Transcatheter Aortic Valve Prosthesis Research Articles

Acquired Thrombocytopenia in Contemporary Transcatheter Aortic Valve Prosthesis.

Postprocedural thrombocytopenia is a known phenomenon following transcatheter aortic valve implantation (TAVI). The aim of this study is to evaluate whether postinterventional platelet kinetics differ when comparing the current generation of balloon-expandable valve (BEV) and self-expanding valve (SEV) prostheses. We performed a retrospective analysis of patients undergoing TAVI at our facility between 2017 and 2019. Patients were stratified according to the type of prosthesis used: BEV or SEV. Hematocrit-corrected platelet counts were calculated to account for dilution. Nadir platelet counts (lowest recorded platelet count), drop platelet counts (DPC; highest relative platelet drop from baseline), and severity of thrombocytopenia during the discourse and at discharge were assessed. Of the 277 included patients, 212 received SEV and 65 BEV. BEV patients were younger (81.8 ± 4.4 years vs 79.7 ± 6.8 years, p = 0.03). Further demographic characteristics were similar between groups. Implanted SEV were larger (p < 0.001) and had shorter procedural times (p < 0.01). There were no significant differences in postprocedural discourse. Postinterventional platelet drop was more pronounced in BEV patients in several evaluated metrics: mean DPC (24.3 ± 10.9% vs 18.8 ± 14.8%, p < 0.01), patients with DPC > 30% (n = 19, 29.2%, vs n = 33, 15.6%, p = 0.02), and also when comparing platelet kinetics. Despite improvements in outcome, the current generation of balloon-expandable TAVI prostheses carries a predisposition for postprocedural thrombocytopenia even when the effects of dilution are accounted for.

Reduced Order Modeling for Real-Time Stent Deformation Simulations of Transcatheter Aortic Valve Prostheses.

Computational modeling can be a critical tool to predict deployment behavior for transcatheter aortic valve replacement (TAVR) in patients with aortic stenosis. However, due to the mechanical complexity of the aortic valve and the multiphysics nature of the problem, described by partial differential equations (PDEs), traditional finite element (FE) modeling of TAVR deployment is computationally expensive. In this preliminary study, a PDEs-based reduced order modeling (ROM) framework is introduced for rapidly simulating structural deformation of the Medtronic Evolut R valve stent frame. Using fifteen probing points from an Evolut model with parametrized loads enforced, 105 FE simulations were performed in the so-called offline phase, creating a snapshot library. The library was used in the online phase of the ROM for a new set of applied loads via the proper orthogonal decomposition-Galerkin (POD-Galerkin) approach. Simulations of small radial deformations of the Evolut stent frame were performed and compared to full order model (FOM) solutions. Linear elastic and hyperelastic constitutive models in steady and unsteady regimes were implemented within the ROM. Since the original POD-Galerkin method is formulated for linear problems, specific methods for the nonlinear terms in the hyperelastic case were employed, namely, the Discrete Empirical Interpolation Method. The ROM solutions were in strong agreement with the FOM in all numerical experiments, with a speed-up of at least 92% in CPU Time. This framework serves as a first step toward real-time predictive models for TAVR deployment simulations.

Surgical treatment of complex double valve endocarditis involving transcatheter aortic valve prosthesis: Utility of the commando procedure

Surgical treatment of complex double valve endocarditis involving transcatheter aortic valve prosthesis: Utility of the commando procedure

Long-term durability of self-expanding and balloon-expandable transcatheter aortic valve prostheses: UK TAVI registry.

With expansion of transcatheter aortic valve implantation (TAVI) into younger patients, valve durability is critically important. We aimed to evaluate long-term valve function and incidence of severe structural valve deterioration (SVD) among patients ≥ 10-years post-TAVI and with echocardiographic follow-up at least 5-years postprocedure. Data on patients who underwent TAVI from 2007 to 2011 were obtained from the UK TAVI registry. Patients with paired echocardiograms postprocedure and ≥5-years post-TAVI were included. Severe SVD was determined according to European task force guidelines. 221 patients (79.4 ± 7.3 years; 53% male) were included with median echocardiographic follow-up 7.0 years (range 5-13 years). Follow-up exceeded 10 years in 43 patients (19.5%). Valve types were the supra-annular self-expanding CoreValve (SEV; n = 143, 67%), balloon-expandable SAPIEN/XT (BEV; n = 67, 31%), Portico (n = 4, 5%) and unknown (n = 7, 3%). There was no difference between postprocedure and follow-up peak gradient in the overall cohort (19.3 vs. 18.4 mmHg; p = NS) or in those with ≥10-years follow-up (21.1 vs. 21.1 mmHg; p = NS). Severe SVD occurred in 13 patients (5.9%; median 7.8-years post-TAVI). Three cases (23.1%) were due to regurgitation and 10 (76.9%) to stenosis. Valve-related reintervention/death occurred in 5 patients (2.3%). Severe SVD was more frequent with BEV than SEV (11.9% vs. 3.5%; p = 0.02), driven by a difference in patients treated with small valves (BEV 28.6% vs. SEV 3.0%; p < 0.01). Hemodynamic function of transcatheter heart valves remains stable up to more than 10 years post-TAVI. Severe SVD occurred in 5.9%, and valve-related death/reintervention in 2.3%. Severe SVD was more common with BEV than SEV.

Analysis of thrombosis risk of commissural misaligned transcatheter aortic valve prostheses using particle image velocimetry

Abstract Due to excellent clinical results, transcatheter aortic valve replacement (TAVR) has evolved to a treatment option for patients with low surgical risk, resulting in an increasing demand for durable heart valve prostheses. Durability of TAVR could be limited by leaflet thrombosis. Thrombus formation in the aortic root is mainly affected by the hemodynamic situation, which is dependent on the positioning of the implant. We investigated the flow field in the aortic root after TAVR implantation by means of particle image velocimetry. To quantify the influence of the implant-position with respect to an alignment or misalignment of the leaflet commissures on the thrombogenic potential, we used a transport equation for residence time (RT) to consider washout behavior. Furthermore, we introduced a shear effect criterion (SIE) to address platelet activation as a measure for a potential thrombus formation. Misaligned implantation of a TAVR resulted in a reversed direction of rotation of the occurring recirculation area. This led to fluid flow with comparable areas of increased relative blood RT (RTaligned: 97.6%, RTmisaligned: 88.0%) and a smaller area of low shear load for the misaligned TAVR (SIEaligned: 57.7%, SIEmisaligned: 3.70%) into the sinus region, indicating a higher potential for thrombus formation.

Analysis on the effects of hypo-attenuated leaflet thickening on the hemodynamics of transcatheter aortic valve prostheses by means of particle image velocimetry

Abstract The minimally invasive therapy for the treatment of aortic valve regurgitation and stenosis, transcatheter aortic valve replacement (TAVR), is an alternative to surgical valve replacement. Promising clinical results led to the consideration of expanding the use of TAVR in younger patients with lower surgical risk. This implies a longer durability of the TAVR. In relation to the durability of the TAVR, thickening of TAVR leaflets, including reduced motion, has been clinically observed. The aim of this study was to analyse the effects of valve leaflet thickening with reduced leaflet kinematics on the hemodynamics. We measured the flow through a TAVR under pulsatile conditions by using phase-resolved particle image velocimetry (PIV). It has been shown that flow conditions alter in a pathological manner in a TAVR replica with thickened leaflets compared with thin leaflets. In detail, shear stress and Reynolds stress increased by up to a factor of two and additionally the washout behaviour was worse for thickened leaflets. This suggests that a thickened valve is at higher risk for platelet activation and aggregation. This could lead to a self-reinforcing process in which the formation of a thickened valve promotes thrombus formation, which in turn promotes further progression of the thickening.

Computation of flow through TAVI device by means of physics informed neural networks

Abstract Cardiovascular diseases are among the most common diseases with high mortality, including aortic valve stenosis and insufficiency. Minimally invasive implantation of transcatheter aortic valve prosthesis (TAVI) has become the standard procedure for patients with increased risk for open surgery. It is commonly accepted that the long-term outcome of aortic valve replacement depends on hemodynamic performance. This motivates the analysis of the velocity field in the vicinity of the TAVI. Computational fluid dynamics (CFD) methods have been established in the past, but show limitations in terms of computational effort when rapid design optimization or patient-specific decision making in real time is required. In this study we show the usage of PINNs for predicting fluid flow through a TAVI device. We also show a method of enforcing boundary conditions for this specific problem. Due to the physics involved in the training process, this principle does in theory not require additional training data. To validate the method, we performed CFD simulations that solved the Navier-Stokes equations be means of finite volume methods. Besides the good estimation of the main flow components, discrepancies between CFD and PINN results are present. Nevertheless, the flow structures have certain similarities in the coarse spatial localization of the vortex patterns occurring in flow around the TAVI device.

Deformation of Transcatheter Aortic Valve Prostheses: Implications for Hypoattenuating Leaflet Thickening and Clinical Outcomes.

Although transcatheter aortic valve replacement (TAVR) therapy continues to grow, there have been concerns about the occurrence of hypoattenuating leaflet thickening (HALT), which may affect prosthesis function or durability. This study aimed to examine prosthesis frame factors and correlate their extent to the frequency of HALT and clinical outcomes. We prospectively examined 565 patients with cardiac computed tomography screening for HALT at 30 days after balloon-expandable SAPIEN3 and self-expanding EVOLUT TAVR. Deformation of the TAVR prostheses, asymmetric prosthesis leaflet expansion, prosthesis sinus volumes, and commissural alignment were analyzed on the postprocedural computed tomography. For descriptive purposes, an index of prosthesis deformation was calculated, with values >1.00 representing relative midsegment underexpansion. A time-to-event model was performed to evaluate the association of HALT with the clinical outcome. Overall, HALT was present in 21% of SAPIEN3 patients and in 16% of EVOLUT patients at 30 days after TAVR. The occurrence of HALT was directly associated with greater prosthesis frame deformation (P<0.001), worse asymmetry of the leaflets (P<0.001), and smaller TAVR neosinus volumes (P<0.001). These relations were present in both prosthetic types and in all of their size ranges (all P<0.05). In multivariable analyses that include clinical variables previously associated with HALT (eg, anticoagulant therapy), variables of TAVR prosthesis deformation remained predictive of HALT. Although HALT was not associated with changes in prosthetic hemodynamics, its presence was associated with the risk of mortality at 1 year, with respect to greater incidences of all-cause mortality (hazard ratio, 2.98 [95% CI, 1.57-5.63]; P=0.001), cardiac death (hazard ratio, 4.58 [95% CI, 1.81-11.6]; P=0.001), and a composite outcome of all-cause mortality and heart failure hospitalization (hazard ratio, 1.94 [95% CI, 1.14-3.30]; P=0.02) with adjustment for age, sex, and comorbidities. Nonuniform expansion of TAVR prostheses resulting in frame deformation, asymmetric leaflet, and smaller neosinus volume is related to occurrence of HALT in patients who undergo TAVR. These data may have implications for both prosthesis valve design and deployment techniques to improve clinical outcomes for these patients.

Macroscopic and microscopic features of surgically explanted transcatheter aortic valve prostheses.

With the extended indications of transcatheter aortic valve (TAV) replacement (TAVR) to lower-risk patients, there is an increasing number of patients requiring surgical explantation of failed TAV. We sought to describe macroscopic and microscopic features of surgically explanted percutaneous aortic valve prostheses. Preoperative and surgical characteristic of patients undergoing surgical explantation of TAV were retrospectively analyzed from 2007 to 2020. Surgical and pathologic features of these valves, and outcomes of the surgical valve replacement were described. Out of 1764 patients who underwent a TAVR procedure, 21 were operated for TAV failure. Isolated or combined indications for surgery included: significant paravalvular leak (n = 15), delayed prosthesis migration (n = 5), significant increase of trans-TAV gradients (n = 6), and endocarditis (n = 3). Mean time elapsed between TAVR and explantations was 674.9 ± 803.9 days. Macroscopic lesions found on explanted percutaneous valves were severe adhesions to the aorta (n = 10), calcifications (n = 7), leaflet thrombosis (n = 4), and vegetations (n = 3). Except for patients with endocarditis, one or more pathological lesions were found in 15 patients. Pathology analyses on these valves showed fibro-calcific degenerations (n = 12), pannus formation (n = 9), and chronic inflammation (n = 3). One patient (4.8%) died after surgical explantation, and 13 (61.9%) had concomitant procedures. The survival rate at 1 year was 94.4%. Microscopic findings of fibro-calcific leaflet degeneration, and pannus formation in addition to macroscopic calcification and thrombosis present early, (within a mean of 2 years) after TAVR. Further investigation with a higher number of patients and echocardiographic follow-up is warranted.

The results of the application of a new technique of open implantation of self-opening transcatheter aortic valves in an experiment

Background. In recent years, transcatheter implantation of the aortic valve has become increasingly performed as an alternative to "open" prosthetics. The undoubted advantage of this technology is its minimally invasive nature, which in most cases provides a favorable clinical outcome of the intervention. The transcatheter method of aortic valve prosthetics does not require sternotomy and connection of an artificial circulation device, which significantly reduces the risk of postoperative mortality and complications. However, despite all the advantages of the existing models, they are not without drawbacks that force researchers to develop and test new transcatheter valves. The problem of experimental studies of new models of self-opening transcatheter aortic valves is mainly determined by the anatomical features of the aortic root of animals. In this regard, the development of a reliable method of implantation of valve prostheses in the experiment is an urgent problem of preclinical testing.Aim. Development of a protocol for open implantation of a transcatheter aortic valve in experiment and evaluation of long-term results.Methods. To develop an experimental model, pigs of the "Landras" breed, females weighing 129.83 ± 9 kg were used. Transcatheter aortic valve implantation was performed under conditions of artificial circulation and moderate hypothermia (33-34°C) through a transverse aortotomy under the control of vision. During the experiment, invasive monitoring of blood pressure, central venous pressure, heart rhythm, body temperature, blood gas composition, activated clotting time was performed. The correct positioning and hemodynamic parameters after implantation were evaluated using transesophageal echocardiography.Results. In a series of chronic experiments, 18 open implantations of self-opening transcatheter aortic valves were performed. Successful positioning was achieved in 100% of cases. The developed protocol of open implantation made it possible to achieve reliable fixation of the prosthesis in the orthotopic position, as well as to prevent the migration of the prosthesis, the development of mitral regurgitation, paraaortic fistulas and coronary circulation disorders.Conclusion. In the course of the study, a simple and effective method of open implantation of a transcatheter aortic heart valve prosthesis was developed in an experiment. Received 1 October 2021. Revised 1 November 2021. Accepted 12 November 2021. Funding: This work was carried out within the framework of the state task of Ministry of Health of Russian Federation No. 121032300337-5. Conflict of interest: Authors declare no conflict of interest. Contribution of the authorsConception and study design: M.O. Zhulkov, D.A. Sirota, K.V. Kozyr, D.S. SergeevichevData collection and analysis: M.O. ZhulkovDrafting the article: M.O. ZhulkovCritical revision of the article: D.A. Sirota, A.M. ChernyavskiyExperimental part: M.O. Zhulkov, H.A. Agaeva, A.K. Sabetov, I.S. Zykov, A.R. TarkovaFinal approval of the version to be published: M.O. Zhulkov, K.V. Kozyr, I.S. Zykov, A.R. Tarkova, H.A. Agaeva, A.K. Sabetov, D.A. Sirota, D.S. Sergeevichev, A.M. Chernyavski

Balloon expandable vs. self-expandable transcatheter aortic valve prosthesis short-term results of retrospective study

Transcutaneous aortic valve implantation has been established as an effective method for the treatment of highgrade aortic stenosis in non-operative, high-risk for conventional surgery patients. According to the developed implantation technologies, the prostheses are divided into balloon-expandable valve prostheses (balloon-expandable valves, BEV) and self-expanding valve prostheses (self-expanding prostheses SEV). The two types of devices have different models for implantation, stratum architecture, cusps characteristics, leading to different hemodynamics, frequency of use and performance of normal prosthesis function. The research aims to monitor the short-term results, up to 1 month after discharge, in terms of mortality, the manifestation of heart failure, (para) prosthetic regurgitation, implantation of a pacemaker, and vascular complications. Materials and methods: the article presents a retrospective follow-up of a total of 230 high-risk for conventional cardiac surgery patients with high-grade aortic stenosis treated in a cardiology clinic at UMHAT St. Ekaterina Sofia until 2020, divided into two groups depending on the implanted type of prosthesis. Conclusions: The results obtained based on our experience prove the safety of new prostheses. When choosing between BEV and SEV, the best clinical outcome requires a good knowledge of the strengths and weaknesses of using medical devices with a personalized approach consistent with the clinical and anatomical characteristics of the patient.

Update on supra-annular sizing of transcatheter aortic valve prostheses in raphe-type bicuspid aortic valve disease according to the LIRA method.

Recent evidence has shown that transcatheter heart valve (THV) anchoring in bicuspid aortic valve (BAV) patients occurs at the level of the raphe, known as the LIRA (Level of Implantation at the RAphe) plane. Our previous work in a cohort of 20 patients has shown that the delineation of the perimeter and device sizing at this level is associated with optimal procedural outcome. The goals of this study were to confirm the feasibility of this method, evaluate 30-day outcomes of LIRA sizing in a larger cohort of patients, assess interobserver variation and reproducibility of this sizing methodology, and analyse the interaction of LIRA-sized prostheses with the surrounding anatomy. The LIRA sizing method was applied to consecutive patients presenting to our centre with raphe-type BAV disease between November 2018 and October 2021. Supra-annular self-expanding THVs were sized based on baseline CT scan perimeters at the LIRA plane and the virtual basal ring. In cases where there was discrepancy between the two measurements, the plane with the smallest perimeter was considered the reference for prosthesis sizing. Post-procedural device success, defined according to Valve Academic Research Consortium-2 (VARC-2) criteria, was evaluated in the overall cohort. A total of 50 patients (mean age 80 ± 6 years, 70% male) with raphe-type BAV disease underwent transcatheter aortic valve replacement (TAVR) using different THV prostheses. The LIRA plane method appeared to be highly successful (100% VARC-2 device success) with no procedural mortality, no valve migration, no moderate-severe paravalvular leak, and low transprosthetic gradients (residual mean gradient 8.2 ± 3.4 mmHg). There were no strokes, no in-hospital or 30-day mortality, and an incidence of in-hospital pacemaker implantation of 10%. Furthermore, measurement of the LIRA plane perimeter was highly reproducible between observers (r = 0.980; P < 0.001) and predictive of the post-procedural prosthetic valve perimeter on CT scanning (r = 0.981; P < 0.001). We confirm the feasibility of supra-annular sizing using the LIRA method in a large cohort of patients with high procedural success and good clinical outcomes at 30 days. Application of the LIRA method optimizes THV prosthesis sizing in patients with raphe-type BAV disease.

Risk of conduction disturbances following different transcatheter aortic valve prostheses: the role of aortic valve calcifications.

OBJECTIVESTo assess the impact of prosthesis choice and aortic valve calcifications on the occurrence of conduction disturbances after transcatheter aortic valve implantation (TAVI).METHODSWe retrospectively analyzed the preoperative clinical characteristics, electrocardiograms, contrast-enhanced multidetector computed tomography scans and procedural strategies of patients who underwent TAVI in our center between January 2012 and June 2017. Quantification of calcium volume was performed for each aortic cusp above (aortic valve) and below (left ventricular outflow tract, LVOT) the basal plane. Multivariate analysis was performed to evaluate risk factors for the onset of new bundle branch block (BBB), transient and permanent atrioventricular block (tAVB, pAVB).RESULTSA total of 569 patients were included in the study. Six different prostheses were implanted (Edwards Sapien XT, n = 162; Edwards Sapien 3, n = 240; Medtronic CoreValve, n = 27; Medtronic CoreValve Evolut R, n = 21; Symetis Acurate, n = 56; Symetis Acurate neo, n = 63). The logistic regression analysis for BBB showed association with baseline left anterior hemiblock. The logistic regression for tAVB, found the prior valvuloplasty and the balloon post-dilatation associated with the outcome. Baseline left and right BBB, degree of oversizing, and LVOT calcification beneath the non-coronary cusp were associated with pAVB. Neither the prosthesis model, nor the use of a self-expandable prosthesis showed statistical significance with the above-mentioned outcomes on univariate analysis. CONCLUSIONSLVOT calcification beneath the non-coronary cusp, baseline left anterior hemiblock, right BBB, balloon post-dilatation, prior valvuloplasty and oversizing are independently associated with postprocedural conduction disturbances after TAVI. Use of a self-expandable prosthesis may show a lower incidence of AVB, if applied in lower calcified aortic valves.

Successful delayed endovascular correction of migration of transcatheter aortic valve prosthesis in left ventricle outflow tract: case report

We report the successful endovascular correction of the migration of a transcatheter aortic valve prosthesis in the left ventricle outflow tract (LVOT). A 72-old man was underwent transcatheter aortic valve implantation (TAVI) at Almazov National Medical Research Centre for severe aortic stenosis. During the procedure, the self-expanding prosthesis dislocated 10–12 mm into the LVOT. The frame was optimised with the use of a balloon catheter, and aortic regurgitation I-II degree was achieved. However, on day 17 of hospitalisation, acute heart failure with episodes of asystole occurred as a result of severe paravalvular regurgitation; cardiopulmonary resuscitation was necessary. The prosthesis malpositioning was corrected by traction with endovascular snare devices. The patient was stable during the postprocedural period and discharged on day 31. Dislocation of self-expanding prostheses into the LVOT is a complication specific to TAVI that may quickly aggravate a patient’s condition; therefore, correction of valve malpositioning should be performed as soon as possible. The case reported here in an illustration of successful endovascular correction of dislocation performed with the snare traction technique. This bail-out approach can be used by interventional cardiologists in similar situations. Received 27 May 2021. Revised 29 July 2021. Accepted 30 July 2021. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest. Contribution of the authorsLiterature review: A.D. Gorovaya, D.D. Zubarev, A.A. ProkhorikhinDrafting the article: A.D. Gorovaya, V.S. Krasnov, A.A. ProkhorikhinCritical revision of the article: A.D. Gorovaya, M.A. Chernyavskiy, A.A. ProkhorikhinSurgical treatment: D.D. Zubarev, V.S. Krasnov, A.A. ProkhorikhinFinal approval of the version to be published: A.D. Gorovaya, D.D. Zubarev, V.S. Krasnov, M.A. Chernyavskiy, A.A. Prokhorikhin

467 Update on supra-annular sizing of transcatheter aortic valve prostheses in raphe-type bicuspid aortic valve disease according to the LIRA method

Abstract Aims Transcatheter Aortic Valve Replacement (TAVR) in patients with bicuspid aortic valve (BAV) still represents a challenge due to the peculiar anatomy and the lack of consensus for the optimal CT scan sizing method for prosthesis selection. Recent evidences have shown that transcatheter heart valve (THV) anchoring in BAV patients might occur at the raphe-level, known as the LIRA (Level of Implantation at the RAphe) plane. Furthermore, a novel supra-annular sizing method based on the measurement of the perimeter at the raphe-level (LIRA-method) was shown to be safe and effective in 20 consecutive BAV patients with severe aortic stenosis. The purpose of this study was to confirm the safety and the efficacy of the LIRA method in a larger study population. Methods and results the LIRA plane method was applied to all consecutive patients with raphe-type BAV disease between November 2018 to September 2021 in our centre. We prospectively sized TAVI prosthesis according to the manufacture recommendations on the basis of baseline CT scan perimeters at the LIRA plane. Post-procedural device success, defined according to Valve Academic Research Consortium-2 (VARC-2) criteria, was evaluated in the overall cohort. Forty-four patients were identified as having a raphe-type BAV disease at pre-TAVI CT scans. Mean patient age was 80 ± 6.2 years and 74% were males; median Society of Thoracic Surgeons (STS) predicted risk of mortality score was 4.3 (3.0–6.5). Three different BAV anatomies (36 patients with BAV type 1 with calcific raphe, 5 patients with BAV type 1 with fibrotic raphe, and 3 patients with BAV type 2) were implanted with different types of TAVI prostheses (6 Acurate Neo 2,16 Acurate Neo, 21 Core Valve Evolut R/Pro , 1 Lotus) sized prospectively according to the LIRA plane method. In all patients, there was a significant discrepancy between LIRA and virtual basal ring (VBR) measurements with LIRA plane perimeter smaller than VBR perimeter (mean perimeter LIRA 73.1 ± 8.3 mm vs. mean perimeter VBR 81.5 ± 6.6 mm; P &amp;lt; 0.001). The prostheses were sized according to the manufacture recommendations on the basis of the LIRA plane perimeter (diameter prosthesis implanted/diameter prosthesis according to LIRA plane = 1) (DPI/DP LIRA = 1) and significantly downsized according to the VBR perimeter (DPI/DP VBR 0.89; P &amp;lt; 0.001). The median prosthesis size was 25 mm (23–27). Pre-dilatation was frequently performed (86%) with a median balloon size of 20 mm (18–22), whereas post-dilatation was applied in 27% of the cases with a median balloon size of 23 mm (20–26). The LIRA plane method appeared to be highly successful (100% VARC-2 device success) with no procedural mortality, no valve migration, residual trivial/mild paravalvular leak with no cases of moderate-severe regurgitation and low transprosthetic gradient (residual mean gradient of 8.3 ± 3.5 mmHg) with no cases of mean gradient &amp;gt;20 mmHg pre-discharge. The rate of new pacemaker implantation was 9%. Conclusions Supra-annular sizing according to the LIRA plane method confirmed to be safe with a high device success in a larger study population. The application of the LIRA plane method might optimize TAVI prosthesis sizing in patients with raphe-type BAV disease.

Comparison of valve durability among different transcatheter and surgical aortic valve prostheses: a network meta-analysis

Abstract Background Durability of different transcatheter heart valve (THV) is critical as the indication of transcatheter aortic valve replacement (TAVR) expands to patients with longer life-expectancy. Purpose We aimed to compare the durability of THV systems (balloon-expandable [BE] and self-expandable [SE]) and surgical aortic valve replacement (SAVR) prosthesis. Methods PUBMED and EMBASE were searched through February 2021 for randomized trials investigating parameters of valve durability after TAVR and/or SAVR in severe aortic stenosis. A network meta-analysis using random-effect model was performed. Synthesis was performed with 5-year follow-up data for echocardiographic outcomes and longest available follow-up data for clinical outcomes. Results Ten trials with a total of 9,388 patients (BE-THV: 2,562; SE-THV 2,863; SAVR:3,963) were included. Follow-up ranged from 1–6 years. SE-THV demonstrated significantly larger effective orifice area, lower mean aortic valve gradient (AVG), and less increase in mean AVG at 5-years compared to BE-THV and SAVR (Figure 1). Structural valve deterioration (SVD) was less frequent in SE-THV compared to BE-THV and SAVR (HR 0.14, 95% CI 0.07–0.27; HR 0.34, 95% CI 0.24–0.47, respectively) (Figure 1). Total moderate-severe aortic regurgitation and re-intervention was more frequent in BE-THV (HR 4.21, 95% CI 2.40–7.39; HR 2.22, 95% CI 1.16–4.26, respectively) and SE-THV (HR 7.51, 95% CI 3.89–14.5; HR 2.86, 95% CI 1.59–5.13, respectively) compared to SAVR. Conclusion TAVR with SE-THV demonstrated favorable forward-flow hemodynamics and lowest risk of SVD compared to BE-THV and SAVR at mid-term. However, both THV systems suffer an increased risk of aortic regurgitation and re-intervention, and long-term data from newer generation valve is warranted. Funding Acknowledgement Type of funding sources: None.

Numerical and experimental justification of transcatheter aortic valve prosthesis design

Objective: to justify the design of a self-expanding transcatheter aortic valve prosthesis based on a biomaterial stabilized with ethylene glycol diglycidyl ether using numerical simulation and a series of field experiments with working prototypes to determine the consistency of the proposed design solutions.Material and methods. Numerical computer models of a developed aortic valve prosthesis intended for transcatheter implantation, as well as prototypes of the most promising concepts for a series of field tests, were used in the work. Computer 3D models were subjected to numerical analysis in the Abaqus/CAE environment (Dassault Systemes, France) based on the finite element method with iterative design optimization and repeated numerical experiments. Physical prototypes of the transcatheter prosthesis were subjected to a series of mechanical tests for axial and radial compression, as well as tests on a Vivitro hydrodynamic stand (Vivitro Labs, Canada) under simulated normal flow. All studies were carried out in a comparative aspect with a similar transcatheter aortic valve prosthesis (control), the CoreValve™ bioprosthesis (Medtronic, Inc., USA).Results. Computer simulation demonstrates the stress-strain state values that do not significantly exceed the critical levels (628 and 756 MPa versus the threshold value 1080 MPa) for two basic concepts of support frames. The fatigue strength based on the calculation of the mean and alternating stresses corresponding to normo- and hypertensive states based on the Goodman diagrams, did not reveal any evidence that the threshold values (destruction area after 200 million cycles) were exceeded. The hydrodynamic characteristics of working prototypes made on the basis of computer models correspond to the testing data of CoreValve™ clinical bioprosthesis: the effective orifice area was 1.97 cm2, the mean transprosthetic gradient was 8.9 mm Hg, the regurgitant volume was 2.2–4.1 mL per cycle depending on the prototype model.Conclusion. Generally, experiments carried out showed the consistency of the concepts, including from the point of view of implementation of the leaflet apparatus based on xenogeneic tissues treated with ethylene glycol diglycidyl ether.

Effective Orifice Area of Balloon-Expandable and Self-Expandable Transcatheter Aortic Valve Prostheses: An Echo Doppler Comparative Study.

Published data on the size-specific effective orifice area (EOA) of transcatheter heart valves (THVs) remain scarce. Here, we sought to investigate the intra-individual changes in EOA and mean transvalvular aortic gradient (MG) of the Sapien 3 (S3), CoreValve (CV), and Evolut R (EVR) prostheses both at short-term and at 1-year follow-up. The study sample consisted of 260 consecutive patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI). EOAs and MGs were measured with Doppler echocardiography for the following prostheses: S3 23 mm (n = 74; 28.5%), S3 26 mm (n = 67; 25.8%), S3 29 mm (n = 20; 7.7%), CV 23 mm (n = 2; 0.8%), CV 26 mm (n = 15; 5.8%), CV 29 mm (n = 24; 9.2%), CV 31 mm (n = 9; 3.5%), EVR 26 mm (n = 22; 8.5%), and EVR 29 mm (n = 27; 10.4%). Values were obtained at discharge, 1 month, 6 months, and 1 year from implantation. At discharge, EOAs were larger and MGs lower for larger-size prostheses, regardless of being balloon-expandable or self-expandable. In patients with small aortic annulus size, the hemodynamic performances of CV and EVR prostheses were superior to those of S3. However, we did not observe significant differences in terms of all-cause mortality according to THV type or size. Both balloon-expandable and self-expandable new-generation THVs show excellent hemodynamic performances without evidence of very early valve degeneration.

The Role of Cardiac Computed Tomography in Valve Disease and Valve Intervention Planning

This review aims to provide an overview of cardiac CT role in detection of valvular lesions and in transcatheter valve replacement. Modern CT scans and protocols allow valve evaluation with high spatial and temporal resolution with reduced radiation dose. Cardiac CT is now mainstay of transcatheter aortic valve replacement (TAVR) planning. It plays a role in sizing of transcatheter aortic valve prosthesis, risk assessment for potential complications, prediction of ideal fluoroscopic angles, and selection of vascular access. Cardiac CT’s role in transcatheter mitral, pulmonic, and tricuspid valve replacements has evolved in conjunction with these new procedures. We summarize the role of cardiac CT in the context of valvular diseases and transcatheter valve replacement planning.

Impact of aortic annulus geometry according to ISO 5840:2019 (draft) on hydrodynamic performance of transcatheter aortic valve prostheses

Abstract To assess the hydrodynamic performance of transcatheter aortic valve prostheses (TAVP), in vitro test using pulse duplicators is required. Test conditions as well as minimum performance criteria are specified in ISO 5840- 3:2013 and ISO 5840-3:2019-draft. In the 2019 published draft, modifications regarding hydrodynamic testing are proposed. Among others, the geometrical configuration of the fixation has changed, with the intention to improve the anatomical representation as well as the comparability of results from different test laboratories. We analyzed the consequences of altered annulus fixations regarding native leaflets as well as a step in the proximal area of the protheses to prevent their migration. The analyses were conducted with regard to the degree of calcification of the annulus ring on hydrodynamic parameters. By using 3D stereolithography printing technology, molds for casting of silicone elastomer of annulus models with and without native leaflets were manufactured. A modular system enabled us to use the same annulus ring to model the degree of calcification as well as different step sizes. We performed in vitro hydrodynamic testing according to ISO 5840-3:2019-draft of a selfexpandable valve prototype with porcine pericardial leaflets by using a commercially available pulse duplicator system. As expected, regurgitation increases with increasing degree of calcification, whereby the use of a step has no influence on the backflow of fluid during diastole. The effective orifice area (EOA) of the valve showed a clear tendency with respect to radial protrusion of the step. The EOA decreased as the radial protrusion increased. We also present a suggestion to prevent migration without affecting the general test results, by using a novel step design. We also found that the novel annulus model with native leaflet drastically reduced the regurgitation.