Pulmonary Valve Replacement Research Articles

Abstract 4135534: Total and Regional Lung Volumes And Pulmonary Blood Flow In Repaired Tetralogy Of Fallot - Smaller Lungs And A Maldistribution of Flow

Introduction: Many pts with repaired tetralogy of Fallot (rTOF) are left with residual pulmonary regurgitation (PR) and poor exercise performance. Small studies in young children suggest that the total lung volume of rTOF pts are smaller than normal and may contribute to these sequelae. As exercise and cardiac performance are intimately related to lung function, it’s surprising that few rTOF studies have investigated cardiopulmonary interactions. Aims: To determine if regional and total lung volumes in rTOF pts are the same size as normals and if the larger amount of forward blood flow courses to the bigger lung. We hypothesized that this may not be the case. Methods: rTOF patients undergoing clinically indicated cardiac magnetic resonance (CMR) were evaluated for lung volumes using dark blood imaging (figure) and blood flow to the branch pulmonary arteries (bPA) using velocity mapping. Significance < P=0.05. Results: Eleven rTOF patients and 25 normal controls were studied. Total control lung volume was significantly larger than those of rTOF. Regional rTOF right and left lung volumes were smaller than their respective control lung volumes, barely missed statistical significance (table). In 6 rTOF pts with CMR prior to and after pulmonary valve replacement (PVR), lung volumes did not differ between the 2 timepoints (1034 vs 998 cc/m 2 respectively). Only 3/11 (27%) rTOF pts had the higher bPA flow coursing to the higher regional lung. The ratio of right bPA forward flow/right lung volume to left bPA forward flow/left lung volume ranged from 0.72-1.51 (ideal balanced flow to each lung would be 1), implying a maldistribution of flow. Conclusion: rTOF patients have smaller total lung volumes than controls with no change after PVR in our study. In addition, only a small proportion of rTOF patients have the larger amount of flow coursing to the larger lung. The ratio of individual bPA flow to individual lung volume implies a maldistribution of pulmonary flow relative to the respective lung volume. Our findings may have implications for timing of PVR, partially explaining PR and poor exercise performance. Flow limiters placed by cath or surgery may be able to redistribute the appropriate flow to regional lung fields.

Abstract 4143242: Right Ventricular Remodeling During the First Decade After Tetralogy of Fallot Repair: An Echocardiographic Study

Background: After TOF repair (TOFr), pulmonary regurgitation resulting in right ventricular (RV) dilatation and dysfunction is common. We have previously demonstrated that RV function (RVF) improves in the first two years after TOFr, however RV changes in the first decade after TOFr are less known. We investigated RVF and RV size (termed remodeling) using echocardiography during the first decade after TOFr. Methods: Retrospective cohort study of patients who underwent TOFr and were followed at our institution from 3/2012 to 12/2023. Those with at least two echocardiograms separated by one year were included. Two patients that received a pulmonary valve replacement were excluded. After confirming intra- and inter-reader reproducibility, RV remodeling was assessed offline by global longitudinal strain (GLS), free wall strain (FWS), fractional area change (FAC), end systolic area (ESA/BSA) and end diastolic area (EDA/BSA). RVF changes over time were assessed with multivariable linear mixed effects models adjusting for perioperative covariates. Two years after TOFr (Y2) was used as reference given RVF peaks at this point following surgery. Results: Out of 758 echocardiograms from 116 patients, 688 were suitable for analysis. Median age at TOFr was 3.5 months (IQR:1.92, 4.89). Compared to Y2, we identified the largest decline in RVF at Year 3, with no worsening from year to year until Y10. There were no associations of perioperative covariates with RVF except for ventriculotomy (FAC) and residual pulmonary stenosis (FWS). There was no progression in RV remodeling over the first decade after TOFr. (Graph, table). Conclusion: After the initial 2-year improvement following TOFr, RVF worsens but remains stable throughout the first decade with stable RV size accounting for BSA. Our findings augment the knowledge of RV remodeling during childhood and could help guide outpatient follow up, counseling, frequency of echocardiograms, and timing of the first cardiac MR.

Severity of native pulmonary annular hypoplasia and late outcomes of tetralogy of Fallot: retrospective cohort study.

Pulmonary annular hypoplasia and valvar dysplasia are key morphological features affecting long-term outcomes of tetralogy of Fallot. This retrospective study aimed to analyse factors affecting contemporary long-term outcomes with a focus on pulmonary annular growth and function over time. 131 consecutive isolated tetralogy of Fallot repairs performed between 2004 and 2014 at University Children's Hospital Zurich were included. Median age and weight at the time of repair were 4.8 (interquartile range [IQR] 3.2-6.3) months and 6.1 (IQR 5.1-7) kg, respectively. Based on the severity of native pulmonary annular hypoplasia, the cohort was divided into group 1 (preoperative pulmonary annular Z score < -4; n = 20), group 2 (Z score -2 to -4; n = 56) and group 3 (Z score > -2; n = 54). A transannular patch was used in 88/131 (67.2%) patients: 80%, 67.9% and 61.1% in groups 1, 2 and 3, respectively. The primary outcome was defined as right ventricular outflow tract (RVOT) reoperation or pulmonary valve replacement. Secondary outcome was composite pulmonary valve dysfunction defined as peak gradient >40 mm Hg or severe pulmonary regurgitation at follow-up. A multiple Cox regression model was used to quantify the association of age at tetralogy of Fallot repair, preoperative pulmonary annular Z score and RVOT approach with primary and secondary outcome. Follow-up was 98.5% complete, with a median follow-up duration of 9.6 (95% confidence interval [CI] 9-10.4) years. All patients were alive at last follow-up resulting in 100% survival. 20/131 patients underwent pulmonary valve replacement (14 surgical and 6 catheter interventional) while 5/131 underwent RVOT reoperations other than valve replacement. The Kaplan-Meier 10-year freedom from primary outcome was 85% (95% CI 78-92%); 69% (46-100%), 91% (82-100%) and 84% (74-95%) for groups 1, 2 and 3, respectively (log rank p = 0.16). Composite dysfunction at follow-up was observed in 29.8% (overall): 45%, 28.6% and 25.9% for groups 1, 2 and 3, respectively (p = 0.12). The multiple Cox regression analysis for primary outcome indicated that the use of a transannular patch results in a Hazard Ratio (HR) of 3.3 (95% CI 0.7-14.7, p = 0.13). Additionally, the presence of composite dysfunction at discharge results in a HR of 2.1 (95% CI 0.8-5.4, p = 0.1). Age (in months) with a HR of 0.8 (95% CI 0.6-1, p = 0.06) and group 2 with a HR of 0.4 (95% CI 0.14-1.2, p = 0.11) showed a trend to being protective for the primary outcome. However, the 95% CI of all estimates included the HR of 1. Transannular patch use and composite dysfunction at discharge, although not statistically significant at 5% level, may be associated with pulmonary valve replacement and RVOT reoperation. Avoiding the use of a transannular patch or using reconstructive techniques to achieve a better composite dysfunction at discharge could reduce the primary outcome. Large multicentre studies are needed to demonstrate more precisely the impact of pulmonary annulus Z scores on outcome.

The Electrical Substrate of the Right Ventricle in Valvar Pulmonary Stenosis: Early Observations from Electrophysiology Studies Prior to Pulmonary Valve Replacement

The Electrical Substrate of the Right Ventricle in Valvar Pulmonary Stenosis: Early Observations from Electrophysiology Studies Prior to Pulmonary Valve Replacement

The impact of tricuspid regurgitation on the timing of pulmonary valve replacement in adult patients after Tetralogy of Fallot repair

Abstract Background Tricuspid regurgitation (TR) in patients with repaired tetralogy of Fallot (rTOF) is an important finding with a wide spectrum of etiologies. TR represents an important risk factor in adult patients with rTOF, influencing clinical outcomes and the requirement for additional surgical interventions. In this study, we reviewed the long-term outcomes of TR in ACHD patients with rTOF as well as its impact on the timing of surgical pulmonary valve replacement (PVR). Methods This was a retrospective analysis of a single institutional cohort which included 149 ACHD patients with a history of rTOF (transannular patch only) with CMR data, complete follow-up, and a recent (&amp;lt; 1 year) outpatient clinic visit. Results Overall follow-up time was 25.5 years (95% CI 24.5,26.4). Between 2002 and 2021, 93 patients required isolated PVR at a mean time from TOF repair of 16.6 years (95% CI 15.5,17.7) and at a mean age of 17.9 years (95% CI 16.8,19.0). In the whole cohort, significant TR was associated with a two-fold increase in the likelihood of requiring PVR (log-rank p = 0-.0023, HR 2.02; 1.09-4-47). Moderate to severe TR was more frequent in those who underwent VSD closure through a right atriotomy (17 versus 0, p = .0002) and affected time to PVR (13.9 versus 16.3 years, p = .0071), with equal preoperative RVEDVi at CMR. After PVR, RVEDVi normalized in all patients, regardless of the preoperative amount of TR (median 115.3 ml/m2 versus 112.3 ml/m2, p = .7). At a median time of 6.5 years from PVR, 13 patients (13/93, 14%) underwent redo PVR. Conclusions The preoperative severity of tricuspid regurgitation (TR) may have a substantial role on the likelihood of patients needing PVR at a younger age. This, in turn, could result in a reduced duration of freedom from valve failure. Replacing the pulmonary valve too early can effectively increase the lifetime number of procedures, preserving the function of the tricuspid valve at the time of TOF repair is of paramount importance.

A 2D echocardiographic method for accurate right ventricular quantification using deep learning

Abstract Background/Introduction Transthoracic two-dimensional echocardiography (2DE) remains the backbone for non-invasive assessment of the right ventricle (RV) size and function. However, calculation of RV end-diastolic (RVEDV), end-systolic volume (RVESV) and ejection fraction (RVEF) cannot be performed using 2DE due to the complex RV shape (1), whereas currently used, respective 2DE indices lack diagnostic accuracy. Deep learning (DL) may be able to assist in developing new 2DE methods for RV quantification. Purpose To develop a novel DL-based 2DE method for quantitative evaluation of RV size and function without geometric assumptions. Methods 50 adult patients underwent 2DE and CMR within 30 days as part of routine cardiac care between 6/2020 – 9/2021 at a medical center. We excluded patients with prior cardiac surgery of the RV, tricuspid or pulmonic valve repair or replacement, complex congenital heart disease, more than small pericardial effusion, cardiac tamponade, atrial fibrillation at the time of either study, severe RV dysfunction or inadequate imaging quality. End-diastolic and end-systolic areas derived from planimetry of 8 2DE RV views, along with patient age and gender, were to used to train and test a DL algorithm, namely the Feature-Tokenizer and Transformer (Figure 1) in order to predict the corresponding, CMR-derived, RVEDV or RVESV, and subsequently calculate RVEF. We used 5-fold cross-validation for training and evaluation. We assessed the relative importance of each 2DE view using gain metric-powered explainability analysis and subsequently performed a sensitivity analysis to identify optimal combinations of views. Variability analysis was performed for a random subcohort of 10 patients. Results Median age was 51 (interquartile range 32-62) and 42% were women. Mean RVEDV, RVESV and RVEF) by CMR were 163±70ml, 82±42ml and 51±8% respectively. Six patients (12%) had RV dilatation and 9 (18%) had RV dysfunction when using published CMR criteria. Explainability analysis showed that the 3 most important views were parasternal long axis (PLAX) (relative feature importance [RFI] = 0.197), 4-chamber (RFI=0.145) and parasternal short axis at the base (PSAX-base) (RFI=0.112). The 3-view combination of PLAX, 4-chamber and PSAX-base achieved high accuracy when compared to CMR (R2=0.964, absolute percentage error [APE]=8.09±12.07% for RV volumes and APE=9.86±10.68% for RVEF). Good (intraclass correlation coefficient [ICC]&amp;gt;0.75) to excellent (ICC&amp;gt;0.90) intra- and interobserver variability was found for these 3 views. Conclusions We propose an innovative, clinically applicable DL-based 2DE method for quantification of RV size and function that requires manual RV planimetry of 3 views, namely 4-chamber, PLAX and PSAX-base (Figure 2). This method may revolutionize 2DE RV assessment. Further studies with largest number of patients and wider range of RV size and function are needed to validate this method.Deep learning architectureGraphical abstract

Left Anterior Minithoracotomy for Pulmonary Valve Replacement in Adults.

Surgical interventions on the pulmonary valve in adults have been increasing over the years, as patients with congenital heart diseases are experiencing extended lifespans. Reoperations involving multiple sternotomies exhibit elevated morbidity and mortality rates. With nearly two decades of experience in minimally invasive video-assisted mitral valve surgery, we have chosen the left anterior minithoracotomy approach for addressing the pulmonary valve and right ventricular outflow tract in adult patients. The technique demonstrates safety based on initial outcomes, minimizing potential complications from multiple cardiac reapproaches. Our series of five patients demonstrated an absence of postoperative complications or mortality.

Adaptation of Aortic Bioprosthetic Valves for Pulmonary Position: Comparative Analysis of Transcatheter and Surgical Valves.

Pulmonary valve dysfunction is common in congenital heart disease, often leading to interventions like right ventricular outflow tract reconstruction. Transcatheter pulmonary valve replacement (TPVR) has emerged as a successful alternative to surgery, showcasing promising outcomes for managing postoperative RVOT complications. The study aimed to compare two bioprosthetic valves-Carpentier Edwards Perimount Magna Ease surgical valve and Edwards SAPIEN 3 transcatheter valve-originally designed for aortic use but adapted for pulmonary applications. The hemodynamic characteristics of a 26-mm SAPIEN 3 and a 25-mm Magna Ease were assessed in a pulse duplicator under both pulmonary and aortic conditions. Furthermore, detailed structural analyses of the leaflets were conducted using computational simulations under these conditions. The results highlighted significant differences in the hydrodynamic and structural characteristics of these two bioprosthetic valves when exposed to pulmonary versus aortic conditions. The study enhances our understanding of the biomechanics involved in surgical and transcatheter pulmonary valve replacement.

A 3D Statistical Shape Model of the Right Ventricular Outflow Tract in Pulmonary Valve Replacement Patients Post-Surgical Repair.

Assessment of the right ventricular outflow tract and pulmonary arteries (RVOT) for percutaneous pulmonary valve implantation (PPVI) uses discrete measurements (diameters and lengths) from medical images. This multi-centre study identified the 3D RVOT shape features prevalent in patients late after surgical repair of congenital heart disease (CHD). A 3D RVOT statistical shape model (SSM) was computed from 81 retrospectively selected CHD patients (14.7 ± 6.8 years) who required pulmonary valve replacement late after surgical repair. A principal component analysis identified prevalent shape features (modes) within the population which were compared with standard geometric measurements (diameter, length and surface area) and between sub-groups of diagnosis, RVOT type and dysfunction. Shape mode 1 and 2 represented RVOT size and curvature and tapering and length, respectively. Shape modes 3-5 related to branch pulmonary artery calibre, conical vs. bulbous RVOTs and RVOT curvature, respectively. Tetralogy of Fallot, transannular patch type and regurgitant RVOTs were larger and straighter while conduit and stenotic types were longer and more cylindrical than other subgroups. This SSM analysed the main 3D shape features present in a population of RVOTs, exploiting the wide 3D anatomical information provided by routine imaging. This morphological information may have implications for PPVI patient selection and device design.

TCT-120 Comparison of Percutaneous and Surgical Pulmonic Valve Replacement: Analysis From Nationwide Readmission Database

TCT-120 Comparison of Percutaneous and Surgical Pulmonic Valve Replacement: Analysis From Nationwide Readmission Database

TCT-117 Trends and Outcomes of Percutaneous vs Surgical Pulmonary Valve Replacement in Patients With Prior Tetralogy of Fallot Repair

TCT-117 Trends and Outcomes of Percutaneous vs Surgical Pulmonary Valve Replacement in Patients With Prior Tetralogy of Fallot Repair

Burden of reintervention after tetralogy of Fallot repair: A joint pediatric and adult congenital experience over 30 years

ObjectiveThere is a high burden of reintervention after repair of tetralogy of Fallot (TOF). We compare procedural burden and late outcomes in valve-sparing repair (VSR) and transannular patch (TAP) cohorts over 30 years. MethodsPatients undergoing TOF repair (1990-2021, excluding complex TOF) were included in this study (n = 1239) with subsequent comparisons between TAP (n = 550) and VSR (n = 648) cohorts. Descriptive statistics, cumulative incidence frequencies, survival analysis, and propensity matching (n = 425) were used to analyze reintervention burden and survival. ResultsOverall survival of the cohort was 96.7% at 15 years and 95.6% at 25 years, with similar survival between TAP and VSR cohorts (P = .22). The TAP cohort had increased incidence of procedural burden at 25 years (TAP 69.8% vs VSR 37.2%; P < .001), with 34.6% undergoing ≥2 reinterventions. The TAP cohort had higher incidence of surgical pulmonary valve replacement at 15 years (TAP 20.7% vs VSR 7.6%; P < .001) and placement of pulmonary artery stents (TAP 20.2% vs VSR 4.9%; P < .001). By contrast, VSR had higher incidence of right ventricular outflow tract (RVOT) reoperation at 15 years (VSR 7.3% vs TAP 3.6%; P = .047). After propensity score matching there was no survival advantage between the VSR and TAP cohorts (Era 2), whereas the need for RVOT reoperation was not different between the 2 cohorts (P = .060). ConclusionsThe procedural burden remains high following TOF repair. TAP is associated with higher procedural burden in matched and nonmatched cohorts. VSR has increased risk of reoperation for RVOT obstruction only in nonmatched comparisons. Anatomical complexity and surgical repair strategy influence procedural burden following TOF repair.

Incidence of Infective Endocarditis Post-TPVR with MELODY Valve in Pediatric Patients: A Systematic Review and Meta-Analysis.

Infective Endocarditis (IE) has emerged to be one of the most impactful adverse complications post-transcatheter procedures, especially Transcatheter Pulmonary Valve Replacement (TPVR). We conducted a systematic review and meta-analysis with the aim of identifying the incidence of IE post-TPVR with the MELODY valve in the pediatric population. A comprehensive literature search was performed across several prominent databases, including PubMed/MEDLINE, SCOPUS, and Science Direct. Studies compared the clinical outcomes of pediatric patients who received TPVR using the MELODY valve. Data extraction was done for variables like the total pediatric patient population that underwent TPVR with MELODY valve, mean age, the sex of the patients, the incidence rate of IE following the procedure, and the duration between the procedure and the occurrence of IE. Inverse Variance was used to estimate the incidence of IE in patients who underwent TPVR with respective 95% confidence interval (CI). In total, 4 studies with 414 pediatric patients who underwent TPVR using the MELODY valve were included in the study. The mean age of the study population was 12.7 ± 3.11 years. The pooled incidence of IE following TPVR with MELODY valve in the pediatric population was 17.70% (95% Cl 3.84-31.55; p<0.00001). Additionally, the mean length of duration to develop IE following TPVR with MELODY valve in the pediatric population was 2.18 years (95% Cl 0.35-4.01; p<0.00001). Our meta-analysis reveals that IE post-TPVR with MELODY valve in pediatric patients is a significant complication, clinically and statistically. Further research needs to be done to understand the risk factors and develop better management strategies.

Computational haemodynamics for pulmonary valve replacement by means of a reduced fluid-structure interaction model.

Pulmonary valve replacement (PVR) consists of substituting a patient's original valve with a prosthetic one, primarily addressing pulmonary valve insufficiency, which is crucially relevant in Tetralogy of Fallot repairment. While extensive clinical and computational literature on aortic and mitral valve replacements is available, PVR's post-procedural haemodynamics in the pulmonary artery and the impact of prosthetic valve dynamics remain significantly understudied. Addressing this gap, we introduce a reduced Fluid-Structure Interaction (rFSI) model, applied for the first time to the pulmonary valve. This model couples a three-dimensional computational representation of pulmonary artery haemodynamics with a one-degree-of-freedom model to account for valve structural mechanics. Through this approach, we analyse patient-specific haemodynamics pre and post PVR. Patient-specific geometries, reconstructed from CT scans, are virtually equipped with a template valve geometry. Boundary conditions for the model are established using a lumped-parameter model, fine-tuned based on clinical patient data. Our model accurately reproduces patient-specific haemodynamic changes across different scenarios: pre-PVR, six months post-PVR, and a follow-up condition after a decade. It effectively demonstrates the impact of valve implantation on sustaining the diastolic pressure gradient across the valve. The numerical results indicate that our valve model is able to reproduce overall physiological and/or pathological conditions, as preliminary assessed on two different patients. This promising approach provides insights into post-PVR haemodynamics and prosthetic valve effects, shedding light on potential implications for patient-specific outcomes.

Isolated pulmonary valve endocarditis in a pediatric patient with down syndrome

BackgroundIsolated pulmonary valve endocarditis (IPE) accounts for less than 2% of all infective endocarditis patients. It is commonly associated with several predisposing factors, including intravenous drug use (IVDU) and congenital heart disease. The most common causative pathogens of IPE are Staphylococcus aureus and Streptococcus viridans. We report a Down’s syndrome patient with IPE and with no standard risk factors caused by the rare pathogen Acinetobacter spp. This led to respiratory failure and systemic infection due to septic pulmonary emboli. Early elective surgery was decided upon as the patient was no longer responding to medical therapy, and his clinical condition was worsening over time.Case presentationA 15-year-old male with Down syndrome and no underlying heart defect presented with a 3-month history of episodic fever, nausea, vomiting, and diarrhea. Transthoracic echocardiography (TTE) revealed large vegetation on the pulmonary valve leaflet, another mobile mass at the pulmonary artery bifurcation, and severe pulmonary regurgitation. Serial blood cultures isolated Acinetobacter spp. Despite initial antibiotic therapy, the patient continued to have sepsis, unresolved vegetations, and developed life-threatening complications and respiratory distress, which convinced us to perform a pulmonary valve replacement surgery with a homograft. After surgery, the patient recovered and was discharged on the ninth postoperative day (POD).ConclusionThis report highlights IPE’s diagnostic and therapeutic challenges, alongside the importance of a comprehensive cardiopulmonary workup in patients with unexplained fever, sepsis, and pulmonary symptoms, even without typical risk factors. Based on the patient’s aggravating condition despite medical treatment, early surgical intervention and pulmonary valve replacement were deemed crucial. However, there still needs to be a definitive guideline on when and how surgery should be performed in patients with complicated IPE, especially in pediatric patients.

Transcatheter Pulmonary Valve Replacement in Middle and Late Adulthood

Transcatheter pulmonary valve replacement (TPVR) is now frequently performed in patients with adult congenital heart disease. As the life expectancy of the population with adult congenital heart disease continues to improve, more patients will require pulmonary valve intervention. This study details the short-term and midterm clinical outcomes of patients aged ≥40 years who underwent TPVR. We performed an institutional retrospective cohort study that included patients aged ≥40 years who underwent TPVR (and clinical follow-up) from January 1, 2012 to January 1, 2024. Descriptive analyses, Kaplan-Meier survival analysis, and Cox proportional hazard modeling were used to determine outcomes and risk factors affecting survival. The study included 67 patients, and median age at TPVR was 48 years (43 to 57). Median hospital length of stay after TPVR was 1 day (1 to 3); periprocedural complications occurred in 5 patients, and acute kidney injury occurred in 1 patient. Median duration of follow-up was 3.5 years (0.1 to 9.7). There were 9 total deaths, and 1-, 3-, and 5-year Kaplan-Meier survival after TPVR was 95%, 91%, and 82%, respectively. Moderate or worse right ventricular dysfunction was present in 22 patients before TPVR and in 20 patients after TPVR. Inpatient status before TPVR negatively affected survival (hazard ratio 24.7, 3.3 to 186.1, p = 0.002). In conclusion, TPVR was performed in patients aged ≥40 years with favorable periprocedural and midterm follow-up outcomes including survival, but right ventricular dysfunction did not improve, and further exploration of the ideal timing of TPVR in this age group is warranted.

Beating Heart Pulmonary Valve Replacement: Technique of Pulmonary Valve Replacement with a Biological Valve

Pulmonary valve replacement is traditionally performed using cardioplegia in order to induce cardiac arrest during the operation. However, the induction of cardiac arrest is known to be associated with several postoperative complications. Therefore, over the years new cardioprotective techniques have been introduced: one of which is the on-pump beating heart technique. The technique of pulmonary valve replacement on a beating heart could be efficacious in reducing the incidence of cardiac dysfunction or injury which can be associated with the use of cardioplegia. Such as the avoidance of aortic cross-clamping observed in the beating heart technique may be linked with lower risks of stroke and other aortic complications. Therefore, the technique that we present combines the advantages of operating on a beating heart and being on-pump in the context of complex re-do operations of the pulmonary valve.

Management of Fallot's Uncorrected Tetralogy in Adulthood: A Narrative Review.

The majority of cyanotic congenital cardiac defects are caused by the tetralogy of Fallot. Some symptoms include a biventricular connection of the aortic root, right ventricular hypertrophy, blockage of the right ventricular outflow tract, and a ventricular septal defect. Our understanding of tetralogy of Fallot (TOF) has significantly advanced since it was first described in 1888, and early diagnosis has led to improved surgical management and increased life expectancy. Adults with unrepaired and repaired TOF present with a range of late complications, including heart failure, the need for re-interventions, and late arrhythmias. Right ventricular (RV) failure, often caused by chronic pulmonary regurgitation, is a significant cause of heart failure in patients with TOF. Current treatment options are limited, and mainstay surgical procedures such as pulmonary-valve replacement (PVR), trans-annular repair (TAR), or infundibular widening repair have not shown a significant reduction in preventing right ventricular (RV) failure or death. Here, we explain the mechanisms of RV failure in ToF, chronic pulmonary regurgitation, heart failure, and secondary polycythemia. HF management in untreated adults is discussed. The progression of the disease, as well as complications, are also discussed. The treatment plan and the need to investigate the best management approach for this unsolved problem are included. This review aims to fill the knowledge gaps and supply valuable information regarding mechanisms of RV failure, chronic pulmonary regurgitation, and secondary polycythemia. To summarize, a new combat strategy must be found to battle RVF, and a more profound vision of these mechanisms is required. If it is not corrected, it will be one of the future research lines that will contribute to designing more efficacious treatment techniques for adults with TOF.

4-Dimensional Right Ventricular Outflow Tract Segmentation to Evaluate Candidacy for Transcatheter Pulmonary Valve Replacement.

Candidacy for transcatheter pulmonary valve replacement utilizing newer valve platforms is aided by industry-driven fit analyses. We report augmentation of this decision-making process by visualization of 4-dimensional cine imaging of patient-specific right ventricular outflow tract anatomy and a virtual valve model within a virtual reality platform.

Transcatheter pulmonary valve replacement after arterial switch operation.

Patients with d-transposition of the great arteries (d-TGA) who have undergone an arterial switch operation (ASO) can develop right ventricular outflow tract (RVOT) dysfunction with pulmonary regurgitation (PR) or stenosis. In these patients, treatment may include transcatheter pulmonary valve replacement (TPVR). Coronary compression is a contraindication occurring in 5% of typical TPVR cases. After ASO, there are various anatomical considerations that can confound TPVR, including potential coronary artery compression. Our goal is to understand feasibility of TPVR in patients following ASO. This was a retrospective multicenter cohort study of patients with RVOT dysfunction after ASO who underwent cardiac catheterization with intention to perform TPVR from 2008 to 2020. Across nine centers, 33 patients met inclusion criteria. TPVR was successful in 22 patients (66%), 19 receiving a Melody valve and 3 a SAPIEN valve. RVOT stenosis in isolation or with PR dictated need for TPVR in nearly all patients. One serious adverse event occurred with valve embolization. After TPVR, the RVOT peak gradient decreased from 43 to 9 mm Hg (p < 0.001); PR was trivial/none in all but one patient, in whom it was mild. Coronary compression prohibiting TPVR occurred in eight patients (24%) and two patients (6%) had severe aortic regurgitation from aortic root deformation precluding TPVR. Seven patients underwent RVOT reintervention with a median of 5.3 years post-TPVR. TPVR in patients with d-TGA after ASO is feasible, but in this cohort, coronary compression or aortic root distortion precluded TPVR in one-third of patients. The rate of RVOT reintervention after TPVR was higher in this cohort of ASO patients that in prior studies.