Transcatheter Aortic Valve Replacement to Treat Pure Aortic Regurgitation on Noncalcified Native Valves

TAVR as an Alternative to SAVR for Pure Native Aortic Regurgitation

Although transcatheter aortic valve replacement was originally fulfilling an unmet clinical need in the elderly population suffering from tricuspid aortic valve stenosis, its use has been progressively expanded to other groups of patients. In this review, we focus on pure native aortic valve regurgitation, which is in most cases a degenerative disease and therefore frequently diagnosed in elderly patients with comorbidities. Symptoms tend to appear late in the disease, when left ventricular dilation and systolic dysfunction are associated owing to excessive volume overload. It is often combined with a dilated aortic annulus and ascending aorta. Surgical aortic valve replacement remains the criterion standard treatment for severe aortic regurgitation. However, for patients at prohibitive surgical risk, transcatheter aortic valve replacement represents an attractive alternative. Various technical challenges are the absence of calcium at the level of the annulus, which means there are no anchoring points or fluoroscopic landmarks, the difficulty of valve sizing, and the increased stroke volume secondary to the aortic regurgitation, making valve deployment more unstable than in the setting of aortic stenosis. The first-generation transcatheter valves were associated with a higher mortality rate and lower procedural success related to increased risk of paravalvular leak and valve migration requiring a second valve or annular rupture than the more recent off-label or on-label transcatheter valves. Early studies with the dedicated on-label devices showed safety and promising results and will undoubtedly serve in the future a growing number of patients with native aortic regurgitation at prohibitive risk for surgery.

Transfemoral transcatheter aortic valve replacement for pure native aortic regurgitation: one-year outcomes of a single-center study

BACKGROUND

Evidence about safety and efficacy of transcatheter aortic valve replacement (TAVR) with the Venus A-Valve system (Venus Medtech, Hangzhou, China) remains limited for patients with pure native aortic regurgitation (PNAR).

OBJECTIVES

The single-center study sought to report the one-year clinical outcomes of the Venus A-Valve in the treatment of PNAR.

METHODS

This study was a retrospective analysis of prospectively collected data. Data was from all consecutive patients who had PNAR and underwent TAVR with the Venus A-Valve system at our center from July 2020 and June 2021. Procedural and clinical outcomes up to one year were analyzed using Valve Academic Research Consortium-2 criteria.

RESULTS

A total of 45 consecutive patients with PNAR underwent transfemoral TAVR with the Venus A-Valve system. The Mean age was 73.5 ± 5.5 years and 26.7% were female. All the TAVR procedures were performed via transfemoral access. Implantations were successful in 44 cases (97.8%). Only one patient was converted to surgical aortic valve replacement. No patient died intraoperatively. No second valve was implanted. In-hospital mortality rate was 2.3%. The one-year all-cause mortality rate was 4.7% without cardiovascular related death. No patient had moderate or severe paravalvular leakage during follow-up. At one year, the mean pressure gradient was 8.8 ± 0.9 mmHg, and left ventricular ejection fraction increased to 61.5 ± 3.6%.

CONCLUSIONS

This single-center study demonstrated the safety and efficacy of transfemoral TAVR with the Venus A-Valve in the treatment of patients with PNAR.

Transcatheter aortic valve implantation using the SAPIEN 3 valve to treat aortic regurgitation: The French multicentre S3AR study

BACKGROUND

Transcatheter aortic valve implantation now has a major role in the treatment of patients with severe aortic stenosis. However, evidence is scarce on its feasibility and safety to treat patients with pure aortic regurgitation.

AIMS

We sought to evaluate the results of transcatheter aortic valve implantation using the balloon-expandable SAPIEN 3 transcatheter heart valve (Edwards Lifesciences, Irvine, CA, USA) in patients with pure aortic regurgitation on native non-calcified valves.

METHODS

We conducted a retrospective and prospective French multicentre observational study. We included all patients with symptomatic severe pure aortic regurgitation on native non-calcified valves, contraindicated to or at high risk for surgical valve replacement, who underwent transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve.

RESULTS

A total of 37 patients (male sex, 73%) with a median age of 81years (interquartile range 69-85years) were screened using transthoracic echocardiography and computed tomography and were included at eight French centres. At baseline, 83.8% of patients (n=31) had dyspnoea New York Heart Association class≥III. The device success rate was 94.6% (n=35). At 30days, the all-cause mortality rate was 8.1% (n=3) and valve migration occurred in 10.8% of cases (n=4). Dyspnoea New York Heart Association class≤II was seen in 86.5% of patients (n=32), and all survivors had aortic regurgitation grade≤1. At 1-year follow-up, all-cause mortality was 16.2% (n=6), 89.7% (n=26/29) of survivors were in New York Heart Association class≤II and all had aortic regurgitation grade≤2.

CONCLUSION

Transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve seems promising to treat selected high-risk patients with pure aortic regurgitation on non-calcified native valves, contraindicated to surgical aortic valve replacement.

Overinflation of balloon-expandable valves for transcatheter treatment of pure noncalcified native aortic regurgitation: How much oversizing is needed and achievable?

Transcatheter aortic valve implantation (TAVI) in noncalcified pure aortic valve regurgitation is challenging as dedicated valves are not widely available. We present a case series of four inoperable patients who underwent compassionate TAVI for this indication at our institution with a balloon-expandable valve. In this context, we analyzed the relevant technical aspects such as the need for larger oversizing of the transcatheter prosthesis and the safety and limits of valve overexpansion.

A study on correlation between preprocedural CT indexes and procedural success rate of transfemoral transcatheter aortic valve replacement with different self-expanding valves (VitaFlow or VenusA-Valve) in patients with pure native aortic regurgitation

BACKGROUND

The rate of procedural success of transfemoral transcatheter aortic valve replacement (TAVR) with self-expanding valves in patients with pure native aortic regurgitation (PNAR) is quite low. Which anatomy evaluated by computed tomography (CT) as well as which kind of self-expanding valve is associated with higher success rate remain unknown. The aims of this study were to evaluate the relationship between preprocedural CT indexes and procedural success rate and to compare the procedural success rates between 2 kinds of self-expanding valves with different shaped frameworks.

METHODS

This was a retrospective comparative study. The study enrolled the symptomatic patients with severe PNAR, who were treated by transfemoral TAVR using a VenusA-Valve (Venus Medtech, Hangzhou, China) or a VitaFlow valve (Microport, Shanghai, China) at Zhongshan Hospital, Fudan University from October 2018 to December 2020. The procedural success rate (VARC-2 standard) was recorded. Preprocedural CT data were collected, including the perimeters of the aortic annulus (AA), left ventricular outflow tract (LVOT), sinotubular junction (STJ), and ascending aorta (AAO) and the angle of the aortic root. Leaflet thickening was evaluated qualitatively.

RESULTS

A total of 77 patients with a mean Society of Thoracic Surgeons (STS) score of 7.7±5.9 underwent TAVR. The total rate of procedural success was 80.5%. In the successful procedure group, the circumferences of the AA, LVOT, and STJ measured by CT were significant smaller than those in the failed procedure group (P=0.02, P=0.002 and P=0.045, respectively). Meanwhile, there were more patients with leaflet thickening in the successful procedure group (58.1% vs. 20.0%; P=0.02). The VenusA-Valve and the Vita-Flow valve were used in 47 patients and 30 patients, respectively. The procedural success rate was significantly higher in the VitaFlow group than in the VenusA-Valve group (93.3% vs. 72.3%; P=0.048), which was mainly due to the lower incidence of second transcatheter heart valves implantations in the VitaFlow group (6.7% vs. 27.7%; P=0.048).

CONCLUSIONS

Severe PNAR patients with a smaller AA, LVOT, and STJ and leaflet thickening might have a higher success rate in transfemoral TAVR using a self-expanding valve. The self-expanding valve with a non-A-shaped framework might be a better choice for improved procedural outcomes.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.

Challenging Anatomies for TAVR-Bicuspid and Beyond

Transcatheter aortic valve replacement has emerged as the standard treatment for the majority of patients with symptomatic aortic stenosis. As transcatheter aortic valve replacement expands to patients across all risk groups, optimal patient selection strategies and device implantation techniques become increasingly important. A significant number of patients referred for transcatheter aortic valve replacement present with challenging anatomies and clinical indications that had been historically considered a contraindication for transcatheter aortic valve replacement. This article aims to highlight and discuss some of the potential obstacles that are encountered in clinical practice with a particular emphasis on bicuspid aortic valve disease.

Complex transcatheter aortic valve replacement in aortic regurgitation and transcatheter mitral annuloplasty in severe dextrocardia

A 70-year-old female with symptomatic severe native aortic regurgitation, acquired dextrocardia, moderate-to-severe secondary mitral regurgitation and prohibitive surgical risk was admitted for transcatheter aortic valve replacement. A balloon-expendable Sapien 3 Ultra valve was implanted successfully. After 6 months, the patient remained symptomatic due to the concomitant moderate-to-severe secondary mitral regurgitation. Transcatheter mitral valve repair using a Carillon Mitral Contour System was performed resulting in a significant reduction of mitral regurgitation and uneventful follow-up. Most importantly, other transcatheter repair techniques would not have been feasible due to the impossible transoesophageal echocardiography guidance. This is the first case of transcatheter aortic valve replacement in a patient with native aortic regurgitation, acquired dextrocardia and severe aortic annulus malrotation using a balloon-expendable valve. Moreover, it is the first transcatheter mitral valve repair procedure using Carillon device performed by a cardiac surgeon.

Sapien 3 Embolization From Ventricle to Aorta in the Setting of Noncalcified Aortic Regurgitation

Transcatheter aortic valve replacement is currently used off-label for noncalcified aortic valve regurgitation and therefore is restricted to selected cases. In this setting we describe a rare complication of Sapien 3 (Edwards Lifesciences, Irvine, California) embolization from the left ventricle to the descending aorta. Given their technical challenges, such procedures require specific considerations and management. (Level of Difficulty: Advanced.).

Transcatheter treatment of native aortic valve regurgitation: Results from an international registry using the transfemoral ACURATE neo valve

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Native aortic valve regurgitation (NAVR) presents technical challenges for TAVR.

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This is the largest study on NAVR patients treated with the ACURATE neo valve.

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Intraprocedural mortality was 0%, device success 87.5% and moderate PVL rate 8.3%.

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Device success tended to be higher with perimeter-based >10% oversizing.

Background

Transcatheter aortic valve replacement (TAVR) has been validated for the treatment of severe symptomatic aortic stenosis in patients at high and intermediate surgical risk. Recently, TAVR has been proposed as an alternative to medical therapy in inoperable patients with severe native aortic valve regurgitation (NAVR). This multicenter international registry sought to evaluate safety and efficacy of TAVR with the self-expandable ACURATE neo valve in a cohort of patients with NAVR.

Methods

A total of 24 patients with severe NAVR treated by TAVR between September 2016 and October 2018 in 13 European centers were included. Clinical, procedural and follow up data were inserted in a dedicated database. Outcomes were codified according to Valve Academic Research Consortium-2 criteria.

Results

Mean age was 79.4 years, 58.4% were female. Mean EuroSCORE II and STS score were 5% and 3.9%, respectively. Device success was 87.5%. Moderate paravalvular leak (PVL) was found in two (8.3%) of patients, both with a perimeter oversizing index <10%. Implantation of a second device was necessary in three cases (12.5%), one for severe PVL and two for device displacement. New pacemaker implantation rate was 21.1%. At 30 days, stroke and all-cause mortality rates were 0% and 4.1%, respectively.

Conclusions

This multicenter study suggests good feasibility and early safety of transfemoral TAVR with the self-expandable ACURATE neo device in patients with severe NAVR refused for surgery. Rates of moderate PVL, new pacemaker implantation and need for a second valve were higher than those reported for TAVR in aortic stenosis.

Urgent transcatheter aortic valve replacement for severe acute aortic regurgitation following open mitral valve surgery

Transcatheter aortic valve replacement (TAVR) is not currently approved for pure native valve aortic incompetence, and is typically performed on a compassionate basis in selected patients who are at high risk for conventional surgery. We describe the first use of TAVR to treat iatrogenic severe acute pure aortic incompetence following mitral valve surgery. A 71-year-old gentleman developed life-threatening acute aortic regurgitation (AR) within hours of a very challenging fifth open heart mitral valve replacement. Careful inspection of echocardiographic and computed tomographic imaging identified the cause as a disrupted left coronary cusp at the commissure caused by the surgical mitral annular reconstruction. Medical management with afterload reduction failed with recurrent pulmonary edema, and a sixth open heart surgery was deemed prohibitively high risk. The lack of aortic annular calcium onto which anchors a transcatheter valve was a concern for TAVR. However, we postulated that the struts of the mitral valve bioprosthesis would offer some support to the TAVR valve. We opted for a self-expanding system because of concerns about potential unfavorable interaction between the balloon onto which balloon-expandable bioprosthesis is mounted and the struts of the mitral bioprosthesis, and because the Evolut R system has additional anchoring points at the crown which might enhance transcatheter valve stability in the non-calcified annulus, compared with the Edwards Sapien system. Transfemoral TAVR, performed with a Medtronic Evolut R 34 mm system under general anesthesia and using moderately rapid ventricular pacing, was successful with minimal residual AR. On follow-up 1 month later the patient was asymptomatic, and the aortic and mitral bioprostheses were functioning normally on echocardiogram.

TAVI for Pure Native Aortic Regurgitation: Are We There Yet?

Treatment of degenerative aortic stenosis has been transformed by transcatheter aortic valve implantation (TAVI) over the past 10-15 years. The success of various technologies has led operators to attempt to broaden the indications, and many patients with native valve aortic regurgitation have been treated 'off label' with similar techniques. However, the alterations in the structure of the valve complex in pure native aortic regurgitation are distinct to those in degenerative aortic stenosis, and there are unique challenges to be overcome by percutaneous valves. Nevertheless some promise has been shown with both non-dedicated and dedicated devices. In this article, the authors explore some of these challenges and review the current evidence base for TAVI for aortic regurgitation.

Recent developments and controversies in transcatheter aortic valve implantation

Interventional cardiology has been revolutionised by transcatheter aortic valve implantation (TAVI), which has become established as the benchmark treatment for severe aortic stenosis in patients at high risk for surgical aortic valve replacement (AVR). Increased procedural familiarity and progression in device technology has enabled improvements to be made in complication rates, which have led to a commensurate expansion in the use of TAVI; it is now a viable alternative to AVR in patients at intermediate surgical risk, and has been used in cohorts such as those with bicuspid aortic valves or pure, severe aortic regurgitation. Given the rapid expansion in the use of TAVI, including cohorts of younger patients with fewer co-morbidities, attention must be paid to further reducing remaining complications, such as cardiac tamponade or stroke. To this end, novel techniques and devices have been devised and trialled, with varying levels of success. Furthermore, significant work has gone into refining the technique with exploration of alternative imaging modalities, as well as alternative access routes to provide greater options for patients with challenging vascular anatomy. Whilst significant progress has been made with TAVI, areas of uncertainty remain such as the management of concomitant coronary artery disease and the optimum post-procedure antiplatelet regimen. As such, research in this field continues apace, and is likely to continue as use of TAVI becomes more widespread. This review provides a summary of the existing evidence, as well as an overview of recent developments and contentious issues in the field of TAVI.

Transcatheter aortic valve replacement: The year in review 2016

Transcatheter aortic valve replacement (TAVR) continued to make major strides in 2016, simultaneously expanding its application to lower risk patients as well as more technically challenging subsets of patients with aortic stenosis (AS). The two major accomplishments this year were the establishment of TAVR as the preferred treatment strategy over surgical aortic valve replacement (SAVR) in intermediate risk patients, and initial signals that TAVR and SAVR may be clinically equivalent in low-risk populations. Meanwhile, there is continued expansion of TAVR to challenging clinical subsets (bicuspid aortic valve [BAV], patients with concomitant advanced coronary artery disease [CAD], and failed surgical bioprostheses), and encouraging initial experiences with newer transcatheter heart valve systems. This paper summarizes the major research studies published on TAVR in 2016.