Long-Term Effects of Pulmonary Valve Implantation and Prosthesis Evolution in Patients with Repaired Tetralogy of Fallot. / Efeitos de Longo Prazo do Implante Valvar Pulmonar e Evolução da Prótese em Pacientes com Tetralogia de Fallot Corrigida.

BACKGROUND: Pulmonary valve regurgitation is a significant long-term complication in patients with tetralogy of Fallot (TOF). OBJECTIVE: This study aims to investigate the effects of pulmonary valve implantation (PVI) on the anatomy and function of the right ventricle (RV) and the long-term evolution of the implanted prosthesis in the pulmonary position. METHODS: A single-center retrospective cohort analysis was performed in 56 consecutive patients with TOF who underwent PVI. The study included patients of both sexes, aged ≥ 12 years, and involved assessing clinical and surgical data, pre- and post-operative cardiovascular magnetic resonance imaging, and echocardiogram data more than 1 year after PVI. RESULTS: After PVI, there was a significant decrease in RV end-systolic volume indexed by body surface area (BSA), from 89 mL/BSA to 69 mL/BSA (p < 0.001) and indexed RV end-diastolic volume, from 157 mL/BSA to 116 mL/BSA (p < 0.001). Moreover, there was an increase in corrected RV ejection fraction [ RVEFC = net pulmonary flow (pulmonary forward flow - regurgitant flow) / R V end-diastolic volume ] from 23% to 35% (p < 0.001) and left ventricular ejection fraction from 58% to 60% (p = 0.008). However, a progressive increase in the peak pulmonary valve gradient was observed over time, with 25% of patients experiencing a gradient exceeding 60 mmHg. Smaller prostheses (sizes 19 to 23) were associated with a 4.3-fold higher risk of a gradient > 60 mmHg compared to larger prostheses (sizes 25 to 27; p = 0.029; confidence interval: 1.18 to 17.8). CONCLUSION: As expected, PVI demonstrated improvements in RV volumes and function. Long-term follow-up and surveillance are crucial for assessing the durability of the prosthesis and detecting potential complications. Proper sizing of prostheses is essential for improved prosthesis longevity.

Differences in Right Heart Function After Pulmonary Valve Replacement in Patients With Pulmonary Valve Stenosis Versus Tetralogy of Fallot.

BACKGROUND: There are limited data about the impact of timing of pulmonary valve replacement (PVR) on right heart reverse remodeling in patients with pulmonary regurgitation following intervention for isolated pulmonary valve stenosis (PS). This study compared differences in postprocedural right heart reverse remodeling after early versus late PVR (defined as PVR before versus after attainment of the conservative consensus criteria proposed by Bokma et al, 2018) in patients with prior intervention for PS, using patients with tetralogy of Fallot as the reference group. METHOD AND RESULTS: Right atrial reservoir strain and right ventricular free wall strain was measured at baseline, 1 and 3 years after PVR. There were 114 patients with PS (early PVR, 87 [76%]; late PVR, 27 [24%]) and 291 patients with tetralogy of Fallot (early PVR, 197 [67%]; late PVR, 96 [33%]). The PS group had greater improvement in right atrial reservoir strain at 1 year (12%±4% versus 8%±4%; P<0.001) and 3 years (15%±6% versus 9%±6%; P<0.001), and a greater improvement in right ventricular free wall strain at 1 year (12%±4% versus 7%±3%, P=0.008) and 3-years (16%±6% versus 12%±5%; P=0.01) after PVR compared with the tetralogy of Fallot group. There was no difference in right heart reverse remodeling between patients who underwent early versus later PVR within the PS group. In contrast, late PVR was associated with less right heart reverse remodeling within the tetralogy of Fallot group. CONCLUSIONS: These data suggest that patients with palliated PS presenting pulmonary regurgitation have a more benign clinical course, and hence delaying PVR in this population may be appropriate.

Left anterior mini-thoracotomy: an alternative approach for pulmonary valve replacement after surgically corrected tetralogy of fallot.

INTRODUCTION: Pulmonary regurgitation (PR) remains a common sequela in patients following surgically corrected TOF, and may lead to progressive right ventricle dilatation and dysfunction. The conventional approach of redo-sternotomy for pulmonary valve replacement (PVR) is associated with increased operative time as well as risks of bleeding and injury to the heart and great vessels. Thus, left anterior mini-thoracotomy has become an alternative approach in eliminating the risks of redo-sternotomy in these patients. This series aimed to determine the outcomes of minimally invasive pulmonary valve replacement after surgical TOF correction. METHODS: A retrospective analysis was conducted on 24 patients with severe PR post-surgical TOF correction who underwent left anterior mini-thoracotomy PVR in Penang General Hospital from January 2021 to January 2023. RESULTS: The median age was 23.5 years (I.Q.range 17.6-36.3), with a male:female ratio of 1:4. Majority of patients had mild to moderate symptoms prior to surgery and 19 patients (79.1%) were on regular diuretics medication. All patients had severe free-flow PR with evidence of right ventricular dilatation and dysfunction. Magnetic Resonance Imaging and computed tomography of pulmonary artery were performed prior to surgery. Minimally invasive PVR was performed on all patients via left upper anterior mini-thoracotomy and femoral-femoral bypass without cardioplegic arrest. The operative time and cardiopulmonary bypass time were 208 (I.Q.range 172-324) and 98.6 minutes(I.Q.range 87.4-152.4) respectively. The time to wean off inotropes postoperatively was 6.2 hours (I.Q.range1.4-14.8), and no postoperative arrhythmia and chest re-exploration were reported. Most patients stayed in Intensive Care Unit (ICU) for 10.8 hours (I.Q.range 8.4-36.5), and the total hospital stay was 4.2 days (I.Q.range 3.4-7.6). 2 patients (11.1%) required blood transfusion postoperative. There was no paravalvular leak and no mortality during the follow-up period of up to 28 months. CONCLUSION: Minimally invasive PVR after surgical correction of TOF is a safe alternative to the conventional redo-sternotomy approach in patients with favorable anatomy. This approach is able to reduce the risks associated with redo-sternotomy, particularly bleeding and injury to mediastinal structures, with the additional benefit of expedited recovery and hospital discharge. Our series has shown a safe and efficient approach in these patients with favorable outcomes.

Extravascular protrusion of the Alterra adaptive prestent identified on surveillance computed tomography imaging.

BACKGROUND: The Alterra adaptive prestent is a novel self-expanding device designed to provide a landing zone for the 29 mm SAPIEN 3 valve to treat pulmonary regurgitation in patients with a right ventricular outflow tract that is too large for a balloon expandable valve alone. The mechanism of fixation for the Alterra prestent is radial force from the self-expanding stent frame, combined with a unique set of flared "tines" that protrude from both ends of the stent. AIMS, METHODS, AND RESULTS: In this report, we describe 6 patients who underwent uncomplicated transcatheter pulmonary valve replacement with an Alterra adaptive prestent and SAPIEN 3 valve and had surveillance chest computed tomography (CT) scans performed 1 day to 21 months after implant. In each patient, the CT scan demonstrated extravascular extension of a portion of the Alterra prestent, without clinical sequelae, but with extension into the ascending aorta in 1 patient and contact with the ascending aorta, left pulmonary vein, or left atrial appendage in 3 others. CONCLUSIONS: Surveillance CT imaging shows that the Alterra prestent can perforate the pulmonary artery and/or right ventricle. Although no sequelae were seen in these patients, prestent perforation has the potential to be clinically important. Implanters should be aware of this finding and its potential implications. As experience with the Alterra prestent grows, it will be important to further define the risk factors, incidence, and implications of this phenomenon.

Melody transcatheter pulmonary valve replacement: a single-center case series in Southeast Asia.

BACKGROUND: Studies of transcatheter pulmonary valve replacement (TPVR) with the Melody valve have demonstrated good clinical and hemodynamic outcomes. Our study analyzes the midterm clinical and hemodynamic outcomes for patients who underwent Melody valve implantation in Southeast Asia. METHODS: Patients with circumferential conduits or bioprosthetic valves and experiencing post-operative right ventricular outflow tract (RVOT) dysfunction were recruited for Melody TPVR. RESULTS: Our cohort (n = 14) was evenly divided between pediatric and adult patients. The median age was 19 years (8-38 years), a male-to-female ratio of 6:1 with a median follow-up period of 48 months (16-79 months), and the smallest patient was an 8-year-old boy weighing 18 kg. All TPVR procedures were uneventful and successful with no immediate mortality or conduit rupture. The primary implant indication was combined stenosis and regurgitation. The average conduit diameter was 21 ± 2.3 mm. Concomitant pre-stenting was done in 71.4% of the patients without Melody valve stent fractures (MSFs). Implanted valve size included 22-mm (64.3%), 20-mm (14.3%), and 18-mm (21.4%). After TPVR, the mean gradient across the RVOT was significantly reduced from 41 mmHg (10-48 mmHg) to 16 mmHg (6-35 mmHg) at discharge, p < 0.01. Late follow-up infective endocarditis (IE) was diagnosed in 2 patients (14.3%). Overall freedom from IE was 86% at 79 months follow-up. Three patients (21.4%) developed progressive RVOT gradients. CONCLUSION: For patients in Southeast Asia with RVOT dysfunction, Melody TPVR outcomes are similar to those reported for patients in the US in terms of hemodynamic and clinical improvements. A pre-stenting strategy was adopted and no MSFs were observed. Post-implantation residual stenosis and progressive stenosis of the RVOT require long term monitoring and reintervention. Lastly, IE remained a concern despite vigorous prevention and peri-procedural bacterial endocarditis prophylaxis.

Tetralogy of Fallot regurgitation energetics and kinetics: an intracardiac flow analysis of the right ventricle using computational fluid dynamics.

Repaired Tetralogy of Fallot (rTOF) patients suffer from pulmonary regurgitation and may require pulmonary valve replacement (PVR). Cardiac magnetic resonance imaging (cMRI) guides therapy, but conventional measurements do not quantify the intracardiac flow effects from pulmonary regurgitation or PVR. This study investigates intracardiac flow parameters of the right ventricle (RV) of rTOF by computational fluid dynamics (CFD). cMRI of rTOF patients and controls were retrospectively included. Feature-tracking captured RV endocardial contours from long-axis/short-axis cine. Ventricular motion was reconstructed via diffeomorphic mapping, serving as domain boundary for CFD simulations. Vorticity (1/s), viscous energy loss (ELoss, mJ/L) and turbulent kinetic energy (TKE, mJ/L) were quantified in RV outflow tract (RVOT) and RV inflow. These parameters were normalized against total RV kinetic energy (KE) and RV inflow vorticity to derive dimensionless metrics. Vorticity contours by Q-criterion were qualitatively compared. rTOF patients (n = 15) had mean regurgitant fraction 38 ± 12% and RV size 162 ± 35 mL/m2. Compared to controls (n = 12), rTOF had increased RVOT vorticity (142.6 ± 75.6/s vs. 40.4 ± 11.8/s, p < 0.0001), Eloss (55.6 ± 42.5 vs. 5.2 ± 4.4 mJ/L, p = 0.0004), and TKE (5.7 ± 5.9 vs. 0.84 ± 0.46 mJ/L, p = 0.0003). After PVR, there was decrease in normalized RVOT Eloss/TKE (p = 0.0009, p = 0.029) and increase in normalized tricuspid inflow vorticity/KE (p = 0.0136, p = 0.043), corresponding to reorganization of the "donut"-shaped tricuspid ring-vortex. The intracardiac flow in rTOF patients can be simulated to determine the impact of PVR and improve the clinical indications guided by cardiac imaging.

Finite element modeling with patient-specific geometry to assess clinical risks of percutaneous pulmonary valve implantation.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is a non-surgical treatment for right ventricular outflow tract (RVOT) dysfunction. During PPVI, a stented valve, delivered via catheter, replaces the dysfunctional pulmonary valve. Stent oversizing allows valve anchoring within the RVOT, but overexpansion can intrude on the surrounding structures. Potentially dangerous outcomes include aortic valve insufficiency (AVI) from aortic root (AR) distortion and myocardial ischemia from coronary artery (CA) compression. Currently, risks are evaluated via balloon angioplasty/sizing before stent deployment. Patient-specific finite element (FE) analysis frameworks can improve pre-procedural risk assessment, but current methods require hundreds of hours of high-performance computation. METHODS: We created a simplified method to simulate the procedure using patient-specific FE models for accurate, efficient pre-procedural PPVI (using balloon expandable valves) risk assessment. The methodology was tested by retrospectively evaluating the clinical outcome of 12 PPVI candidates. RESULTS: Of 12 patients (median age 14.5 years) with dysfunctional RVOT, 7 had native RVOT and 5 had RV-PA conduits. Seven patients had undergone successful RVOT stent/valve placement, three had significant AVI on balloon testing, one had left CA compression, and one had both AVI and left CA compression. A model-calculated change of more than 20% in lumen diameter of the AR or coronary arteries correctly predicted aortic valve sufficiency and/or CA compression in all the patients. CONCLUSION: Agreement between FE results and clinical outcomes is excellent. Additionally, these models run in 2-6 min on a desktop computer, demonstrating potential use of FE analysis for pre-procedural risk assessment of PPVI in a clinically relevant timeframe.

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.

Flow pattern analysis of right ventricular outflow tract in repaired tetralogy of Fallot through 4D flow MRI.

Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.

The adaptability of the Pulsta valve to the diverse main pulmonary artery shape of native right ventricular outflow tract disease.

BACKGROUND: Pulsta valve is increasingly used for percutaneous pulmonary valve implantation (PPVI) in patients with a large native right ventricular outflow tract (RVOT). This study aims to elucidate the outcomes of Pulsta valve implantation within the native RVOT and assess its adaptability to various native main pulmonary artery (PA) anatomies. METHODS: A multicenter retrospective study included 182 patients with moderate to severe pulmonary regurgitation in the native RVOT who underwent PPVI with Pulsta valves® between February 2016 and August 2023 at five Korean and Taiwanese tertiary referral centers. RESULTS: Pulsta valve implantation was successful in 179 out of 182 patients (98.4%) with an average age of 26.7 ± 11.0 years. The median follow-up duration was 29 months. Baseline assessments revealed enlarged right ventricle (RV) volume (mean indexed RV end-diastolic volume: 163.1 (interquartile range, IQR: 152.0-180.3 mL/m²), which significantly decreased to 123.6(IQR: 106.6-137.5 mL/m2  after 1 year. The main PA types were classified as pyramidal (3.8%), straight (38.5%), reverse pyramidal (13.2%), convex (26.4%), and concave (18.1%) shapes. Pulsta valve placement was adapted, with distal main PA for pyramidal shapes and proximal or mid-PA for reverse pyramidal shapes. Two patients experienced Pulsta valve embolization to RV, requiring surgical removal, and one patient encountered valve migration to the distal main PA, necessitating surgical fixation. CONCLUSIONS: Customized valve insertion sites are pivotal in self-expandable PPVI considering diverse native RVOT shape. The rather soft and compact structure of the Pulsta valve has characteristics to are adaptable to diverse native RVOT geometries.

Morphometrics predicts the differential regurgitant fraction in bilateral pulmonary arteries of patients with repaired tetralogy of fallot.

In patients with repaired tetralogy of Fallot (rTOF), the regurgitant fraction (RF) in left pulmonary artery (LPA) and right pulmonary artery (RPA) is usually unequal. The morphometrics may play a crucial role in this RF discrepancy. Cardiovascular MR of 79 rTOF patients and 20 healthy controls were retrospectively enrolled. Forty-four from the 79 patients were matched in age, sex and body surface area to the 20 controls and were investigated for: (1) phase-contrast flow of main pulmonary artery (MPA), LPA, and RPA; (2) vascular angles: the angles between the thoracic anterior-posterior line (TAPL) with MPA (θM-AP), MPA with RPA (θM-R), and MPA with LPA (θM-L); (3) cardiac angle, the angle between TAPL and the interventricular septum; (4) area ratio of bilateral lung and hemithorax regions. Compared with the 20 controls, the 44 rTOF patients exhibited wider θM-AP, sharper θM-L angle, and a smaller θM-L/θM-R ratio. In the 79 rTOF patients, LPA showed lower forward, backward, and net flow, and greater RF as compared with RPA. Multivariate analysis showed that the RF of LPA was negatively associated with the θM-L/θM-R ratio and the age at surgery (R2 = 0.255). Conversely, the RF of RPA was negatively associated with the left lung/left hemithorax area ratio and cross-sectional area (CSA) of LPA, and positively associated with CSA of RPA and MPA (R2 = 0.366). In rTOF patients, the RF of LPA is more severe than that of RPA, which may be related to the vascular morphometrics. Different morphometric parameters are independently associated with the RF of LPA or RPA, which may offer potential insights for surgical strategies.

Bilateral Harmony™ valve placement in branch pulmonary arteries.

While newer self-expanding pulmonic valves were primarily designed for larger right ventricular outflow tracks, there are instances where even larger anatomies cannot accommodate these devices. In this report, we describe the successful implantation of two Harmony™ valves in bilateral branch pulmonary arteries after exhausting other options.

Growth of the right ventricular outflow tract in repaired tetralogy of Fallot: A longitudinal CMR study.

BACKGROUND: Many patients with repaired tetralogy of Fallot require pulmonary valve replacement (PVR) due to significant pulmonary regurgitation (PR). Transcatheter PVR (TPVR) is an equally effective and less invasive alternative to surgical PVR but many native right ventricular outflow tracts (RVOTs) are too large for TPVR at time of referral. Understanding the rate of growth of the RVOT may help optimize timing of referral. This study aims to examine the longitudinal growth of the native RVOT over time in repaired tetralogy of Fallot (TOF). METHODS: A retrospective review of serial cardiac MRI cardiovascular magnetic resonance (CMR) data from 121 patients with repaired TOF and a native RVOT (median age at first CMR 14.7 years, average interval between the first and last CMR of 8.1 years) was performed to measure serial changes in RVOT diameter, cross-sectional area, perimeter-derived diameter, and length. RESULTS: All parameters of RVOT size continued to grow with increasing age but growth was more rapid in the decade after TOF repair (for minimum systolic diameter, mean increase of 5.7 mm per 10 years up to year 12, subsequently 2.3 mm per 10 years). The RVOT was larger with a transannular patch and in patients without pulmonary stenosis (p < 0.001 for both), but this was not associated with rate of growth. More rapid RVOT enlargement was noted in patients with larger right ventricular end-diastolic volume (RVEDV), higher PR fraction, and greater rates of increases in RVEDV and PR (p < 0.001 for all) CONCLUSIONS: in patients with repaired TOF, using serial CMR data, we found that RVOT size increased progressively at all ages, but the rate was more rapid in the first decade after repair. More rapid RVOT enlargement was noted in patients with a larger RV, more PR, and greater rates of increases in RV size and PR severity. These results may be important in considering timing of referral for transcatheter pulmonary valves, in planning transcatheter and surgical valve replacement, and in designing future valves for the native RVOT.

Multicenter Experience for Early and Mid-Term Outcome of MyVal Transcatheter Pulmonary Valve Implantation.

Transcatheter pulmonary valve implantation (TPVI) is a surgical alternative for correcting dysfunctional right ventricular outflow tract in previously operated patients. MyVal transcatheter heart valve (THV) (Meril Life Sciences, India), a new transcatheter valve designed for aortic position has recently been reported to be implanted in pulmonary position. Myval transcatheter valve were implanted in patients with stenosed dysfunctional conduits, severe regurgitation from transannular patch or dysfunctional surgical pulmonary valves (Bioprosthesis). Procedural details and post-TPVI follow-up were analysed. Myval TPVI was used in Fifty three patients with median age of 15 years (IQR 12-19.5 years). Almost sixty percent of the patients were male, with a median weight of 50 kg (31-63 kg). Prestenting was used in more than 80 percent of patients (n = 45 patients), while 6 patients had a prior surgical valve implantation. After Myval TPVI implantation, the peak instantaneous gradient across the RVOT decreased from a median of 23.5 mmHg (IQR 10-53 mmHg) pre-procedure to 10 mmHg (IQR 5-16 mmHg) post-procedure. The median fluoroscopy time for the procedure was 35 min (IQR 23.5-44 min). The large sizes-mainly the 29-mm and 32 mm Myval (Navigator, Meril Life Sciences Pvt Ltd, India), were the most used size in 40% (n = 22) of the cases each. The median contrast volume used during the procedure was 247 mL (IQR 120-300 mL). Patients were followed for a median period of 360 days (IQR 164-525 days). At the last clinic follow-up, there was no tricuspid valve regurgitation. Moderate neo-pulmonary valve regurgitation was reported in three cases. Early experience of TPVI with MyVal is encouraging with procedural success in all patients and acceptable mid-term outcomes.

Transcatheter pulmonary valve replacement in surgically-created double-barrel right ventricular outflow tracts: A single center case-series.

This manuscript describes the feasibility and approach to the assessment and performance of transcatheter pulmonary valve replacement (tPVR) in patients with surgically-created "double-barrel" right ventricular outflow tracts (RVOT). Patients with tetralogy of Fallot may have coronary anomalies which prohibit the performance of traditional tetralogy of Fallot repair. In certain cases, this may necessitate the placement of a right ventricle to pulmonary artery conduit in addition to the native RVOT, which is left in situ, creating so-called "double-barrel" RVOTs. When these patients develop RVOT dysfunction later in life, they would typically be referred for reoperation due to concerns for risk of coronary compression associated with a transcatheter approach. However, whether a transcatheter approach with valve replacement in the native RVOT is feasible or safe is unknown. This was a retrospective review of patients with a surgically created "double-barrel" RVOTs who underwent cardiac catheterization for assessment of tPVR at Boston Children's Hospital. From July 2012 to July 2022, there were four patients with "double-barrel" RVOTs who underwent assessment for tPVR. The age at catheterization ranged between 22 and 39 years. In three out of four patients, coronary compression testing was negative. These three patients had successful tPVR in the native RVOT. At follow up, all three patients were free of greater than mild regurgitation by echocardiogram and had a maximum instantaneous gradient across the RVOT ranging between 20 and 33 mmHg. Performance of tPVR in patients with surgically created "double-barrel" RVOTs is feasible. The safety of this procedure depends crucially on coronary artery assessment at all stages.

Predictive value of Cardiac Magnetic Resonance: new and old parameters in the natural history of repaired Tetralogy of Fallot.

BACKGROUND: Patients with repaired Tetralogy of Fallot (rTOF) often develop pulmonary regurgitation (PR) and right ventricle (RV) dysfunction, experiencing increased mortality and morbidity rates in adulthood. Pulmonary valve replacement (PVR) timing to address PR is controversial. Cardiac Magnetic Resonance (CMR) is the gold standard for morpho-functional evaluation of complex cardiopathies. This study aims to identify CMR parameters predictive of adverse outcomes to help defining the best therapeutic management of rTOF patients. METHODS: 130 rTOF patients who underwent CMR (2006-2019) were enrolled in this retrospective single-center study. CMR, clinical, ECG and exercise data were analyzed. Univariate and multivariate analyses identified clinical and CMR parameters predictive of adverse outcomes both individually (e.g., death, arrhythmias, heart failure (HF), pharmacological therapy, QRS ≥ 160ms) and as composite outcome. RESULTS: Univariate analysis confirmed RV volumes and RV ejection fraction corrected for PR as adverse outcome predictors and identified interesting correlations: pulmonary artery bifurcation geometry and abnormal interventricular septum (IVS) motion with arrhythmias (p < .001; p = .037), HF (p = .049; p = .005), composite outcome (p = .039; p = .009); right atrium (RA) dimensions with the composite outcome and the outcomes individually (p < .001). The best predictive models by multivariate analysis included sex (male), RV and RA dilation for QRS ≥ 160ms, time form repair to CMR, age at TOF repair and IVS fibrosis for pharmacological therapy. CONCLUSIONS: Besides RV volumes, new adverse prognostic factors could guide rTOF therapeutic management: pulmonary arteries morphology, abnormal IVS motion, RV dysfunction, RA dilation. Perspective multicentric evaluation is needed to specify their effective role.

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.