Implantation of the Medtronic Harmony Transcatheter Pulmonary Valve Improves Right Ventricular Size and Function in an Ovine Model of Postoperative Chronic Pulmonary Insufficiency

Fifteen years of experience with the melody™ TPV for percutaneous pulmonary valve replacement

BACKGROUND

The Melody™ TPV has been used as an alternative to surgical pulmonary valve replacement; limited medium-term follow-up data are available.

AIMS

To report the follow-up data of all Melody™ TPVs implanted locally over a 15-year period (2006-2021).

METHODS

Single-centre non-randomised prospective observational study of all implanted Melody™ valves in the pulmonary position.

RESULTS

234 Melody™ valves were implanted at a mean age of 20.8 ± 24.6y. Indications for valve implantation included: pulmonary stenosis (47.2%,) regurgitation (30.9%), and mixed pathology (21.9%). The implant zone substrate consisted of homograft in 52.6%, patched right ventricular outflow tract in 33.8%, and bioprostheses in 13.6% of the cases. Valve survival at 10 years was 89% and 72% at 15 years follow-up. Pulmonary stenosis and pulmonary and tricuspid valve regurgitation demonstrated no significant evolution over the 15-year follow-up. Over the study period, there were 7 deaths at a mean age of 54.2 ± 21.1y; none was valve related. Valve failure was observed in 22 cases (9.4%), mainly due to endocarditis 13/22 (59.0%). The overall incidence of endocarditis was 1.5% per patient-year and occurred in 10.2% (n = 24) of patients 2.7 ± 1.6y after TPV, mostly in younger men (median 18.3, range 8.1 - 49.5 y). Balloon dilatation to accommodate for somatic growth was successful in all 17 (7.3%) attempted cases.

CONCLUSION

The Melody™ valve had a low risk for valve failure with overall well-preserved valve function over up to 15 years of follow-up. Endocarditis remains a concern. The Melody™ valve is competitive with other surgical and percutaneous conduits.

Right ventricular outflow tract landing zone perimeter / circularised diameter - new imaging standards in pulmonary valve replacement reporting

BACKGROUND

Right ventricular outflow tract intervention spans transcatheter, surgical, or hybrid pulmonary valve replacement methodologies. Standardised pre-procedure workup includes cardiac MRI to identify an intended valve site (landing zone). Our institutional practice includes measurement of the right ventricular outflow tract perimeter (circumference) of this site in end-systole. Our primary aim was to compare patients by their perimeter values to the palliative interventions performed (transcatheter versus surgical/hybrid methodologies).

METHODS

Retrospective review of patients undergoing pulmonary valve replacement from January 2017 to 2021. We performed perimeter measurements at the intended valve site on advanced imaging; the outcomes of interventions were outlined via descriptive and statistical analyses.

RESULTS

A total of 37 patients underwent pulmonary valve replacement that met study criteria - 21 transcatheter, 7 surgical, and 9 hybrid. Median age at intervention was 26 years (range 8-70). The mean end-systolic perimeter of the transcatheter cohort was 88.9 ± 8.7 mm and in the surgical/hybrid cohort measured 106.6 ± 7.5 mm. For the transcatheter cohort, the median "circularised" diameter derived from the perimeter measurement (divided by π) was 27.7 mm (range 24.3-32.4). Notably, this correlated (r = 0.93, p < 0.01) with the median diameter of the narrowest region during actual transcatheter right ventricular outflow tract balloon sizing (lateral imaging) of 27.1 mm (range 23.2-30.1).

CONCLUSIONS

Right ventricular outflow tract perimeter measurement to determine circularised diameter is useful in planning pulmonary valve replacement in terms of candidacy of transcatheter versus the need for a surgical/hybrid approach. The circularised diameter correlates with transcatheter right ventricular outflow tract balloon sizing.

The Future of Paediatric Heart Interventions: Where Will We Be in 2030?

Purpose of Review

Cardiac catheterization therapies to treat or palliate infants, children and adults with congenital heart disease have developed rapidly worldwide in both technical innovation and device development in the previous three decades. By reviewing of current status of novel or development of devices and techniques, we will discuss what is likely to happen in paediatric heart intervention in the next decade.

Recent Findings

Recently, biodegradable stents and devices, transcatheter pulmonary valve implantation for the native right ventricle outflow tract and MRI-guided interventions have been progressing rapidly with good immediate to early results. These are expected to be introduced and spread in the next decade although there are still challenges to overcome.

Summary

The future of paediatric heart intervention is very promising with rapid development of technological progress.

Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is recognized as a feasible and low risk alternative to surgery to treat dysfunctional right ventricular outflow tract (RVOT) in usually pluri-operated patients. Evolving technology allowed to develop different kind of prosthesis and to go from an initial treatment exclusively of stenotic conduit to an actual approach extended also to wide native RVOT. The Melody transcatheter pulmonary valve (TPV) and the Edwards Sapien valve are nowadays the most commonly implanted prostheses. However, other devices have been developed to treat large RVOT (i.e., the Venus p-valve, the Medtronic Harmony TPV, the Alterra Adaptive Prestent, and the Pulsta valve). Indications for PPVI are the same as for surgical interventions on pulmonary valve, with limits related to the maximum diameter of the available percutaneous prosthesis. Therefore, an accurate preoperative evaluation is of paramount importance to select patients who could benefit from this procedure. The overall periprocedural mortality incidence is around 1.4%, while freedom from RVOT reintervention ranges from 100% at 4 months to 70% at 70 months, according to the different published studies.

Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is recognized as a feasible and low risk alternative to surgery to treat dysfunctional right ventricular outflow tract (RVOT) in usually pluri-operated patients. Evolving technology allowed to develop different kind of prosthesis and to go from an initial treatment exclusively of stenotic conduit to an actual approach extended also to wide native RVOT. The Melody transcatheter pulmonary valve (TPV) and the Edwards Sapien valve are nowadays the most commonly implanted prostheses. However, other devices have been developed to treat large RVOT (i.e., the Venus p-valve, the Medtronic Harmony TPV, the Alterra Adaptive Prestent, and the Pulsta valve). Indications for PPVI are the same as for surgical interventions on pulmonary valve, with limits related to the maximum diameter of the available percutaneous prosthesis. Therefore, an accurate preoperative evaluation is of paramount importance to select patients who could benefit from this procedure. The overall periprocedural mortality incidence is around 1.4%, while freedom from RVOT reintervention ranges from 100% at 4 months to 70% at 70 months, according to the different published studies.

Branch Pulmonary Artery Valve Implantation Reduces Pulmonary Regurgitation and Improves Right Ventricular Size/Function in Patients With Large Right Ventricular Outflow Tracts

OBJECTIVES

The authors sought to assess the intermediate-term effects of percutaneous placed valves in the branch pulmonary artery (PA) position.

BACKGROUND

Most patients with large right ventricular outflow tracts (RVOTs) are excluded from available percutaneous pulmonary valve options. In some of these patients, percutaneous branch PA valve implantation may be feasible. The longer-term effects of valves in the branch PA position is unknown.

METHODS

Retrospective data were collected on patients with significant pulmonary regurgitation who had a percutaneous branch PA valve attempted.

RESULTS

Percutaneous branch PA valve implantation was attempted in 34 patients (18 bilateral and 16 unilateral). One-half of the patients were in New York Heart Association (NHYA) functional class III or IV pre-implantation. There were 2 failed attempts and 6 procedural complications. At follow-up, only 1 patient had more than mild valvar regurgitation. The right ventricular end-diastolic volume index decreased from 147 (range: 103 to 478) ml/m² to 101 (range: 76 to 429) ml/m², p < 0.01 (n = 16), and the right ventricular end-systolic volume index decreased from 88.5 (range: 41 to 387) ml/m² to 55.5 (range: 40.2 to 347) ml/m², p < 0.01 (n = 13). There were 5 late deaths. At a median follow-up of 2 years, all other patients were in NYHA functional class I or II.

CONCLUSIONS

Percutaneous branch PA valve implantation results in a reduction in right ventricular volume with clinical benefit in the intermediate term. Until percutaneous valve technology for large RVOTs is refined and more widely available, branch PA valve implantation remains an option for select patients.

Novel use of a 3D printed heart model to guide simultaneous percutaneous repair of severe pulmonary regurgitation and right ventricular outflow tract aneurysm

We describe percutaneous repair of severe pulmonary regurgitation and a right ventricular outflow tract pseudoaneurysm in a 19-year-old patient after repair of pulmonary atresia, ventricular septal defect, and major aortopulmonary collaterals. A 3D printed model of his heart was used to simulate percutaneous repair with a closure device in the aneurysm neck and a Venus P-valve in the right ventricular outflow tract. The encouraging findings from the simulation allowed us to plan the complex procedure effectively with a successful outcome and avoidance of surgery.

Toward predictive modeling of catheter-based pulmonary valve replacement into native right ventricular outflow tracts

BACKGROUND

Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF) leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement has become a reality. However, predicting a secure, atraumatic implantation of a catheter-based device remains a significant challenge due to the complex and dynamic nature of the right ventricular outflow tract (RVOT). We sought to quantify the differences in compression and volume for actual implants, and those predicted by pre-implant modeling.

METHODS

We used custom software to interactively place virtual transcatheter pulmonary valves (TPVs) into RVOT models created from pre-implant and post Harmony valve implant CT scans of 5 ovine surgical models of TOF to quantify and visualize device volume and compression.

RESULTS

Virtual device placement visually mimicked actual device placement and allowed for quantification of device volume and radius. On average, simulated proximal and distal device volumes and compression did not vary statistically throughout the cardiac cycle (P = 0.11) but assessment was limited by small sample size. In comparison to actual implants, there was no significant pairwise difference in the proximal third of the device (P > 0.80), but the simulated distal device volume was significantly underestimated relative to actual device implant volume (P = 0.06).

CONCLUSIONS

This study demonstrates that pre-implant modeling which assumes a rigid vessel wall may not accurately predict the degree of distal RVOT expansion following actual device placement. We suggest the potential for virtual modeling of TPVR to be a useful adjunct to procedural planning, but further development is needed.

Recent advances in transcatheter management of pulmonary regurgitation after surgical repair of tetralogy of Fallot

Surgical repair of tetralogy of Fallot (ToF) in childhood is associated with generally good outcomes, and almost all children can be expected to survive until adulthood. However, significant pulmonary regurgitation leading to progressive right ventricular dilatation is common in teenagers or young adults because of the nature of the surgical intervention. In patients whose repair included placement of a right ventricle to pulmonary artery conduit, it has been possible to place a stented valve within the conduit to treat this. Pulmonary regurgitation after repair of ToF via a transannular patch technique has historically involved repeat surgery as the dimensions of the right ventricular outflow tract have been too large for commercially available valves. This review summarises the novel transcatheter valves available for management of pulmonary regurgitation after surgical repair of ToF in patients in whom the dimensions of the right ventricular outflow tract have previously been considered too large for transcatheter valve implantation.

Innovative interventional catheterization techniques for congenital heart disease

Since 1929, when the first cardiac catheterization was safely performed in a human by Dr. Werner Forssmann (on himself), there has been a rapid progression of cardiac catheterization techniques and technologies. Today, these advances allow us to treat a wide variety of patients with congenital heart disease using minimally invasive techniques; from fetus to infants to adults, and from simple to complex congenital cardiac lesions. In this article, we will explore some of the exciting advances in cardiac catheterization for the treatment of congenital heart disease, including transcatheter valve implantation, hybrid procedures, biodegradable technologies, and magnetic resonance imaging (MRI)-guided catheterization. Additionally, we will discuss innovations in imaging in the catheterization laboratory, including 3D rotational angiography (3DRA), fusion imaging, and 3D printing, which help to make innovative interventional approaches possible.

Transcatheter pulmonary valve implantation: will it replace surgical pulmonary valve replacement?

INTRODUCTION

Right ventricular outflow tract (RVOT) dysfunction is a common hemodynamic challenge for adults with congenital heart disease (ACHD), including patients with repaired tetralogy of Fallot (TOF), truncus arteriosus (TA), and those who have undergone the Ross procedure for congenital aortic stenosis and the Rastelli repair for transposition of great vessels. Pulmonary valve replacement (PVR) has become one of the most common procedures performed for ACHD patients. Areas covered: Given the advances in transcatheter technology, we conducted a detailed review of the available studies addressing the indications for PVR, historical background, evolving technology, procedural aspects, and the future direction, with an emphasis on ACHD patients. Expert commentary: Transcatheter pulmonary valve implantation (TPVI) is widely accepted as an alternative to surgery to address RVOT dysfunction. However, current technology may not be able to adequately address a subset of patients with complex RVOT morphology. As the technology continues to evolve, new percutaneous valves will allow practitioners to apply the transcatheter approach in such patients. We expect that with the advancement in transcatheter technology, novel devices will be added to the TPVI armamentarium, making the transcatheter approach a feasible alternative for the majority of patients with RVOT dysfunction in the near future.

Patient Selection Process for the Harmony Transcatheter Pulmonary Valve Early Feasibility Study

This early feasibility study was designed to obtain in vivo data to confirm assumptions on device loading conditions of the Medtronic Harmony transcatheter pulmonary valve (TPV). Secondary objectives included procedural feasibility, safety, and valve performance. The Harmony TPV was developed for nonsurgical pulmonary valve replacement in non-right ventricle-pulmonary artery conduit patients. The Native Outflow Tract TPV Research Clinical Study was the first study approved under the Food and Drug Administration Early Feasibility Study guidance. Enrollment required that patient anatomy be precisely matched to the single-size Harmony TPV implant, necessitating a rigorous selection process. The study was nonrandomized, prospective, and performed at 3 sites. All patients met standard indications for surgical pulmonary valve replacement. The goal of the screening committee was to match the candidate anatomy to predetermined engineering criteria thought to be predictive of secure Harmony TPV implantation for the single-size device under study. A majority of the screening committee was required to recommend a patient as eligible for implant. A total of 270 patients underwent prescreening cardiac magnetic resonance imaging, 66 were enrolled and received a computed tomography scan (24%), 21 met criteria for implant and were catheterized (8%), and 20 underwent implant. Nineteen of 20 met criteria for implant success. In conclusion, the Medtronic Harmony TPV represents an emerging therapeutic option for patients with complex postoperative right ventricular outflow tract failure. The initial clinical evaluation of this technology was unique, and the highly variable anatomy of this population required careful screening to ensure acceptable device fit.

Pulmonic Valve Disease: Review of Pathology and Current Treatment Options

PURPOSE OF REVIEW

Our review is intended to provide readers with an overview of disease processes involving the pulmonic valve, highlighting recent outcome studies and guideline-based recommendations; with focus on the two most common interventions for treating pulmonic valve disease, balloon pulmonary valvuloplasty and pulmonic valve replacement.

RECENT FINDINGS

The main long-term sequelae of balloon pulmonary valvuloplasty, the gold standard treatment for pulmonic stenosis, remain pulmonic regurgitation and valvular restenosis. The balloon:annulus ratio is a major contributor to both, with high ratios resulting in greater degrees of regurgitation, and small ratios increasing risk for restenosis. Recent studies suggest that a ratio of approximately 1.2 may provide the most optimal results. Pulmonic valve replacement is currently the procedure of choice for patients with severe pulmonic regurgitation and hemodynamic sequelae or symptoms, yet it remains uncertain how it impacts long-term survival. Transcatheter pulmonic valve replacement is a rapidly evolving field and recent outcome studies suggest short and mid-term results at least equivalent to surgery. The Melody valve® was FDA approved for failing pulmonary surgical conduits in 2010 and for failing bioprosthetic surgical pulmonic valves in 2017 and has been extensively studied, whereas the Sapien XT valve®, offering larger diameters, was approved for failing pulmonary conduits in 2016 and has been less extensively studied. Patients with pulmonic valve disease deserve lifelong surveillance for complications. Transcatheter pulmonic valve replacement is a novel and attractive therapeutic option, but is currently only FDA approved for patients with failing pulmonary conduits or dysfunctional surgical bioprosthetic valves. New advances will undoubtedly increase the utilization of this rapidly expanding technology.

Recent advances in pediatric interventional cardiology

During the last 10 years, there have been major technological achievements in pediatric interventional cardiology. In addition, there have been several advances in cardiac imaging, especially in 3-dimensional imaging of echocardiography, computed tomography, magnetic resonance imaging, and cineangiography. Therefore, more types of congenital heart diseases can be treated in the cardiac catheter laboratory today than ever before. Furthermore, lesions previously considered resistant to interventional therapies can now be managed with high success rates. The hybrid approach has enabled the overcoming of limitations inherent to percutaneous access, expanding the application of endovascular therapies as adjunct to surgical interventions to improve patient outcomes and minimize invasiveness. Percutaneous pulmonary valve implantation has become a successful alternative therapy. However, most of the current recommendations about pediatric cardiac interventions (including class I recommendations) refer to off-label use of devices, because it is difficult to study the safety and efficacy of catheterization and transcatheter therapy in pediatric cardiac patients. This difficulty arises from the challenge of identifying a control population and the relatively small number of pediatric patients with congenital heart disease. Nevertheless, the pediatric interventional cardiology community has continued to develop less invasive solutions for congenital heart defects to minimize the need for open heart surgery and optimize overall outcomes. In this review, various interventional procedures in patients with congenital heart disease are explored.