Valve-in-Valve Transcatheter Mitral Valve Replacement: A Large First-in-Human 13-Year Experience.

BACKGROUND: Favourable early outcomes have been reported following valve-in-valve transcatheter mitral valve replacement (TMVR). However, reports of long-term outcomes are lacking. We aimed to evaluate early and late outcomes in a large first-in-human valve-in-valve TMVR 13-year experience. METHODS: All patients undergoing valve-in-valve TMVR in our centre from 2008 to 2021 were included. Clinical and echocardiographic outcomes, defined according to the Mitral Valve Academic Research Consortium, were reported. RESULTS: A total of 119 patients were analysed: mean age 76.8 ± 10.2 years, mean Society of Thoracic Surgeons score 10.7 ± 6.8%, 55.4% female, 63.9% transapical access. Thirty-day mortality was 2.5% for the total population and 0.0% after transseptal TMVR. Maximum follow-up was 13.1 years. During a median follow-up of 3.4 years (interquartile range 1.8-5.3 years), 55 patients (46.2%) died, mainly from noncardiovascular causes. Valve hemodynamics were acceptable at 5 years, with 2.5% structural dysfunction. Patients treated from 2016 on (n = 68; 57.1%), following the advent of routine use of the Sapien 3 valve, CT screening, and transseptal access, were compared with those treated before 2016 (n = 51; 42.9%). Patients from 2016 on had a higher technical success rate (100.0% vs 94.1%; P = 0.04), shorter hospitalisation (P < 0.001), trending lower 30-day mortality (1.5% vs 3.9%; P = 0.4) and better 5-year survival (74.7% vs 41.1%; P = 0.03). CONCLUSIONS: Valve-in-valve TMVR can be performed with little morbidity and low mortality. Mid- to long-term survival remains limited owing to advanced age and comorbidities. Structural bioprosthetic valve dysfunction was rare and redo TMVR feasible in selected patients. Outcomes continue to improve, but the role for valve-in-valve TMVR in lower surgical risk patients remains unclear.

Timing of bioprosthetic valve fracture in transcatheter valve-in-valve intervention: impact on valve durability and leaflet integrity.

BACKGROUND: Bioprosthetic valve fracture (BVF) can be used to improve transcatheter heart valve (THV) haemodynamics following a valve-in-valve (ViV) intervention. However, whether BVF should be performed before or after THV deployment and the implications on durability are unknown.  Aims: We sought to assess the impact of BVF timing on long-term THV durability. METHODS: The impact of BVF timing was assessed using small ACURATE neo (ACn) or 23 mm SAPIEN 3 (S3) THV deployed in 21 mm Mitroflow valves compared to no-BVF controls. Valves underwent accelerated wear testing up to 200 million (M) cycles (equivalent to 5 years). At 200M cycles, THV were evaluated by hydrodynamic testing, second-harmonic generation (SHG) microscopy, scanning electron microscopy (SEM) and histology. RESULTS: At 200M cycles, the regurgitant fraction (RF) and effective orifice area (EOA) for the ACn were 8.03±0.30%/1.74±0.01 cm2 (no BVF), 12.48±0.70%/1.97±0.02 cm2 (BVF before ViV) and 9.29±0.38%/2.21±0.0 cm2 (BVF after ViV), respectively. For the S3 these values were 2.63±0.51%/1.26±0.01 cm2, 2.03±0.42%/1.65±0.01 cm2, and 1.62±0.38%/2.22±0.01 cm2, respectively. Further, SHG and SEM revealed a higher degree of superficial leaflet damage when BVF was performed after ViV for the ACn and S3. However, the histological analysis revealed significantly less damage, as determined by matrix density analysis, through the entire leaflet thickness when BVF was performed after ViV with the S3 and a similar but non-significant trend with the ACn.  Conclusions: BVF performed after ViV appears to offer superior long-term EOA without increased RF. Ultrastructure leaflet analysis reveals that the timing of BVF can differentially impact leaflets, with more superficial damage but greater preservation of overall leaflet structure when BVF is performed after ViV.

Hybrid Approach Using the Cusp-Overlap Technique for Transcatheter Aortic Valve Replacement With a Balloon-Expandable Valve.

BACKGROUND: The cusp-overlap (CO) technique has recently been advocated and is being increasingly adopted for self-expandable transcatheter heart valve (THV) implantation. OBJECTIVES: The aim of this study was to evaluate the feasibility, implantation depth, and outcomes of the CO technique for the balloon-expandable SAPIEN 3 THV. METHODS: The CO technique was used in consecutive patients undergoing balloon-expandable THV implantation at one center between April 2021 and March 2022. Optimal fluoroscopic angles were determined from preprocedural computed tomography and confirmed on predeployment angiography. The THV radiolucent line was positioned 2 to 4 mm below the noncoronary cusp in the CO view, and positioning was confirmed in the 3-cusp view. Postdeployment THV implantation depth was assessed in both views. One-month outcomes were assessed using Valve Academic Research Consortium 3 criteria. RESULTS: Among 137 patients eligible for the CO technique, the CO view was not used because of unfavorable ergonomics in 27 patients (26.5%) and hemodynamic instability in 8 patients (7.8%). Among 102 patients, the mean age was 81.1 ± 6.6 years, the mean Society of Thoracic Surgeons score was 3.3% ± 2.2%, and 64.7% were men. The mean measured THV implantation depth was 3.0 ± 1.4 mm in the CO view and 2.5 ± 1.4 mm in the 3-cusp view. At 1-month follow-up, 1 patient (1.0%) had died, 1 (1.0%) had had a stroke, and 7 (6.8%) had undergone permanent pacemaker implantation. CONCLUSIONS: The CO technique is feasible and safe and may facilitate more accurate balloon-expandable THV positioning, especially when deep implantation needs to be avoided. Further studies are required to explore potential reduction in atrioventricular conduction block, pacemakers, or paravalvular regurgitation.

Coronary Access Following Redo TAVR: Impact of THV Design, Implant Technique, and Cell Misalignment.

BACKGROUND: The implications and potential challenges of coronary access after redo transcatheter aortic valve replacement (TAVR) are unknown. OBJECTIVES: The authors sought to evaluate the impact of different transcatheter heart valve (THV) designs, neoskirt height, implant technique, and cell misalignment on coronary access after redo TAVR. METHODS: Different THV designs (Sapien 3 [Edwards Lifesciences LLC], Evolut Pro [Medtronic], ACURATE neo [Boston Scientific Corporation], and Portico [Abbott Structural Heart]) and sizes were implanted inside Sapien XT (Edwards Lifesciences LLC) and Evolut R (Medtronic) THVs, which were modeled as the "failed" THVs, at different implant depths. Valve combinations underwent micro-computed tomography to determine the neoskirt height and dimensions of the lowest accessible cell for potential coronary access. This was compared with dimensions of 6-F/7-F/8-F coronary guiding catheters. RESULTS: Redo TAVR combinations resulted in a wide range of neoskirt heights (15.4-31.6 mm) and a variable diameter of the lowest accessible cell (1.9-21.8 mm). An ACURATE neo implanted in a Sapien XT resulted in the largest accessible cells, whereas a Portico implanted in a Sapien XT resulted in the lowest neoskirt heights. The smallest accessible cell was observed in the Evolut Pro-in-Evolut R configuration with higher neoskirt heights. Redo TAVR in a tall frame valve with supra-annular leaflets caused a taller neoskirt height. In Evolut-in-Evolut combinations, misalignment of the cells of the 2 THVs reduced the cell area by 30% to 50% compared with an aligned configuration. CONCLUSIONS: This study demonstrates that different redo TAVR combinations are not equivalent in terms of future coronary access. Redo TAVR using a tall frame valve in a failed tall frame valve and misaligned cells may lead to potentially challenging coronary access.

Impact of Commissural Misalignment on Hydrodynamic Function Following Valve-in-Valve Intervention With the ACURATE neo.

BACKGROUND: Limited evidence is available regarding valve-in-valve (VIV) intervention with the ACURATE neo transcatheter heart valve (THV). Low implantation has demonstrated leaflet interaction between the surgical bioprosthesis and the THV, leading to impaired hydrodynamic performance. It is unknown if commissural alignment (CA) can affect this phenomenon. Novel techniques have now been developed to achieve CA with the ACURATE neo THV. OBJECTIVES: The aim of this study was to assess the impact of commissural misalignment (CMA) on hydrodynamic function following VIV intervention with the ACURATE neo THV using a bench model. METHODS: VIV intervention was performed with the ACURATE neo (a self-expanding THV with supra-annular leaflet position) implanted deep in the surgical bioprosthetic aortic valve (Mitroflow). Hydrodynamic function at CA (0°) and 3 different degrees of CMA (30°, 60°, and 90°) was tested. As per the International Organization for Standardization, a regurgitant fraction <20% is considered optimal. RESULTS: Following VIV, the central THV regurgitant fraction at 0°, 30°, 60°, and 90° of CMA was 8.6% ± 2.0%, 30.3% ± 12.0%, 42.6% ± 11.9%, and 66.7% ± 25.4% (P < 0.0001), respectively. On high-speed video there was no evidence of leaflet interaction at CA, whereas at 30°, 60°, and 90° of CMA there was clear evidence of THV leaflet interaction with those of the surgical valve, leading to impaired leaflet closure and to severe central THV regurgitation. CONCLUSIONS: In VIV using the ACURATE neo THV at deep implantation, increasing degree of CMA was associated with THV leaflet interaction with those of the surgical valve and worsening regurgitant fraction. THV leaflet interaction was prevented when there was CA.

TAVI in 2022: Remaining issues and future direction.

Since the first-in-human procedure in 2002, transcatheter aortic valve implantation (TAVI) has become a well-established therapeutic option for severe aortic stenosis, and is offered increasingly to patients at lower surgical risk, who are typically younger. Increasing lifespan carries concerns that "minor" complications that may have little impact in elderly patients could have a greater long-term impact in younger patients. Issues such as mild paravalvular regurgitation, hypoattenuated leaflet thickening, atrioventricular block with need for permanent pacemaker implantation or future coronary access may have a substantial cumulative undesirable impact. Additionally, as with surgical bioprosthetic valves, transcatheter bioprosthetic valves will eventually degenerate, and may require repeat intervention. Although durability data for transcatheter heart valves (THVs) is encouraging, very late data are lacking. Redo TAVI has been shown to be feasible with acceptable outcomes in patients with failed THVs, but in some patients, anatomical or device considerations may preclude a repeatable procedure because of the risk of coronary obstruction. Various strategies for lifetime management in this lower-risk and younger population have been proposed: surgical aortic valve replacement (SAVR) first, followed by TAVI; TAVI then SAVR; TAVI then TAVI, etc. A tailored approach may be considered according to patient co-morbidities, anatomy and the relative advantages and disadvantages of the two therapies. This review offers an overview of current challenges when considering TAVI in populations at lower risk, and summarizes the different approaches that have been developed to address these concerns.

Late Balloon Valvuloplasty for Transcatheter Heart Valve Dysfunction.

BACKGROUND: Transcatheter heart valve (THV) dysfunction with an elevated gradient or paravalvular leak (PVL) may be documented late after THV implantation. Medical management, paravalvular plugs, redo THV replacement, or surgical valve replacement may be considered. However, late balloon dilatation is rarely utilized because of concerns about safety or lack of efficacy. OBJECTIVES: We aimed to evaluate the safety and efficacy of late dilatation in the management of THV dysfunction. METHODS: All patients who underwent late dilatation for symptomatic THV dysfunction at 2 institutions between 2016 and 2021 were identified. Baseline, procedural characteristics, and clinical and echocardiographic outcomes were documented. THV frame expansion was assessed by multislice computed tomography before and after late dilatation. RESULTS: Late dilatation was performed in 30 patients a median of 4.6 months (IQR: 2.3-11.0 months) after THV implantation in the aortic (n = 25; 83.3%), mitral (n = 2; 6.7%), tricuspid (n = 2; 6.7%) and pulmonary (n = 1; 3.3%) position. THV underexpansion was documented at baseline, and frame expansion substantially improved after late dilatation. The mean transvalvular gradient fell in all patients. For aortic THVs specifically, mean transaortic gradient fell from 25.4 ± 13.9 mm Hg to 10.8 ± 4.1 mm Hg; P < 0.001. PVL was reduced to ≤mild in all 11 patients with a previous >mild PVL. Embolic events, stroke, annular injury, and bioprosthetic leaflet injury were not observed. Symptomatic benefit was durable at 19.6 months (IQR: 14.8-36.1 months) follow-up. CONCLUSIONS: Balloon dilatation late after THV implantation appears feasible and safe in appropriately selected patients and may result in THV frame expansion resulting in improvements in hemodynamic performance and PVL.

Transcatheter Tricuspid Valve Replacement With the EVOQUE System: 1-Year Outcomes of a Multicenter, First-in-Human Experience.

OBJECTIVES: The aim of this study was to report the midterm outcomes at 1 year in the expanded first-in-human experience with the transfemoral EVOQUE system (Edwards Lifesciences) for tricuspid regurgitation (TR). BACKGROUND: Untreated TR is associated with excess mortality and morbidity. The first-in-human experience with the EVOQUE tricuspid valve replacement system reported favorable 30-day outcomes with no mortality in a compassionate use population. METHODS: Twenty-seven patients with severe TR were treated with the EVOQUE system in a compassionate use experience at 7 centers between May 2019 and July 2020. All patients had clinical right-sided heart failure (HF) and were deemed inoperable and unsuitable for transcatheter edge-to-edge repair by the institutional heart teams. The clinical outcomes collected included all-cause mortality, symptom status, TR severity, HF hospitalization, and major adverse cardiovascular events. RESULTS: At baseline, all patients (age: 77 ± 8 years, 89% female) were at high surgical risk (mean Society of Thoracic Surgeons score: 8.6% ± 5.5%), with 89% New York Heart Association functional class III/IV. TR was predominantly functional in etiology (19/27, 70%). At 1 year, mortality was 7% (2/27), 70% of patients were New York Heart Association functional class I/II, and 96% and 87% of patients had a TR grade ≤2+ and ≤1+, respectively. Between 30 days and 1 year, 2 patients experienced HF hospitalizations, and 1 patient required a new pacemaker implantation. CONCLUSIONS: In this early, compassionate use experience, the transfemoral transcatheter EVOQUE tricuspid valve replacement system demonstrated durable efficacy, persistent improvement in symptom status, and low rates of mortality and HF hospitalizations at a 1-year follow-up. Further studies are underway to validate its efficacy.

Transcatheter solutions for transcatheter aortic valve replacement dysfunction: is redo transcatheter aortic valve replacement a durable option?

As transcatheter aortic valve replacement (TAVR) expands into a younger and lower risk cohort of patients, many important clinical questions are raised, including the one of overall valve durability. Bioprosthetic valve dysfunction (BVD) is a complex clinical issue, of which structural valve deterioration (SVD) is a subcategory. Similar to surgical bioprosthesis, transcatheter heart valves (THVs) can fail over the years however, data on long-term THVs durability is lacking, especially in the lower risk cohort. Surgical explant with open aortic surgery or a second THV, described as redo-TAVR, are feasible options when the first THV fails. However long-term data in these patients is even more limited. Important clinical considerations such as the mechanism(s) of THV dysfunction, the type and timing of the second procedure must be carefully considered. There are also inherently important clinical concerns regarding redo-TAVR, such as coronary access and higher post procedure gradients. In the present keynote lecture, we review the diagnosis of THV dysfunction and transcatheter options available when SVD occurs.