In vitro evaluation of implantation depth in valve-in-valve using different transcatheter heart valves

Hemodynamic effect of supra-annular implantation of SAPIEN 3 balloon expandable valve

The hemodynamic impact of the implantation depth for balloon-expandable valves is under-investigated, especially with higher implantation techniques. We assessed the hemodynamic performance of supra-annular SAPIEN 3 valve implantation. This retrospective study involved consecutive patients who underwent transcatheter aortic valve replacement (TAVR) using the SAPIEN 3. The device implantation depth and transcatheter heart valve (THV) leaflet-nadir position were angiographically analyzed, and supra-annular implantation was defined as a higher leaflet-nadir position than the original annular line. The Doppler hemodynamic status was evaluated at patient discharge. Among 184 patients, 120 (65%) underwent supra-annular implantation, and their mean implantation depth was significantly lower than that of intra-annular implantation (1.1 vs. 5.2 mm, p < 0.001). No patients developed valve embolization or coronary occlusion, and none required the TAV-in-TAV procedure. Two (1.6%) patients in the supra-annular implantation group had a mild or greater paravalvular leak. Echocardiography demonstrated that supra-annular implantation had better hemodynamic performance, showing a larger indexed effective orifice area (iEOA) compared with intra-annular implantation (1.09 vs. 0.97 cm2/m2, p < 0.01). There was a weak but negative correlation between the implantation depth and iEOA (r =  - 0.27, p < 0.01). Moderate or severe prosthesis-patient mismatch (PPM) was found in 35.9% of the intra-annular group and 9.2% of supra-annular of the supra-annular group (p < 0.01). In the multivariable analysis, supra-annular implantation was an independent predictor of better THV function (iEOA > 0.85). Supra-annular SAPIEN 3 implantation provides beneficial hemodynamic effects and reduces the PPM risk.

Aortic Valve-in-Valve Procedures: Challenges and Future Directions

Aortic valve-in-valve (ViV) procedures are increasingly performed for the treatment of surgical bioprosthetic valve failure in patients at intermediate to high surgical risk. Although ViV procedures offer indisputable benefits in terms of procedural time, in-hospital length of stay, and avoidance of surgical complications, they also present unique challenges. Growing awareness of the technical difficulties and potential threats associated with ViV procedures mandates careful preprocedural planning. This review article offers an overview of the current state-of-the-art ViV procedures, with focus on patient and device selection, procedural planning, potential complications, and long-term outcomes. Finally, it discusses current research efforts and future directions aimed at improving ViV procedural success and patient outcomes.

Valve-in-Valve Transcatheter Aortic Valve Replacement: From Pre-Procedural Planning to Procedural Scenarios and Possible Complications

Over the last decades, bioprosthetic heart valves (BHV) have been increasingly implanted instead of mechanical valves in patients undergoing surgical aortic valve replacement (SAVR). Structural valve deterioration (SVD) is a common issue at follow-up and can justify the need for a reintervention. In the evolving landscape of interventional cardiology, valve-in-valve transcatheter aortic valve replacement (ViV TAVR) has emerged as a remarkable innovation to address the complex challenges of patients previously treated with SAVR and has rapidly gained prominence as a feasible technique especially in patients at high surgical risk. On the other hand, the expanding indications for TAVR in progressively younger patients with severe aortic stenosis pose the crucial question on the long-term durability of transcatheter heart valves (THVs), as patients might outlive the bioprosthetic valve. In this review, we provide an overview on the role of ViV TAVR for failed surgical and transcatheter BHVs, with a specific focus on current clinical evidence, pre-procedural planning, procedural techniques, and possible complications. The combination of integrated Heart Team discussion with interventional growth curve makes it possible to achieve best ViV TAVR results and avoid complications or put oneself ahead of time from them.

Clinical and Hemodynamic Outcomes of Balloon-Expandable Mitral Valve-in-Valve Positioning and Asymmetric Deployment: The VIVID Registry

BACKGROUND

Mitral valve-in-valve (ViV) is associated with suboptimal hemodynamics and rare left ventricular outflow tract (LVOT) obstruction.

OBJECTIVES

This study aimed to determine whether device position and asymmetry are associated with these outcomes.

METHODS

Patients undergoing SAPIEN 3 (Edwards Lifesciences) mitral ViV included in the VIVID (Valve-in-Valve International Data) Registry were studied. Clinical endpoints are reported according to Mitral Valve Academic Research Consortium definitions. Residual mitral valve stenosis was defined as mean gradient ≥5 mm Hg. Depth of implantation (percentage of transcatheter heart valve [THV] atrial to the bioprosthesis ring) and asymmetry (ratio of 2 measures of THV height) were evaluated.

RESULTS

A total of 222 patients meeting the criteria for optimal core lab evaluation were studied (age 74 ± 11.6 years; 61.9% female; STS score = 8.3 ± 7.1). Mean asymmetry was 6.2% ± 4.4%. Mean depth of implantation was 19.0% ± 10.3% atrial. Residual stenosis was common (50%; mean gradient 5.0 ± 2.6 mm Hg). LVOT obstruction occurred in 7 cases (3.2%). Implantation depth was not a predictor of residual stenosis (OR: 1.19 [95% CI: 0.92-1.55]; P = 0.184), but more atrial implantation was protective against LVOT obstruction (0.7% vs 7.1%; P = 0.009; per 10% atrial, OR: 0.48 [95% CI: 0.24-0.98]; P = 0.044). Asymmetry was found to be an independent predictor of residual stenosis (per 10% increase, OR: 2.30 [95% CI: 1.10-4.82]; P = 0.027).

CONCLUSIONS

Valve stenosis is common after mitral ViV. Asymmetry was associated with residual stenosis. Depth of implantation on its own was not associated with residual stenosis but was associated with LVOT obstruction. Technical considerations to reduce postdeployment THV asymmetry should be considered.

Coronary Perfusion After Valve-in-Valve Transcatheter Aortic Valve Implantation in Small Aortic Root: In Vitro Experimental Assessment

Coronary flow obstruction following transcatheter aortic valve-in-valve implantation (VIV-TAVI) is associated with a high mortality risk. The aim of this work was to quantify the coronary perfusion after VIV-TAVI in a high-risk aortic root anatomy. 3D printed models of small aortic root were used to simulate the implantation of a TAVI prosthesis (Portico 23) into surgical prostheses (Trifecta 19 and 21). The aortic root models were tested in a pulsatile in vitro bench setup with a coronary perfusion simulator. The tests were performed at baseline and post-VIV-TAVI procedure in aligned and misaligned commissural configurations under simulated hemodynamic rest and exercise conditions. The experimental design provided highly controllable and repeatable flow and pressure conditions. The left and right coronary mean flow did not differ significantly at pre- and post-VIV-TAVI procedure in any tested configurations. The commissural misalignment did not induce any significant alterations to the coronary flow. High-risk aortic root anatomy did not trigger coronary ostia obstruction or coronary flow alteration after transcatheter aortic valve implantation in a surgical bioprosthesis as shown from in-vitro flow loop tests.

Deformation of Transcatheter Heart Valve Following Valve-in-Valve Transcatheter Aortic Valve Replacement: Implications for Hemodynamics

BACKGROUND

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) may be associated with adverse hemodynamics, which might affect clinical outcomes.

OBJECTIVES

This study sought to evaluate the extent and predictors of transcatheter heart valve (THV) deformity in ViV TAVR and the relation to postprocedural hemodynamics.

METHODS

We examined 53 patients who underwent ViV TAVR in surgical heart valves with self-expanding Evolut prostheses. THV deformation was examined using cardiac computed tomography prospectively performed 30 days after ViV TAVR, and correlated with 30-day echocardiographic hemodynamic data.

RESULTS

Near complete expansion of the functional portion of the implanted ViV prostheses (ie, >90%) was observed in 16 (30.2%) patients. Factors related to greater expansion of the functional portion and consequently larger neosinus volume were absence of polymer surgical frame, higher implantation and use of balloon aortic valvuloplasty or bioprosthetic valve fracture during the procedure (all P < 0.05). Underexpansion of the functional portion, but not the valve inflow frame, was closely associated with mean gradient and effective orifice area at 30 days on echocardiography, with and without adjustment for the sizes of the THV and surgical heart valve.

CONCLUSIONS

Underexpansion of the functional portion of THV prostheses is common during ViV TAVR, occurs more frequently with deep implantation and the presence of a polymer surgical stent frame, and is associated with worse postprocedural hemodynamics. Procedural techniques, such as higher implantation and balloon postdilatation, may be used to help overcome problems with THV underexpansion and improve clinical outcomes.

Hemodynamic follow-up after valve-in-valve TAVR for failed aortic bioprosthesis

BACKGROUND

"valve-in-valve" TAVR (VIV-TAVR) is established and provides good initial clinical and hemodynamic outcomes. Lacking long-term durability data baffle the expand to lower risk patients. For those purposes, the present study adds a hemodynamic 3-years follow-up.

METHODS

A total of 77 patients underwent VIV-TAVR for failing aortic bioprosthesis during a 7-years period. Predominant mode of failure was stenosis in 87.0%. Patients had a mean age of 79.4 ± 5.8 years and a logistic EuroSCORE of 30.8 ± 15.7%. The Society of Thoracic Surgeons-PROM averaged 5.79 ± 2.63%. Clinical results and hemodynamic outcomes are reported for 30-days, 1-, 2-, and 3-years. Completeness of follow-up was 100% with 44 patients at risk after 3-years. Follow-up ranged up to 7.1 years.

RESULTS

Majority of the surgical valves were stented (94.8%) with a mean labeled size of 23.1 ± 2.3 mm and true-ID of 20.4 ± 2.6 mm. A true-ID ≤21 mm had 58.4% of the patients. Self-expanding valves were implanted in 68.8% (mean labeled size 24.1 ± 1.8 mm) and balloon-expanded in 31.2% (mean size 24.1 ± 1.8 mm). No patient died intraoperatively. Hospital mortality was 1.3% and three-years survival 57.1%. All patients experienced an initial significant dPmean-reduction to 16.8 ± 7.1 mmHg. After 3-years mean dPmean raised to 26.0 ± 12.2 mmHg. This observation was independent from true-ID or type of transcatheter aortic valve replacement (TAVR)-prosthesis. Patients with a true-ID ≤21 mm had a higher initial (18.3 ± 5.3 vs. 14.9 ± 7.1 mmHg; p = .005) and dPmean after 1-year (29.2 ± 8.2 vs. 13.0 ± 6.7 mmHg; p = .004). There were no significant differences in survival.

CONCLUSIONS

VIV-TAVR is safe and effective in the early period. In surgical valves with a true-ID ≤21 mm inferior hemodynamic and survival outcomes must be expected. Nonetheless, also patients with larger true-IDs showed steadily increasing transvalvular gradients. This raises concern about durability.

Balloon Fracturing Valve-in-Valve: How to Do It and a Case Report of TAVR in a Rapid Deployment Prosthesis

Transcatheter aortic valve replacement (TAVR) to treat degeneration of bioprosthetic heart valves (BHVs), called as valve-in-valve (ViV), is becoming a key feature since the number of BHVs requiring intervention is increasing and many patients are at high risk for a redo cardiac surgery. However, a TAVR inside a small previous cardiac valve may lead to prosthesis-patient mismatch (PPM) and not be as effective as we hoped for. An effective option to decrease the chance of PPM is to fracture the previous heart valve implanted using a high-pressure balloon. By performing a valve fracture, the inner valve ring of small BHVs can be opened up by a single fracture line, allowing subsequent implantation of a properly sized transcatheter heart valve, without increasing substantially the procedure risk. In this article, we provide a step-by-step procedure on how to safely and properly fracture a BHV and report a case of a TAVR in a degenerated rapid deployment valve.

First transfemoral TAV-in-TAV implantation of an ACURATE neo2 into a degenerated Lotus prosthesis

We report the first transcatheter aortic valve (TAV)-in-TAV implantation of an ACURATE neo2 into a degenerated Lotus prosthesis. Despite the good final result in this case, TAV-in-TAV of the ACURATE neo2 into a Lotus prosthesis may not be the first choice, as potential pitfalls must be taken into account.

Bioprosthetic valve fracture: a practical guide

Valve-in-valve transcatheter aortic valve replacement (VIV TAVR) is currently indicated for the treatment of failed surgical tissue valves in patients determined to be at high surgical risk for re-operative surgical valve replacement. VIV TAVR, however, often results in suboptimal expansion of the transcatheter heart valve (THV) and can result in patient-prosthesis mismatch (PPM), particularly in small surgical valves. Bioprosthetic valve fracture (BVF) and bioprosthetic valve remodeling (BVR) can facilitate VIV TAVR by optimally expanding the THV and reducing the residual transvalvular gradient by utilizing a high-pressure inflation with a non-compliant balloon to either fracture or stretch the surgical valve ring, respectively. This article, along with the supplemental video, will provide patient selection, procedural planning and technical insights for performing BVF and BVR.

Transcatheter valve-in-valve implantation in degenerated surgical aortic and mitral bioprosthesis: Current state and future perspectives

The use of bioprosthetic valves for treating patients with severe valve disease has increased over the last 2 decades, and, as a consequence, a growing number of patients with failing surgical bioprosthesis is expected in the near future. In this setting, valve-in-valve (ViV) transcatheter aortic/mitral valve replacement (TAVR and TMVR) has emerged as an alternative to redo surgery. Despite the increasing experience in ViV procedures, the development of these techniques faces several specific challenges, mainly related to the unique anatomical and physiological characteristics presented in ViV-TAVR/TMVR. Subsequently, various approaches have been proposed to overcome ViV-related complications and pitfalls. A growing body of evidence is currently available concerning early- and long-term clinical outcomes of patients undergoing ViV-TAVR/TMVR. These data should be comprehensively evaluated by the Heart Team in the decision-making process involving patients with failing surgical bioprostheses. In this review, we aimed to delineate the technical challenges and risks associated with ViV-TAVR and ViV-TMVR, provide an updated overview of the main clinical results, and summarize the future perspectives of this evolving field.

Permanent Pacemaker Implantation Following Valve-in-Valve Transcatheter Aortic Valve Replacement: VIVID Registry

BACKGROUND

Permanent pacemaker implantation (PPI) remains one of the main drawbacks of transcatheter aortic valve replacement (TAVR), but scarce data exist on PPI after valve-in-valve (ViV) TAVR, particularly with the use of newer-generation transcatheter heart valves (THVs).

OBJECTIVES

The goal of this study was to determine the incidence, factors associated with, and clinical impact of PPI in a large series of ViV-TAVR procedures.

METHODS

Data were obtained from the multicenter VIVID Registry and included the main baseline and procedural characteristics, in-hospital and late (median follow-up: 13 months [interquartile range: 3 to 41 months]) outcomes analyzed according to the need of periprocedural PPI. All THVs except CoreValve, Cribier-Edwards, Sapien, and Sapien XT were considered to be new-generation THVs.

RESULTS

A total of 1,987 patients without prior PPI undergoing ViV-TAVR from 2007 to 2020 were included. Of these, 128 patients (6.4%) had PPI after TAVR, with a significant decrease in the incidence of PPI with the use of new-generation THVs (4.7% vs. 7.4%; p = 0.017), mainly related to a reduced PPI rate with the Evolut R/Pro versus CoreValve (3.7% vs. 9.0%; p = 0.002). There were no significant differences in PPI rates between newer-generation balloon- and self-expanding THVs (6.1% vs. 3.9%; p = 0.18). In the multivariable analysis, older age (odds ratio [OR]: 1.05 for each increase of 1 year; 95% confidence interval [CI]: 1.02 to 1.07; p = 0.001), larger THV size (OR: 1.10; 95% CI: 1.01 to 1.20; p = 0.02), and previous right bundle branch block (OR: 2.04; 95% CI: 1.00 to 4.17; p = 0.05) were associated with an increased risk of PPI. There were no differences in 30-day mortality between the PPI (4.7%) and no-PPI (2.7%) groups (p = 0.19), but PPI patients exhibited a trend toward higher mortality risk at follow-up (hazard ratio: 1.39; 95% CI: 1.02 to 1.91; p = 0.04; p = 0.08 after adjusting for age differences between groups).

CONCLUSIONS

In a contemporary large series of ViV-TAVR patients, the rate of periprocedural PPI was relatively low, and its incidence decreased with the use of new-generation THV systems. PPI following ViV-TAVR was associated with a trend toward increased mortality at follow-up.

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.

Long-term outcomes after transcatheter aortic valve implantation in failed bioprosthetic valves

Aims

Due to bioprosthetic valve degeneration, aortic valve-in-valve (ViV) procedures are increasingly performed. There are no data on long-term outcomes after aortic ViV. Our aim was to perform a large-scale assessment of long-term survival and reintervention after aortic ViV.

Methods and results

A total of 1006 aortic ViV procedures performed more than 5 years ago [mean age 77.7 ± 9.7 years; 58.8% male; median STS-PROM score 7.3% (4.2–12.0)] were included in the analysis. Patients were treated with Medtronic self-expandable valves (CoreValve/Evolut, Medtronic Inc., Minneapolis, MN, USA) (n = 523, 52.0%), Edwards balloon-expandable valves (EBEV, SAPIEN/SAPIEN XT/SAPIEN 3, Edwards Lifesciences, Irvine, CA, USA) (n = 435, 43.2%), and other devices (n = 48, 4.8%). Survival was lower at 8 years in patients with small-failed bioprostheses [internal diameter (ID) ≤ 20 mm] compared with those with large-failed bioprostheses (ID &gt; 20 mm) (33.2% vs. 40.5%, P = 0.01). Independent correlates for mortality included smaller-failed bioprosthetic valves [hazard ratio (HR) 1.07 (95% confidence interval (CI) 1.02–1.13)], age [HR 1.21 (95% CI 1.01–1.45)], and non-transfemoral access [HR 1.43 (95% CI 1.11–1.84)]. There were 40 reinterventions after ViV. Independent correlates for all-cause reintervention included pre-existing severe prosthesis–patient mismatch [subhazard ratio (SHR) 4.34 (95% CI 1.31–14.39)], device malposition [SHR 3.75 (95% CI 1.36–10.35)], EBEV [SHR 3.34 (95% CI 1.26–8.85)], and age [SHR 0.59 (95% CI 0.44–0.78)].

Conclusions

The size of the original failed valve may influence long-term mortality, and the type of the transcatheter valve may influence the need for reintervention after aortic ViV.

Hemodynamic and Imaging Assessment of Transcatheter Aortic Valve Replacement with the Inovare® Proseal using Multislice Computed Tomography

Objective

To evaluate the hemodynamic performance (i.e., gradients and paravalvular leakage [PVL]) of the new and experimental Braile Inovare^® Proseal. Additionally, we aimed to assess pre and postoperatively the aortic annulus and the transcatheter prosthesis using multislice computed tomography (MSCT).

Methods

Patients were selected by a multidisciplinary heart team and referred for transcatheter aortic valve replacement (TAVR). MSCT was performed before and after surgery. Measurements of the aortic valve and prosthesis were conducted and correlated with the valve gradient and residual PVL.

Results

Twenty-one patients were selected for the protocol. Patients had a mean age of 79 years and 38% of them were of female sex. The mean EuroSCORE II value was 12.5%±10.8. Mean gradient was reduced from 45.8±11.04 mmHg to 5.59±2.61 mmHg and there were no instances of PVL worse than mild. There were no cases of coronary obstruction or procedural death. Circularity was present in all prostheses evaluated. Circularity indexes for the prostheses were: inflow 0.05±0.03, middle third 0.04±0.02, and outflow 0.04±0.02 (P=0.08). The mean distance between the prosthesis and the left and right coronary ostia were 14.8 mm±3.3 and 17.3 mm±3, respectively. Oversizing was appropriate with a mean of 22.14%±6%.

Conclusion

Braile Inovare^® Proseal transcatheter device has demonstrated low gradients with low rates of PVL. Oversizing by annular measurements was adequate. MSCT was adequate to evaluate device sizing and has demonstrated preserved expansibility and circularity in the evaluated cases.

Impact of implant depth on hydrodynamic function of the ALLEGRA bioprosthesis in valve-in-valve interventions

AIMS

We aimed to assess the impact of implant depth on hydrodynamic function following valve-in-valve (VIV) intervention using the ALLEGRA transcatheter heart valve (THV) in three different surgical valve designs.

METHODS AND RESULTS

Multiple implantation depths (+2 mm, -2 mm and -6 mm) were tested using a 23 mm ALLEGRA THV for VIV intervention in 19 mm, 21 mm, 23 mm, and 25 mm Epic, Mitroflow and Magna Ease bioprosthetic valves. Multimodality imaging and hydrodynamic evaluation was performed at each implantation depth. The 23 mm ALLEGRA valve had gradients <20 mmHg in the Mitroflow and Epic valves sized ≥21 mm, and in all sizes of the Magna Ease valve. Gradients did not increase significantly at lower implantation depths. The 19 mm Epic (+2 mm: 20.1±0.6 mmHg, -2 mm: 18.8±0.5 mmHg, -6 mm: 22.8±0.3 mmHg) and 19 mm Mitroflow (+2 mm: 24.1±0.2 mmHg, -2 mm: 31.5±0.3 mmHg, -6 mm: 25.6±0.2 mmHg) valves had elevated mean gradients. In larger sized surgical valves (≥23 mm) the regurgitant fraction was higher at low implantation depths. Pinwheeling was significantly worse in the smaller sized (≤21 mm) surgical valves and also at low (<-2 mm) implantation depth.

CONCLUSIONS

The 23 mm ALLEGRA valve had favourable (<20 mmHg) gradients in all surgical valves sized ≥21 mm, even when the THV was implanted low. In 19 mm sized Mitroflow and Epic valves, gradients were elevated (>20 mmHg). While there was no major difference in mean transvalvular gradients, leaflet pinwheeling was worse at lower implantation depths.

Imaging for Predicting and Assessing Prosthesis-Patient Mismatch After Aortic Valve Replacement

Prosthesis-patient mismatch (PPM) occurs when the effective orifice area (EOA) of the prosthetic valve is too small in relation to a patient's body size, thus resulting in high residual postoperative pressure gradients across the prosthesis. Severe PPM occurs in 2% to 20% of patients undergoing surgical aortic valve replacement (AVR) and is associated with 1.5- to 2.0-fold increase in the risk of mortality and heart failure rehospitalization. The purpose of this article is to present an overview of the role of multimodality imaging in the assessment, prediction, prevention, and management of PPM following AVR. The risk of PPM can be anticipated at the time of AVR by calculating the predicted indexed from the normal reference value of EOA of the selected prosthesis and patient's body surface area. The strategies to prevent PPM at the time of surgical AVR include: 1) implanting a newer generation of prosthetic valve with better hemodynamic; 2) enlarging the aortic root or annulus to accommodate a larger prosthetic valve; or 3) performing TAVR rather than surgical AVR. The identification and quantitation of PPM as well as its distinction versus prosthetic valve stenosis is primarily based on transthoracic echocardiography, but important information may be obtained from other imaging modalities such as transesophageal echocardiography and multidetector computed tomography. PPM is characterized by high transprosthetic velocity and gradients, normal EOA, small indexed EOA, and normal leaflet morphology and mobility. Transesophageal echocardiography and multidetector computed tomography are particularly helpful to assess prosthetic valve leaflet morphology and mobility, which is a cornerstone of the differential diagnosis between PPM and pathologic valve obstruction. Severe symptomatic PPM following AVR with a bioprosthetic valve may be treated by redo surgery or the transcatheter valve-in-valve procedure with fracturing of the surgical valve stent.

Valve-in-Valve TAVR: State-of-the-Art Review

An increasing number of surgically implanted bioprostheses will require re-intervention for structural valve deterioration. Valve-in-valve transcatheter aortic valve replacement (ViV TAVR) has become an alternative to reoperative surgery, currently approved for high-risk and inoperable patients. Challenges to the technique include higher rates of prosthesis–patient mismatch and coronary obstruction, compared to native valve TAVR. Herein, we review results of ViV TAVR and novel techniques to overcome the aforementioned challenges.

Structural valve deterioration does not alter tissue valves' radiopaque landmarks: Implications for valve-in-valve therapy

BACKGROUND

Valve-in-valve is established as a safe and efficient alternative to redo surgery in the treatment of structural valve deterioration (SVD). In vitro models rely on the radiopaque landmarks of undeteriorated tissue valves to establish the optimal implantation level of the transcatheter heart valves inside the deteriorated valves. In computed assisted procedures, the radiopaque landmarks of the deteriorated valves may be used to guide valve implantation through image fusion. The purpose of this study is to determine whether SVD alters the radiopaque landmarks of stented tissue valves.

METHODS

Our approach was based on the computation of relevant anatomical measurements from CT images. Radiopaque landmarks of degenerated bioprostheses and the corresponding undeteriorated valves were extracted to create surface meshes and cloud points using grey-level thresholding. 3D registration using an iterative closest point algorithm was used to align the corresponding cloud points, while the modified Hausdorff Distance was applied to determine the differences between them.

RESULTS

The proposed evaluation was performed on 19 degenerated tissue valves. 15 valves were scanned from patients evaluated for valve-in-valve procedures, and 4 bioprostheses were scanned after surgical extraction during redo aortic valve replacement. All the degenerated valves were compared to the corresponding undeteriorated models. Overall, the mean difference between degenerated and undeteriorated valves was 0.33 ± 0.12 mm. The maximum observed registration error was 0.66 mm.

CONCLUSIONS

Our study demonstrates no significant difference between the radiopaque landmarks of deteriorated and undeteriorated bioprostheses after the occurrence of SVD. Our findings suggest therefore that SVD does not alter radiopaque landmarks of stented tissue valves. These results validate in-vitro studies of optimal transcatheter heart valves implantation inside deteriorated tissue valves based on their radiopaque landmarks, and allow the use of non-deteriorated valves' imaging features in computer assisted valve-in-valve procedures.

Transcatheter aortic valve-in-valve implantation for failed surgical bioprosthetic valves. A minimalist approach without contrast aortography or echocardiographic guidance

OBJECTIVES

To demonstrate safety, feasibility and short-term clinical outcomes after transcatheter aortic valve-in-valve (ViV) implantation under local anesthesia without contrast aortography or echocardiographic guidance.

BACKGROUND

Transcatheter ViV implantation is an emerging treatment modality for patients with degenerative surgical bioprostheses. Given the radiopaque properties of the surgical aortic valve (SAV) frame, ViV procedures can often be performed with fluoroscopic guidance alone.

METHODS

ViV implantation was performed in 37 patients with SAV failure under local anesthesia without contrast aortography. Clinical and echocardiographic data were obtained at baseline, discharge, and 30 days.

RESULTS

Mean age was 74 ± 10 years and STS predicted risk of mortality was 5.6 ± 2.4%. Mean transaortic gradient decreased from 39.4 ± 15.5 mmHg to 13 ± 6.3 mmHg at discharge (p < .001), and 20 ± 7.5 mmHg at 30 days (p < .001 compared to baseline), aortic valve area increased from 0.9 ± 0.3 cm² to 1.2 ± 0.4 cm² at 30 days (p = .007). No patient had more than mild aortic regurgitation. Hospital discharge occurred at a median of 2.6 ± 4.4 days. At 30-day follow-up there were no deaths, myocardial infarctions, strokes, repeat hospital admissions for heart failure, or renal failure. One patient (2.7%) required a new pacemaker. 93% of the patients were in New York Heart Association functional class I or II.

CONCLUSIONS

Transcatheter aortic ViV implantation for selected patients with degenerative surgical bioprostheses under local anesthesia without aortography or echocardiographic guidance is feasible and safe.

Transcatheter aortic valve replacement in failed surgical valves

Aortic valve-in-valve is a less invasive alternative to surgical redo in the treatment of failed bioprosthetic valves. While only inoperable patients underwent the procedure before, operators currently offer it to those at lower risk and worldwide experience is in the thousands. Early mortality has diminished in recent analyses and improvements in symptoms and quality of life have been documented. Main considerations with aortic valve-in-valve include elevated postprocedural gradients, coronary obstruction and leaflet thrombosis. Risk factors for each of these adverse events have been described at length. Aortic valve-in-valve offers a safe and effective option in the management of failed bioprosthetic valves.

Haemodynamic outcomes following aortic valve-in-valve procedure

Background and objectives

Transcatheter aortic valve-in-valve implantation (ViV) has emerged as a valuable technique to treat failed surgical bioprostheses (BPs) in patients with high risk for redo surgical aortic valve replacement (SAVR). Small BP size (≤21 mm), stenotic pattern of degeneration and pre-existing prosthesis–patient mismatch (PPM) have been associated with worse clinical outcomes after ViV. However, no study has evaluated the actual haemodynamic benefit associated with ViV. This study aims to compare haemodynamic status observed at post-ViV, pre-ViV and early after initial SAVR and to determine the factors associated with worse haemodynamic outcomes following ViV, including the rates of high residual gradient and ‘haemodynamic futility’.

Methods

Early post-SAVR, pre-ViV and post-ViV echocardiographic data of 79 consecutive patients who underwent aortic ViV at our institution were retrospectively analysed. The primary study endpoint was suboptimal valve haemodynamics (SVH) following ViV defined by the Valve Academic Research Consortium 2 as the presence of high residual aortic mean gradient (≥20 mm Hg) and/or at least moderate aortic regurgitation (AR). Haemodynamic futility of ViV was defined as <10 mm Hg decrease in mean aortic gradient and no improvement in AR compared with pre-ViV.

Results

SVH was found in 61% of patients (57% high residual gradient, 4% moderate AR) after ViV versus 24% early after SAVR. Pre-existing PPM and BP mode of failure by stenosis were independently associated with the primary endpoint (OR: 2.87; 95% CI 1.08 to 7.65; p=0.035 and OR: 3.02; 95% CI 1.08 to 8.42; p=0.035, respectively) and with the presence of high residual gradient (OR: 4.38; 95% CI 1.55 to 12.37; p=0.005 and OR: 5.37; 95% CI 1.77 to 16.30; p=0.003, respectively) following ViV. Criteria of ViV haemodynamic futility were met in 7.6% overall and more frequently in patients with pre-existing PPM and stenotic BP (18.5%) compared with other patients (2.0%). ViV restored haemodynamic function to early post-SAVR level in only 34% of patients.

Conclusion

Although ViV was associated with significant haemodynamic improvement compared with pre-ViV in >90% of patients, more than half harboured SVH outcome. Furthermore, only one-third of patients had a restoration of valve haemodynamic function to the early post-SAVR level. Pre-existing PPM and stenosis pattern of BP degeneration were the main factors associated with SVH and haemodynamic futility following ViV. These findings provide strong support for the prevention of PPM at the time of initial SAVR and careful preprocedural patient screening.

Implantation Depth and Rotational Orientation Effect on Valve-in-Valve Hemodynamics and Sinus Flow

BACKGROUND

This study evaluated the effect of transcatheter aortic valve implantation depth and rotation on pressure gradient (PG), leakage fractions (LF), leaflet shear stress, and sinus washout in an effort to understand factors that may dictate optimal positioning for valve-in-valve (ViV) procedures. Sinus flow stasis is often associated with prosthetic leaflet thrombosis. Although recent ViV in vitro studies highlighted potential benefits of transcatheter aortic valve supraannular implantation to minimize PGs, the relationship between transcatheter aortic valve depth and other determinates of valve function remains unknown. Among these, LFs, shear stress, and poor sinus washout have been associated with poorer valve outcomes.

METHODS

ViV hemodynamic performance was evaluated in vitro vs axial positions -9.8, -6.2, 0, and +6 mm and angular orientations 0, 30, 60, and 90 degrees in a degenerated surgical aortic valve. PGs, LFs, and sinus shear stress and washout were compared. Leaflet high-speed imaging and particle-image velocimetry were performed to elucidate hemodynamic mechanisms.

RESULTS

(1) The PG varies as a function of axial position, with supraannular deployments yielding a maximum benefit of 7.85 mm Hg less than PGs for subannular deployments irrespective of commissural alignment (p < 0.01); (2) in contrast, LF decreased in relationship to subannular deployment; and (3) at peak systole, sinus flow shear stress increased with deployment depth as did sinus washout with and without coronary flow.

CONCLUSIONS

First, supraannular axial deployment is associated with lower PGs irrespective of commissural alignment. Second, subannular deployment is associated with more favorable sinus hemodynamics and less LF. Further in vivo studies are needed to substantiate these observations and facilitate optimal prosthesis positioning during ViV procedures.

Effect of severe bioprosthetic valve tissue ingrowth and inflow calcification on valve-in-valve performance

While in vivo studies clearly demonstrate that supra-annular Valve-in-Valve (ViV) implantation provides the highest probability for optimal post-ViV pressure gradients (PG), there is still no physical insight into explaining anomalies where some supra-annular ViV implantations yield high pressure gradients while some sub-annular implantations yield low pressure gradients. The aim of this study is to explain how severe tissue ingrowth and calcification (TIC) in a surgical aortic valve (SAV) can be one physical mechanism leading to anomalous ViV performance characteristic. The ViV hemodynamic performance was evaluated as a function of axial positioning -9.8, -6.2, 0, and +6 mm in SAVs with and without TIC. Effective orifice area (EOA) and PG were compared. Leaflet high-speed imaging and particle image velocimetry were performed to elucidate flutter and forward jet characteristics. ViV without TIC showed significantly lower PG and greater EOA (p < 0.01). EOA and PG improve with supra-annular deployment (p < 0.01) while for ViV with TIC, EOA and PG worsen as the deployment varies from -9.8 mm to 0 mm (p < 0.01) only to recover at + 6 mm (p < 0.01). Separated jet flow at the TIC site, and consequently induced stronger TAV leaflet fluttering highlight the dynamic compromising nature of TIC on jet width and performance reduction. We conclude that the inflow TIC greatly influence ViV performance due to dynamic effects that results in a real anomalous performance characteristic different than that seen in most ViV in vivo. Further in vivo studies are needed to evaluate ViV outcomes in the presence of severe TIC in SAVs.

Optimising the Haemodynamics of Aortic Valve-in-valve Procedures

Bioprosthetic surgical valves are increasingly implanted during cardiac surgery, instead of mechanical valves. These tissue valves are associated with limited durability and as a result transcatheter valve-in-valve procedures are performed to treat failed bioprostheses. A relatively common adverse event of aortic valve-in-valve procedures is residual stenosis. Larger surgical valve size, supra-annular transcatheter heart valve type, as well as higher transcatheter heart valve implantation depth, have all been shown to reduce the incidence of elevated post-procedural gradients. With greater understanding of technical considerations and surgical planning, valve-in-valve procedures could be more effective and eventually may become the standard of care for our increasingly ageing and comorbid population with failed surgical bioprostheses.

Optimizing hemodynamics of transcatheter aortic valve-in-valve implantation in 19-mm surgical aortic prostheses

OBJECTIVE

To demonstrate the feasibility of achieving good hemodynamic results with valve-in-valve transcatheter aortic valve replacement (ViV TAVR) for degenerated 19 mm surgical bioprosthetic valves.

BACKGROUND

Considerable controversy exists regarding ViV TAVR within 19mm surgical prostheses due to concerns of elevated valve gradients and mortality.

METHODS

Among all patient undergoing ViV TAVR between 7/2016 and 4/2017 for symptomatic severe bioprosthetic aortic stenosis (AS), five had a 19 mm surgical valve in place and were included in this publication. None of the patients had patient-prosthesis mismatch. Aggressive post-dilation was performed in four out of five cases using a special technique we describe below.

RESULTS

In all cases, mean aortic valve (AV) gradients significantly improved post-ViV TAVR, particularly after post-dilation. Interestingly, high pressure post-dilation of the ViV resulted in an increase in the diameter of surgical valve stent frame dimensions in nearly all patients who underwent post-dilation.

CONCLUSIONS

Good hemodynamic outcome is possible with aggressive post-dilation in patients with 19 mm failed surgical bioprostheses. High-risk patients with 19 mm failed surgical prostheses who do not otherwise have viable surgical options should be considered for ViV TAVR.

The Fluid Mechanics of Transcatheter Heart Valve Leaflet Thrombosis in the Neosinus

BACKGROUND

Transcatheter heart valve (THV) thrombosis has been increasingly reported. In these studies, thrombus quantification has been based on a 2-dimensional assessment of a 3-dimensional phenomenon.

METHODS

Postprocedural, 4-dimensional, volume-rendered CT data of patients with CoreValve, Evolut R, and SAPIEN 3 transcatheter aortic valve replacement enrolled in the RESOLVE study (Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Dysfunction With Multimodality Imaging and Its Treatment with Anticoagulation) were included in this analysis. Patients on anticoagulation were excluded. SAPIEN 3 and CoreValve/Evolut R patients with and without hypoattenuated leaflet thickening were included to study differences between groups. Patients were classified as having THV thrombosis if there was any evidence of hypoattenuated leaflet thickening. Anatomic and THV deployment geometries were analyzed, and thrombus volumes were computed through manual 3-dimensional reconstruction. We aimed to identify and evaluate risk factors that contribute to THV thrombosis through the combination of retrospective clinical data analysis and in vitro imaging in the space between the native and THV leaflets (neosinus).

RESULTS

SAPIEN 3 valves with leaflet thrombosis were on average 10% further expanded (by diameter) than those without (95.5±5.2% versus 85.4±3.9%; P<0.001). However, this relationship was not evident with the CoreValve/Evolut R. In CoreValve/Evolut Rs with thrombosis, the thrombus volume increased linearly with implant depth (R²=0.7, P<0.001). This finding was not seen in the SAPIEN 3. The in vitro analysis showed that a supraannular THV deployment resulted in a nearly 7-fold decrease in stagnation zone size (velocities <0.1 m/s) when compared with an intraannular deployment. In addition, the in vitro model indicated that the size of the stagnation zone increased as cardiac output decreased.

CONCLUSIONS

Although transcatheter aortic valve replacement thrombosis is a multifactorial process involving foreign materials, patient-specific blood chemistry, and complex flow patterns, our study indicates that deployed THV geometry may have implications on the occurrence of thrombosis. In addition, a supraannular neosinus may reduce thrombosis risk because of reduced flow stasis. Although additional prospective studies are needed to further develop strategies for minimizing thrombus burden, these results may help identify patients at higher thrombosis risk and aid in the development of next-generation devices with reduced thrombosis risk.

On the Mechanics of Transcatheter Aortic Valve Replacement

Transcatheter aortic valves (TAVs) represent the latest advances in prosthetic heart valve technology. TAVs are truly transformational as they bring the benefit of heart valve replacement to patients that would otherwise not be operated on. Nevertheless, like any new device technology, the high expectations are dampened with growing concerns arising from frequent complications that develop in patients, indicating that the technology is far from being mature. Some of the most common complications that plague current TAV devices include malpositioning, crimp-induced leaflet damage, paravalvular leak, thrombosis, conduction abnormalities and prosthesis-patient mismatch. In this article, we provide an in-depth review of the current state-of-the-art pertaining the mechanics of TAVs while highlighting various studies guiding clinicians, regulatory agencies, and next-generation device designers.

Bioprosthetic Valve Fracture During Valve-in-valve TAVR: Bench to Bedside

Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) has been established as a safe and effective means of treating failed surgical bioprosthetic valves (BPVs) in patients at high risk for complications related to reoperation. Patients who undergo VIV TAVR are at risk of patient-prosthesis mismatch, as the transcatheter heart valve (THV) is implanted within the ring of the existing BPV, limiting full expansion and reducing the maximum achievable effective orifice area of the THV. Importantly, patient-prosthesis mismatch and high residual transvalvular gradients are associated with reduced survival following VIV TAVR. Bioprosthetic valve fracture (BVF) is as a novel technique to address this problem. During BPV, a non-compliant valvuloplasty balloon is positioned within the BPV frame, and a highpressure balloon inflation is performed to fracture the surgical sewing ring of the BPV. This allows for further expansion of the BPV as well as the implanted THV, thus increasing the maximum effective orifice area that can be achieved after VIV TAVR. This review focuses on the current evidence base for BVF to facilitate VIV TAVR, including initial bench testing, procedural technique, clinical experience and future directions.