Transcatheter Aortic Valve Replacement for Pure Native Aortic Valve Regurgitation: The PANTHEON International Project

Aortic regurgitation: from mechanisms to management

Aortic regurgitation (AR) is a common clinical disease associated with significant morbidity and mortality. Investigations based largely on non-invasive imaging are pivotal in discerning the severity of disease and its impact on the heart. Advances in technology have contributed to improved risk stratification and to our understanding of the pathophysiology of AR. Surgical aortic valve replacement is the predominant treatment. However, its use is limited to patients with an acceptable surgical risk profile. Transcatheter aortic valve implantation is an alternative treatment. However, this therapy remains in its infancy, and further data and experience are required. This review article on AR describes its prevalence, mechanisms, diagnosis and treatment.

Outcomes of transcatheter aortic valve implantation for native aortic valve regurgitation

BACKGROUND

Large datasets of transcatheter aortic valve implantation (TAVI) for pure aortic valve regurgitation (PAVR) are scarce.

AIMS

We aimed to report procedural safety and long-term clinical events (CE) in a contemporary cohort of PAVR patients treated with new-generation devices (NGD).

METHODS

Patients with grade III/IV PAVR enrolled in the FRANCE-TAVI Registry were selected. The primary safety endpoint was technical success (TS) according to Valve Academic Research Consortium 3 criteria. The co-primary endpoint was defined as a composite of mortality, heart failure hospitalisation and valve reintervention at last follow-up.

RESULTS

From 2015 to 2021, 227 individuals (64.3% males, median age 81.0 [interquartile range {IQR} 73.5-85.0] years, with EuroSCORE II 6.0% [IQR 4.0-10.9]) from 41 centres underwent TAVI with NGD, using either self-expanding (55.1%) or balloon-expandable valves (44.9%; p=0.50). TS was 85.5%, with a non-significant trend towards increased TS in high-volume activity centres. A second valve implantation (SVI) was needed in 8.8% of patients, independent of valve type (p=0.82). Device size was ≥29 mm in 73.0% of patients, post-procedure grade ≥III residual aortic regurgitation was rare (1.2%), and the permanent pacemaker implantation (PPI) rate was 36.0%. At 30 days, the incidences of mortality and reintervention were 8.4% and 3.5%, respectively. The co-primary endpoint reached 41.6% (IQR 34.4-49.6) at 1 year, increased up to 61.8% (IQR 52.4-71.2) at 4 years, and was independently predicted by TS, with a hazard ratio of 0.45 (95% confidence interval: 0.27-0.76); p=0.003.

CONCLUSIONS

TAVI with NGD in PAVR patients is efficient and reasonably safe. Preventing the need for an SVI embodies the major technical challenge. Larger implanted valves may have limited this complication, outweighing the increased risk of PPI. Despite successful TAVI, PAVR patients experience frequent CE at long-term follow-up.

Single-center experience with self-expanding transcatheter aortic valve system for symptomatic high-risk patients with severe aortic regurgitation: One-year outcomes

AIMS

To evaluate the safety and efficacy of transcatheter aortic valve implantation (TAVI) for the treatment of aortic regurgitation (AR).

METHODS

From September 2019 to February 2022, 62 patients who underwent transfemoral TAVI procedure for pure, symptomatic severe AR with the VitaFlow system were enrolled in the current study. The outcomes were assessed according to the Valve Academic Research Consortium 3 criteria. Procedural results and clinical outcomes for 1 year were analyzed.

RESULTS

The mean age was 71.56 ± 7.34 years and 58.1% were male. The mean Society of Thoracic Surgeons score was 5.44 ± 3.22%. The device success rate was 79.0%. Only one patient was converted to open surgery. The in-hospital mortality rate was 1.6%. The 1-year all-cause mortality rate was 6.5%. The new permanent pacemaker implantation rate was 29.0% in-hospital and 30.7% at 1-year follow-up. The second valve implantation rate was 14.5%. No patient developed more than moderate paravalvular leakage during follow-up. The mean ejection fraction improved from 54.05 ± 10.83% at baseline to 59.32 ± 8.70% (p < 0.001 compared with baseline) at 12 months. Left ventricular end-diastolic diameter decreased from 61.62 ± 5.58 mm at baseline to 55.20 ± 4.51 mm (p < 0.001 compared with the baseline) at 12 months.

CONCLUSIONS

Transfemoral TAVI procedure shows efficacy in treating patients with severe pure native AR. The safety is improved with the development of the VitaFlow system.

Performance of balloon-expandable transcatheter bioprostheses in inoperable patients with pure aortic regurgitation of a native valve: The BE-PANTHEON international project

BACKGROUND

The off-label utilization of transcatheter heart valve (THV) devices for the treatment of inoperable or high-surgical risk patients with pure native aortic valve regurgitation (NAVR) has demonstrated suboptimal outcomes, both with self- and balloon-expandable (BE) devices. The aim of this study is to compare the use of different BE scaffolds in treating pure NAVR.

METHODS

Consecutive patients with pure severe NAVR who were deemed to be at high-risk and were treated with last-generation BE-THVs among seventeen Centers in Europe and US. Technical and device success rates were the primary objectives.

RESULTS

Between February 2018 and July 2023, among 144 patients, 41 (28 %) received a MyVal device and 103 (72 %) were treated with a Sapien THV. Patients treated with a MyVal THV had an extra-large annulus more frequently compared to the Sapien group (49%vs.20 %, p < 0.001). Technical and device success rates were 90 % and 81 %, respectively, p > 0.1. The rate of THV migration/embolization (MyVal 4.9%vs. Sapien 11 %, p = 0.4) and second valve needed (4.9%vs.7.8 %, p = 0.7) were numerically lower in the MyVal group, whereas the rate of at least moderate paravalvular leak (15%vs.7.8 %, p = 0.2) and permanent pacemaker implantation (25%vs.18 %, p = 0.16) were numerically higher in the Myval group.

CONCLUSIONS

Off-label use of BE devices for pure NAVR represents a potential alternative in high-risk patients in the absence of dedicated devices. However, BE in NAVR is associated with suboptimal outcomes. The availability of larger THV sizes may introduce transcatheter aortic valve replacement as an effective treatment for patients traditionally deemed unsuitable.

NON-STANDARD ABBREVIATIONS AND ACRONYMS

AR = aortic regurgitation, BE = balloon-expandable, NAVR = native aortic valve regurgitation, PM = pacemaker, TAVR = transcatheter aortic valve replacement, THV = transcatheter heart valve, TVEM = transcatheter valve embolization and migration, VARC-3 = Valve Academic Research Consortium 3.

Performance of Purpose-Built vs Off-Label Transcatheter Devices for Aortic Regurgitation: The PURPOSE Study

BACKGROUND

Severe pure aortic regurgitation (AR) carries a high mortality and morbidity risk, and it is often undertreated because of the inherent surgical risk. Transcatheter heart valves (THVs) have been used off-label in this setting with overall suboptimal results. The dedicated "purpose-built" Jena Valve Trilogy (JVT, JenaValve Technology) showed an encouraging performance, although it has never been compared to other THVs.

OBJECTIVES

The aim of our study was to assess the performance of the latest iteration of THVs used off-label in comparison to the purpose-built JVT in inoperable patients with severe AR.

METHODS

We performed a multicenter, retrospective registry with 18 participating centers worldwide collecting data on inoperable patients with severe AR of the native valve. A bicuspid aortic valve was the main exclusion criterion. The primary endpoints were technical and device success, 1-year all-cause mortality, and the composite of 1-year mortality and the heart failure rehospitalization rate.

RESULTS

Overall, 256 patients were enrolled. THVs used off-label were used in 168 cases (66%), whereas JVT was used in 88 (34%). JVT had higher technical (81% vs 98%; P < 0.001) and device success rates (73% vs 95%; P < 0.001), primarily driven by significantly lower incidences of THV embolization (15% vs 1.1%; P < 0.001), the need for a second valve (11% vs 1.1%; P = 0.004), and moderate residual AR (10% vs 1.1%; P = 0.007). The permanent pacemaker implantation rate was comparable and elevated for both groups (22% vs 24%; P = 0.70). Finally, no significant difference was observed at the 1-year follow-up in terms of mortality (HR: 0.99; P = 0.980) and the composite endpoint (HR: 1.5; P = 0.355).

CONCLUSIONS

The JVT platform has a better acute performance than other THVs when used off-label for inoperable patients with severe AR. A longer follow-up is conceivably needed to detect a possible impact on prognosis.

Transcatheter Aortic Valve Implantation for Severe Chronic Aortic Regurgitation

Transcatheter aortic valve implantation (TAVI) has revolutionised the management of aortic valve disease, offering a less invasive alternative to traditional surgical valve replacement for severe aortic stenosis (AS). TAVI for pure aortic regurgitation (AR) is less well established, and, in fact, it was previously labelled as a relative contraindication. However, TAVI has been utilised for selected cases of pure or predominant AR. The primary limitations regarding the use of TAVI in AR are related to the absence of anatomical factors seen in patients with AS that have contributed to the safe and stable functioning of current-generation prostheses. These include aortic root dilatation, mobile valve leaflets and labile blood pressure within the aortic root, which may further increase the risk of valve migration and periprosthetic leak after deployment. Furthermore, patients with AR have more heterogeneous aortic root anatomies when compared to the population of patients with calcific or degenerative AS. This review article describes the current evidence for the off-label use of TAVI in pure AR and the various clinical syndromes associated with AR where there may be specific challenges in the application of TAVI.

Transcatheter aortic valve implantation in patients with high-risk symptomatic native aortic regurgitation (ALIGN-AR): a prospective, multicentre, single-arm study

BACKGROUND

Surgery remains the only recommended intervention for patients with native aortic regurgitation. A transcatheter therapy to treat patients at high risk for mortality and complications with surgical aortic valve replacement represents an unmet need. Commercial transcatheter heart valves in pure aortic regurgitation are hampered by unacceptable rates of embolisation and paravalvular regurgitation. The Trilogy transcatheter heart valve (JenaValve Technology, Irvine, CA, USA) provides a treatment option for these patients. We report outcomes with transfemoral transcatheter aortic valve implantation (TAVI) in patients with pure aortic regurgitation using this dedicated transcatheter heart valve.

METHODS

The ALIGN-AR trial is a prospective, multicentre, single-arm study. We recruited symptomatic patients (aged ≥18 years) with moderate-to-severe or severe aortic regurgitation at high risk for mortality and complications after surgical aortic valve replacement at 20 US sites for treatment with the Trilogy transcatheter heart valve. The 30-day composite primary safety endpoint was compared for non-inferiority with a prespecified performance goal of 40·5%. The primary efficacy endpoint was 1-year all-cause mortality compared for non-inferiority with a performance goal of 25%. This trial is registered with ClinicalTrials.gov, NCT04415047, and is ongoing.

FINDINGS

Between June 8, 2018, and Aug 29, 2022, we screened 346 patients. We excluded 166 (48%) patients and enrolled 180 (52%) patients with symptomatic aortic regurgitation deemed high risk by the heart team and independent screening committee assessments. The mean age of the study population was 75·5 years (SD 10·8), and 85 (47%) were female, 95 (53%) were male, and 131 (73%) were White. Technical success was achieved in 171 (95%) patients. At 30 days, four (2%) deaths, two (1%) disabling strokes, and two (1%) non-disabling strokes occurred. Using standard Valve Academic Research Consortium-2 definitions, the primary safety endpoint was achieved, with events occurring in 48 (27% [97·5% CI 19·2-34·0]) patients (pnon-inferiority<0·0001), with new pacemaker implantation in 36 (24%) patients. The primary efficacy endpoint was achieved, with mortality in 14 (7·8% [3·3-12·3]) patients at 1 year (pnon-inferiority<0·0001).

INTERPRETATION

This study shows the safety and effectiveness of treating native aortic regurgitation using a dedicated transcatheter heart valve to treat patients with symptomatic moderate-to-severe or severe aortic regurgitation who are at high risk for mortality or complications after surgical aortic valve replacement. The observed short-term clinical and haemodynamic outcomes are promising as are signs of left ventricular remodelling, but long-term follow-up is necessary.

FUNDING

JenaValve Technology.

Treatment options for isolated aortic valve insufficiency: a review

Aortic insufficiency (AI) is a valvular disease with increasing prevalence in older patients. The modern era provides numerous options for the management of AI which is explored here. Traditional interventions included aortic valve replacement with either mechanical or bioprosthetic aortic valves. While the former is known for its durability, it has grown out of favor due to the potential complications of anticoagulation. The preference for bioprosthetic valves is thus on the rise, especially with the advancements of transcatheter technology and the use of valve-in-valve therapy. Surgical options are also no longer limited to replacement but include complex techniques such as those required for aortic valve repair, Ozaki neocuspidization, Ross procedure and valve-sparring aortic root repair. Transcatheter options for the management of AI are not commercially available currently; however, preliminary data from ad-hoc trials, showed promising results and potential use of transcatheter technology in a variety of patients with pure AI.

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.

Transcatheter Aortic Valve Implantation to Treat Degenerated Aortic, Mitral and Tricuspid Bioprosthesis

Transcatheter aortic valve implantation (TAVI) is now well established as the treatment of choice for patients with native aortic valve stenosis who are high or intermediate risk for surgical aortic valve replacement. Recent data has also supported the use of TAVI in patients at low surgical risk and also in anatomical subsets that were previously felt to be contra-indicated including bicuspid aortic valves and aortic regurgitation. With advancements and refinements in procedural techniques, the application of this technology has now been further expanded to include the management of degenerated bioprosthesis. After the demonstration of feasibility and safety in the management of degenerated aortic bioprosthetic valves, mitral and tricuspid bioprosthetic valve treatment is now also well-established and provides an attractive alternative to performing redo surgery. In this review, we appraise the latest clinical evidence and highlight procedural considerations when utilising TAVI technology in the management of degenerated aortic, mitral or tricuspid prosthesis.

Assessment of the Severity of Aortic Regurgitation by Noninvasive Imaging : Non-invasive MMI for AR

PURPOSE OF THE REVIEW

The role of multimodality imaging in the evaluation of patients with aortic regurgitation is summarized in this review.

RECENT FINDINGS

The etiology (mechanism) of the aortic regurgitation and the severity of aortic regurgitation and hemodynamic consequences are key in the decision making of patients with severe aortic regurgitation. While echocardiography remains as the leading technique to assess all these parameters, other imaging techniques have become essential for the accurate assessment of aortic regurgitation severity and the timing of aortic intervention. The anatomic suitability of transcatheter aortic valve implantation in inoperable patients with severe aortic regurgitation is usually assessed with computed tomography. Aortic regurgitation is a prevalent disease with various pathophysiological mechanisms that need a personalized treatment. The evaluation of the mechanism and severity of aortic regurgitation can be initially performed with echocardiography. Three-dimensional techniques, including echocardiography, have become very relevant for accurate assessment of the regurgitation severity and its hemodynamic consequences. Assessment of myocardial tissue characteristics with cardiac magnetic resonance is key in the risk stratification of patients and in the timing of aortic intervention. Computed tomography is important in the assessment of aortic dimensions and selection of patients for transcatheter aortic valve implantation.

Native aortic valve regurgitation: TAVR's place in the PANTHEON

The PANTHEON (Performance of Currently Available traNscaTHEter Aortic Valve Platforms in Inoperable Patients With Pure Aortic regurgitatiON of a native valve) study examined transcatheter aortic valve replacement in patients with severe pure native aortic valve regurgitation. With a real-world dataset from 16 centres in Europe and the USA, the study encompassed 201 patients. The major complications included valve embolization or migration in 12.4%, moderate to severe aortic regurgitation in 9.5% cases and need for permanent pacemaker in 22.3% cases. Self-expanding and balloon-expandable devices demonstrated similar outcomes. Those experiencing valve embolization or migration had higher 1-year adverse event rates.