First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog

Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog. A one-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty, leading two years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities. Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for four years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any relevant leaflet or stent alterations. This case provides a proof of concept in interventional veterinary cardiology, showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function.

Cell signaling and tissue remodeling in the pulmonary autograft after the Ross procedure: A computational study

In the Ross procedure, a patient's pulmonary valve is transplanted in the aortic position. Despite advantages of this surgery, reoperation is still needed in many cases due to excessive dilatation of the pulmonary autograft. To further understand the failure mechanisms, we propose a multiscale model predicting adaptive processes in the autograft at the cell and tissue scale. The cell-scale model consists of a network model, that includes important signaling pathways and relations between relevant transcription factors and their target genes. The resulting gene activity leads to changes in the mechanical properties of the tissue, modeled as a constrained mixture of collagen, elastin and smooth muscle. The multiscale model is calibrated with findings from experiments in which seven sheep underwent the Ross procedure. The model is then validated against a different set of sheep experiments, for which a qualitative agreement between model and experiment is found. Model outcomes at the cell scale, including the activity of genes and transcription factors, also match experimentally obtained transcriptomics data.

Hemodynamics and wall shear metrics in a pulmonary autograft: Comparing a fluid-structure interaction and computational fluid dynamics approach

OBJECTIVE

In young patients, aortic valve disease is often treated by placement of a pulmonary autograft (PA) which adapts to its new environment through growth and remodeling. To better understand the hemodynamic forces acting on the highly distensible PA in the acute phase after surgery, we developed a fluid-structure interaction (FSI) framework and comprehensively compared hemodynamics and wall shear-stress (WSS) metrics with a computational fluid dynamic (CFD) simulation.

METHODS

The FSI framework couples a prestressed non-linear hyperelastic arterial tissue model with a fluid model using the in-house coupling code CoCoNuT. Geometry, material parameters and boundary conditions are based on in-vivo measurements. Hemodynamics, time-averaged WSS (TAWSS), oscillatory shear index (OSI) and topological shear variation index (TSVI) are evaluated qualitatively and quantitatively for 3 different sheeps.

RESULTS

Despite systolic-to-diastolic volumetric changes of the PA in the order of 20 %, the point-by-point correlation of TAWSS and OSI obtained through CFD and FSI remains high (r > 0.9, p < 0.01) for TAWSS and (r > 0.8, p < 0.01) for OSI). Instantaneous WSS divergence patterns qualitatively preserve similarities, but large deformations of the PA leads to a decrease of the correlation between FSI and CFD resolved TSVI (r < 0.7, p < 0.01). Moderate co-localization between FSI and CFD is observed for low thresholds of TAWSS and high thresholds of OSI and TSVI.

CONCLUSION

FSI might be warranted if we were to use the TSVI as a mechano-biological driver for growth and remodeling of PA due to varying intra-vascular flow structures and near wall hemodynamics because of the large expansion of the PA.

Letter to the Editor Ross procedure valve function, clinical outcomes and predictors after 25 years follow up

The following letter presents an answer of a comment of our work titled "Ross procedure: valve function, clinical outcomes and predictors after 25 years' follow-up," recently published in your journal by Rangwala et al.1 As our colleagues point out, the Ross procedure has excellent survival rates but a significant risk of valve dysfunction and therefore reintervention at follow-up. Although the survival advantage with the Ross procedure appears to be consistent compared with mechanical valve substitutes, this benefit is not as clear compared with biological valve substitutes. However, biological valve substitutes also have significant reintervention rates during follow-up. The different surgical modifications of the Ross procedure have not clearly demonstrated better results in follow-up in terms of autograft reintervention. This procedure can be performed in a medium-volume center with good results as long as adequate patient selection and adequate surgical training are carried out.

Survival after partial heart transplantation in a piglet model

Partial heart transplantation (PHT) is a novel surgical approach that involves transplantation of only the part of the heart containing a valve. The rationale for this approach is to deliver growing heart valve implants that reduce the need for future re-operations in children. However, prior to clinical application of this approach, it was important to assess it in a preclinical model. To investigate PHT short-term outcomes and safety, we performed PHT in a piglet model. Yorkshire piglets (n = 14) were used for PHT of the pulmonary valve. Donor and recipient pairs were matched based on blood types. The piglets underwent PHT at an average age of 44 days (range 34-53). Post-operatively, the piglets were monitored for a period of two months. Of the 7 recipient piglets, one mortality occurred secondary to anesthesia complications while undergoing a routine echocardiogram on post-operative day 19. All piglets had appropriate weight gain and laboratory findings throughout the post-operative period indicating a general state of good health and rehabilitation after undergoing PHT. We conclude that PHT has good short-term survival in the swine model. PHT appears to be safe for clinical application.

Transcatheter-Based Interventions for Tetralogy of Fallot Across All Age Groups

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Palliative procedures, either surgical or transcatheter, aim to improve oxygen saturation, affording definitive procedures at a later stage. Transcatheter interventions have been used before and after surgical palliative or definitive repair in children and adults. This review aims to provide an overview of the different catheter-based interventions for TOF across all age groups, with an emphasis on palliative interventions, such as patent arterial duct stenting, right ventricular outflow tract stenting, or balloon pulmonary valvuloplasty in infants and children and transcatheter pulmonary valve replacement in adults with repaired TOF, including the available options for a large, dilated native right ventricular outflow tract.

Transcatheter Pulmonary Valve Replacement With the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot

BACKGROUND

Anatomic selection for Harmony valve implant is determined with the aid of a screening report and perimeter plot (PP) that depicts the perimeter-derived radius along the right ventricular outflow tract (RVOT) and projects device oversizing. The PP provides an estimation of suitability for implant, but its sensitivity as a screening method is unknown. This study was performed to describe anatomic features and outcomes in patients who underwent Harmony TPV25 implant despite a PP that predicted inadequate oversizing.

METHODS

We reviewed RVOT anatomic features and measurements in patients who underwent transcatheter pulmonary valve replacement with the Harmony TPV25 device despite a PP that predicted inadequate oversizing.

RESULTS

This study included 22 patients. There were no unsuccessful implants or adverse valve-related events. Anatomic features varied, but all patients fit into 1 of 3 anatomic types characterized by differences in RVOT dimensions. Type 1 patients (n=9) had a long RVOT with a choke point and a wide main pulmonary artery. Type 2 patients (n=6) had a short RVOT that was pyramidal in shape, with no choke point, and extensive main pulmonary artery lengthening/expansion during systole. Type 3 patients (n=7) had a short, bulbous main pulmonary artery with a choke point and an open pulmonary artery bifurcation.

CONCLUSIONS

Transcatheter pulmonary valve replacement with the Harmony valve is feasible in some patients whose PP fit analysis predicts inadequate oversizing. All cases in this series fit into 1 of 3 anatomic patterns, which are not identified in the screening report. Implanters must review cases individually to assess the feasibility of the implant.

Bicuspidisation of unicuspid stenotic pulmonary valve in a nine-year-old male

We report the case of a 9-year-old male with severe congenital pulmonary valve stenosis referred to our centre for percutaneous valvotomy. On admission, trans-thoracic echocardiogram confirmed a unicuspid pulmonary valve with a peak/mean pulmonary valve gradient of 91/53 mmHg and a pulmonary annulus of 13.8 mm (-0.8 Z Score). It also showed an enlarged RV (RV/LV ratio 0,9). During cardiac catheterisation, an additional atrial septal defect (secundum) with significant left to right shunt (Qp/Qs > 2) was diagnosed, which was not amenable to percutaneous closure. The patient was referred for surgical repair.The atrial septal defect was closed by a direct running suture. The repair of the unicuspid valve consisted in bicuspidisation by a large commissurotomy to the left anterior wall of the pulmonary artery. The neo-commissure was created with two separate patches of autologous pericardium secured to the wall of the pulmonary root. The adjustment of the effective height of the pulmonary valve leaflets was done by trimming the patches and a triangular plication of the newly created posterior leaflet. Perioperative echocardiogram showed a peak gradient of 15 mm Hg and trivial pulmonary regurgitation. The total cross-clamp time was 92 min and the bypass time 123 min with a favourable evolution after the surgery.The particularity of the case is represented by the complexity of the bicuspidisation procedure. Using this technique, a tailored approach is needed for every patient.

Impact of pulmonary valve replacement on ventricular function and cardiac events in patients with tetralogy of Fallot. A retrospective cohort study

INTRODUCTION AND OBJECTIVES

Our aim was to assess the impact of prosthetic pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot (rTOF) on changes in biventricular volumes and function and on adverse cardiac events.

METHODS

Adults with rTOF were identified from the SACHER-registry. Data from serial cardiac magnetic resonance imaging, echocardiography, exercise capacity and n-terminal pro b-type natriuretic peptide (NT-proBNP) were collected. The primary endpoint was right ventricular ejection fraction (RVEF) as measured by cardiac magnetic resonance. Secondary endpoints were biventricular volumes, left ventricular ejection fraction, exercise capacity and NT-proBNP levels, and time to adverse cardiac outcomes (atrial and ventricular arrhythmia, endocarditis). Associations between previous PVR and longitudinal changes in functional outcomes and time to adverse cardiac outcomes were analyzed using linear mixed-effects models and Cox proportional hazards models, respectively.

RESULTS

A total of 308 patients (153 with and 155 without PVR) with 887 study visits were analyzed. Previous PVR was not significantly associated with changes in RVEF (CE, -1.33; 95%CI, -5.87 to 3.21; P=.566). Previous PVR was associated with lower right ventricular end-diastolic volume but had no significant effect on left ventricular ejection fraction, exercise capacity, or NT-proBNP-levels. Previous PVR was associated with an increased hazard of atrial arrhythmias (HR, 2.09; 95%CI, 1.17-3.72; P=.012) and infective endocarditis (HR, 12.72; 95%CI, 4.69-34.49; P<.0001) but not with an increased hazard of sustained ventricular arrhythmias (HR, 0.64; 95%CI, 0.18-2.27; P=.490).

CONCLUSIONS

Previous PVR was not significantly associated with changes in RVEF but was associated with an increased risk of atrial arrhythmias and infective endocarditis.

Creating a flow restrictor in ductal stenting: a novel technique

Ductal stenting has transformed the care of neonates with ductal-dependent critical CHD, especially in low-income countries. In small infants, a 3.5- or 4-mm stent may lead to too much pulmonary blood flow resulting in pulmonary oedema. We herein presented a novel technique to restrict ductal stent flow in a premature neonate with pulmonary atresia and intact ventricular septum following radiofrequency perforation of the pulmonary valve.

Neurocognitive function and health-related quality of life in adolescents and young adults with CHD with pulmonary valve dysfunction

BACKGROUND

Neurocognitive impairment and quality of life are two important long-term challenges for patients with complex CHD. The impact of re-interventions during adolescence and young adulthood on neurocognition and quality of life is not well understood.

METHODS

In this prospective longitudinal multi-institutional study, patients 13-30 years old with severe CHD referred for surgical or transcatheter pulmonary valve replacement were enrolled. Clinical characteristics were collected, and executive function and quality of life were assessed prior to the planned pulmonary re-intervention. These results were compared to normative data and were compared between treatment strategies.

RESULTS

Among 68 patients enrolled from 2016 to 2020, a nearly equal proportion were referred for surgical and transcatheter pulmonary valve replacement (53% versus 47%). Tetralogy of Fallot was the most common diagnosis (59%) and pulmonary re-intervention indications included stenosis (25%), insufficiency (40%), and mixed disease (35%). There were no substantial differences between patients referred for surgical and transcatheter therapy. Executive functioning deficits were evident in 19-31% of patients and quality of life was universally lower compared to normative sample data. However, measures of executive function and quality of life did not differ between the surgical and transcatheter patients.

CONCLUSION

In this patient group, impairments in neurocognitive function and quality of life are common and can be significant. Given similar baseline characteristics, comparing changes in neurocognitive outcomes and quality of life after surgical versus transcatheter pulmonary valve replacement will offer unique insights into how treatment approaches impact these important long-term patient outcomes.

Risk Factors for Coronary Artery Complications After Prosthetic Pulmonary Valve Implantation in Patients With Congenital Heart Disease

BACKGROUND

Coronary artery complications (CACs) in patients who undergoing prosthetic pulmonary valve implantation for congenital heart disease can lead to fetal outcomes. However, the incidence of and risk factors for CACs in these patients remain unknown.

METHODS AND RESULTS

A retrospective cohort study was conducted on patients who underwent cardiac computed tomography or invasive coronary angiography after prosthetic pulmonary valve implantation at Seoul National University Hospital from June 1986 to May 2021. Among 341 patients, 25 (7.3%) were identified with CACs, and 2 of them died. Among the patients with CACs, congenital coronary anomalies and an interarterial course of the coronary artery were identified in 11 (44%) and 18 (72%) patients, respectively. Interarterial and intramural courses of the coronary artery were associated with a 4.4- and 10.6-fold increased risk of CACs, respectively. Among patients with tetralogy of Fallot and pulmonary atresia, the aortic root was rotated further clockwise in patients with coronary artery compression compared to those without it (mean [±SD] 128.0±19.9° vs. 113.5±23.7°; P=0.024). The cut-off rotation angle of the aorta for predicting the occurrence of coronary artery compression was 133°.

CONCLUSIONS

Perioperative coronary artery evaluation and prevention of CACs are required in patients undergoing prosthetic pulmonary valve implantation, particularly in those with coronary artery anomalies or severe clockwise rotation of the aortic root.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

BACKGROUND

Due to the wide variety of morphology, size, and dynamics, selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation (PPVI). This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional (3D)-printed models for planning PPVI with the Venus P-valve.

METHODS

Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.

RESULTS

3D model bench testing altered treatment strategy in all patients (100%). One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly. In the remaining 14 patients, valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery. In four patients, it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract (RVOT) ( n = 2) or risk of compression coronary artery ( n = 2). Concerning sizing, we found that an oversize of 2-5 mm suffices. Anchoring of the valve was dictated by the flaring of the in- and outflow portion in the pulmonary artery. PPVI was successful in all 14 patients (absence of valve migration, no coronary compression, and none-to-mild residual pulmonary regurgitation [PR]). The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group (36 [2] vs. 32 [4], Z = -3.77, P <0.001).

CONCLUSIONS

In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique, as 2-5 mm sufficed.

Early Outcomes From a Multicenter Transcatheter Self-Expanding Pulmonary Valve Replacement Registry

BACKGROUND

Transcatheter pulmonary valve replacement (TPVR) with the self-expanding Harmony valve (Medtronic) is an emerging treatment for patients with native or surgically repaired right ventricular outflow tract (RVOT) pulmonary regurgitation (PR). Limited data are available since U.S. Food and Drug Administration approval in 2021.

OBJECTIVES

In this study, the authors sought to evaluate the safety and short-term effectiveness of self-expanding TPVR in a real-world experience.

METHODS

This was a multicenter registry study of consecutive patients with native RVOT PR who underwent TPVR through April 30, 2022, at 11 U.S.

CENTERS

The primary outcome was a composite of hemodynamic dysfunction (PR greater than mild and RVOT mean gradient >30 mm Hg) and RVOT reintervention.

RESULTS

A total of 243 patients underwent TPVR at a median age of 31 years (Q1-Q3: 19-45 years). Cardiac diagnoses were tetralogy of Fallot (71%), valvular pulmonary stenosis (21%), and other (8%). Acute technical success was achieved in all but 1 case. Procedural serious adverse events occurred in 4% of cases, with no device embolization or death. Hospital length of stay was 1 day in 86% of patients. Ventricular arrhythmia prompting treatment occurred in 19% of cases. At a median follow-up of 13 months (Q1-Q3: 8-19 months), 98% of patients had acceptable hemodynamic function. Estimated freedom from the composite clinical outcome was 99% at 1 year and 96% at 2 years. Freedom from TPVR-related endocarditis was 98% at 1 year. Five patients died from COVID-19 (n = 1), unknown causes (n = 2), and bloodstream infection (n = 2).

CONCLUSIONS

In this large multicenter real-world experience, short-term clinical and hemodynamic outcomes of self-expanding TPVR therapy were excellent. Ongoing follow-up of this cohort will provide important insights into long-term outcomes.

Pulmonary valve replacement in tetralogy of Fallot - who and how?

BACKGROUND AND AIM

Pulmonary regurgitation is the most common complication in repaired tetralogy of Fallot patients. Severe chronic pulmonary regurgitation can be tolerated for decades, but if not treated, it can progress to symptomatic, irreversible right ventricular dilatation and dysfunction. We investigated clinical associations with pulmonary valve replacement among patients with significative pulmonary regurgitation and how interventional developments can change their management.

METHODS

All adult patients with repaired tetralogy of Fallot who were followed at an adult CHD Clinic at a single centre from 1980 to 2022 were included on their first outpatient visit. Follow-up was estimated from the time of correction surgery until one of the following events occurred first: pulmonary valve replacement, death, loss to follow-up or conclusion of the study.

RESULTS

We included 221 patients (116 males) with a median age of 19 (18-25). At a median age of 33 (10) years old, 114 (51%) patients presented significant pulmonary regurgitation. Among patients with significant pulmonary regurgitation, pulmonary valve replacement was associated with male gender, older age at surgical repair, and longer QRS duration in adulthood. Pulmonary valve replacement was performed in 50 patients, including four transcatheter pulmonary valve implantations, at a median age of 34 (14) years.

CONCLUSION

Pulmonary regurgitation affects a large percentage of tetralogy of Fallot adult patients, requiring a long-term clinical and imaging follow-up. Sex, age at surgical repair and longer QRS are associated with the need of PVR among patients with significative pulmonary regurgitation. Clinical practice and current literature support TPVI as the future gold standard intervention.

Decellularized Pulmonary Xenograft Matrix PplusN versus Cryopreserved Homograft for RVOT Reconstruction during Ross Procedure in Adults

BACKGROUND

 Decellularized pulmonary homografts are being increasingly adopted for right ventricular outflow tract reconstruction in adult patients undergoing the Ross procedure. Few reports presented Matrix PplusN xenograft (Matrix) in a negative light. The objective of this study was to compare our midterm outcomes of Matrix xenograft versus standard cryopreserved pulmonary homograft (CPHG).

METHODS

 Eighteen patients received Matrix xenograft between January 2012 and June 2016, whereas 66 patients received CPHG. Using nonparametric statistical tests and survival analysis, we compared midterm echocardiographic and clinical outcomes between the groups.

RESULTS

 Except for significant age difference (the Matrix group was significantly older with 57 ± 8 years than the CPHG group, 48 ± 9 years, p = 0.02), the groups were similar in all other baseline characteristics. There were no significant differences in cardiopulmonary bypass times (208.3 ± 32.1 vs. 202.8 ± 34.8) or in cross-clamp times (174 ± 33.9 vs. 184.4 ± 31.1) for Matrix and CPHG, respectively. The Matrix group had significantly inferior freedom from reintervention than the CPHG group with 77.8 versus 98.5% (p = 0.02). Freedom from pulmonary valve regurgitation ≥ 2 was not significantly different between the groups with 82.4 versus 90.5% for Matrix versus CPHG, respectively. After median follow-up of 4.9 years, Matrix xenograft developed significantly higher peak pressure gradients compared with CPHG (20.4 ± 15.5 vs. 12.2 ± 9.0 mm Hg; p = 0.04).

CONCLUSION

 After 5 years of clinical and echocardiographic follow-up, the decellularized Matrix xenograft had inferior freedom from reintervention compared with the standard CPHG. Closer follow-up is necessary to avoid progression of valve failure into right ventricular deterioration.

First in vivo Experiment with PulmValve Endobronchial Valve: Feasibility, Efficiency, and Safety

INTRODUCTION

Endoscopic lung volume reduction with endobronchial valves has been widely recognized for treating hyperinflation in advanced chronic obstructive pulmonary disease and emphysema patients. The main challenges include the technical complexity of upper lobe implantation and the number of endobronchial valves required. These issues might be addressed by placing larger diameter valves in the lobar bronchus. This study evaluated the feasibility, efficiency, and safety of the new valve PulmValve (model PV-13) in porcine models.

METHODS

Six PV-13 valves were bronchoscopically implanted into the caudal lobe bronchus of six healthy pigs. The procedure time, valve deployment, and removability were recorded. Follow-up examinations included blood tests, chest CT scans, and bronchoscopy at 30 min, 14 days, 28 days, and 84 days post-procedure, with necropsy and pathological evaluations after the final follow-up examination.

RESULTS

The successful in vivo deployment and removal of PV-13 valves was established, with a median procedure time of 6.5 min. The distal lung volume reduction was evident at 30 min post-operation and was persistently monitored on day 84. No migration or malfunction of any PV-13 valves was detected, but a mild angle deviation was found in 3 cases. Coughing was observed in four pigs within the first 7 days and localized granulation tissue was observed in all pigs. No cases of pneumothorax, diffuse pneumonia, or hemoptysis were detected.

CONCLUSIONS

In this study, we report the successful implantation and removal of a new valve PulmValve in a short operation time. Complete lobar atelectasis was induced without device migration, malfunction, or severe complications. Further studies are warranted to evaluate the long-term, sustained effects and potential benefits in human patients.