Self-Expanding Prostheses for Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative to surgical aortic valve replacement in patients who are considered high surgical risk or inoperable due to advanced age and comorbidities. Randomized trial and registry data have demonstrated the safety and efficacy of TAVR in such patients. Currently available transcatheter heart valves (THVs) employ either balloon-expandable or self-expanding designs, and several new designs have shown promising early results. Differences in valve design may offer specific advantages for accurate deployment and minimizing complications. This article reviews several designs of self-expanding THVs that are currently available or have undergone successful implantation in humans. Additional studies are required to compare the relative performance of these devices.     

TAVR for Failed Surgical Aortic Bioprostheses Using a Self-Expanding Device: 1-Year Results From the Prospective VIVA Postmarket Study

ObjectivesThe VIVA (Valve in Valve) trial was designed to systematically and prospectively collect data regarding the use of transcatheter aortic valve replacement in patients with failing surgical aortic bioprostheses at high-risk for reoperation.BackgroundSurgical aortic valve replacement has been the standard of care in symptomatic patients with aortic valve disease. However, bioprosthetic valves degenerate over time, requiring redo surgery.MethodsVIVA is an international, observational, single-arm, postmarket study conducted at 23 sites that enrolled 202 patients with symptomatic degeneration of an aortic bioprosthesis eligible for elective treatment with a CoreValve or Evolut R self-expanding transcatheter aortic valve.ResultsPatients were elderly (mean age 79.9 years), 47.5% were men, and they had a mean Society of Thoracic Surgeons score of 6.6%. Although 41.8% of patients had surgical bioprostheses with labeled size ≤21 mm, valve hemodynamic parameters were markedly improved from baseline (mean aortic valve gradient 35.0 ± 16.3 mm Hg) to discharge (17.5 ± 8.6 mm Hg) and were sustained at 1 year (15.5 ± 7.5 mm Hg). At 1 year, total aortic regurgitation greater than mild was measured in 1.1% of patients. Clinical outcomes at 30 days demonstrated low mortality (2.5%), no disabling strokes, a 0.5% rate of acute kidney injury, and an 8.0% rate of new pacemaker implantation. At 1 year, the mortality rate remained low (8.8%), with 1 disabling stroke (0.6%). Five patients (2.5%) experienced coronary artery obstructions, 3 during and 1 immediately after the procedure and 1 several months later.ConclusionsDegenerated surgical bioprostheses can be safely treated with the CoreValve or Evolut R platform using the catheter-based valve-in-valve procedure. Excellent 1-year clinical and hemodynamic outcomes were achieved in this real-world patient population. (CoreValve VIVA Study Evaluation of the Clinical Outcomes of CoreValve in Degenerative Surgical Aortic Bioprosthesis; NCT02209298)     

1-Year Outcomes of the CENTERA-EU Trial Assessing a Novel Self-Expanding Transcatheter Heart Valve

Objectives

The purpose of this study is to report the 1-year results of the CENTERA-EU trial.

Quantitative Angiographic Assessment of Aortic Regurgitation After Transcatheter Implantation of the Venus A-valve: Comparison with Other Self-Expanding Valves and Impact of a Learning Curve in a Single Chinese Center

Objectives:We aimed to compare the quantitative angiographic aortic regurgitation (AR) into the left ventricular out flow tract (LVOT-AR) of five different types of transcatheter self-expanding valves and to investigate the impact of the learning curve on post-TAVR AR.Background:Quantitative video densitometric aortography is an objective, accurate, and reproducible tool for assessment of AR following TAVR.Methods and results:This retrospective academic core-lab analysis, analyzed 1150 consecutive cine aortograms performed immediately post-TAVR. Quantitative angiographic AR of post-procedural aortography in 181 consecutive patients, who underwent TAVR with the Venus A-valve in a single Chinese center, were compared to the results of Evolut Pro, Evolut R, CoreValve, (Medtronic, Dublin, Ireland) and Acurate Neo (Boston Scientific, Massachusetts, US) transcatheter heart valves (THVs), from a previously published pooled database. Among the 181 aortograms of patients treated with the Venus A-Valve, 113 (62.4%) were analyzable for quantitative assessment of AR. The mean LVOT-AR was 8.9% ± 10.0% with 14.2% of patients having moderate or severe AR in the Venus A-valve group. No significant difference in mean LVOT-AR was observed between Evolut Pro, Evolut R, Acurate Neo, and Venus A-valve. The incidence of LVOT-AR >17%, which correlates with echocardiographic derived ≥ moderate AR, with the Evolut Pro was lower than with the Venus A-valve (5.3% vs. 14.2%, p = 0.034), but was not different from the Evolut R (5.3% vs. 8.8%, p = 0.612), or the Acurate Neo (5.3% vs. 11.3% p = 0.16) systems. A landmark analysis after recruitment of the first half of patients treated with the Venus A valve (N = 56), showed a significantly lower mean LVOT-AR in the second half of the series (11.3% ± 11.9% vs. 6.5% ± 7.1%, p = 0.011). The incidence of LVOT-AR >17% in the latest 57 cases was also numerically lower (7.0% vs. 21.4%, p = 0.857) and compared favorably with the best in class of the self-expanding valves.ConclusionThe Venus A-valve has comparable mean LVOT-AR to other self-expanding valves but has a higher rate of moderate or severe AR than the Evolut Pro THV. However, after completion of a learning phase, results improved and compared favorably with the best in class of the commercially available self-expanding valves. These findings should be confirmed in prospective randomized comparisons of AR between different THVs.     

Balloon-Expandable Prostheses for Transcatheter Aortic Valve Replacement

The implantation of a transcatheter heart valve (THV) through a balloon-expandable system played a major role in the early stages of transcatheter aortic valve replacement (TAVR). The technology consists of sewing a foldable biological cardiac valve inside a metallic stent frame, and then crimping the device into a balloon in order to implant the valve at the level of the aortic annulus through balloon inflation. The use of balloon-expandable valves underwent a rapid expansion in the years following the pioneering experience of 2002, and recent large multicenter trials and registries have confirmed the safety and efficacy of TAVR using balloon-expandable valves. The randomized Placement of Aortic Transcatheter Valves (PARTNER) trial showed both the superiority and non-inferiority of TAVR with the balloon-expandable Edwards-Sapien system compared to medical treatment (non-operable patients) and surgical aortic valve replacement (high risk patients), respectively. Balloon-expandable valves have been associated with excellent hemodynamic results (residual mean gradient < 15 mm Hg in most cases), though residual paravalvular aortic regurgitation is frequent (trivial or mild in the majority of patients, moderate or severe in < 10%). Valve durability studies with up to 5-year follow-up have shown maintained valve hemodynamics over time with only a minimal decrease in valve area and no increase in aortic regurgitation. Future improvements in the balloon-expandable THV technology such as implementing anti-paravalvular leak features (ex. Sapien 3 valve), and showing its efficacy for the treatment of non-high risk patients (ongoing PARTNER II trial) will probably lead to broader use in a lower risk population in the near future.     

The BASILICA Trial: Prospective Multicenter Investigation of Intentional Leaflet Laceration to Prevent TAVR Coronary Obstruction

ObjectivesThe BASILICA (Bioprosthetic or native Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery obstruction during TAVR) investigational device exemption trial was a prospective, multicenter, single-arm safety and feasibility study.BackgroundCoronary artery obstruction is a rare but devastating complication of transcatheter aortic valve replacement (TAVR). Current stent-based preventative strategies are suboptimal. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (BASILICA) is a novel transcatheter technique performed immediately before TAVR to prevent coronary artery obstruction.MethodsSubjects with severe native or bioprosthetic aortic valve disease at high or extreme risk for surgery, and at high risk of coronary artery obstruction, were included. The primary success endpoint was successful BASILICA and TAVR without coronary obstruction or reintervention. The primary safety endpoint was freedom from major adverse cardiovascular events. Data were independently monitored. Endpoints were independently adjudicated. A core laboratory analyzed computed tomography images.ResultsBetween February 2018 and July 2018, 30 subjects were enrolled. Primary success was met in 28 (93%) subjects. BASILICA traversal and laceration was successful in 35 of 37 (95%) attempted leaflets. There was 100% freedom from coronary obstruction and reintervention. Primary safety was met in 21 (70%), driven by 6 (20%) major vascular complications related to TAVR but not BASILICA. There was 1 death at 30 days. There was 1 (3%) disabling stroke and 2 (7%) nondisabling strokes. Transient hemodynamic compromise was rare (7%) and resolved promptly with TAVR.ConclusionsBASILICA was feasible in both native and bioprosthetic valves. Hemodynamic compromise was uncommon. Safety was acceptable and needs confirmation in larger studies. BASILICA appears effective in preventing coronary artery obstruction from TAVR in subjects at high risk.     

Transcatheter Aortic Valve Replacement With Next-Generation Self-Expanding Devices: A Multicenter,Retrospective, Propensity-Matched Comparison of Evolut PRO Versus Acurate neo Transcatheter Heart Valves

Objectives

The aim of this study was to compare transcatheter aortic valve replacement (TAVR) with the Acurate neo (NEO) and Evolut PRO (PRO) devices.

Role of Transcatheter Aortic Valve Implantation (TAVI) Versus Conventional Aortic Valve Replacement in the Treatment of Aortic Valve Disease

Conventional aortic valve replacement (AVR) surgery has been in clinical use since 1960. Results, particularly in high-risk populations such as the very elderly and frail, continue to improve in response to the challenges posed by this growing segment of the patient population. Transcatheter aortic valve implantation (TAVI) is a fairly recent development, performed for the first time in 2002. The last decade has seen an exponential growth in the application of this technology in higher-risk populations. Results of recent randomized prospective trials demonstrate both the future promise and current problems of the TAVI approach. Many patients deemed inoperable for AVR have been treated successfully by TAVI. However, elevated procedural and late mortality rates, excessive early and late stroke, and a significant incidence of periprosthetic aortic valve insufficiency and patient-prosthesis mismatch all suggest caution in extending this technology to patients able to undergo conventional AVR with a low risk of early or late complications.     

Incidence,Predictors, and Clinical Impact of Prosthesis–Patient Mismatch Following Transcatheter Aortic Valve Replacement in Asian Patients: The OCEAN-TAVI Registry

Objectives

The authors sought to investigate the prevalence, risk factors, and mid-term mortality in Asian patients with prosthesis–patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR).

Effect of SAPIEN 3 Transcatheter Valve Implantation on Health Status in Patients With Severe Aortic Stenosis at Intermediate Surgical Risk: Results From the PARTNER S3i Trial

Objectives

The aim of this study was to evaluate whether transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve (S3-TAVR) results in improved quality of life (QoL) compared with previous-generation TAVR devices or surgical aortic valve replacement (SAVR).

Bioprosthetic Valve Performance After Transcatheter Aortic Valve Replacement With Self-Expanding Versus Balloon-Expandable Valves in Large Versus Small Aortic Valve Annuli: Insights From the CHOICE Trial and the CHOICE-Extend Registry

Objectives

The aim of this study was to compare self-expanding and balloon-expandable transcatheter heart valves (THVs) in large versus small aortic valve annuli.

1-Year Clinical Outcomes in Women After Transcatheter Aortic Valve Replacement: Results From the First WIN-TAVI Registry

Objectives

This study sought to examine the safety and performance of contemporary transcatheter aortic valve replacement (TAVR) in an exclusive all-women TAVR population, and to further investigate the potential impact of female sex–specific characteristics on composite 1-year clinical outcomes.

Prognostic Impact of Low-Flow Severe Aortic Stenosis in Small-Body Patients Undergoing TAVR: The OCEAN-TAVI Registry

Objectives

This study aimed to analyze the prognostic impact of low-flow (LF) severe aortic stenosis in small-body patients undergoing transcatheter aortic valve replacement (TAVR).

Initial German Experience With Transapical Implantation of a Second-Generation Transcatheter Heart Valve for the Treatment of Aortic Regurgitation

ObjectivesThis analysis reports on the initial German multicenter experience with the JenaValve (JenaValve Technology GmbH, Munich, Germany) transcatheter heart valve for the treatment of pure aortic regurgitation.BackgroundExperience with transcatheter aortic valve implantation (TAVI) for severe aortic regurgitation is limited due to the risk of insufficient anchoring of the valve stent within the noncalcified aortic annulus.MethodsTransapical TAVI with a JenaValve for the treatment of severe aortic regurgitation was performed in 31 patients (age 73.8 ± 9.1 years) in 9 German centers. All patients were considered high risk for surgery (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation] 23.6 ± 14.5%) according to a local heart team consensus. Procedural results and clinical outcomes up to 6 months were analyzed.ResultsImplantation was successful in 30 of 31 cases (aortic annulus diameter 24.7 ± 1.5 mm); transcatheter heart valve dislodgement necessitated valve-in-valve implantation in 1 patient. Post-procedural aortic regurgitation was none/trace in 28 of 31 and mild in 3 of 31 patients. During follow-up, 2 patients underwent valvular reinterventions (surgical aortic valve replacement for endocarditis, valve-in-valve implantation for increasing paravalvular regurgitation). All-cause mortality was 12.9% and 19.3% at 30 days and 6 months, respectively. In the remaining patients, a significant improvement in New York Heart Association class was observed and persisted up to 6 months after TAVI.ConclusionsAortic regurgitation remains a challenging pathology for TAVI. After initial demonstration of feasibility, this multicenter study revealed the JenaValve transcatheter heart valve as a reasonable option in this subset of patients. However, a significant early noncardiac mortality related to the high-risk population emphasizes the need for careful patient selection.     

Use of a Repositionable and Fully Retrievable Aortic Valve in Routine Clinical Practice: The RESPOND Study and RESPOND Extension Cohort

Objectives

The authors sought to evaluate 1-year clinical outcomes with the Lotus valve (Boston Scientific, Marlborough, Massachusetts) in a large international, multicenter prospective registry including patients eligible for transcatheter aortic valve replacement (TAVR) based on heart team consensus.

Prior Balloon Valvuloplasty Versus Direct Transcatheter Aortic Valve Replacement: Results From the DIRECTAVI Trial

ObjectivesThe aim of this study was to evaluate device success of transcatheter aortic valve replacement (TAVR) using new-generation balloon-expandable prostheses with or without balloon aortic valvuloplasty (BAV).BackgroundRandomized studies are lacking comparing TAVR without BAV against the conventional technique of TAVR with BAV.MethodsDIRECTAVI (Direct Transcatheter Aortic Valve Implantation) was an open-label noninferiority study that randomized patients undergoing TAVR using the Edwards SAPIEN 3 valve with or without prior balloon valvuloplasty. The primary endpoint was the device success rate according to Valve Academic Research Consortium-2 criteria, which was evaluated using a 7% noninferiority margin. The secondary endpoint included procedural and 30-day adverse events.ResultsDevice success was recorded for 184 of 236 included patients (78.0%). The rate of device success in the direct implantation group (n = 97 [80.2%]) was noninferior to that in the BAV group (n = 87 [75.7%]) (mean difference 4.5%; 95% confidence interval: −4.4% to 13.4%; p = 0.02 for noninferiority). No severe prosthesis-patient mismatch or severe aortic regurgitation occurred in any group. In the direct implantation group, 7 patients (5.8%) required BAV to cross the valve. Adverse events were related mainly to pacemaker implantation (20.9% in the BAV group vs. 19.0% in the direct implantation group; p = 0.70). No significant difference was found between the 2 strategies in duration of procedure, contrast volume, radiation exposure, or rate of post-dilatation.ConclusionsDirect TAVR without prior BAV was noninferior to the conventional strategy using BAV with new-generation balloon-expandable valves, but without procedural simplification. BAV was needed to cross the valve in a few patients, suggesting a need for upstream selection on the basis of patient anatomy. (TAVI Without Balloon Predilatation [of the Aortic Valve] SAPIEN 3 [DIRECTAVI]; NCT02729519)