulation >60° and LVOT >27 mm were predictive respectively of ≥moderate PVL and deep implantation specifically in Evolut-R 34 mm patients.

Transcatheter Aortic Valve Replacement for Degenerated Transcatheter Aortic Valves: The TRANSIT International Project.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has determined a paradigm shift in the treatment of patients with severe aortic stenosis. However, the durability of bioprostheses is still a matter of concern, and little is known about the management of degenerated TAV. We sought to evaluate the outcomes of patients with a degenerated TAV treated by means of a second TAVR. METHODS: The TRANSIT is an international registry that included cases of degenerated TAVR from 28 centers. Among around 40 000 patients treated with TAVR in the participating centers, 172 underwent a second TAVR: 57 (33%) for a mainly stenotic degenerated TAV, 97 (56%) for a mainly regurgitant TAV, and 18 (11%) for a combined degeneration. Overall, the rate of New York Heart Association class III/IV at presentation was 73.5%. RESULTS: Valve Academic Research Consortium 2 device success rate was 79%, as a consequence of residual gradient (14%) or regurgitation (7%). At 1 month, the overall mortality rate was 2.9%, while rates of new hospitalization and New York Heart Association class III/IV were 3.6% and 7%, respectively, without significant difference across the groups. At 1 year, the overall mortality rate was 10%, while rates of new hospitalization and New York Heart Association class III/IV were 7.6% and 5.8%, respectively, without significant difference across the groups. No cases of valve thrombosis were recorded. CONCLUSIONS: Selected patients with a degenerated TAV may be safely and successfully treated by means of a second TAVR. This finding is of crucial importance for the adoption of the TAVR technology in a lower risk and younger population. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04500964.

Transcatheter Aortic Valve Replacement for Degenerated Transcatheter Aortic Valves: The TRANSIT International Project

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has determined a paradigm shift in the treatment of patients with severe aortic stenosis. However, the durability of bio prostheses is still a matter of concern, and little is known about the management of degenerated TAV. We sought to evaluate the outcomes of patients with a degenerated TAV treated by means of a second TAVR. METHODS: The TRANSIT is an international registry that included cases of degenerated TAVR from 28 centers. Among around 40 000 patients treated with TAVR in the participating centers, 172 underwent a second TAVR: 57 (33%) for a mainly stenotic degenerated TAV, 97 (56%) for a mainly regurgitant TAV, and 18 (11%) for a combined degeneration. Overall, the rate of New York Heart Association class III/IV at presentation was 73.5%. RESULTS: Valve Academic Research Consortium 2 device success rate was 79%, as a consequence of residual gradient (14%) or regurgitation (7%). At 1 month, the overall mortality rate was 2.9%, while rates of new hospitalization and New York Heart Association class III/IV were 3.6% and 7%, respectively, without significant difference across the groups. At 1 year, the overall mortality rate was 10%, while rates of new hospitalization and New York Heart Association class III/IV were 7.6% and 5.8%, respectively, without significant difference across the groups. No cases of valve thrombosis were recorded. CONCLUSIONS: Selected patients with a degenerated TAV may be safely and successfully treated by means of a second TAVR. This finding is of crucial importance for the adoption of the TAVR technology in a lower risk and younger population.

Italian Society of Interventional Cardiology (GIse) registry Of Transcatheter treatment of mitral valve regurgitaTiOn (GIOTTO): impact of valve disease aetiology and residual mitral regurgitation after MitraClip implantation.

AIMS: The Italian Society of Interventional Cardiology (GIse) registry Of Transcatheter treatment of mitral valve regurgitaTiOn (GIOTTO) was conceived in order to assess the safety and efficacy of MitraClip therapy in Italy. The aim of this study was to assess procedural and mid-term outcomes, and clinical and echocardiographic predictors of mid-term mortality after MitraClip therapy, stratifying the results according to the diagnosis of functional and degenerative mitral regurgitation (FMR vs. DMR). METHODS AND RESULTS: Between January 2016 and March 2020, 1659 patients were prospectively included in the GIOTTO registry (FMR 59.4% vs. DMR 40.6%). Acute Mitral Valve Academic Research Consortium (MVARC) technical success was achieved in 97.2% of patients, without differences between FMR and DMR and with sustained results at 30 days. In the study population, all-cause mortality was 4.0%, 17.5% and 34.6% at 30 days, 1 year and 2 years, respectively. Cardiovascular death was the most frequent cause of mortality. Overall hospitalization rates were 6.3%, 23.4% and 31.7% at 30 days, 1 year and 2 years, respectively. The most frequent cause of hospitalization was heart failure, particularly in the first 30 days. FMR and MVARC structural and functional failure were strongly associated with 1-year mortality. Residual mitral regurgitation 1+ (rMR) was independently related to a reduced risk of 1-year mortality (hazard ratio 0.62; P = 0.005). Coherently, at 2-year follow up, FMR was associated with worse outcomes than DMR, and Kaplan-Meier all-cause mortality was related to rMR. CONCLUSIONS: Functional mitral regurgitation aetiology affects 1-year mortality after MitraClip implantation, and differences in mortality and hospitalization rates between FMR and DMR can be observed within 2 years. Optimal rMR 1+ was correlated to a more favourable mid-term outcome, particularly in FMR.

Performance of high conformability vs. high radial force devices in the virtual treatment of TAVI patients with bicuspid aortic valve.

OBJECTIVE: Transcatheter Aortic Valve Implantation (TAVI) is a consolidated procedure showing a low operative risk and excellent long-term outcomes in patients with aortic stenosis. Patients presenting a bicuspid aortic valve (BAV) often require valve replacement due to the highly calcific nature of the aortic leaflets. However, BAV patients have usually been contraindicated for TAVI due to their complex valve anatomy. The aim of this work was to compare the performance of devices featuring high conformability (HC) against those with high radial force (HRF). METHODS: Four BAV patients undergoing TAVI were retrospectively selected. The aortic roots including the native leaflets and calcifications were reconstructed from pre-operative Computed Tomography scans. In each patient, both HC and HRF devices were virtually implanted using Finite Element Analysis simulations. After implantation, paravalvular orifice area, von Mises stress distribution, root contact area, and device eccentricity were calculated. RESULTS: Simulations showed good agreement with intraoperative imaging. In 3 out of 4 patients, the HRF device resulted in a lower paravalvular area than the HC. Stress distribution was also more homogeneously distributed in the HRF group as compared with the HC group. Despite their lower adaptability, HRF devices showed consistently higher stent-root contact area. CONCLUSION: HRF devices showed improved results with respect to HC valves after being deployed in BAV anatomies. We hypothesize that the ability to reshape the annulus is the major determinant of success in this subgroup of patients featuring highly calcified leaflets.

Impact of aortic angle on transcatheter aortic valve implantation outcome with Evolut-R, Portico, and Acurate-NEO.

OBJECTIVES: To investigate paravalvular leak (PVL) and devices success rates according to aortic angle (AA) in patients undergoing transcatheter aortic valve implantation (TAVI) with three new-generation self-expanding devices. BACKGROUND: The impact of aortic angle (AA) on TAVI device success and PVL rates is controversial. METHODS: This retrospective study included 392 patients submitted to TAVI for severe aortic stenosis with Portico, Evolut-R and Acurate-NEO, and available AA measurements at computed tomography (CT) angiography. AA was calculated from the implantation projection and was defined as the angle between the plane of aortic annulus and an ideal horizontal plane. Aorta was defined horizontal if AA>57° (75th percentile). RESULTS: In the horizontal group, the rates of moderate/severe PVL was higher in the Evolut-R group (20.8%), which was also characterized by a lower implant compared to that of Acurate-NEO, whereas device success was comparable among the three devices. AA was a significant predictor of moderate/severe PVLs (AUC 0.72, p = .002) only in the Evolut-R population. On multivariate analysis, calcium volume 850HU, bicuspid aortic valve, and implantation depth at the level of left coronary cusp were independent predictors of moderate/severe PVL. On univariate analysis in the horizontal aorta population, implantation depth was confirmed among the most significant predictors of moderate/severe PVL. CONCLUSIONS: Despite comparable device success rates, horizontal aorta represented a technical challenge only in the Evolut-R subgroup, which showed higher rates of moderate/severe PVL than Portico and Acurate-NEO, and was associated with a low implant.

Outcome of transcatheter aortic valve replacement in bicuspid aortic valve stenosis with new-generation devices.

OBJECTIVES: To compare device success and paravalvular leak rates of 3 new-generation transcatheter aortic valve replacement devices in patients with bicuspid aortic valve stenosis and to test their biomechanical performance in a computer-based simulation model of aortic root with increasing ellipticity. METHODS: This retrospective multicentre study included 56 bicuspid aortic valve patients undergoing transcatheter aortic valve replacement with new-generation devices: Lotus/Lotus Edge (N = 15; 27%), Evolut-R (N = 20; 36%) and ACURATE neo (N = 21; 37%). Three virtual simulation models of aortic root with increasing index of eccentricity (0-0.25-0.5) were implemented. Stress distribution, stent-root contact area and paravalvular orifice area were computed. RESULTS: Device success was achieved in 43/56 patients (77%) with comparable rates among Lotus (87%), Evolut-R (60%) and ACURATE neo (86%; P = 0.085). Moderate paravalvular leak rate was significantly lower in the Lotus group as compared to Evolut-R group (0% vs 30%; P = 0.027) and comparable to the ACURATE neo group (0% vs 10%; P = 0.33). By index of eccentricity = 0.5, Lotus showed a uniform and symmetric pattern of stress distribution with absent paravalvular orifice area, ACURATE neo showed a mild asymmetry with small paravalvular orifice area (1.1 mm2), whereas a severely asymmetric pattern was evident with Evolut-R, resulting in a large paravalvular orifice area (12.0 mm2). CONCLUSIONS: Transcatheter aortic valve replacement in bicuspid aortic valve patients with new-generation devices showed comparable device success rates. Lotus showed moderate paravalvular leak rate comparable to that of ACURATE neo and significantly lower than Evolut-R. On simulation, Lotus and ACURATE neo showed optimal adaptability to elliptic anatomies as compared to Evolut-R.

Impact of predilatation prior to transcatheter aortic valve implantation with the self-expanding acurate neo device (From the Multicenter NEOPRO Registry)

Safety and feasibility of transfemoral Acurate neo implantation without systematic predilatation are not fully investigated. Our aim was to evaluate the use and impact of pre-implantation balloon aortic valvuloplasty (pre-BAV) before transcatheter aortic valve implantation (TAVI) with Acurate neo. The NEOPRO Registry retrospectively included 1,263 patients who underwent transfemoral TAVI with Acurate neo at 18 centers between January 2012 and March 2018. Information on preBAV was available for 1,262 patients (99.9%). Primary endpoints were pre-discharge moderate-tosevere paravalvular aortic regurgitation (PAR II+), 30-day new permanent pacemaker implantation (PPI), and 30-day all-cause mortality or stroke. A total of 1,262 patients who underwent TAVI with (n=1,051) or without predilatation (n=211) were included. A reduction in the pre-BAV rate was observed during the study period (from 95.7% in the first date quintile to 78.4% in the last date quintile). Patients who underwent pre-BAV had higher degrees of aortic valve (AV) and left ventricular outflow tract (LVOT) calcification. Primary endpoints were similar between pre-BAV and no pre-BAV groups (PAR II+ 5.5% vs. 3.4%, p=0.214; 30-day PPI 9.0% vs. 8.0%, p=0.660; 30-day death or stroke 4.9% vs. 4.4%, p=0.743). The need for postdilatation and other procedural outcomes were comparable between groups. Predilatation did not have a significant impact on primary endpoints across AV and LVOT calcification subgroups (subgroup analyses) and was not independently associated with primary endpoints (multivariate analyses). In conclusion, transfemoral Acurate neo implantation without predilatation appears to be feasible and safe, especially in patients with milder degrees of AV and LVOT calcification. (AU)

Impact of Predilatation Prior to Transcatheter Aortic Valve Implantation With the Self-Expanding Acurate neo Device (from the Multicenter NEOPRO Registry).

Safety and feasibility of transfemoral Acurate neo implantation without systematic predilatation are not fully investigated. Our aim was to evaluate the use and impact of pre-implantation balloon aortic valvuloplasty (pre-BAV) before transcatheter aortic valve implantation (TAVI) with Acurate neo. The NEOPRO Registry retrospectively included 1,263 patients who underwent transfemoral TAVI with Acurate neo at 18 centers between January 2012 and March 2018. Information on pre-BAV was available for 1,262 patients (99.9%). Primary end points were pre-discharge moderate-to-severe paravalvular aortic regurgitation (PAR II+), 30-day new permanent pacemaker implantation, and 30-day all-cause mortality or stroke. A total of 1,262 patients who underwent TAVI with (n = 1,051) or without predilatation (n = 211) were included. A reduction in the pre-BAV rate was observed during the study period (from 95.7% in the first date quintile to 78.4% in the last date quintile). Patients who underwent pre-BAV had higher degrees of aortic valve (AV) and left ventricular outflow tract (LVOT) calcification. Primary endpoints were similar between pre-BAV and no pre-BAV groups (PAR II+ 5.5% vs 3.4%, p = 0.214; 30-day permanent pacemaker implantation 9.0% vs 8.0%, p = 0.660; 30-day death or stroke 4.9% vs 4.4%, p = 0.743). The need for postdilatation and other procedural outcomes were comparable between groups. Predilatation did not have a significant impact on primary endpoints across AV and LVOT calcification subgroups (subgroup analyses) and was not independently associated with primary endpoints (multivariate analyses). In conclusion, transfemoral Acurate neo implantation without predilatation appears to be feasible and safe, especially in patients with milder degrees of AV and LVOT calcification.

Real-World Safety and Efficacy of Transcatheter Mitral Valve Repair With MitraClip: Thirty-Day Results From the Italian Society of Interventional Cardiology (GIse) Registry Of Transcatheter Treatment of Mitral Valve RegurgitaTiOn (GIOTTO).

BACKGROUND: Available scientific evidence of transcatheter mitral valve repair with the MitraClip comes from randomized controlled trials, which showed controversial results that hardly translate into real-world practice, and from registries of relatively small sample size. AIM: To collect real-world data in a multicenter, prospective, country-level registry. METHODS AND RESULT: The Italian Society of Interventional Cardiology (GIse) Registry Of Transcatheter Treatment of Mitral Valve RegurgitaTiOn (GIOTTO) is an ongoing single-arm, multicenter, prospective registry that started enrollment in February 2016. Clinical end points were defined according to the Mitral Valve Academic Research Consortium (MVARC) criteria. From February 2016 to December 2018, 1189 patients (mean age 76 ±â€¯9.1 years) were enrolled. The main MR etiology was functional (64.9%). MVARC technical success was 96.6%. At 30-day follow-up (n = 1131), MVARC device and procedural success were 92.5% and 87% respectively, and all-cause death was 3%. The majority of patients who died at 30-day had functional MR (69.7%). Mixed etiology (OR 0.94, 95% CI 0.02-0.61) and prolonged length of stay in ICU (OR 0.97, 95% CI 0.95-0.99) were found to be negative independent predictors of device success at 30-day. The EuroSCORE II (OR 0.96, 95% CI 0.93-0.99), LVEDV-I (OR 0.99, 95% CI 0.98-0.99) and prolonged length of stay in ICU (OR 0.98, 95% CI 0.97-0.99) were negative independent factors of MVARC procedural success at 30-day. CONCLUSIONS: The GIOTTO registry is one of the largest prospective registries available on MitraClip and shows favorable acute and 30-day safety and efficacy.

Transcatheter Aortic Valve Replacement With Next-Generation Self-Expanding Devices: A Multicenter, Retrospective, Propensity-Matched Comparison of Evolut PRO Versus Acurate neo Transcatheter Heart Valves.

OBJECTIVES: The aim of this study was to compare transcatheter aortic valve replacement (TAVR) with the Acurate neo (NEO) and Evolut PRO (PRO) devices. BACKGROUND: The NEO and PRO bioprostheses are 2 next-generation self-expanding devices developed for TAVR. METHODS: The NEOPRO (A Multicenter Comparison of Acurate NEO Versus Evolut PRO Transcatheter Heart Valves) registry retrospectively included patients who underwent transfemoral TAVR with either NEO or PRO valves at 24 centers between January 2012 and March 2018. One-to-one propensity score matching resulted in 251 pairs. Pre-discharge and 30-day Valve Academic Research Consortium (VARC)-2 defined outcomes were evaluated. Binary logistic regression was performed to adjust the treatment effect for propensity score quintiles. RESULTS: A total of 1,551 patients (n = 1,263 NEO; n = 288 PRO) were included. The mean age was 82 years, and the mean Society of Thoracic Surgeons score was 5.1%. After propensity score matching (n = 502), VARC-2 device success (90.6% vs. 91.6%; p = 0.751) and pre-discharge moderate to severe (II+) paravalvular aortic regurgitation (7.3% vs. 5.7%; p = 0.584) were comparable between the NEO and PRO groups. Furthermore, there were no significant differences in any 30-day clinical outcome between matched NEO and PRO pairs, including all-cause mortality (3.2% vs. 1.2%; p = 0.221), stroke (2.4% vs. 2.8%; p = 1.000), new permanent pacemaker implantation (11.0% vs. 12.8%; p = 0.565), and VARC-2 early safety endpoint (10.6% vs. 10.4%; p = 1.000). Logistic regression on the unmatched cohort confirmed a similar risk of VARC-2 device success, paravalvular aortic regurgitation II+, and 30-day clinical outcomes after NEO and PRO implantation. CONCLUSIONS: In this multicenter registry, transfemoral TAVR with the NEO and PRO bioprostheses was associated with high device success, acceptable rates of paravalvular aortic regurgitation II+, and good 30-day clinical outcomes. After adjusting for potential confounders, short-term outcomes were similar between the devices.

Transcatheter aortic valve replacement with next-generation self-expanding devices: a multicenter, retrospective, propensity-matched comparison of evolut pro versus acurate neo transcatheter heart valves

Abstract OBJECTIVES: The aim of this study was to compare transcatheter aortic valve replacement (TAVR) with the Acurate neo (NEO) and Evolut PRO (PRO) devices. BACKGROUND: The NEO and PRO bioprostheses are 2 next-generation self-expanding devices developed for TAVR. METHODS: The NEOPRO (A Multicenter Comparison of Acurate NEO Versus Evolut PRO Transcatheter Heart Valves) registry retrospectively included patients who underwent transfemoral TAVR with either NEO or PRO valves at 24 centers between January 2012 and March 2018. One-to-one propensity score matching resulted in 251 pairs. Pre-discharge and 30-day Valve Academic Research Consortium (VARC)-2 defined outcomes were evaluated. Binary logistic regression was performed to adjust the treatment effect for propensity score quintiles. RESULTS: A total of 1,551 patients (n = 1,263 NEO; n = 288 PRO) were included. The mean age was 82 years, and the mean Society of Thoracic Surgeons score was 5.1%. After propensity score matching (n = 502), VARC-2 device success (90.6% vs. 91.6%; p = 0.751) and pre-discharge moderate to severe (II+) paravalvular aortic regurgitation (7.3% vs. 5.7%; p = 0.584) were comparable between the NEO and PRO groups. Furthermore, there were no significant differences in any 30-day clinical outcome between matched NEO and PRO pairs, including all-cause mortality (3.2% vs. 1.2%; p = 0.221), stroke (2.4% vs. 2.8%; p = 1.000), new permanent pacemaker implantation (11.0% vs. 12.8%; p = 0.565), and VARC-2 early safety endpoint (10.6% vs. 10.4%; p = 1.000). Logistic regression on the unmatched cohort confirmed a similar risk of VARC-2 device success, paravalvular aortic regurgitation II+, and 30-day clinical outcomes after NEO and PRO implantation. CONCLUSIONS: (AU)

Transcatheter aortic valve implantation in bicuspid anatomy: procedural results with two different types of valves.

BACKGROUND: It is well known that bicuspid valve stenosis can be treated with transcatheter aortic valve implantation (TAVI) even if specific issues can cause problems: dilatation of ascending aorta, possible aorthopathy, eccentricity of the valve and calcium distribution in leaflets and in commissures. We classified Bicuspid aortic valve (BAV) in type 0 (2 cusps and no raphe), and type 1 (2 cusps and one or more raphes). The aim of the present study was to report the results of two types of valve (CoreValve from 2009 to 2016 and Lotus valve from 2014 to 2017) in a consecutive series of BAV patients treated in 2 Italian centers. METHODS: A total of 30 patients with BAV underwent TAVI from September 2009 to March 2017. RESULTS: Mean age was 78±8 years, 54.5% were males and 7.4% had peripheral vasculopathy, 6.5% previous stroke or TIA, 15.6% previous PCI and 9.4% previous coronary artery bypass grafting. Ten patients (30.3%) had a type 1; mean aortic valvular gradient was 57.7±17.7 mmHg; aortic valvular area was 0.7±0.2 mm2, left ventricular ejection fraction was 51.4±10.0% and ascending aorta was 41.0±5.6 mm. Among these 30 patients, 16 of them (group 1) undergone CoreValve implantation and 14 (group 2) undergone Lotus valve implantation. Patients in the first group had a higher Logistic Euroscore (P<0.001) and higher AVA (P=0.026) and valve area CT (P=0.003). Device size in group1 was more often bigger than in group 2 (P<0.001) and postdilatation was never used in the last group. Group 1 had a significant more frequent aortic regurgitation ≥2 assessed with angiography (28.6% vs. 0%; P=0.05). A non-statistically significant higher rate of second valve implantation (6.2% vs. 0%; P=1.00) was also observed. New permanent pacemaker implantation (40.0% vs. 35.7%; P=0.812) was equal in both valves. CONCLUSIONS: Postprocedural aortic regurgitation is still an issue in BAV undergone TAVI when: 1) the annulus is big; 2) when we are using self-expandable valves; and 3) in type 0 valves. Lotus valve, with a higher radial force put in a small annuls seems associated to better procedural outcomes in this subset of patients.

Effect of ZrB2 addition on the oxidation behavior of Si-SiC-ZrB2 composites exposed at 1500°C in air.

BACKGROUND: Silicon carbide ceramics obtained by reactive infiltration of silicon (SRI) have many industrial applications especially involving severe and high temperature conditions. In this study, the oxidation behavior in air of Si-SiC-ZrB2 systems at a high temperature (1500°C) for dwelling times of up to 48 hours was examined. METHODS: The oxidation process was analyzed on the basis of elemental maps and X-ray diffraction patterns taken, respectively, on the core and on the surface of the specimens, together with weight gains and the average thicknesses of the resulting scale. Further, flexural strength at room temperature was examined as a function of different oxidation times. RESULTS: The main chemical reactions and phase transformations involved in the oxidation process are reported. Several oxides were detected on the surface: zirconia, silica, zircon and 3-zirconium monoxide. All of the samples showed a parabolic oxidation kinetics, suggesting that the controlling mechanism was the diffusion; however, even after 48 hours, the oxidation process was not finished - indeed, all of the samples continued to gain weight. CONCLUSIONS: The oxidation of Si-SiC-ZrB2 material produced via SRI was slower compared with previously investigated ZrB2-SiC composites processed with a different techniques and tested in similar conditions. The oxidation mechanism was found to be consistent with the convection cells model.

Enhanced Atomic Desorption of 209 and 210 Francium from Organic Coating.

Controlled atomic desorption from organic Poly-DiMethylSiloxane coating is demonstrated for improving the loading efficiency of 209,210Fr magneto-optical traps. A three times increase in the cold atoms population is obtained with contact-less pulsed light-induced desorption, applied to different isotopes, either bosonic or fermionic, of Francium. A six times increase of 210Fr population is obtained with a desorption mechanism based on direct charge transfer from a triboelectric probe to the adatom-organic coating complex. Our findings provide new insight on the microscopic mechanisms of atomic desorption from organic coatings. Our results, obtained at room temperature so as to preserve ideal vacuum conditions, represent concrete alternatives, independent from the atomic species in use, for high-efficiency laser cooling in critical conditions.

Transcatheter Treatment of Severe Tricuspid Regurgitation With the Edge-to-Edge MitraClip Technique.

BACKGROUND: Current surgical and medical treatment options for severe tricuspid regurgitation (TR) are limited, and additional interventional approaches are required. In the present observational study, the safety and feasibility of transcatheter repair of chronic severe TR with the MitraClip system were evaluated. In addition, the effects on clinical symptoms were assessed. METHODS: Patients with heart failure symptoms and severe TR on optimal medical treatment were treated with the MitraClip system. Safety, defined as periprocedural adverse events such as death, myocardial infarction, stroke, or cardiac tamponade, and feasibility, defined as successful implantation of 1 or more MitraClip devices and reduction of TR by at least 1 grade, were evaluated before discharge and after 30 days. In addition, functional outcome, defined as changes in New York Heart Assocation class and 6-minute walking distance, were assessed. RESULTS: We included 64 consecutive patients (mean age 76.6±10 years) deemed unsuitable for surgery who underwent MitraClip treatment for chronic, severe TR for compassionate use. Functional TR was present in 88%; in addition, 22 patients were also treated with the MitraClip system for mitral regurgitation as a combined procedure. The degree of TR was severe or massive in 88% of patients before the procedure. The MitraClip device was successfully implanted in the tricuspid valve in 97% of the cases. After the procedure, TR was reduced by at least 1 grade in 91% of the patients, thereof 4% that were reduced from massive to severe. In 13% of patients, TR remained severe after the procedure. Significant reductions in effective regurgitant orifice area (0.9±0.3cm2 versus 0.4±0.2cm2; P<0.001), vena contracta width (1.1±0.5 cm versus 0.6±0.3 cm; P=0.001), and regurgitant volume (57.2±12.8 mL/beat versus 30.8±6.9 mL/beat; P<0.001) were observed. No intraprocedural deaths, cardiac tamponade, emergency surgery, stroke, myocardial infarction, or major vascular complications occurred. Three (5%) in-hospital deaths occurred. New York Heart Association class was significantly improved (P<0.001), and 6-minute walking distance increased significantly (165.9±102.5 m versus 193.5±115.9 m; P=0.007). CONCLUSIONS: Transcatheter treatment of TR with the MitraClip system seems to be safe and feasible in this cohort of preselected patients. Initial efficacy analysis showed encouraging reduction of TR, which may potentially result in improved clinical outcomes.