Choosing an appropriate size valve for transcatheter pulmonary valve implantation in a native right ventricle outflow tract

The novel balloon-expandable Myval transcatheter heart valve: systematic review of aortic, mitral, tricuspid and pulmonary indications

INTRODUCTION AND OBJECTIVES

Myval technology represents the first balloon-expandable alternative since the Edwards system became commercially available. Despite certain controversies, its use has rapidly expanded. We aimed to gather all the available literature regarding its indications and outcomes.

METHODS

A comprehensive search of articles published between December 2016 and May 2024 was conducted using BioMedCentral, Google Scholar, and PubMed to evaluate the main outcomes of Myval for native aortic stenosis (AS) (meta-analysis) and off-label uses (systematic review).

RESULTS

A total of 151 studies were identified, and 74 were included in the analysis, covering aortic (n=51), mitral (n=9), tricuspid (n=6), and pulmonary (n=8) valve positions. A meta-analysis of studies on native AS demonstrated that Myval is safe and effective, with a 30-day mortality rate of 1.3%, good hemodynamic performance, low rates of pacemaker implantation (8.8%), and ≥ moderate paravalvular regurgitation (1.3%). Compared with other contemporary devices, Myval was competitive and associated with lower rates of pacemaker implantation. In a systematic review of off-label indications, Myval was also found to be safe and effective. In bicuspid AS, pure regurgitation, and aortic valve-in-valve procedures, success rates were 100%, 92%, and 100%, respectively, with pacemaker rates of 9.9%, 22.2%, and 3%, respectively. For mitral valve-in-valve/in-ring procedures, the success rate was 96.9%, while in tricuspid and pulmonary positions, small case series reported 100% success rates for both, with minimal procedural complications.

CONCLUSIONS

Myval technology is safe and effective for the treatment of native valvular disease and dysfunctional prostheses or rings in all heart valve positions, although larger scale studies are warranted.

Planning transcatheter pulmonary valve implantation in the dysfunctional native RVOT: A semi-automated pipeline for dynamic analysis based on 4D-CT imaging

BACKGROUND AND OBJECTIVE

Dysfunction of the right ventricular outflow tract (RVOT) is a common long-term complication following surgical repair in patients with congenital heart disease. Transcatheter pulmonary valve implantation (TPVI) offers a viable alternative to surgical pulmonary valve replacement (SPVR) for treating pulmonary regurgitation but not all RVOT anatomies are suitable for TPVI. To identify a suitable landing zone (LZ) for TPVI, three-dimensional multiphase (4D) computed tomography (CT) is used to evaluate the size, shape, and dynamic behavior of the RVOT throughout the cardiac cycle. However, manually extracting measurements from multiplanar CT reformats is operator-dependent and time-consuming. Leveraging an optical-flow (OF) algorithm, we proposed a novel semi-automated pipeline for dynamic and comprehensive geometrical analysis of the RVOT anatomy.

METHODS

Upon 4D-CT availability, at a pre-defined reference time-point, the patient-specific anatomy is semi-automatically segmented to generate the corresponding three-dimensional surface, which is navigated through a graphical user interface to define the mid-section of the potential LZ. Based on the axial length of the intended device, the proximal and distal LZ cross-sections are automatically identified. An OF-based algorithm is used to track the three LZ cross-sections frame by frame throughout the cardiac cycle, taking RVOT out-of-plane motion into account to update RVOT contours on each cross-section and to elaborate LZ geometrical changes. Finally, LZ time-dependent geometrical features are quantified and extracted.

RESULTS

The pipeline was successfully applied to a retrospective cohort of patients, with OF-based tracking reporting excellent agreement (r2 = 0.99) compared to manual processing, with a bias < 1% for both LZ area and perimeter, while also significantly improving time efficiency. CT-derived measurements extracted from LZ mid-section were the most influential covariates affecting the likelihood of TPVI feasibility. Among these, the minimum perimeter outperformed all other geometric LZ parameters in classifying patients as suitable for either TPVI or SPVR and achieved the highest area under the curve of 0.99, with accuracy and precision of 0.93 and 0.92, respectively.

CONCLUSIONS

Dynamic OF-based quantification of key RVOT geometric parameters can enhance and expedite the selection process for TPVI candidates and guide optimal valve sizing during TPVI planning.

3D Modeling of Self-Expandable Valves for PPVI in Distinct RVOT Morphologies

Tetralogy of Fallot often requires transannular patch repair, leading to pulmonary insufficiency. Percutaneous pulmonary valve implantation (PPVI) with self-expandable valves offers a promising alternative, especially for enlarged right ventricular Queryoutflow tracts (RVOT). Five RVOT types identified in patients with Tetralogy of Fallot reflect anatomical variations due to disease and prior surgeries. This study assesses the Pulsta THV® valve's in vitro hemodynamic performance across these RVOT morphologies using 3D-printed models. Five RVOT morphologies were recreated as 3D models from patient-specific imaging data. The Pulsta THV® valves, available in 28, 30, and 32 mm sizes, were evaluated using the ViVitro Pulse Duplicator System at three cardiac outputs (2, 3.5, and 5 L/min). Hemodynamic performance was assessed by measuring regurgitation rates and pressure gradients in the left and right pulmonary arteries. The Pulsta THV® performed optimally in RVOT Types 1 and 2, demonstrating lower regurgitation rates and pressure gradients, particularly with larger valve sizes. Conversely, RVOT Types 3 and 5 showed increased pressure gradients and hemodynamic variability, indicating less favorable outcomes. The results highlighted the critical role of precise anatomical compatibility, with larger valve sizes proving more effective in enlarged RVOT geometry. Valve sizes tailored to specific RVOT morphologies can enhance PPVI outcomes. Types 1 and 2 are ideal for PPVI, while Types 3 and 5 present challenges due to hemodynamic variability. This study supports 3D modeling and in vitro testing for pre-procedural planning to reduce complications, with future research exploring dynamic imaging and materials mimicking tissue properties.

Pediatric cardiac interventions: Innovations from India

India, owing to its population structure, faces an enormous burden of children born with congenital heart disease (CHD). Systematic challenges such as limited public health infrastructure, a shortage of trained specialists, and high out-of-pocket expenditures hinder uniform access to comprehensive CHD care. Despite these limitations, Indian pediatric cardiologists have delivered innovative and often cost-effective solutions to challenging clinical problems. Indigenous devices such as the MyVal transcatheter heart valve, Konar-MF (multifunction) occluder, and Zephyr large-diameter stents are significant achievements in their respective fields. Static balloon dilatation of interatrial septum and balloon-assisted atrial septal defect (ASD) device implantation are prime examples of many innovations that were established by Indians and followed across the world. India also helped consolidate significant interventions in children, such as percutaneous transvenous mitral commissurotomy and interventions for aortoarteritis. Notably, Indian centers have published some of the largest series on transcatheter closure of sinus venosus ASD and ruptured sinus of Valsalva aneurysm. Close collaboration with adult coronary interventionalists has facilitated innovations borrowed from coronary chronic total occlusion hardware and techniques to recanalize ductus arteriosus or membranous-type pulmonary atresia. This manuscript discusses some of India's innovative contributions to the field of pediatric cardiac interventions.

[Modern possibilities for transcatheter pulmonary valve replacement]

The literature review is devoted to transcatheter pulmonary valve replacement. The authors summarize the indications, clinical data and current capabilities of transcatheter pulmonary valve replacement. The authors also overviewed modern valves for transcatheter pulmonary artery replacement. Effectiveness of transcatheter pulmonary valve implantation has been substantiated. Various studies comparing the outcomes of different valve systems for endovascular implantation were analyzed. The authors concluded the prospects for transcatheter pulmonary valve implantation.

Role of Computed Tomography before Transcatheter Pulmonary Valve Implantation in Patients with Dysfunctional Native Right Ventricular Outflow Tract

The most performed percutaneous valve replacement procedure is for the aortic valve. In recent years, there have been developments in percutaneous valve replacement methods for other valves, including the pulmonary valve. Computed tomography plays a crucial role in various stages of procedure planning and provides essential information regarding potential complications after the procedure. We present images documenting step by step how to evaluate cardiac computed tomography in the qualification procedure for transcatheter pulmonary valve implantation in patients with dysfunctional native right ventricular outflow tract.