Valve Performance Research Articles

FOPID controller design for pneumatic control valves with ultra-low overshoot, rapid response and enhanced robustness

The performance of pneumatic control valves, characterized by speed, stability, and accuracy, is critical for industrial production and energy efficiency. Traditional PID and fuzzy control methods face limitations in achieving high-precision control due to structural constraints. This study proposes a fractional-order proportional-integral-derivative (FOPID) controller optimized for pneumatic control valves, incorporating a novel overshoot-penalty objective function. To enhance optimization, the Hippopotamus Optimization (HO) is improved with Genetic Algorithm (GA). Simulation and experimental results demonstrate the proposed GAHO-based FOPID controller achieves a settling time of 5.25 s and an overshoot of 0.88%, significantly surpassing conventional methods. These results establish that the proposed FOPID controller as an effective solution for improving the stability, efficiency, and safety of pneumatic control systems in industrial applications.

Dynamic ventricular-arterial coupling during supine ergometry is related to outcome in asymptomatic severe aortic stenosis

Abstract Background Ventricular-arterial coupling (VAC) represents a key pathophysiological component for the preservation of left ventricular (LV) contractile efficiency. Increased age, hypertension and evolving atherosclerosis may induce VAC mismatch in asymptomatic severe aortic stenosis (AS). Purpose Purpose of the study was to assess the effect of supine ergometry (Ex) on VAC in AS and to interrogate potential relationship with the clinical outcome. Methods Forty eight AS patients, followed-up on valve clinic in a tertiary center (age 66±12 years), were referred for Ex. AS-related cardiac events (independent decision for surgery, occurrence of AS-related symptoms) during a follow-up of 33±21 months occurred in 19 patients (EV group). The following parameters were estimated noninvasively both at rest-R/Ex: LV ejection fraction (EF:%), strain (SR:%), transmitral E/e ratio, peak transtricuspid systolic pressure, AV mean gradient (meanGR: mmHg), valvuloarterial impedance (Za: mm Hg·ml-1m2), effective arterial elastance (Ea: mmHg/ml), LV endsystolic elastance (Ees: mmHg/ml) and VAC as the ratio Ea/Ees. Results Event (EV) and non-event (nEV) groups had similar % target heart rate at Ex (96±17 vs 100±12), age (66±12 vs 66±12 years), women/men ratio (9/19 vs 14/29), EF-R (55±8 vs 56±7%), SR-R (15.0±4.0 vs 14.5±3.5%), SR-Ex (16±5 vs 17±4%) but lower EF-Ex (59±9 vs 64±6%, p=0.03). EV group had greater meanGR at R (45±16 vs 37±12mmHg, p=0.03), but similar Za both at R and Ex (2.3±1.0 vs 2.0±0.8mm Hg·ml-1m2 and 2.7±0.8 vs 2.7±1.0mm Hg·ml-1m2). EV group had lower Ees at Ex (4.0±2.0 vs 5.6±2.3mmHg/ml, p=0.026) but similar Ees at R (3.0±1.3 vs 3.3±1.5 mmHg/ml) as well Ea both at R and Ex (2.4±1.0 vs 2.6±1.0 mmHg/ml and 2.7±1.0 vs 3.1±1.1 mmHg/ml). Despite similar VAC at R (0.84±0.24 vs 0.79±0.25), EV group showed worsening VAC during Ex (0.75±0.29 vs 0.58±0.12, p=0.01). Binary logistic regression analysis for events, including the different parameters between groups (meanGR, VAC Ex, EF Ex), selected only the VAC Ex (exp(b)=0.01, p=0.02) as independent predictor. ROC event cut off for VAC Ex was 0.69 (area 0.68, p=0.05, sensitivity 0.6 specificity=0.9, figure 1). Kaplan Meier analysis for the greater values of the VAC Ex than 0.69 showed an increased hazard ratio for events (log rank=6.9 p=0.009, figure 2). Conclusion In asymptomatic patients with AS, noninvasive VAC at Ex provides an independent prognostic yield for cardiac outcome from conventional indices of either LV function or hydraulic aortic valve performance.

Investigation of Factors Influencing Solenoid Valve Speed Response Characteristics of the Common Rail Injector

The dynamic injection characteristics of high-pressure common rail fuel injection systems are determined by the speed response performance of the solenoid valve. A simulation model has been established for investigating the influence mechanism and change law of characteristic parameters on speed response characteristics of the solenoid valve. The speed response characteristics of the solenoid valve, including the average opening speed, the average closing speed, the maximum opening speed, and the maximum closing speed, caused by the changes of characteristic parameters such as pre-tightening force of the solenoid valve spring, mass of the solenoid valve moving parts, diameter of the outflow orifice, diameter of the inflow orifice, diameter of the control piston, and pressure in the common rail, have been studied. The correlation analysis of the influence factors is carried out by using the experimental design method based on the response surface model, and the correlation coefficients between each factor and the speed response characteristics of the solenoid valve are obtained. The results show that both single factors and interaction factors of the parameters are correlated with the speed response characteristics of the solenoid valve. The results of this paper can provide a theoretical reference for the design and optimization of the high-pressure common rail injector.

Research Progress in Pre-Stage Deflection Jet Tube Type Electro-Hydraulic Servo Valve

Background: The pre-stage deflection is a key aspect of the deflector jet tube electrohydraulic servo valve, and its performance not only affects the pressure gain, flow gain, and other important parameters of the servo valve, but also affects the dynamic and static characteristics of the servo valve and electro-hydraulic servo system. Objective: This paper aimed to outline the working principle of the pre-stage deflector jet tube type electro-hydraulic servo valve, and review and analyze its research performance development in five aspects. Method: The research progress in the key indexes of servo valve performance at different stages, the mechanism and phenomenon of the erosion and wear of the pre-stage, the mechanism and characteristics of the pre-stage cavitation, the structural improvement and parameter optimization of the pre-stage, as well as the pre-stage drive mode, has been summarized. Results: It has been found that although a large number of scholars at home and abroad have improved the structure and driving mode of the front stage of the deflecting jet tubular electrohydraulic servo valve and optimized the parameters to improve the performance of the deflecting jet tubular electro-hydraulic servo valve, the internal flow field of the front stage is complex, prone to erosion and cavitation and many complex phenomena, and there are still many aspects to be improved and innovated. Conclusion: This paper has thus summarized the defects of the front-end stage, and put forward three future innovations of miniaturization, intelligence, and multifunction, to contribute innovative ideas to the design of the front-end stage of the deflection jet pipe electro-hydraulic servo valve in the future.

Analysis of internal leakage performance of spool valve based on size chain and part size distribution

Analysis of internal leakage performance of spool valve based on size chain and part size distribution

Initial Multicenter Experience With a Novel Self-Expanding TAVR System in Patients With Aortic Valve Stenosis.

As transcatheter aortic valve replacement is performed increasingly in younger, low-risk patients, the need for commissural alignment and coronary access has increased. Design elements of the JenaValve Trilogy (JVT) transcatheter heart valve (THV) ensure both. This study sought to evaluate the outcome of patients with aortic stenosis (AS) treated with this novel transfemoral, self-expanding THV. We included 43 consecutive patients with severe AS treated with the JVT system at 5 German sites. The primary endpoint of the study was technical success of the procedure. Procedural outcomes, hemodynamic valve performance, and clinical outcomes at 30days were evaluated according to the Valve Academic Research Consortium-3 criteria. The median age was 81 years (Q1-Q3: 77.0-83.9 years) with a median Society of Thoracic Surgeons Risk Score of 3.1% (Q1-Q3: 2.1%-5.9%). Technical success was achieved in 98% (n=42 of 43). One patient was converted to open surgery. The median aortic gradient was 5.0mmHg (Q1-Q3: 4.0-7.0mmHg), and no patient had moderate or greater paravalvular regurgitation (88% [n=37 of 42] with none or trace paravalvular regurgitation). At 30days, major vascular complications and stroke each occurred in 1 (2.3%) patient, 2 (4.7%) patients had died, and permanent pacemaker implantation was needed in 4.9% (n=2 of 41). Overall, early safety at 30days was achieved in 82% (n=27 of 33) of patients. Treatment of AS patients with this novel transfemoral THV system is safe and effective. The JVT offers an excellent alternative to established transcatheter aortic valve replacement prostheses for patients with AS.

Three-Year Outcomes With a Supra-Annular, Self-Expanding Bioprosthesis and a Pericardial Wrap-The FORWARD PRO Study.

The self-expanding, supra-annular Evolut valve is an established platform for Transcatheter Aortic Valve Implantation (TAVI). Evolut PRO introduced an outer sealing wrap to mitigate paravalvular leakage. We evaluated the 3-year clinical outcomes and valve performance of the Evolut PRO in standard clinical practice for severe aortic stenosis (AS) patients at intermediate or higher risk for surgery. The FORWARD PRO prospective, single-arm, multicentre, post-market clinical study enrolled 638 patients with native aortic valve stenosis or failed surgical bioprosthetic aortic valve undergoing TAVI, at intermediate or high risk, with the Evolut PRO valve. Clinical and serial echocardiographic outcomes were followed-up for 3 years. TAVI using Evolut PRO was attempted in 629 AS patients (implanted in 97%) (mean age 81.7 years; STS PROM score, 4.7%). At 3 years all-cause mortality was 25.0%, disabling stroke 6.5% (all-cause mortality or disabling stroke, 28.5%) and rate of new permanent pacemaker implantation 24.7%. Excellent valve haemodynamics were maintained (mean gradient 8.8 ± 4.7 mm Hg; mean effective orifice area 2.0 ± 0.5 cm2) at 3 years. In a paired analysis of patients with ≥ mild paravalvular leakage (PVL) at discharge, more than two-thirds demonstrated improved PVL at 3 years. Patients with ≥ mild PVL at discharge had higher median total calcium volume than those with no/trace PVL (p < 0.001). In clinical practice TAVI with the Evolut PRO valve is associated with favorable clinical outcomes and excellent haemodynamic performance out to 3 years. The observation of improvements in PVL over time warrants further research.

Fabrication and in vivo testing of a sub-mm duckbill valve for hydrocephalus treatment

Hydrocephalus is characterized by the accumulation of excess cerebrospinal fluid (CSF) in the cranium due to an imbalance between production and absorption of CSF. The standard treatment involves the implantation of a shunt to divert excess CSF into the peritoneal cavity, but these shunts exhibit high failure rates over time. In pursuit of improved reliability and performance, this study proposes a miniaturized valve designed to mimic the natural one-way valve function of the arachnoid granulations and thereby replace the shunts. A benchtop testing setup was employed to characterize the behavior of the fabricated valve. Additionally, an animal study was conducted to assess the valve’s in vivo performance. This involved the injection of saline into the lateral ventricle to elevate intracranial pressure (ICP), followed by the drainage of the saline through the valve inserted into the cisterna magna (CM) to reduce pressure. Our prototype features a silicone duckbill valve design combined with a silicone tube as an inlet. Through benchtop testing, the valve exhibited unidirectional flow with negligible reverse leakage, revealing that critical parameters such as the width of the fluid channel (W) and bill length (L) could be controlled to optimize valve performance. Notably, the valve configuration with W= 0.8mm and L < 0.5mm achieved the lowest cracking pressure (2.22 ± 0.07 mmHg) and outflow resistance (22.00 ± 0.70 mmHg/mL/min) within the low cracking pressure range of conventional shunts. Our observations of the in vivo test demonstrated that when untreated states, pressure differences from baseline to peak exceeded 20 mmHg due to the absence of drainage, resulting in sustained pressure elevation. Conversely, upon treating states by removing the clamp, pressure differences from baseline to peak remained below 5 mmHg, indicating effective drainage of injected saline through the valve. These promising results highlight the potential of the miniaturized duckbill valve as an alternative for ICP management in hydrocephalus, offering improved control and reliability compared to conventional shunting systems. Further research is required to evaluate the valve’s performance as a chronic implant.

Numerical and Experimental Determination of the Bore Throughput Controlling the Operation of the Differential Section of a Pneumatic Brake Valve

Purpose: To assess the applicability of computational fluid dynamics (CFDs) in determining the flow parameters of inter-chamber nozzle openings in the differential section of a trailer air brake valve. Methodology: Numerical calculations were performed using SolidWorks Flow Simulation (SW-FS) and Ansys Fluent (A-F) with defined boundaries and initial conditions. The results were validated experimentally using the reservoir method and the lumped method for throughput identification. Results: CFD calculations determined the functional dependence of the mass flow rate on the nozzle diameter for a range of control nozzle bore diameters. The SW-FS 2024 and A-F 2023 software showed a mean difference of 4.66% in the total characteristics. The experimental validation resulted in differences of 6.31% (SW-FS) and 5.79% (A-F) compared to the CFD results. Theoretical contribution: This study fills a research gap in applying CFDs to brake valve performance analyses, providing a foundation for developing more complex numerical models to evaluate individual valve sections. Practical implications: The findings suggest that CFDs can be used to accurately determine the flow parameters of control nozzle orifices, with an average of a 6.05% difference from experimental tests. This approach can potentially streamline the design and optimization process for pneumatic brake valves.

Post-implant transcatheter aortic prosthesis deformation: tricuspid versus bicuspid valve.

We sought to assess whether post-implant transcatheter aortic valve prosthesis multi detector computed characteristics differ between patients with native tricuspid and bicuspid aortic valve stenosis, as well as the effect on valve performance and clinical implications. We analysed 100 consecutive post-implant multi detector computed tomography scans to assess self-expandable prosthesis non-uniform expansion at six pre-specified valvular levels, and other specific parameters, including valvular and perivalvular thrombosis at six months follow-up. Echocardiographic prosthesis performance and clinical outcome was also evaluated. Mean eccentricity was significantly higher in the bicuspid group (0.43 (0.09) vs 0.37 (0.08), p = 0.005, bicuspid vs tricuspid); valvular and perivalvular thrombosis were also significantly more frequent in the bicuspid than in the tricuspid group (81% vs. 36.9%, p = 0.031); there was no significant difference in terms of mean prosthetic gradient at follow-up between (7.31 (5.53 mmHg) vs 7.09 (3.05 mmHg), p = 0.825); EOAi was also similar between bicuspid and tricuspid (1.08 (0.12 cm2) vs 1.03 (0.13 cm2), p = 0.101), with no significant changes compared to discharge. However, the bicuspid valve was associated with a significantly higher risk of adverse events (HR:3.72, 95%CI: 1.07-13.4, p = 0.027). Higher level of eccentricity, which indicates prosthesis deformation, is often detected in bicuspid valves. Although echocardiographic performance was not affected, this might have led to an increased incidence of thrombosis at valvular and perivalvular levels and worse outcomes.

Assessing the Impact of Cardiac Output and Valve Orientation on Bioprosthetic Pulmonary Valve Hemodynamics Using In Vitro 4D-Flow MRI and High-Speed Imaging.

Pulmonary valve replacement (PVR) using bioprosthetic valves is a common procedure performed in patients with repaired Tetralogy of Fallot and other conditions, but these valves frequently become dysfunctional within 15years of implantation. The causes for early valve failure are not clearly understood. The purpose of this study was to explore the impact of changing cardiac output (CO) and valve orientation on local hemodynamics and valve performance. A 25mm bioprosthetic valve was implanted in an idealized 3D-printed model of the right ventricular outflow tract (RVOT). The local hemodynamics at three COs and two valve orientations were assessed using 4D-Flow MRI and high-speed camera imaging. Noticeable differences in jet asymmetry, the amount of recirculation, leaflet opening patterns, as well as the size and location of reversed flow regions were observed with varying CO. Rotation of the valve resulted in drastic differences in reversed flow regions, but not forward flow. Flow features observed in the valve with low CO in this study have previously been correlated with calcification, hemolysis, and leaflet fatigue, indicating their potential negative impact on local hemodynamics and leaflet performance.

Three-Dimensional Pulsating Flow Simulation in a Multi-Point Gas Admission Valve for Large-Bore CNG Engines

This study examines the dynamic fluid behavior of a PWM-controlled Solenoid-Operated Gas Admission Valve (SOGAV) for large-bore CNG engines using 3D Computational Fluid Dynamics (CFD) simulations with dynamic mesh techniques. The research focuses on the influence of orifice geometry variations in the multi-hole restrictor and pressure differentials between the inlet and outlet on flow stability, turbulence, and valve performance. Results demonstrate that multi-hole restrictors with different-sized orifices improve flow uniformity and reduce turbulence, thereby mitigating flow resistance. Transient simulations further reveal standing wave formation and pressure wave interference, emphasizing that steady-state models cannot capture critical transient phenomena, such as accelerated and decelerated jet-like flows and flow separation. These findings provide key insights into SOGAV optimization, contributing to enhanced fuel efficiency and engine responsiveness, meeting the performance requirements of modern gas engines.

Five- Year Outcomes in Low-Risk Patients Undergoing Surgery in the PARTNER 3 Trial.

Surgery remains an important treatment for low-risk patients with severe symptomatic aortic stenosis (AS). This study evaluated 5-year outcomes in low-risk patients undergoing isolated surgical aortic valve replacement (SAVR) or SAVR with concomitant procedures within the randomized Placement of Aortic Transcatheter Valves (PARTNER) 3 trial. In the PARTNER 3 trial, 454 patients underwent surgery for severe, symptomatic, trileaflet AS and were followed up for 5 years. Patients were stratified into those undergoing isolated SAVR (n= 334; 73.6%) vs concomitant SAVR (n= 120; 26.4%). Short- and long-term morbidity was adjudicated by a Clinical Events Committee. Hemodynamic valve performance was evaluated by an echocardiographic core laboratory. Patient-reported health status was measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ). The mean age of participants was 73.6 ± 6.1 years; 71.1% of these patients were male. The median SAVR implant size was 23 mm overall. Five-year all-cause mortality (with vital status sweep) was 9.0% for all patients (8.5% isolated SAVR; 10.2% concomitant SAVR; P= .58), comparable to a recent analysis of low-risk isolated SAVR-treated patients in the STS database (overall mortality, 7.1%). The average 5-year mean gradient was 11.7 ± 5.6 mm Hg overall. Reintervention rates were low in both groups (isolated SAVR, 2.3% vs concomitant SAVR, 5.0%; P= .21), and most patients (isolated SAVR, 87.9%; concomitant SAVR, 86.1%) were alive with no evidence of bioprosthetic valve failure at 5 years. SAVR in low-risk patients in the PARTNER 3 trial demonstrated excellent 5-year outcomes. Five-year mortality was similar in patients undergoing isolated SAVR vs concomitant SAVR. This result was comparable to recently published national SAVR outcomes, thus demonstrating the generalizability of these findings.

Core Laboratory Versus Center-Reported Echocardiographic Assessment of the Native and Bioprosthetic Aortic Valve.

Insights into quantitative differences between core laboratory and center-reported echocardiographic assessment of the native and bioprosthetic aortic valve are lacking. We aimed to explore clinically relevant differences between these evaluations. Data were used from the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Pivotal Trial for the Avalus valve. In this trial, patients with an indication for surgical aortic valve replacement (SAVR) due to aortic stenosis or regurgitation (AR) were enrolled. Serial echocardiographic examinations were performed at each center and blindly reanalyzed by an independent echocardiographic core laboratory (ECL). For the bioprosthetic valve analysis, postoperative data throughout the 5-year follow-up were pooled. Differences between the ECL and the centers in continuous parameters were quantified in mean differences and intraclass correlation coefficients (ICCs). Agreement on AR, paravalvular leak (PVL), and prosthesis-patient mismatch (PPM) classification was investigated using Cohen's kappa coefficients. The analysis on the native aortic valve was performed on 1118 echocardiograms. The relative mean difference was largest for the left ventricular outflow tract (LVOT) area, followed by stroke volume and effective orifice area (index), with center-reported values being 11%-7% higher. High ICCs of around 0.90 were observed for the parameters peak aortic jet velocity, mean pressure gradient, and the velocity-time integral across the aortic valve. Over 5000 echocardiograms were available for the bioprosthetic valve analysis. Therein, comparable results were observed. The kappa coefficient was 0.59 (95% confidence interval [CI] 0.56, 0.63) for agreement on native AR, 0.28 (95% CI 0.18, 0.37) for PVL, and 0.42 (95% CI 0.40, 0.44) for PPM. There is high agreement between the ECL and clinical centers on continuous-wave Doppler-related measurements. In contrast, agreement is low for parameters that involve measurement of the LVOT diameter. These results provide important context for the interpretation of aortic valve performance in studies that lack central ECL evaluation. ClinicalTrials.gov identifier: NCT02088554.

Review of Key Technology and Latest Research Progress of Deflector Jet Servo Valve

Abstract: The deflector jet servo valve has the advantages of strong anti-pollution ability, high reliability and better dynamic performance, so it is widely used in aviation, military and other fields. The research on deflector jet servo valve theory and production is not yet mature. It is expected that through the collation and analysis of the existing data, the method of improving the performance of this kind of valve will be obtained, which will provide the basis for future research and development. By summarizing the research status of the static and dynamic characteristics, pre-stage optimization, mathematical modeling and other parts of the deflector jet servo valve, the technical points and development rules are obtained. By sorting out the relevant patent information in recent years, the vacancy in the patent analysis of the deflector jet servo valve is filled. Based on the summary of the research status of the deflector jet servo valve, combined with the summary of the research status of the deflector jet servo valve, it is pointed out that there are few studies on the performance of deflector jet servo valve under cavitation, noise and extreme temperature. These parameters are of great significance to improve the performance of servo valve, which will be an important research direction in the future. The research status and development trend of the deflector jet servo valve are summarized and analyzed, and various methods that can improve the performance of the servo valve are described, which is of great significance for the subsequent performance improvement and indepth study of such valves.

Study on sealing performance of main gate valve of marine nuclear power plant based on fluid-solid-thermal coupling method

Study on sealing performance of main gate valve of marine nuclear power plant based on fluid-solid-thermal coupling method

Simulation and experiment of static and dynamic characteristics of pilot-operated proportional pressure reducing valve

As an important control component in hydraulic system, the static and dynamic performance of electro-hydraulic proportional valve directly affects the performance of the whole control system. In this paper, through the analysis of the operating principle of a specific pilot-operated proportional reducing valve, two static and dynamic mathematical models are established to simulate the performance of the valve. One model is constructed by empirical formulas, while the other one is corrected through CFD simulation and proportional solenoid test, firstly, a series of flow and fluid force interpolation models are obtained through CFD simulation, replacing the original empirical formulas. Secondly, relevant parameters of the proportional solenoid are corrected by testing its static and dynamic characteristics. To validate the validity of model correction and the accuracy of the corrected model, the static and dynamic experiments of the valve were conducted, and the results are compared with the simulation results of the models, which show that the experimental results are in better agreement with the simulation results of the corrected model. Therefore, this model can be used for further research on the valve.

Early outcomes of the novel Myval THV series compared to SAPIEN THV series and Evolut THV series in individuals with severe aortic stenosis.

There are limited head-to-head randomised trials comparing the performance of different transcatheter heart valves (THVs). We aimed to evaluate the non-inferiority of the balloon-expandable Myval THV series compared to the balloon-expandable SAPIEN THV series or the self-expanding Evolut THV series. The LANDMARK trial randomised 768 patients in a 1:1 ratio, (Myval THV series [n=384] vs contemporary series with 50% SAPIEN THV series [n=192] and 50% Evolut THV series [n=192]). The non-inferiority of Myval over the SAPIEN or Evolut THV series in terms of the 30-day primary composite safety and effectiveness endpoint as per the third Valve Academic Research Consortium (VARC-3) was tested in an intention-to-treat population with a predefined statistical power of 80% (1-sided alpha of 5%) for a non-inferiority margin of 10.44%. The Myval THV series achieved non-inferiority for the primary composite endpoint over the SAPIEN THV series (24.7% vs 24.1%, risk difference [95% confidence interval {CI}]: 0.6% [not applicable {NA} to 8.0]; p=0.0033) and the Evolut THV series (24.7% vs 30.0%, risk difference [95% CI]: -5.3% [NA to 2.5]; p<0.0001). The incidences of pacemaker implantation were comparable (Myval THV series: 15.0%, SAPIEN THV series: 17.3%, Evolut THV series: 16.8%). At 30 days, the mean pressure gradient and effective orifice area were significantly better with the Myval THV series compared to the SAPIEN THV series (p<0.0001) and better with the Evolut THV series than with the Myval THV series (p<0.0001). At 30 days, the proportion of moderate to severe prosthetic valve regurgitation was numerically higher with the Evolut THV series compared to the Myval THV series (7.4% vs 3.4%; p=0.06), while not significantly different between the Myval THV series and the SAPIEN THV series (3.4% vs 1.6%; p=0.32). The Myval THV series is non-inferior to the SAPIEN THV series and the Evolut THV series in terms of the primary composite endpoint at 30 days. ClinicalTrials.gov: NCT04275726; EudraCT number 2020-000,137-40.

Valve Performance Between Latest-Generation Balloon-Expandable and Self-Expandable Transcatheter Heart Valves in a Small Aortic Annulus

BackgroundTranscatheter aortic valve replacement (TAVR) using a self-expandable valve (SEV) promotes better hemodynamics compared with a balloon-expandable valve (BEV) in a small aortic annulus (SAA). ObjectivesThe authors sought to compare hemodynamic properties and clinical outcomes between the latest-generation BEV and SEV after TAVR for SAA. MethodsWe retrospectively analyzed 1,227 patients undergoing TAVR for aortic stenosis with SAA, defined as an annulus area ≤430 mm2, using the BEV (SAPIEN3 Ultra RESILIA, Edwards Lifesciences) and SEV (Evolut FX, Medtronic). The impact of valve design on severe prosthesis–patient mismatch, aortic valve mean pressure gradient ≥20 mm Hg, paravalvular leakage (PVL) ≥ mild, new permanent pacemaker implantation (PMI), and modified VARC-3 device success at discharge was evaluated using logistic regression and propensity score analysis. ResultsOf 1,227 patients, 798 (65.0%) underwent TAVR with BEV implantation. TAVR using BEV had a relatively higher rate of severe prosthesis–patient mismatch (OR: 1.74; 95% CI: 0.54-5.62) and significantly higher incidence of mean pressure gradient ≥20 mm Hg (OR: 2.05; 95% CI: 0.91-4.62) than that using SEV. By contrast, the BEV showed significantly lower incidence of PVL ≥ mild (OR: 0.19; 95% CI: 0.14-0.26), and new PMI (OR: 0.53; 95% CI: 0.33-0.86). The rate of device success was comparable between the BEV and the SEV. These results were confirmed by propensity score analysis. ConclusionsIn TAVR for SAA, SEV demonstrated better hemodynamics than the latest BEV, whereas the latest BEV had lower incidences of PVL ≥ mild and new PMI than the SEV.

TAVI with the ACURATE neo2 in severe bicuspid aortic valve stenosis: the Neo2 BAV Registry.

The ACURATE neo2 is a contemporary transcatheter aortic valve implantation (TAVI) system approved for the treatment of severe aortic stenosis in Europe. The ACURATE neo2 has not been evaluated in bicuspid aortic valve (BAV) stenosis. We sought to evaluate the safety and efficacy of ACURATE neo2 in patients with BAV stenosis. We retrospectively analysed consecutive severe BAV stenosis patients undergoing TAVI with ACURATE neo2 at 10 European centres. Imaging data from preprocedural multislice computed tomography, pre- and postprocedural echocardiography, and procedural cinefluoroscopy were evaluated by a core laboratory. Valve Academic Research Consortium 3 (VARC-3)-defined 30-day procedure safety and efficacy were the primary endpoints. Adverse events were site-reported according to VARC-3 criteria. Among 181 patients with BAV stenosis treated with the ACURATE neo2, the mean age was 77.5±7.2 years, 58.0% were female, and the Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score was 2.3% (1.6-3.7%). Most procedures were transfemoral, and predilatation was performed in all cases. A second valve was required in 4 cases (2.2%). VARC-3-defined technical success was 95.6%. The primary endpoints of device success and early safety occurred in 90.6% and 82.3%, respectively. At 30 days, cardiovascular death occurred in 2.2% (N=4) and stroke in 1.6% (N=3). Core laboratory-adjudicated echocardiography reported an effective orifice area of 2.0 (1.7-2.5) cm2 and a mean transvalvular gradient of 6.5 (4.6-9.0) mmHg. Half of all cases (51.2%) had no paravalvular leak, while moderate leak occurred in 4.3%. A new permanent pacemaker was required in 11 patients (6.5%). The ACURATE neo2 demonstrated favourable clinical outcomes and bioprosthetic valve performance at 30 days in selected patients with severe BAV stenosis.