Transcatheter Valve-in-Valve Implantation for Failed Surgical Bioprosthetic Valves

Standardization and validation of neoLVOT assessment using three-dimensional trans-esophageal echocardiography before trans-catheter mitral valve replacement

BACKGROUND

Trans-catheter mitral valve replacement (TMVR) procedures had emerged as an alternative solution for patients who are at high risk for mitral valve surgery. Although cardiac computed tomography (CT) remains the standard method for procedural planning, there is no full agreement on the best systolic phase for quantitation of the neoLVOT. Furthermore, a new three-dimensional trans-esophageal echocardiography (3DTEE) based software was developed to serve as filter and or an alternative for patients who cannot have CT due to any contraindication.

AIM

To determine the systolic phase of the cardiac cycle that shows the narrowest NeoLVOT area in order to standardize the way of using these software and then to validate the 3DTEE-based software against the CT-based one as a gold standard, in mitral valve annulus (MA) and NeoLVOT assessment.

METHODS

A single center, observational, retrospective study. Initially, a sample of 20 patients (age 62 ± 4 years, 70% men) had CT-based analysis at mid-diastole (80%), early-systole (10%), mid-systole (20%), late-systole (30%-40%), in order to detect the best systolic phase at which the neoLVOT area is the narrowest after TMVR. Then, the end systolic phase was standardized for the analysis of 49 patients (age 57 ± 6 years, 60% men), using both the commercially available CT-based software and the newly available 3DTEE-based software (3mensio Structural Heart, Pie Medical Imaging, The Netherlands). The 3DTEE derived parameters were compared with the gold standard CT-based measurements.

RESULTS

The neoLVOT area was significantly narrower at end-systole (224 ± 62 mm2), compared to early-systole (299 ± 70 mm2) and mid-systole (261 ± 75 mm2), (p = .005). Excellent correlation was found between 3DTEE and CT measurements for MA AP diameter (r = .96), IC diameter (r = .92), MA area (r = .96), MA perimeter (r = .94) and NeoLVOT area (r = .96), (all p-values < .0001). Virtual valve sizing was based on annulus measurement and was identical between CT and 3DTEE. Interobserver and intraobserver agreements were excellent for all the measurements with ICCs > .80.

CONCLUSIONS

End-systole is the phase that shows the narrowest neoLVOT and hence should be the standard phase used during the analysis. The 3DTEE based analysis using this new software is reliable compared to the CT-based analysis and can be serve as an alternative analysis tool in patients who cannot have CT for any clinical contraindication or as a screening test and/or filter for all patients before proceeding to a detailed CT scan.

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.

Impact of different in vitro models on functional performance of the self-expanding transcatheter heart valve

OBJECTIVES

Transcatheter heart valves (THVs) are investigated according to International Organization for Standardization requirements using in vitro heart simulators to evaluate hydrodynamic performance. In contrast to surgical valves, a THV's performance heavily depends on the configuration and shape of the aortic anulus. In International Organization for Standardization regulations, there is no detailed definition for the construction of a compartment in which a THV has to be tested. Therefore, the aim of this in vitro study was to compare different in vitro models for functional testing of THVs.

METHODS

Porcine aortic conduits (23-mm diameter) were implanted in Dacron prostheses and calcified with double-distilled water and calcification buffer at 37°C over 83 million cycles in a Hi-Cycler (durability testing) mimicking nearly 3 patient-years. Hydrodynamic testing of Evolut PRO 26 mm was performed within 3 models (plexiglass, native conduit and calcified conduit; all 23-mm diameter) at a frequency of 64 bpm and different stroke volumes (55-105 ml).

RESULTS

Calcified conduits showed significantly higher mean pressure gradients (MPG) and lower effective orifice areas (EOA) in comparison to native conduits (without THV; P < 0.001). EOA and MPG of Evolut PRO differed depending on the model tested. Calcified conduits resulted in the lowest EOA and highest MPG of the THV compared to plexiglass and the native conduit. Full expansion of the THV was least impaired in the native conduit, while lowest geometric orifice area, lowest minimal internal diameter and highest pin-wheeling index of Evolut PRO were seen in the calcified conduit.

CONCLUSIONS

Full expansion and functional performance of the Evolut PRO THV depends on the configuration of the testing compartment in an in vitro setting.

Towards Longitudinal Monitoring of Leaflet Mobility in Prosthetic Aortic Valves via In-Situ Pressure Sensors: In-Silico Modeling and Analysis

BACKGROUND

Transcatheter aortic valves (TAVs) are susceptible to leaflet thrombosis which may lead to thromboembolic events, and early detection and intervention are believed to be the key to avoiding such adverse outcomes. An embedded sensor system installed on the valve stent, coupled with an appropriate machine learning-based continuous monitoring algorithm can facilitate early detection to predict severity of reduced leaflet motion (RLM) and avoid adverse outcomes.

METHODS

We present a data-driven, in silico, proof-of-concept analysis of a pressure microsensor based system for quantifying RLM in TAVs. We generate a dataset of 21 high-fidelity transvalvular flow simulations with healthy and mildly stenotic TAVs to train a logistic regression model to correlate individual leaflet mobility in each simulation with principal components of corresponding hemodynamic pressure recorded at strategic locations of the TAV stent. A separate test dataset of 7 simulations is also generated for prospective assessment of model performance.

RESULTS

An array of 6 sensors embedded on the TAV stent, with two sensors tracking individual leaflet, successfully correlates leaflet mobility with recorded pressure. The sensors are placed along leaflet centerlines, one in the sinus, and the other at the sino-tubular junction. The regression model is tuned using cross-validation to achieve high accuracy on both training (R² = 0.93) and test (R² = 0.77) sets.

CONCLUSION

Discrete blood pressure recordings on TAV stents can be successfully correlated with individual leaflet mobility. Further development of this technology can enable longitudinal monitoring of TAVs and early detection of valve failure.

Multicenter experience with valve-in-valve transcatheter aortic valve replacement compared with primary, native valve transcatheter aortic valve replacement

BACKGROUND

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) offers an alternative to reoperative surgical aortic valve replacement. The short- and intermediate-term outcomes after ViV TAVR in the real world are not entirely clear.

PATIENTS AND METHODS

A multicenter, retrospective analysis of a consecutive series of 121 ViV TAVR patients and 2200 patients undergoing primary native valve TAVR from 2012 to 2017 at six medical centers. The main outcome measures were in-hospital mortality, 30-day mortality, stroke, myocardial infarction, acute kidney injury, and pacemaker implantation.

RESULTS

ViV patients were more likely male, younger, prior coronary artery bypass graft, "hostile chest," and urgent. 30% of the patients had Society of Thoracic Surgeons risk score <4%, 36.3% were 4%-8% and 33.8% were >8%. In both groups many patients had concomitant coronary artery disease. Median time to prosthetic failure was 9.6 years (interquartile range: 5.5-13.5 years). 82% of failed surgical valves were size 21, 23, or 25 mm. Access was 91% femoral. After ViV, 87% had none or trivial aortic regurgitation. Mean gradients were <20 mmHg in 54.6%, 20-29 mmHg in 30.6%, 30-39 mmHg in 8.3% and ≥40 mmHg in 5.87%. Median length of stay was 4 days. In-hospital mortality was 0%. 30-day mortality was 0% in ViV and 3.7% in native TAVR. There was no difference in in-hospital mortality, postprocedure myocardial infarction, stroke, or acute kidney injury.

CONCLUSION

Compared to native TAVR, ViV TAVR has similar peri-procedural morbidity with relatively high postprocedure mean gradients. A multidisciplinary approach will help ensure patients receive the ideal therapy in the setting of structural bioprosthetic valve degeneration.

Transcatether Aortic Valve Implantation to Treat Degenerated Surgical Bioprosthesis: Focus on the Specific Procedural Challenges

Actually transcatheter aortic valve implantation within failed surgically bioprosthetic valves (VIV-TAVI) is an established procedure in patients at high risk for repeat surgical aortic valve intervention. Although less invasive than surgical reintervention, VIV-TAVI procedure offers potential challenges, such as higher rates of prosthesis-patient mismatch and coronary obstruction. Thus, optimal procedural planning plays an important role to minimize the risk of procedure complications. In this review, we describe the key points of a VIV-TAVI procedure to optimize outcomes and reduce the risk of procedure complications.

Dynamic Echocardiographic Imaging of a Valve-in-Valve Mitral Prosthesis

Dynamic imaging of heart valves and specifically prosthetic valves is a central benefit of echocardiography. Most bioprosthetic heart valves degenerate over a given time and hence require repeat valve replacement which carries a significant risk of morbidity and mortality. Reoperation is the standard of care and may still be required after the first successful surgery due to complications disrupting either mechanical or bioprosthetic valves. Such complications can be delayed or even prevented if optimal prosthesis selection is individualized according to patients’ medical and postimplantation follow-up. We present the case of an 84-year-old woman where an open-heart valve-in-valve approach, implanting a mechanical valve in a failed bioprosthetic valve, produced a unique image on transthoracic echocardiography which needs to be recognized by imagers for appropriate patient diagnosis and management.

Trans-Catheter Valve-in-Valve Implantation for the Treatment of Aortic Bioprosthetic Valve Failure

Aortic valve-in-valve (ViV) procedure is a valid treatment option for patients affected by bioprosthetic heart valve (BHV) degeneration. However, ViV implantation is technically more challenging compared to native trans-catheter aortic valve replacement (TAVR). A deep knowledge of the mechanism and features of the failed BHV is pivotal to plan an adequate procedure. Multimodal imaging is fundamental in the diagnostic and pre-procedural phases. The main challenges associated with ViV TAVR consist of a higher risk of coronary obstruction, severe post-procedural patient-prosthesis mismatch, and a difficult coronary re-access. In this review, we describe the principles of ViV TAVR.

Current state of transcatheter mitral valve implantation in bioprosthetic mitral valve and in mitral ring as a treatment approach for failed mitral prosthesis

With heightened awareness of mitral valve disease and improvement in surgical techniques, the use of mitral valve bioprostheses has increased. There is a large aging population with prior surgical valvular interventions. Limited durability of the prosthesis due to valvular degeneration over time may necessitate the need for repair or replacement of the prior prosthesis in the future. This usually entails another surgical intervention in this population with elevated risk for a reoperation. There is an ongoing clinical need for newer, less invasive options that are feasible and carry a lower complication rate. The advent of transcatheter heart valve (THV) therapies has opened up a wide range of therapeutic options for treatment of a failed bioprosthesis. Their safety and feasibility are now well established. This article serves as a review of the currently available THVs for implantation in the mitral position, the pre-procedural assessment, the challenges associated with implantation, as well as outcomes associated with a mitral valve-in-valve (VIV) and a mitral valve-in-ring (VIR) procedure.

Detecting Aortic Valve Anomaly From Induced Murmurs: Insights From Computational Hemodynamic Models

Patients who receive transcatheter aortic valve replacement are at risk for leaflet thrombosis-related complications, and can benefit from continuous, longitudinal monitoring of the prosthesis. Conventional angiography modalities are expensive, hospital-centric and either invasive or employ potentially nephrotoxic contrast agents, which preclude their routine use. Heart sounds have been long recognized to contain valuable information about individual valve function, but the skill of auscultation is in decline due to its heavy reliance on the physician's proficiency leading to poor diagnostic repeatability. This subjectivity in diagnosis can be alleviated using machine learning techniques for anomaly detection. We present a computational and data-driven proof-of-concept analysis of a novel, auscultation-based technique for monitoring aortic valve, which is practical, non-invasive, and non-toxic. However, the underlying mechanisms leading to physiological and pathological heart sounds are not well-understood, which hinders development of such a technique. We first address this by performing direct numerical simulations of the complex interactions between turbulent blood flow in a canonical ascending aorta model and dynamic valve motion in 29 cases with healthy and stenotic valves. Using the turbulent pressure fluctuations on the aorta lumen boundary, we model the propagation of heart sounds, as elastic waves, through the patient's thorax. The heart sound may be recorded on the epidermal surface using a stethoscope/phonocardiograph. This approach allows us to correlate instantaneous hemodynamic phenomena and valve motion with the acoustic response. From this dataset we extract "acoustic signatures" of healthy and stenotic valves based on principal components of the recorded sound. These signatures are used to train a linear discriminant classifier by maximizing correlation between recorded heart sounds and valve status. We demonstrate that this classifier is capable of accurate prospective detection of anomalous valve function and that the principal component-based signatures capture prominent audible features of heart sounds, which have been historically used by physicians for diagnosis. Further development of such technology can enable inexpensive, safe and patient-centric at-home monitoring, and can extend beyond transcatheter valves to surgical as well as native valves.

Access options for transcatheter mitral valve implantation in patients with prior surgical bioprosthesis

BACKGROUND

Transcatheter mitral valve-in-valve (TMVIV) procedure, either transapical (TA) or trans-septal (TS) has become a valuable alternative to conventional redo surgery in case of failing mitral bioprosthesis with good clinical outcomes. Here we present our fourteen-year institutional experience.

METHODS

All consecutive patients treated with TMVIV with either TA or TS access at our centre between July 2007 and July 2020 were included. Periprocedural and 30-day follow-up (FU) results are reported and TA and TS data are compared.

RESULTS

Eighty-two patients were included, of those 60 (73.2%) were TA while 22 (26.8%) were TS. Men represented 51.2% of the population with a mean age of 77.3±9.0 years. STS score and EuroSCORE II were 11.4%±6.2% and 11.5%±6.5% respectively. Baseline characteristics of TA and TS groups were comparable. TMVIV was performed at a median time of 9.3 years [interquartile range (IQR), 7.9-12.0 days] from the initial mitral valve surgery. Balloon expandable transcatheter heart valve (THV) prostheses (Edwards LifeSciences Corp., Irvine, CA, USA) were used exclusively. Technical success was 97.6% (96.7% and 100.0% for TA and TS respectively) with two (2.4%) periprocedural death, both in the TA group (P=0.533). We observed four (4.9%) left ventricular outflow tract (LVOT) obstructions with one being hemodynamically significant. Six (7.3%) major bleeding occurred in the TA group, not significantly different from TS group (P=0.279). The median length of stay was 6 days (IQR, 4-12 days, 1.5 vs. 7.0 days for TS and TA groups respectively, P=0.001). The overall 30-day mortality rate was 3.7%. We also observed three (3.7%) structural valve deteriorations and in one (1.2%) case the patient required redo mitral surgery at two months. Eighty-seven-point-eight percent of patients were I-II New York Heart Association (NYHA) class. At 30-day FU mean transmitral valve gradient was 7.3±2.7 mmHg and one patient (1.2%) had mitral regurgitation greater than mild. TA and TS groups were comparable.

CONCLUSIONS

Our 14-year single-center experience with TMVIV confirms procedural safety and is an effective alternative to redo surgery with comparable results with both TA and TS. With device, technical improvements and increasing operators' experience, TS is the preferred option for TMVIV. However, in some highly selected patient, TA may still play an important role.

First successful transcatheter valve-in-valve implantation into a failed mechanical prosthetic aortic valve facilitated by fracturing of the leaflets: a case report

Background

Degenerated and failed bioprosthetic cardiac valves can safely be treated with transcatheter valve-in-valve implantation in patients at high risk for reoperation. So far, non-functional mechanical valves must be treated with a surgical redo. Breaking the carbon leaflets before implanting a transcatheter valve into the remaining ring has never been described before.

Case summary

Here, we present the case of a 65-year-old male patient with severe heart failure, poor left ventricular function based on a fully immobile disc of his mechanical bileaflet aortic valve implanted 7 years ago. After the heart team declined to reoperate the patient due to his extremely high risk, we considered a transcatheter valve-in-valve implantation as the ultimate treatment approach. After successful interventional cracking of the leaflets in vitro, this approach, together with implanting a balloon-expandable transcatheter aortic valve replacement (TAVR) into the remaining ring, was performed under cerebral protection. The intervention resulted in a fully functional TAVR, improvement of heart function, and early discharge from the hospital.

Discussion

This case demonstrates the possibility to implant a transcatheter valve successfully into a non-functional mechanical bileaflet aortic prosthesis after fracturing the carbon discs while the brain is protected by a filter system. Critical steps of the procedure were identified. This new therapeutic approach might be offered to a limited patient cohort who is not eligible for a surgical redo.

Mortality and Reoperation Risk After Bioprosthetic Aortic Valve Replacement in Young Adults With Congenital Heart Disease

Bioprosthetic aortic valve replacement (bAVR) in patients with congenital heart disease is challenging due to age, size and complexity. Our objective was to assess survival and identify predictors of re-operation. Data were retrospectively collected for 314 patients undergoing bAVR at 8 centers from 2000-2014. Kaplan-Meier estimation of time to re-operation and Cox regression were utilized. Average age was 45.2 years (IQR 17.8-71.1) and 30% were <21. Indications were stenosis (48%), regurgitation (28%) and mixed (18%). Twenty-eight (9%) underwent prior AVR. Median valve size was 23mm (IQR 21, 25). Implanted valves included CE (Carpentier-Edwards) Perimount (47%), CE Magna/Magna Ease (29%), Sorin Mitroflow (9%), St Jude (2%) and other (13%). Median follow-up was 2.9 (IQR 1.2, 5.7) years. Overall, 11% required re-operation, 35% of whom had a Mitroflow and 65% were <21 years old. Time to re-operation varied among valve type (p=0.020). Crude 3-year rate was 20% in patients ≤21. Smaller valve size indexed to BSA was associated with re-operation (21.7 vs. 23.5 mm/m²). Predictors of reintervention by multivariable analysis were younger age (29% increase in hazard per 5-year decrease, p<0.001), Mitroflow (HR=4 to 8 versus other valves), and smaller valve size (20% increase in hazard per 1 mm decrease, p=0.002). The overall 1, 3 and 5-year survival rates were 94%, 90% and 85% without differences by valve (p=0.19). A concerning reduction in 5-year survival after bAVR is shown. Re-operation is common and varies by age and valve type. Further research is needed to guide valve choice and improve survival.

Prosthetic Valve Monitoring via In Situ Pressure Sensors: In Silico Concept Evaluation using Supervised Learning

PURPOSE

Patients receiving transcatheter aortic valve replacement (TAVR) can benefit from continuous, longitudinal monitoring of valve prosthesis to prevent leaflet thrombosis-related complications. We present a computational proof-of-concept study of a novel, non-invasive and non-toxic valve monitoring technique for TAVs which uses pressure measurements from microsensors embedded on the valve stent. We perform a data-driven analysis to determine the signal processing and machine learning required to detect reduced mobility in individual leaflets.

METHODS

We use direct numerical simulations to describe hemodynamic differences in transvalvular flow in ascending aorta models with healthy and stenotic valves. A Cartesian-grid flow solver and a reduced-order valve model simulate the complex dynamics of blood flow and leaflet motion, respectively. The two-way fluid-structure interaction coupling is achieved using a sharp interface immersed boundary method.

RESULTS

From a dataset of 21 simulations, we show leaflets with reduced mobility result in large, asymmetric pressure fluctuations in their vicinity, particularly in the region extending from the aortic sinus to the sino-tubular junction (STJ). We train a linear classifier algorithm by correlating sinus and STJ pressure measurements on the stent surface to individual leaflet status. The algorithm was shown to have >90% accuracy for prospective detection of individual leaflet dysfunction.

CONCLUSIONS

We demonstrate that using only two discrete pressure measurements, per leaflet, on the TAV stent, individual leaflet status can be accurately predicted. Such a sensorized TAV system could enable safe and inexpensive detection of prosthetic valve dysfunction.

Neo-LVOT and Transcatheter Mitral Valve Replacement: Expert Recommendations

With the advent of transcatheter mitral valve replacement (TMVR), the concept of the neo-left ventricular outflow tract (LVOT) was introduced and remains an essential component of treatment planning. This paper describes the LVOT anatomy and provides a step-by-step computed tomography methodology to segment and measure the neo-LVOT while discussing the current evidence and outstanding challenges. It also discusses the technical and hemodynamic factors that play a major role in assessing the neo-LVOT. A summary of expert-based recommendations about the overall risk of LVOT obstruction in different scenarios is presented along with the currently available methods to reduce the risk of LVOT obstruction and other post-procedural complications.

Invasive Hemodynamic Characteristics in Patients Undergoing Transcatheter Tricuspid Valve-In-Valve Implantation for Treatment of Tricuspid Stenosis

Background:

We sought to describe invasive hemodynamic measurements in patients with tricuspid stenosis (TS) undergoing transcatheter tricuspid valve-in-valve (TVIV) implantation immediately pre- and postimplantation. Development of TS in patients who have undergone surgical tricuspid valve replacement with a bioprosthetic valve is a serious complication that leads to elevated right atrial (RA) pressures and decreased cardiac output. Transcatheter TVIV implantation is a viable alternative to surgical tricuspid valve replacement, but data on the hemodynamic consequences of TVIV for the treatment of severe TS are currently limited to echocardiographic assessment of Doppler-derived gradients.

Methods:

Eleven patients undergoing transcatheter TVIV implantation with moderate to severe bioprosthetic valve stenosis were selected for retrospective review. Right atrial mean pressure, right ventricular (RV) systolic and end-diastolic pressure, mean diastolic RA-RV pressure gradient, pulmonary artery capillary wedge pressure, pulmonary artery systolic, end-diastolic and mean pressures, and pulmonary artery pulsatility index (PAPi) both before and after transcatheter valve placement were collected from catheterization reports.

Results:

After transcatheter TVIV implantation, the mean TS gradient decreased significantly ( P < .01), while the mean RV end-diastolic pressure increased ( P = .046). Pulmonary artery pulsatility index also increased as the TS was relieved ( P = .039).

Conclusions:

Tricuspid valve-in-valve implantation results in immediate relief of TS, leading to increased RV preload with resultant augmentation of RV and pulmonary pressures. Increased PAPi following the procedure demonstrates acute improvement in RV output but remains low due to the failure of the RA pressure to decline significantly immediately following intervention.

Successful implantation of self-expanding valve for a failed stentless prosthesis

Valve-in-valve transcatheter aortic valve implantation is currently used for failed bioprosthesis. The use of a transcatheter prosthesis in a regurgitant noncalcified root implanted Medtronic Freestyle prosthesis is particularly challenging. We present a successful transaxillary valve-in-valve implantation of a self-expandable transcatheter aortic valve prosthesis in a failed Freestyle bioprothesis implanted eleven years earlier. Tips and tricks are discussed.

A Computational Study on Deformed Bioprosthetic Valve Geometries: Clinically Relevant Valve Performance Metrics

Transcatheter aortic valves (TAV) are symmetrically designed, but they are often not deployed inside cylindrical conduits with circular cross-sectional areas. Many TAV patients have heavily calcified aortic valves, which often result in deformed prosthesis geometries after deployment. We investigated the effects of deformed valve annulus configurations on a surgical bioprosthetic valve as a model for TAV. We studied valve leaflet motions, stresses and strains, and analog hydrodynamic measures (using geometric methods), via finite element (FE) modeling. Two categories of annular deformations were created to approximate clinical observations: (1) noncircular annulus with valve area conserved, and (2) under-expansion (reduced area) compared to circular annulus. We found that under-expansion had more impact on increasing stenosis (with geometric orifice area metrics) than noncircularity, and that noncircularity had more impact on increasing regurgitation (with regurgitation orifice area metrics) than under-expansion. We found durability predictors (stress/strain) to be the highest in the commissure regions of noncircular configurations such as EllipMajor (noncircular and under-expansion areas). Other clinically relevant performance aspects such as leaflet kinematics and coaptation were also investigated with the noncircular configurations. This study provides a framework for choosing the most challenging TAV deformations for acute and long-term valve performance in the design and testing phase of device development.

Study Protocol for Transcatheter Aortic Valve Replacement for a Degenerated Aortic Bioprosthesis in a Japanese Cohort

Background: The valve-in-valve (VIV) procedure is being increasingly performed in high-risk patients with a degenerated bioprosthesis in an aortic position in Western countries. The early safety and efficacy of the VIV procedure, however, remain unclear in Japanese patients with a small aortic annulus. We present the protocol for a study designed to evaluate the early safety and efficacy of the VIV procedure in the aortic position in Japanese patients.

Methods and Results: The prospective, single-center, non-comparative, clinical study of the VIV procedure for the aortic position (AORTIC VIV study) commenced in August 2016 and will end in March 2020. Patients will be monitored for ≥1 month after the VIV procedure. The targeted number of patients is 11. Eligible patients are those who have undergone transcatheter aortic valve replacement for a surgical valve (including stented or stentless bioprosthetic valves), or for a transcatheter heart valve. The VIV procedure is performed in high-operative-risk patients with substantial prosthetic valve stenosis, and regurgitation and heart failure resistant to medical treatment (unless the patient meets an exclusion criterion). The safety and efficacy of the VIV procedure will be evaluated in accordance with the Valve Academic Research Consortium-2 initiative.

Conclusions: The AORTIC VIV study will clarify the early safety and efficacy of the VIV procedure in Japanese patients.

A comparison of valve-in-valve transcatheter aortic valve replacement in failed stentless versus stented surgical bioprosthetic aortic valves

Objectives

The objectives of this study were to compare short‐ and intermediate‐term clinical outcomes, procedural complications, TAVR prosthesis hemodynamics, and paravalvular leak (PVL) in stentless and stented groups.

Background

Valve‐in‐valve (ViV) transcatheter aortic valve replacement (TAVR) is an alternative to surgical redo for bioprosthetic valve failure. There have been limited data on ViV in stentless surgical valves.

Methods

We retrospectively analyzed 40 patients who underwent ViV TAVR in prior surgical bioprosthetic valves at Wake Forest Baptist Medical Center from October 2014 to September 2017. Eighty percent (32/40) ViV TAVRs were in stentless, while 20% (8/40) were in stented bioprosthetic valves.

Results

The primary mode of bioprosthetic valve failure for ViV implantation in the stentless group was aortic insufficiency (78%, 25/32), while in the stented group was aortic stenosis (75%, 6/8). The ViV procedure success was 96.9% (31/32) in stentless group and 100% in stented group (8/8). There were no significant differences in all‐cause mortality at 30 days between stentless and stented groups (6.9%, 2/31 versus 0%, 0/8, P = 0.33) and at 1 year (0%, 0/25 versus 0%, 0/5). In the stentless group, 34.4% (11/32) required a second valve compared to the stented group of 0% (0/8). There was a significant difference in the mean aortic gradient at 30‐day follow‐up (12.33 ± 6.33 mmHg and 22.63 ± 8.45 mmHg in stentless and stented groups, P < 0.05) and at 6‐month follow‐up (9.75 ± 5.07 mmHg and 24.00 ± 11.28 mmHg, P < 0.05), respectively.

Conclusions

ViV in the stentless bioprosthetic aortic valve has excellent procedural success and intermediate‐term results. Our study shows promising data that may support the application of TAVR in stentless surgical aortic valve. However, further and larger studies need to further validate our single center's experience.

Percutaneous tricuspid valve implantation in failing bioprosthesis

Severe tricuspid valve (TV) dysfunction in patients with congenital heart disease (CHD) is usually treated by open heart surgery in relatively young patients. If a valve plasty is not possible, a biological valve is implanted with a limited durability. Due to valve degeneration repeated valve exchanges are necessary in these patients. To expand the lifetime of a bioprosthesis in tricuspid position percutaneous TV implantation (PTVI) was introduced recently. PTVI is a promising new catheter interventional technology. The current review summarizes the indication for PTVI, describes the procedure itself and gives an outlook on medium to long-term results of this catheter intervention. PTVI in patients with severe TV dysfunction is less invasive, safe and effective, if performed by an experienced operator, and may help to reduce the total number of open-heart surgeries during a patient's life time. However, further studies with larger patient numbers and longer follow-up are needed.

Ten-year experience of tricuspid valve replacement with the St. Jude medical valve

Bioprosthetic valves for tricuspid valve replacement (TVR) have become increasingly popular in recent years, but mechanical valves remain valuable, particularly for the patients who want to avoid reoperation for bioprostheses malfunction. The aim of this study was to review our 10-year experience in adult patients who underwent TVR with the St. Jude Medical (SJM) valve. From 2005 to 2015, 265 TVRs with SJM valves were performed at our institution. The mean age at operation was 44.1 ± 9.7 years, and 207 cases (78.1%) were female. The mean follow-up was 4.9 ± 2.7 years. Preoperative atrial fibrillation was present in 199 cases (75.1%) and ascites in 26 (9.8%). Of all cases, 88.7% were characterized as New York Heart Association class III or IV. The hospital mortality was 6.4%. There were 9 deaths (3.8%) during late follow-up. The overall survival rates were 89.2% ± 2.2% at 5 years and 86.6% ± 2.9% at 10 years. The linearized rates of valve thrombosis and bleeding events were 0.8%/patient-year and 1.5%/patient-year, respectively. Three cases (1.3%) were reoperated due to prosthetic valve thrombosis. There was no reoperation for sperivalvular leakage and structural failure. The freedom from reoperation was 98.6% ± 0.8% at 5 years and 98.6% ± 0.8% at 10 years. The SJM valve in the tricuspid position is a reliable mechanical prosthesis with a low rate of valve thrombosis and reoperation. It is a reasonable choice for the patients who require mechanical valve replacement in the tricuspid position.

Left ventricular outflow obstruction predicts increase in systolic pressure gradients and blood residence time after transcatheter mitral valve replacement

Left ventricular outflow tract (LVOT) obstruction is a relatively common consequence of transcatheter mitral valve replacement (TMVR). Although LVOT obstruction is associated with heart failure and adverse remodelling, its effects upon left ventricular hemodynamics remain poorly characterised. This study uses validated computational models to identify the LVOT obstruction degree that causes significant changes in ventricular hemodynamics after TMVR. Seven TMVR patients underwent personalised flow simulations based on pre-procedural imaging data. Different virtual valve configurations were simulated in each case, for a total of 32 simulations, and the resulting obstruction degree was correlated with pressure gradients and flow residence times. These simulations identified a threshold LVOT obstruction degree of 35%, beyond which significant deterioration of systolic function was observed. The mean increase from baseline (pre-TMVR) in the peak systolic pressure gradient rose from 5.7% to 30.1% above this threshold value. The average blood volume staying inside the ventricle for more than two cycles also increased from 4.4% to 57.5% for obstruction degrees above 35%, while the flow entering and leaving the ventricle within one cycle decreased by 13.9%. These results demonstrate the unique ability of modelling to predict the hemodynamic consequences of TMVR and to assist in the clinical decision-making process.

Transcatheter Aortic Valve-in-Valve Procedure in Patients with Bioprosthetic Structural Valve Deterioration

Surgical aortic valve replacement is the gold standard procedure to treat patients with severe, symptomatic aortic valve stenosis or insufficiency. Bioprosthetic valves are used for surgical aortic valve replacement with a much greater prevalence than mechanical valves. However, bioprosthetic valves may fail over time because of structural valve deterioration; this often requires intervention due to severe bioprosthetic valve stenosis or regurgitation or a combination of both. In select patients, transcatheter aortic valve replacement is an alternative to surgical aortic valve replacement. Transcatheter valve-in-valve (ViV) replacement is performed by implanting a transcatheter heart valve within a failing bioprosthetic valve. The transcatheter ViV operation is a less invasive procedure compared with reoperative surgical aortic valve replacement, but it has been associated with specific complications and requires extensive preoperative work-up and planning by the heart team. Data from experimental studies and analyses of results from clinical procedures have led to strategies to improve outcomes of these procedures. The type, size, and implant position of the transcatheter valve can be optimized for individual patients with knowledge of detailed dimensions of the surgical valve and radiographic and echocardiographic measurements of the patient's anatomy. Understanding the complexities of the ViV procedure can lead surgeons to make choices during the original surgical valve implantation that can make a future ViV operation more technically feasible years before it is required.

Mitroflow Aortic Bioprosthesis Failure in Type B Aortic Dissection: Preventive Left Main Stenting in Transapical Transcatheter Aortic Valve Implantation Strategy

Mitroflow aortic prosthesis dysfunction in case of complex vascular disease is considered a challenging scenario. Because of the high risk for surgical reoperation and the presence of chronic aortic dissection originated from a calcified Kommerel diverticulum, we considered to perform a transapical valve-in-valve transcatheter aortic valve implantation (TAVI) procedure. Myocardial ischemia is a dreadful complication reported in valve-in-valve TAVI procedures, mainly in patients with degenerated Mitroflow aortic bioprostheses. Because of the narrow shape of Valsalva sinuses and the short distance between Mitroflow annulus and left coronary ostium, to overcome the risk of possible Mitroflow leaflets displacement during TAVI expansion thus overlapping coronary ostia, we performed a preventive angioplasty. Then, we implanted a bare metal stent on the left main protruding in the aortic root. At 3 years follow-up the patient was in good clinical conditions.

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.

Matched Comparison of Self-Expanding Transcatheter Heart Valves for the Treatment of Failed Aortic Surgical Bioprosthesis

Background—

Transcatheter valve-in-valve implantation is an established therapy for high-risk patients with failed surgical aortic bioprosthesis. There are limited data comparing outcomes of valve-in-valve implantation using different transcatheter heart valves (THV).

Methods and Results—

Patients included in the Valve-in-Valve International Data registry (VIVID) and treated with self-expanding THV devices were analyzed using centralized core laboratory blinded to clinical events. St. Jude Medical Portico versus Medtronic CoreValve were compared in a 1:2 fashion after propensity score matching. A total of 162 patients, Portico- (n=54) and CoreValve- (n=108) based valve-in-valve procedures comprised the study population with no significant difference in baseline characteristics (age, 79±8.2 years; 60% women; mean STS [Society of Thoracic Surgery] score 8.1±5.5%). Postimplantation, CoreValve was associated with a larger effective orifice area (1.67 versus 1.31 cm 2 ; P =0.001), lower mean gradient (14±7.5 versus 17±7.5 mm Hg; P =0.02), and lower core laboratory–adjudicated moderate-to-severe aortic insufficiency (4.2% versus 13.7%; P =0.04), compared with Portico. Procedural complications including THV malpositioning, second THV requirement, or coronary obstruction were not significantly different between the 2 groups. Survival and stroke rates at 30 days were similar, but overall mortality at 1 year was higher among patients treated with Portico compared with CoreValve (22.6% versus 9.1%; P =0.03).

Conclusions—

In this first matched comparison of THVs for valve-in-valve implantations, Portico and CoreValve demonstrated differences in postprocedural hemodynamics and long-term clinical outcomes. Although this could be related to THV design characteristics, the impact of other procedural factors cannot be excluded and require further evaluation.

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.

Transcatheter Valve Unable to Cure Patient-Prosthesis Mismatch of Mosaic Bioprosthesis

Transcatheter aortic valve implantation (TAVI) has been recently established as a less invasive alternative to conventional aortic valve replacement (CAVR) in patients presenting with expected high procedural risk. The rapid technologic advances and the recent improvement of clinical outcomes with TAVI have made it possible to treat degenerated bioprosthesis using the valve-in-valve implantation concept (Walther T, Simon P, Dewey T, et al. Transapical minimally invasive aortic valve implantation: multicenter experience. Circulation 2007;116(11, Suppl):I240–I245; Webb JG, Pasupati S, Humphries K, et al. Percutaneous transarterial aortic valve replacement in selected high-risk patients with aortic stenosis. Circulation 2007;116(7):755–763). Recently, concerns were raised regarding the appropriate sizing of transcatheter valve prosthesis and its effect on residual stenosis (Klaaborg KE, Egeblad H, Jakobsen CJ, et al. Transapical transcatheter treatment of a stenosed aortic valve bioprosthesis using the Edwards SAPIEN Transcatheter Heart Valve. Ann Thorac Surg 2009;87(6):1943–1946; Zedig R, Achouh P, Berrebi A, et al. Valve- in- a- valve implantation: a word of caution. Ann Thorac Surg 2009;87:1943–1946), eventually resulting in a patient–prosthesis mismatch (PPM). We report a case with severe PPM after inserting a 23-mm Sapien (Edwards Lifesciences, Irvine, United States) valve into degenerated 23-mm Medtronic Mosaic prosthesis (Medtronic, Minneapolis, Minnesota, United States).

Management of children with congenital heart defect: state of the art and future prospects

The treatment of children with congenital heart defects has evolved in the last 60 years from conservative care to a highly specialized management where advances in imaging, surgical, interventional and support techniques meet together to ensure satisfactory development and good quality of life to the child and to the upcoming grown up. Management of congenital heart defects best begins before birth with the aim, whenever possible, to maintain or establish biventricular physiology or, if this is excluded, to optimize the conditions for univentricular physiology. Current research in the field of genetics, device bioengineering and miniaturization, stem cell therapy, and fusion imaging technology is expected to help to improve further patient outcome. In this review, current management strategies and future prospects are discussed.

Transcatheter Valve Underexpansion Limits Leaflet Durability: Implications for Valve-in-Valve Procedures

Transcatheter aortic valve (TAV) implantation within a failed bioprosthetic valve is a growing trend for high-risk patients. The non-compliant stent of the previous prosthesis may prevent full expansion of the TAV, which has been shown to distort the leaflet configuration, and has been hypothesized to adversely affect durability. In this study, TAV leaflet fatigue damage under cyclic pressurization in the setting of stent underexpansion by 0 (fully expanded), 1, 2 and 3 mm was simulated using finite element analysis to test this hypothesis. In the 2 and 3 mm underexpanded devices, the TAV leaflets exhibited severe pin-wheeling during valve closure, which increased leaflet stresses dramatically, and resulted in accelerated fatigue damage of the leaflets. The leaflet fatigue damage in the 1 mm underexpanded case was similar to that in the fully expanded case. Clinically a range of 10-15% underexpansion is generally considered acceptable; however, it was observed in this study that ≥2 mm (≥9.1%) underexpansion, will significantly impact device durability. Further study is necessary to determine the impact of various deployment conditions, i.e. non-uniform and non-circular deployments and different implantation heights, on differing TAV devices, but it is clear that the normal TAV leaflet configuration must be preserved in order to preserve durability.

Valve-in-Valve Replacement Using a Sutureless Aortic Valve

BACKGROUND We present a unique case of a 61-year-old female patient with homograft deterioration after redo surgery for prosthetic valve endocarditis with root abscess. CASE REPORT The first operation was performed for type A dissection with root, arch, and elephant trunk replacement of the thoracic aorta. The present re-redo surgery was performed as valve-in-valve with a sutureless aortic bioprosthesis. The postoperative course was uneventful and the patient was discharged on day 6. CONCLUSIONS The current case report demonstrates that sutureless bioprostheses are an attractive option for surgical valve-in-valve procedures, which can reduce morbidity and mortality.