Transcatheter Aortic Valve Prosthesis Research Articles

Risk factors for permanent pacemaker implantation in patients receiving a balloon-expandable transcatheter aortic valve prosthesis.

Permanent pacemaker implantation (PPI) is a widely recognized complication associated with TAVI (incidence up to 20%). Smaller registries have identified several variables associated with PPI. The objective was to validate patient- and transcatheter aortic valve implantation (TAVI)-related procedural variables associated with PPI. We performed a retrospective analysis of patients from six European centers undergoing TAVI with the Edwards SAPIEN 3 prosthesis. Baseline variables and pre-procedural ECG characteristics and CT-scans were taken into account. Data for 1745 patients were collected; 191 (10.9%) required PPI after TAVI. The baseline variables pulmonary hypertension (OR 1.64; 95% CI 1.01-2.59), QRS duration > 117ms (OR 2.58; 95% CI 1.73-3.84), right bundle branch block (RBBB; OR 5.14; 95% CI 3.39-7.72), left anterior hemi block (OR 1.92; 95% CI 1.19-3.02) and first-degree atrioventricular block (AVB, OR 1.63; 95%CI 1.05-2.46) were significantly associated with PPI. RBBB (OR 8.11; 95% CI 3.19-21.86) and first-degree AVB (OR 2.39; 95% CI 1.18-4.66) remained significantly associated in a multivariate analysis. Procedure-related variables included access site (TF; OR 1.97; 95% CI 1.07-4.05), implanted valve size (29mm; OR 1.88; 95% CI 1.35-2.59), mean TAVI valve implantation depth below the annulus > 30% (OR 3.75; 95% CI 2.01-6.98). Patients receiving PPI had longer ICU stays and later discharges. Acute kidney injury stage 2/3 was more common in patients with PPI until discharge (15.2 vs. 3.1%; p = 0.007), but was not statistically significant thereafter. Further differences in outcomes at 30days did not reach significance. The data will aid pre- and post-procedural patient management and prevent adverse long-term outcomes.Clinical Trial: NCT03497611.

Supra-annular sizing of transcatheter aortic valve prostheses in raphe-type bicuspid aortic valve disease: the LIRA method

BackgroundRecent evidence shows that THV prostheses anchoring occurs at the raphe-level, known as LIRA plane, in raphe-type bicuspid aortic valve (BAV) disease. The purpose of this study was to evaluate the application of a novel supra-annular sizing method, known as Level of Implantation at the RAphe (LIRA) method, to optimize transcatheter heart valve (THV) prosthesis sizing in raphe-type BAV disease. Methods and resultsThe LIRA method was applied to all consecutive patients with raphe-type BAV disease between November 2018 to January 2020 in our centre. THV prostheses were sized on the basis of baseline CT scan perimeters at the LIRA plane and at the virtual basal ring. In case of discrepancy between the two plane 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. 20 patients (mean patient age 81 ± 5.4 years, 70% males) were identified as having a raphe-type BAV disease at pre-procedural CT scans and were implanted with different types of 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 gradient (residual mean gradient of 8.2 ± 2.9 mm Hg). ConclusionsSupra-annular sizing according to the LIRA method appeared to be safe with a high device success. The application of the LIRA method might optimize THV prosthesis sizing in patients with raphe-type BAV disease.

The Distinguish Method of Severe Aortic Stenosis Treatment Geriatric High Mortality Risk Patients

Aim To improve quality of treatment for senile patients with pronounced aortic stenosis (AS).Material and methods Aortic valve stenosis (AS) is the most common valve pathology in cardiosurgical patients. Surgical correction of aortic valve (AV) stenosis accounts for 10 to 22 % of open-heart operations. 125 patients with pronounced AS were treated in the N. N. Burdenko Main Military Clinical Hospital between 2010 and 2017. This study was based on the implementation of new, minimally invasive methods in our clinic in 2013: balloon aortic valvuloplasty (BAVP) of the aortic valve and transcatheter aortic valve prosthesis (TCAVP).Results In the group of patients receiving the drug therapy alone, the in-hospital mortality was 2 %. At the time of maximum follow-up duration (3 years), the survival rate was 50.5 %. In the group of patients who underwent the AV replacement with extracorporeal circulation, the 3 year postoperative mortality was 16.6 %. There was no 3 year mortality in the group of patients who underwent TCAVP. The short-term beneficial effect of BAVP was confirmed.Conclusion An algorithm was developed for medical care of patients older than 75 with pronounced AS; the place of BAVP in the step-by-step management of these patients was determined. Using the developed approach in the management of these patients provided a 32 % (p<0.05) increase in the number of cases of radical surgical care.

Early restenosis of a direct flow transcatheter aortic valve prosthesis

Due to limited case numbers, severe Direct flow™ transcatheter device restenosis is, until now, a rare event with unknown long-term incidence, but challenging several treatment strategies. This case report gives an overview of possible interventional treatment considerations in this context that might occur more often in the future due to expected valve deterioration processes in the next years.

Guidewire Lost During the Deployment of a Nonretrievable Transcatheter Aortic Valve Prosthesis: A Nightmare Solution

An 86-year-old woman with symptomatic severe aortic stenosis was referred for transcatheter aortic valve replacement. Before the implantation of an ACURATE neo (Boston Scientific, Marlborough, Massachusetts), valvuloplasty was successfully performed. After advancing the prosthesis delivery system to

Assessment of the Effects of Deformation of the Fibrous Ring of the Aortic Valve on the Hydrodynamic Characteristics of Transcatheter Prostheses In Vitro

Questions of the occurrence of transprosthesis regurgitation after transcathether prosthetization of the aortic valve are discussed. We present results from hydrodynamic tests of prototype transcatheter aortic valve prostheses with different methods of attachment of the valve leaflets in conditions of deformation of the fibrous ring. Prototype prostheses with attachment of the leaflets of the valve apparatus above the seating zone of the frame of the prosthesis demonstrated optimal hydrodynamic characteristics.

Treatment of failed aortic bioprostheses: An evaluation of conventional redo surgery and transfemoral transcatheter aortic valve-in-valve implantation

BackgroundThe use of bioprostheses for surgical aortic valve replacement increased substantially within the last years. In case of prosthesis failure, re-SAVR is standard of care, whereas valve-in-valve deployment of a transfemoral transcatheter aortic valve prosthesis (VinV-TFAVI) has recently emerged as an alternative. We sought to evaluate early safety, clinical efficacy, and all-cause 1-year-mortality of VinV-TFAVI and redo surgery for failing aortic bioprostheses (re-SAVR). Methods and resultsPatients receiving either VinV-TFAVI (n = 147) or re-SAVR (n = 111) for a degenerated aortic bioprosthesis between 01/2006 and 05/2017 were included in this analysis. All-cause 1-year mortality was the primary outcome measure. Early safety and clinical efficacy according to VARC-2 endpoint definitions were evaluated at 30 days.Baseline characteristics differed significantly between both groups including age, STS-PROM, and incidence of relevant comorbidities. Re-stenosis was the predominant mode of failure in 45.9% of re-SAVR and 63.1% of VinV-TFAVI patients. The rate of “early safety” endpoints was lower with VinV-TFAVI (17.7% vs. 64.9%, p < 0.01), the rate of “clinical efficacy” endpoints was lower, e.g. better with re-SAVR (53.1% vs. 32.4%, p < 0.01). All-cause 1-year-mortality (VinV-TFAVI 8.8% vs re-SAVR 9.9%, p = 0.84) was not different. Treatment strategy was not associated with 1-year-mortality in a Cox regression analysis. The incidence of prosthesis-patient-mismatch was higher in VinV-TFAVI compared to re-SAVR. ConclusionVinV-TFAVI represents a viable alternative for treatment of degenerated aortic bioprostheses in patients at increased surgical risk. However, in patients at low risk for reoperation, a better clinical efficacy and acceptable safety may favour re-SAVR.

P3698Long-term durability of transcatheter aortic valve prostheses: results of a center

Abstract The durability of transcatheter heart valves and long-term clinical outcomes are unknown. The aim of this study was to evaluate clinical and hemodynamic outcomes between 5 to 9 years after Transcatheter Aortic Valve Implantation (TAVI). Methods Between April 2008 and December 2012, 305 patients underwent TAVI for the treatment of severe symptomatic aortic stenosis with the auto-expandable prosthesis. Results The mean age, logistic EuroSCORE and STS score were 79.3±6.5 years, 19.4±12% and 6.6±4% respectively. Mean aortic valve gradient decreased from 48.7±15 mm Hg to 8.9±4.3 mmHg after TAVI, to 11.1±9 mm Hg at 4 years, and 22.7±12 mmHg at 5 years (p for post-TAVI trend 0.03). Mean aortic valve area increased from 0.63±0.16 cm2 to 1.57±0.3cm2 after TAVI to 1.48±0.2 at 4 years and 0.97±0.3 cm2 at 5 years (p for post-TAVI trend 0.01). Mean left ventricular ejection fraction increased from 61.1±15% to 65.5±11% after TAVI, to 58.2±17% at 4 years and 60.7±8% at 5 years (p for post-TAVI trend 0.001). Late mortality after a mean of 4.15±2.4 years 58% and in only 34.1% patients was cardiovascular mortality. Survival rates at 1 to 9 years were at 87.5%, 79%, 73.1%, 65.6%, 55.4%, 48.2%, 41.9%, 37.3% and 35.1% respectively. At 5 years, 3 patients had severe prosthetic valve dysfunction (severe stenosis and moderate transvalvular regurgitation). Median survival time after TAVI was 6 years (95% confidence interval [CI]: 5.89 to 6.28), and the risk of death was significantly increased in patients with frailty (adjusted hazard ratio [HR]: 1.864; 95% CI: 1.204 to 2.886), p=0.001, Charlson index [HR= 1.243 (95% CI 1.148–1.346), p&lt;0.001], and left ventricular ejection fraction [HR= 1.012; (95% CI 1.001–1.024)p=0.044]. Conclusions Our study demonstrated favorable long-term outcomes after TAVI. Signs of prosthetic valve failure were observed in 0.97% of patients

Medium-term results of transcatheter implantation of MedLab-CT aortic valve prosthesis

Aim. To assess the clinical and hemodynamic results of transcatheter aortic valve replacement with the MedLab-CT prosthesis. Material and methods. MedLab-CT is the first Russian transcatheter implantable cardiac valve prosthesis. It is a balloon — an expandable stent, the cusps of which are made of 0,1 mm thick polytetrafluoroethylene plates. The use of synthetic material for the manufacture of the locking mechanism of the transcatheter implantable cardiac valve prostheses is a priority choice in the world. The reason was the hypothesis suggesting the absence of biodegradation of polytetrafluoroethylene in the body. The mechanical stability of the valve was tested on the pulse duplicator with a load equivalent to 10 years of functioning in the aortic position. The study included 69 patients who underwent implantation of the MedLab-CT prosthesis. One of the exclusion criteria for surviving patients was a follow-up period of less than 6 months. We estimated survival and incidence of clinically significant stroke, as well as hemodynamic parameters according to echocardiography for up to 3 years. Thirty nine patients were examined by face-toface approach, the rest ones underwent a telephone questionnaire survey. Results. The average follow-up was 9,6 months, the maximum — 3 years. Most patients belonged to the elderly group (average age 73,3 years). For 51 patients (74%) according to the EuroSCORE scale and for 37 (54%), according to the STS scale, a high risk of surgical intervention was determined: ≥8%.Mortality rate was 13% — 6 deaths were noted at the hospital stage, 3 patients died in the long term. No strokes recorded. In the face-to-face group, mean gradient on the aortic valve prosthesis was determined to be 8,41±4,21 mm Hg; insufficiency due to paraprosthetic fistulas not higher than I degree was observed in 7 patients (18%), not higher than II degree — in 1 patient; cases of transvalvular aortic insufficiency was not revealed. Conclusion. The results on the studied parameters are comparable with the data presented by foreign randomized clinical trials of imported models of transcatheter aortic valve prostheses.

Transcatheter mitral valve replacement: current status

After aortic valve stenosis, mitral regurgitation (MR) is the second most common valvular disease, particulary affecting older patients. Optimal medical treatment within the context of heart failure therapy is the favored first-line therapy for secondary MR. If symptoms persist despite optimal medical therapy, surgical or transcatheter mitral valve repair is indicated (recommendation class IIb). In contrast, surgical treatment is essential for patients with symptomatic primary MR and left-ventricular ejection fraction (LVEF) >30% and justifiable perioperative risk (repair preferred over replacement, recommendation classI); for high-risk patients, interventional transcatheter mitral valve repair (especially by "edge-to-edge-reconstruction") is aviable option (recommendation class IIb).Recently, transcatheter mitral valve replacement (TMVR) has come into focus as another attractive treatment option and is currently under intensive research. At first, the TMVR was used both for patients with symptomatic insufficiency or stenosis after biological mitral valve replacement (Bio-MKE) or after reconstruction as a"valve-in-valve" or "valve-in-ring" procedure. Therefore, transcatheter aortic valve prostheses were used.In the past few years several dedicated TMVR prostheses were developed for the treatment of native MR. So far, no TMVR prosthesis is CE-certified. All of the following TMVR methods are under clinical evaluation in the scope of pivotal trials. The interdisciplinary heart team, consisting of experienced cardiologists and heart surgeons develops apatient-specific, individual treatment concept considering the particular MR etiology, pre-existing comorbidities, age, clinical symptoms, and status.

Influence of leaflet geometry on hydrodynamic performance of transcatheter aortic valve prostheses

Abstract The implantation of transcatheter aortic valve prostheses (TAVP) for therapy of aortic valve stenosis shows more and more clinically non-inferiority results compared to surgical valve replacement in intermediate and low risk patients. Commonly clinically used TAVP are manufactured from chemically fixed xenograft leaflet material, e.g. bovine or porcine pericardium. While the clinical use of TAVP currently extends, challenges concerning valve durability and leaflet calcification have to be addressed. In this regard, artificial leaflet materials represent a promising option for a next generation of TAVP. As a first step for the development of TAVP from polymeric nonwoven, the aim of this study was to determine the influence of leaflet geometry on hydrodynamic performance of TAVP prototypes. Based on a parametric model of the valve leaflets, we varied the curvature of the belly line forming the leaflet coaptation area from an initial, quite concave, leaflet geometry with a value of 0.5° to an almost straight geometry for the leaflets with a value 0.15°. Manufacturing of TAVP prototypes was conducted by means of electrospinning technique with a polycarbonate based silicone elastomer. Hydrodynamic characterization according to ISO 5840-3 standards was performed using a pulse duplicator system with a heart rate of 70 BPM, systolic duration of 35%, mean aortic pressure of 100 mmHg and a stroke volume of 96 ml. Cardiac output as well as mean transaortic pressure gradient, closing volume, leakage volume and regurgitation were measured to compare the different leaflet geometries. To summarize, the curvature of the leaflets’ belly has a crucial impact on TAVP hydrodynamics under physiological test conditions. In particular, the opening and closing behavior is strongly influenced by a steeper curvature leading to larger closing volumes and higher regurgitant fractions. Further studies are planned to identify an optimum with respect to leaflet material selection, leaflet geometry and hydrodynamic properties of TAVP.

One-Year Follow-Up of Conduction Abnormalities After Transcatheter Aortic Valve Implantation With the SAPIEN 3 Valve

Long-term evolution of new-onset conduction abnormalities and need of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) have not been extensively evaluated. We describe the incidence and time course of new conduction abnormalities and the rate of PPI with the new-generation transcatheter aortic valve prosthesis Edwards SAPIEN 3 (S3). In total, 266 patients with severe aortic stenosis who underwent TAVI were retrospectively analyzed. Twelve-lead electrocardiograms at baseline, after TAVI, at discharge, at 1-, 6-, and 12-month follow-up were evaluated to identify conduction abnormalities and PPI requirements to investigate the correlates of PPI. After TAVI, a significant increase in PR interval duration and in QRS complex width was observed. New-onset left bundle branch block was observed in 65 patients (24%) after TAVI. The number of patients with left bundle branch block was maximum at hospital discharge and decreased at 12-month follow-up (39% and 32%, respectively). Thirty-five patients (13%) required PPI during the follow-up. However, paced rhythm was only observed in 7% of the patients with a complete 12-month follow-up. Patients who underwent PPI had a higher prevalence of first-degree atrioventricular block, complete right bundle branch block, and wider QRS complex at baseline. Baseline right bundle branch block and QRS width immediately after TAVI were the only variables independently associated with PPI. In conclusion, conduction disorders have a temporary nature after TAVI and showed a trend toward stabilization during the following months. With this new-generation device, the incidence of new conduction abnormalities requiring PPI is relatively low.

Preoperative aortic annulus size assessment by transthoracic echocardiography compared to the size of surgically implanted aortic prostheses

Objectives: The aortic annulus diameter measured by transthoracic echocardiography yields lower values than by computed tomography, and echo-based selection of transcatheter aortic valve prosthesis size has been implied to result in more frequent paravalvular leakage. We investigated the relation of preoperative annulus diameter by echo with the ring size of the aortic prosthesis chosen by direct assessment during open-heart aortic valve replacement.Methods: Preoperative annulus diameter by echo (from parasternal long-axis cross-sections of the left ventricular outflow tract and aortic valve) and implanted prosthetic diameter (tissue annulus diameter, determined intraoperatively using a sizing instrument) were compared retrospectively in 285 consecutive patients undergoing open-heart aortic valve replacement.Results: A total of 285 prostheses (240 biologic and 45 mechanical) were implanted, with prosthetic diameter ranging between 19 and 27 mm. There was a significant linear correlation (P < 0.0001) with r = 0.51, between preoperative annulus diameter by echo (mean 21.8 ± 2.8 mm) and prosthetic diameter (22.9 ± 1.7 mm). Preoperative annulus diameter of patients receiving prostheses no. 21, 23 and 25 mm aortic prostheses (the most frequent prosthesis sizes) were significantly different (P < 0.001) from each other. On average, preoperative annulus diameter by echo underestimated prosthetic diameter by a bias of 1.07 mm.Conclusion: Our data confirm that preoperative echo assessment of the aortic valve may slightly underestimates the optimal surgical prosthesis diameter for the aortic valve annulus.

Estenose aórtica severa associada a aneurisma de aorta abdominal volumoso: tratamento concomitante com troca valvar aórtica transcateter e reparo endovascular do aneurisma

An 85-year-old patient with multiple comorbidities presents with severe symptomatic aortic stenosis and concomitant infrarenal abdominal aortic aneurysm with 100mm in diameter. A transcatheter aortic valve replacement was done along with concomitant percutaneous repair of the aneurysm. The therapeutic strategy was initially to implant the transcatheter aortic valve prosthesis, and then to perform the implantation of the aortic bifurcated endograft, with extensions to the right and to the left, to exclude a large fusiform aneurysm, due to the high [...]

The first experience of implantation of the transcatheter aortal valve prosthesis “MedLab-KT”

Aim.Transcatheter aortic valve replacement in patients with high and extremely high risk has become a routine procedure in many cardiac surgery clinics. Until recently, there were no transcatheter prostheses produced within Russia. This article analyzes the results of applying the first domestic transcatheter aortic valve prosthesis MedLab­KT.Material and methods.In the period from June 2018 to October 2018, 7 operations of transcatheter aortic valve replacement were made using the MedLabKT prosthesis. In all cases, implantation was performed by transapical access.Results.We noted one death. In all cases, paraprosthetic regurgitation was not registrated or was not significant. There are no cases of dislocation of the prosthesis. There were no complications associated with access. In one case, implantation was complicated by myocardial infarction.Conclusion.The first experience of implantation demonstrated the efficacy and safety of using the MedLab­LT prosthesis for transcatheter aortic valve replacement. The analysis of long­term results is required.

The first experience of implantation of the transcatheter aortal valve prosthesis “MedLab-KT”

Aim. Transcatheter aortic valve replacement in patients with high and extremely high risk has become a routine procedure in many cardiac surgery clinics. Until recently, there were no transcatheter prostheses produced within Russia. This article analyzes the results of applying the first domestic transcatheter aortic valve prosthesis MedLab­KT. Material and methods. In the period from June 2018 to October 2018, 7 operations of transcatheter aortic valve replacement were made using the MedLabKT prosthesis. In all cases, implantation was performed by transapical access.Results. We noted one death. In all cases, paraprosthetic regurgitation was not registrated or was not significant. There are no cases of dislocation of the prosthesis. There were no complications associated with access. In one case, implantation was complicated by myocardial infarction.Conclusion. The first experience of implantation demonstrated the efficacy and safety of using the MedLab­LT prosthesis for transcatheter aortic valve replacement. The analysis of long­term results is required.

Early clinical and hemodynamic results of transcatheter aortic valve implantation using the “MedLab-KT” prosthesis

Background. The obvious expansion of mini-invasive technologies is looming large in surgical treatment of heart diseases. Hundreds of thousands of transcatheter aortic valve replacement procedures have been performed in the world today. The improvement in quality and the increase in life expectancy in cohorts of patients who until recently have been considered inoperable are now routinely achievable. A significant limitation of this method for Russian clinics is the absence of domestic transcatheter implantable prosthetic heart valves on the market. During the last five years, such devices have been developed at “MedEng” (Penza, Russia) scientific and production enterprise. We present the first Russian transcatheter aortic valve prosthesis, its leaflets made of polytetrafluoroethylene, components of the delivery system and implantation, as well as the hospital outcomes of clinical trials. Aim. To evaluate the clinical and hemodynamic results of transcatheter aortic valve implantation using a “MedLab-KT” prosthesis during hospital stay.Methods. A prospective study included 54 patients who underwent transcatheter repair of the aortic valve using a “MedLab-KT” prosthesis. To evaluate the frequency of complications, myocardial infarction, strokes, bleeding, deaths during hospital stay and gradient indices on the prosthesis, postoperative ultrasound examination data were obtained and analyzed. Results. The results are comparable with those achieved by using the foreign models known from literature. Conclusion. The clinical and hemodynamic results of using the “MedLab-KT” aortic valve prosthesis can be considered as satisfactory. Funding: The study had no sponsorship. Conflict of interest: The authors declare no conflict of interest. Authors’ contributionConception and study design: V.V. Bazylev, E.V. Rosseykin, A.B. VoevodinData collection and analysis: A.B. Voevodin, A.S. ZakharovaStatistical analysis: A.B. VoevodinDrafting the article: A.B. VoevodinCritical revision of the article: A.B. VoevodinFinal approval of the version to be published: V.V. Bazylev, A.B. Voevodin, A.S. Zakharova, E.V. Rosseykin ORCID IDV.V. Bazylev, https://orcid.org/0000-0001-6089-9722A.B. Voevodin, https://orcid.org/0000-0002-7078-1274A.S. Zakharova, https://orcid.org/0000-0001-7239-2945E.V. Rosseykin, https://orcid.org/0000-0003-0784-2246

The prevalence of computed tomography-defined leaflet thrombosis in intra- versus supra-annular transcatheter aortic valve prostheses.

Leaflet thrombosis (LT) defined by computed tomography (CT) following transcatheter aortic valve replacement (TAVR) has been shown to increase cerebrovascular events. The neo-sinus plays an important role in the development of LT. Intra-annular valves (IAV) have a larger neo-sinus when compared to supra-annular valves (SAV), and has been associated with larger thrombus burden. The prevalence of LT with IAV and SAV in a larger, diverse cohort is unknown. We performed a systematic review to assess the prevalence of LT in IAV versus SAV TAVR prostheses. Inclusion criteria were (1) reported CT-defined LT following TAVR, (2) comparison between LT and non-LT cohort, (3) separate registry/database, and (4) fully published status. A total of 2,013 citations were reviewed and 7 studies were included. Overall, 1,644 patients were included from 7 observational studies and the prevalence of LT following TAVR was 12.8%. The Portico valve system (IAV) had the highest prevalence of LT with 35.2%, followed by Symetis Acurate Neo (SAV) at 15.4% and the Lotus valve system (IAV) at 14.5%. LT occurred more frequently in IAV than SAV (13.5% vs. 7%, P = 0.02). Subanalysis of IAV versus SAV with the exclusion of the Portico valve was performed to ensure results were not influenced by this valve system and revealed IAV still had higher rates of LT (12.1% vs. 7%, P = 0.05). In summary, IAV prostheses appear to be associated with higher rates of LT when compared with SAV.

Aortic regurgitation after transcatheter aortic valve replacement

Abstract The assessment of hydrodynamic performance of transcatheter aortic valve prostheses in vitro is essential for the develosepment and approval of novel devices. Therefore, this study aims to investigate the correlation of target implantation depth and paravalvular regurgitation in a controlled in vitro test situation. We designed a test setup with retrograde steady flow conditions measuring paravalvular regurgitation as a function of increasing pressure on the closed valve ranging from 0 mmHg to 200 mmHg. Our future aim is to benchmark different valve prosthesis designs and describe the correlation between target implantation depth, paravalvular regurgitation and prosthesis design aspects. The current study describes the developed test setup, validation experiments as well as first results for a selfexpanding valve prosthesis. The highest regurgitation was measured at an implantation depth of 2 mm. In fact, regurgitation increases from 26.1 ± 8.2 ml/min at 0 mmHg to 1,490.7 ± 182.7 ml/min at 160 mmHg. The slightest regurgitation, however, was measured for an implantation depth of 6 mm ranging from 2.2 ± 0.6 ml/min at 0 mmHg to 605.8 ± 18.9 ml/min at 200 mmHg.

A matter of thrombosis: different thrombus-like formations in balloon-expandable transcatheter aortic valve prostheses.

Transcatheter aortic valve implantation is a treatment strategy for degenerated aortic valve prostheses, but there is some concern regarding valve thrombosis. The optimal anticoagulation strategy for implantation of a transcatheter aortic valve prosthesis remains unclear. Aortic root models with the Sapien-XT and S3 prostheses (sizes 23 and 26) fixed in a Perimount Magna Ease bioprosthesis (sizes 23 and 25) were constructed. The haemodynamics of the left ventricle were imitated in a proved in vitro model. Milk was used for coagulation after 90s. Different areas of the leaflets (W: wall coagulation, C: commissure coagulation left/right and S: sinus coagulation) were examined and the number of thrombus-like formations was counted. A total of 54% of the thrombus-like formations were found in the sinus, 28% at the wall area, 13% at the right commissure and 10% at the left commissure. Significant differences were detected at the wall area. S3 prostheses had significantly more thrombus-like formations than the XT prostheses. Additionally, in the S3 prostheses, the thrombus-like formation resembled a film whereas in the XT prostheses, the thrombus-like formation was like the crumbs of a cake. We noted exactly the same pattern in explanted prostheses from patients. The Sapien prostheses tend to form thromboses due to their flow properties. More than half of the thrombus-like formations were seen in the sinus. The S3 prostheses had significantly more thrombus-like formations than the XT prostheses in the wall area. There are different patterns of thrombus-like formations in XT and S3 prostheses used for transcatheter aortic valve implantation both in vivo and in vitro.