Transcatheter aortic valve implantation with the NVT Allegra transcatheter heart valve system: first-in-human experience with a novel self-expanding transcatheter heart valve

One-year initial efficacy and safety outcomes of the premounted dry-pericardium Vienna self-expandable transcatheter aortic valve system: A first-in-human VIVA feasibility study

BACKGROUND

The dry-pericardium Vienna transcatheter aortic valve system is repositionable and retrievable, already premounted on the delivery system, eliminating the need for assembly and crimping of the device before valve implantation.

METHODS

The VIVA first-in-human feasibility study, a prospective, nonrandomized, single-center trial, evaluated the Vienna aortic valve in 10 patients with severe symptomatic aortic stenosis, who were at intermediate or high surgical risk. This study, registered at ClinicalTrials.gov (NCT04861805), focused on the safety, feasibility, clinical and hemodynamic performance of the Vienna system up to 1-year follow-up.

RESULTS

The mean patient age was 79 ± 5 years, 60% male. Valve sizes used: 26 mm (10%), 29 mm (30%), 31 mm (60%). Key hemodynamic improvements were significant: mean aortic valve pressure gradient (mmHg) decreased from 48.7 to 8.1, aortic valve area (cm2) increased from 0.75 to 1.91, and maximum jet velocity through the aortic valve (m/s) decreased from 4.41 to 1.95 (p < 0.0001). No moderate/severe paravalvular leakage was observed, and computed tomography scans revealed no evidence of hypo-attenuated leaflet thickening. The study recorded one life-threatening bleeding event, two cases requiring postprocedural pacemaker implantation, and three ischemic events, with only one causing lasting neurological impairment. Importantly, there were no cases of cardiovascular mortality and only one noncardiovascular death, which was confirmed as unrelated to the device.

CONCLUSIONS

The study indicates the Vienna valve as a potential option for severe symptomatic aortic stenosis, designed to streamline the procedure and potentially lower healthcare costs by reducing resource and equipment needs, also procedural errors. Further research is essential to thoroughly evaluate its safety and efficacy.

Comparison of a novel self-expanding transcatheter heart valve with two established devices for treatment of degenerated surgical aortic bioprostheses

AIMS

This study was performed to compare haemodynamic properties of a novel transcatheter heart valve (THV) with two established valve technologies for treatment of failing surgical aortic bioprosthetic valves (SAV). The ALLEGRA THV has been recently described with a proven safety and performance profile.

METHODS AND RESULTS

The study was designed as a retrospective, single-centre study investigating 112 patients (77.7 ± 7.1 years, 53.8% female, STS score 6.8 ± 5.8% and logEuroSCORE I 27.4 ± 16.1%) with failing SAV. Patients were treated with the ALLEGRA THV (NVT, n = 24), the CoreValve/EvolutR (MTD, n = 64) or the Edwards Sapien/Sapien XT/Sapien 3 (EDW, n = 24). Adverse events, haemodynamic outcomes and patient safety were analysed according to VARC-3 definitions. Overall procedural success was high (94.6%), even though 58.9% of the treated SAV were classified as small (true inner diameter < 21 mm). After treatment, the mean pressure gradient was significantly reduced (baseline: 33.7 ± 16.5 mmHg, discharge: 18.0 ± 7.1 mmHg), with a corresponding increase in effective orifice area (EOA). The complication rates did not differ in between groups. There was a trend to lower mean transvalvular gradients after implantation of self-expanding THV with supra-annular valve function, despite a higher frequency of smaller SAVs in the NVT and MTD group. Additionally, comparison between NVT and MTD revealed statistically lower transvalvular gradients (NVT 14.9 ± 5.0 mmHg, MTD 18.7 ± 7.5 mmHg, p = 0.0295) in a subgroup analysis.

CONCLUSIONS

Valve-in-valve (ViV) treatment of failing SAV with supra-annular design like the ALLEGRA THV resulted in favourable haemodynamic outcomes with similar low clinical event rates and may therefore be an interesting alternative for VIV TAVI.

Early Safety and Performance of the Premounted Dry-Pericardium Vienna Self-Expandable Transcatheter Aortic Valve System: 30-Day Outcomes of the First-in-Human VIVA Feasibility Study

The purpose of this first-in-human (FIH) study was to determine the safety and feasibility of the transfemoral premounted dry-pericardium Vienna Self-Expandable Supra-Annular Aortic Valve System. This novel system is repositionable and retrievable and comes already premounted on the delivery system, eliminating the need for assembly and crimping of the device before valve implantation. This is a prospective, nonrandomized, single-arm, single-center, first-stage FIH feasibility study, which will be followed by a second-stage pivotal, multicenter, multinational study in symptomatic patients with severe aortic stenosis. The first-stage FIH study evaluated the safety and feasibility of the device in 10 patients with severe aortic stenosis based on recommendations by the Valve Academic Research Consortium-2 for transcatheter aortic valve implantations. The mean patient age was 79 ± 5 years, 60% were male, and all patients were in New York Heart Association functional class II to III. The primary safety end point was successful when all patients were alive at 30-day follow-up. Device and technical success were observed in all patients. Two patients had a stroke, 1 of which occurred 5 days after the procedure. New permanent pacemakers were implanted in 2 patients (22.2%), of which only 1 was because of complete heart block. Only 1 patient (10%) had moderate paravalvular leak at 30 days. After the procedure, the mean aortic valve gradient decreased from 48.7 ± 10.8 mm Hg to 8.8 ± 4.3 mm Hg. In conclusion, this FIH feasibility study demonstrates successful procedural feasibility, with no 30-day mortality and favorable valve hemodynamic performance, leading to an improvement in quality of life. ClinicalTrials.gov identifier NCT04861805.

Emerging transcatheter heart valve technologies for severe aortic stenosis

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is the standard of care for selected patients with severe aortic stenosis, irrespective of the surgical risk. Over the last two decades of TAVI practice, multiple limitations were identified. In addition, the extension of TAVI into a wider patient spectrum created new challenges.

AREAS COVERED

This review provides an overview of emerging transcatheter heart valves (THVs) beyond the approved contemporary THVs for the treatment of aortic stenosis.

EXPERT OPINION

The incidence of degenerative aortic stenosis is expected to increase with more aging of the population. Therefore, TAVI needs to meet this increase in the number of patients indicated for aortic valve replacement alongside a wide and complex anatomical variability. An increasing number of Aortic THVs are available in the market. This includes upgraded iterations of contemporary devices and innovative devices developed by emerging manufacturers. The new devices aim for the reduction or elimination of undesirable outcomes like paravalvular leakage and conduction disturbances requiring permanent pacemaker implantation. Alternatively, emerging THVs should provide feasibility regarding yet unproven TAVI indications like Bicuspid aortic valve, aortic regurgitation, or very large anatomy. Furthermore, some of the emerging THVs are designed to tackle the long-term durability issue of biological valves.

Transcatheter aortic valve with a novel self-expandable device in patients with previous mechanical mitral valve prosthesis

OBJECTIVES

The aim of this study was to describe the procedural and early outcomes of patients with mechanical mitral valve prosthesis (MVP) undergoing transcatheter aortic valve replacement (TAVR) with a novel self-expandable retrievable device.

BACKGROUND

TAVR in patients with prior MVP may have an increased risk of complications related to device positioning and interference between both prosthetic valves.

METHODS

An observational study was conducted, including eight patients with severe symptomatic aortic stenosis and prior mechanical MVP who underwent TAVR with the novel device Allegra^TM (Biosensors). No transesophageal monitoring was used.

RESULTS

The mean age of the study population was 75 years. The mean distance between MVP and aortic annulus was 3.8 mm. Procedural success was achieved in all patients with no major intraprocedural, in-hospital, or follow-up complications.

CONCLUSIONS

TAVR with Allegra TAVI system in patients with prior MVP offers good procedural and clinical outcomes.

Redo Transcatheter Aortic Valve Implantation with the ALLEGRA Transcatheter Heart Valve: Insights from Bench Testing

PURPOSE

Failure of transcatheter heart valves (THV) may potentially be treated with repeat transcatheter aortic valve implantation (redo TAVI). We assessed hydrodynamic performance, stability and pinwheeling utilizing the ALLEGRA (New Valve Technology, Hechingen, Germany) THV, a CE approved and marketed THV in Europe, inside different THVs.

METHODS

Redo TAVI was simulated with the 27 mm ALLEGRA THV at three implantation depths (-4 mm, 0 mm and +4 mm) in seven different 'failed' THVs: 26 mm Evolut Pro, 25 mm Lotus, 25 mm JenaValve, 25 mm Portico, 23 mm Sapien 3, 27 mm ALLEGRA and M ACURATE neo. Hydrodynamic evaluation was performed according to International Standards Organization 5840-3:2021.

RESULTS

The ALLEGRA THV was stable with acceptable performance (gradient <20 mmHg, effective orifice area >2 cm², and regurgitant fraction <20%) in all 'failed' THVs except the Evolut Pro at -4 mm implantation depth. In this configuration, the outflow of the ALLEGRA frame was constrained by the Evolut Pro THV and the ALLEGRA leaflets were unable to fully close. Pinwheeling was severe for the ALLEGRA in Evolut Pro. The neo-skirt was higher with taller frame THVs.

CONCLUSION

The ALLEGRA THV had favorable hydrodynamic performance, stability and pinwheeling in all redo TAVI samples except the Evolut Pro at low implantation depth with compromised function. The choice of initial THV may have late implications on new THV choice and function.

Transcatheter aortic valve implantation with Allegra: procedural and mid-term outcomes according to experience phase in a high-volume center

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of aortic stenosis. We aimed at appraising effectiveness of a new self-expandable TAVI device.

METHODS

We retrospectively analyzed our institutional experience with Allegra (Biosensors, Morges, Switzerland) for TAVI, focusing on procedural outcomes and 1-month adverse events. We explored the impact of operator experience with this device, dividing patients according to their time of intervention.

RESULTS

Between 2018 and 2021, a total of 50 patients underwent TAVI with Allegra, with average age of 81 years, 80% women, and 50% at low or intermediate surgical risk. No major significant difference in baseline patient features were found when comparing Phase 1 and Phase 2, except for baseline left ventricular ejection fraction and New York Heart Association, which were worse in Phase 1. All procedures were performed transfemorally and percutaneously, with predilation in 94% and postdilation in 36%, yielding device success in 98%, and procedural success in 96%. No significant differences in procedural features were found when comparing Phase 1 vs. Phase 2 (all P>0.05). One-month follow-up was also favorable, with no significant difference in adverse outcomes according to phase, and a total of 1 (4%) death, 1 (4%) myocardial infarction, 1 (4%) minor vascular complication, and 4 (8%) permanent pacemaker implantations. Consistent findings were obtained at exploratory 6-month follow-up.

CONCLUSIONS

The Allegra TAVI device is associated with favorable short-to-midterm outcomes in experienced hands. Operators already proficient with other devices can achieve satisfactory results even in the early phase of adoption of Allegra.

Evolving Devices and Material in Transcatheter Aortic Valve Replacement: What to Use and for Whom

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of aortic stenosis, providing a viable alternative to surgical aortic valve replacement (SAVR) for patients deemed to be at prohibitive surgical risk, but also for selected patients at intermediate or low surgical risk. Nonetheless, there still exist uncertainties regarding the optimal management of patients undergoing TAVR. The selection of the optimal bioprosthetic valve for each patient represents one of the most challenging dilemmas for clinicians, given the large number of currently available devices. Limited follow-up data from landmark clinical trials comparing TAVR with SAVR, coupled with the typically elderly and frail population of patients undergoing TAVR, has led to inconclusive data on valve durability. Recommendations about the use of one device over another in given each patient’s clinical and procedural characteristics are largely based on expert consensus. This review aims to evaluate the available evidence on the performance of different devices in the presence of specific clinical and anatomic features, with a focus on patient, procedural, and device features that have demonstrated a relevant impact on the risk of poor hemodynamic valve performance and adverse clinical events.

Novel self-expanding ALLEGRA transcatheter aortic valve for native aortic stenosis and degenerated bioprosthesis

OBJECTIVES

To investigate the safety and efficacy of the ALLEGRA valve in routine use.

BACKGROUND

The ALLEGRA aortic valve is a self-expanding transcatheter heart valve (THV) with bovine pericardial tissue and was CE approved in March 2017. Its unique design was developed to provide low prosthesis gradients.

METHODS

We analyzed patients receiving an ALLEGRA THV between May 2017 and March 2021 at our center for treatment of aortic valve stenosis or degenerated valve prosthesis. Hemodynamic results and clinical outcome according to the Valve Academic Research Consortium-2 consensus criteria were evaluated at discharge and three months post transcatheter aortic valve replacement (TAVR) procedure. 93 patients with a mean age of 82.5 ± 4.8 years and a median EuroScore II of 4.7 ± 3.4 were treated, 15 of them were valve-in-valve procedures.

RESULTS

Implantation was successful in 97.8% (91/93) and VARC-2 defined device success was achieved in 94.6% (88/93). In-hospital all-cause mortality was 2.2% (2/93). Life-threatening bleeding, major vascular complications and strokes were 3.2% (3/93), 2.2% (2/93) and 3.2% (3/93), respectively. Paravalvular leakage was none to trace in 60.4%, mild in 38.5% and moderate in 1.1%. Permanent pacemaker implantation in pacemaker naive patients was necessary in 9.5% (8/84). Mean gradient at discharge was 8.2 ± 4.3 mmHg for all patients; 7.1 ± 2.6 mmHg in patients treated for stenosis of the native aortic valve and 13.8 ± 6.3 mmHg in patients treated valve-in-valve.

CONCLUSIONS

The ALLEGRA THV provides excellent hemodynamic results and a good safety profile with a low complication rate.

Transcatheter Aortic Valve Replacement: Advances in Procedural Technology and Approaches

Transcatheter aortic valve replacement (TAVR) is now the dominant form of aortic valve replacement in the United States. Continued innovation has allowed the technique to be safe and democratized. New advances will increase the number of patients eligible to receive this therapy while increasing safety and efficiency. Herein, the authors review new TAVR technologies, approaches to valve deployment, and dedicated devices for cerebral embolic protection and vascular closure.

The Allegra transcatheter heart valve: Short term results from a multicenter registry

OBJECTIVES

We aimed to determine the safety and efficacy of the Allegra transcatheter heart valve (THV) for the treatment of severe aortic valve stenosis in a large patient population treated under real-world conditions.

BACKGROUND

The Allegra is a novel self-expanding THV with supra-annular bovine leaflets. The valve is available in three different sizes (23, 27, and 31 mm), all are delivered through an 18F sheath.

METHODS

Consecutive patients undergoing TAVR with the Allegra THV were enrolled in a multicenter-registry. Data were collected throughout initial hospital-stay and at 30-day follow-up. Clinical endpoints were defined according to the updated definitions of the Valve-Academic-Research-Consortium.

RESULTS

This registry included 255 patients (mean age 83 ± 6 years, 48% women) from four European centers. Median European System for Cardiac Operative Risk Evaluation II score (EuroSCORE II) was 3.3% (IQR 1.9-5.8%). Acute device success was 95.7%. The remaining 11 patients had either moderate paravalvular regurgitation immediately after the procedure (7 patients) or the device could not be optimal positioned requiring implantation of a second THV (4 patients). Major vascular complications and major/life-threatening bleedings occurred in 10 (3.9%) and 12 (4.7%) patients, respectively. At 30 day follow-up, mean effective orifice area was 2.2 ± 0.5 cm² , mean gradient was 6.9 ± 3.8 mmHg, 7 (3.3%) patients had more than mild paravalvular leakage, 3 patients (1.2%) had died, 6 patients (2.4%) had a stroke and 30 (12.8%) patients had required implantation of a new permanent pacemaker.

CONCLUSIONS

Transfemoral implantation of the Allegra THV resulted in favorable clinical and echocardiographic outcomes during hospitalization and short-term follow up.

Choice of transcatheter heart valve: should we select the device according to each patient's characteristics or should it be "one valve fits all"?

Since its introduction at the beginning of the century, transcatheter aortic valve replacement (TAVR) has implicated a paradigm shift in the treatment of patients with symptomatic aortic valve stenosis. The past years have brought about major improvements of procedural outcomes owing to advances in imaging and patient selection, global experience, and device technology. Whereas in the early stages of TAVR, only two different devices with limited sizes and access options were used, currently a variety of different transcatheter heart valves (THVs) are available. This has expanded the spectrum of patients that can be treated with TAVR and has allowed for sophisticated device selection tailored to the patients' individual anatomy and comorbidities. The big question is whether such a customized device selection is really necessary-or is there one valve type that fits all patients? With this question in mind, the authors provide an overview of contemporary THVs, including technical specifications and clinical data, that help us to understand the potential value of a differential use of THVs.

Novel Perspective for Antithrombotic Therapy in TAVI

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While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Long-Term Follow-Up of Transcatheter Aortic Valve Implantation With Portico Versus Evolut Devices

New-generation devices such as Evolut and Portico have provided favorable results in patients who underwent transcatheter aortic valve implantation (TAVI) for aortic stenosis, but their comparative effectiveness remains debated, despite its relevance when envisioning TAVI in low-risk patients. We evaluated the safety and efficacy of 2 leading TAVI devices (Evolut and Portico) used by the same team of experienced TAVI operators, focusing on long-term outcomes, including major adverse events (i.e., the composite of death, stroke, myocardial infarction, major vascular complication, or major bleeding). Unadjusted and propensity score-adjusted analyses were carried out. A total of 233 patients were included, 119 (51.1%) receiving Evolut and 114 (49%) Portico. Baseline and procedural data showed significant between-device differences, including functional class, surgical risk, chronic obstructive pulmonary disease, renal function, transesophageal guidance, device size, postdilation, and procedural time (all p <0.05). Yet, acute and in-hospital outcomes were not significantly different (all p >0.05). Follow-up status was ascertained in 228 (98%) patients after 15.0 ± 7.6 months. Unadjusted analysis showed similar rates of major adverse events, as well as the individual risk of death, stroke, myocardial infarction, major vascular complication, major bleeding, and pacemaker implantation (all p >0.05). Even at propensity score-adjusted analysis outcomes were not significantly different with Evolut and Portico (all p >0.05). In conclusion, Evolut and Portico devices yield similarly favorable results at long-term follow-up when used by experienced TAVI operators.

Transcatheter aortic valve replacement: clinical safety and performance data

Introduction: Patients with severe aortic stenosis and regurgitation who are inoperable or at high-risk for surgery can be treated with transcatheter aortic valve replacement (TAVR). The aim of this study was to provide a comprehensive overview of the literature of TAVR and reported clinical and performance outcomes. Areas covered: A total of 16 devices, described in 204 articles describing clinical and performance outcomes, were included. The most frequently observed outcome was 30-day mortality, ranging between 0-23%. Other commonly reported clinical outcomes were 30-day stroke, ranging between 0-14.3% and pacemaker implantation, ranging from 0-44.9%. The most common valve performance outcome was aortic valve regurgitation, however, mostly reported at 7 days follow-up. Next to a follow-up period of 30 days, numerous articles reported outcomes at 6 months and 1 year. The numbers of articles describing outcomes with a longer follow-up as well as including intermediate and low-risk patients were limited. Expert commentary: This literature review provided a clear overview of the reported clinical and performance outcomes of TAVR devices. Despite the frequently used VARC-2 definitions, we identified a huge variation across studies. Future studies using standardized definitions of study set-ups and outcomes are essential and might lead to better insights of TAVR.

The evolution of device technology in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has rapidly evolved and changed the landscape of structural interventional cardiology. Advances in transcatheter heart valve (THV) prostheses and TAVI-enabling devices have simplified the procedure, reduced the risk of complications, improved short- and long-term outcomes and broadened the applications of TAVI, not only in challenging patients and complex anatomies but also in intermediate-risk or even in low-risk patients, where surgical valve replacement constitutes an effective and well-established therapy. In this review article, we provide an overview of the developments in TAVI devices which have played a vital role in TAVI evolution: we describe the prostheses that failed to reach clinical practice, we present the characteristics of the first valves that were tested in the clinical arena, we summarise the evidence from the first studies that highlighted the potential but also the limitations of TAVI, and we present the advanced next-generation THV prostheses that have an improved performance and safety profile.

Transfermoral aortic valve implantation using self-expanding New Valve Technology (NVT) Allegra bioprosthesis: A pilot prospective study

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has become a standard therapeutic option for patients with severe aortic stenosis (AS) at high cardiac surgical risk. The aim of the NAUTILUS study was to investigate the safety and performance of the New Valve Technology (NVT) Allegra bioprosthesis in high-risk patients undergoing TAVI.

METHODS

Twenty seven patients with severe, symptomatic AS at high surgical risk were prospectively enrolled, who underwent treatment using the novel self-expanding NVT Allegra bioprosthesis via transfemoral approach (TF-TAVI). The primary end-point was all-cause mortality at 30 days.

RESULTS

Patients were elderly (83 years, range 75-89 years), and predominantly female (70.4%, n = 19). All patients were deemed to be at high surgical risk, with a mean logistic EuroSCORE of 12.4% (range, 2.8-31.8%). The bioprosthesis was successfully implanted in 96% of the cases (n = 25). The echocardiographic assessment confirmed good hemodynamic profile after implantation of the NVT Allegra bioprosthesis. Complications included cardiac tamponade (4%, n = 1) and the need for permanent pacemaker implantation (8%, n = 2). The analysis of procedural aspects showed a short learning effect related to the precise placement of the valve. A significant improvement in clinical symptoms were observed, and no patients died in-hospital or within 30 days of post-discharge observation.

CONCLUSIONS

This prospective observation shows that the NVT Allegra bioprosthesis was associated with a satisfactory safety profile and a remarkable hemodynamic performance after implantation.

First-in-human implantation of a novel self-expanding supra-annular transcatheter heart valve for transcatheter aortic valve implantation inside a small degenerated aortic surgical bioprosthesis

With next-generation valves such as the ALLEGRA valve from NewValve Technologies (NVT), Hechingen Germany, there is a very likely treatment expansion for patients with aortic valve disease. Besides treatment of native valvular aortic stenosis with the ALLEGRA valve, the special implant mechanism seems to be an appealing concept for patients with degenerated surgical bioprostheses. We report the first case of a transfemoral implantation in small degenerated surgical bioprosthesis of a 76-year-old woman.

TAVI and Post Procedural Cardiac Conduction Abnormalities

Transcatheter aortic valve implantation (TAVI) is a worldwide accepted alternative for treating patients at intermediate or high risk for surgery. In recent years, the rate of complications has markedly decreased except for new-onset atrioventricular and intraventricular conduction block that remains the most common complication after TAVI. Although procedural, clinical, and electrocardiographic predisposing factors have been identified as predictors of conduction disturbances, new strategies are needed to avoid such complications, particularly in the current TAVI era that is moving quickly toward the percutaneous treatment of low-risk patients. In this article, we will review the incidence, predictive factors, and clinical implications of conduction disturbances after TAVI.