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.

Impact of Patient Prosthesis Mismatch on the Outcome of Transcatheter Pulmonic Valve Implantation.

Patient prosthesis mismatch (PPM) is an important factor of the outcome in transcatheter aortic valve implantation. However, the impact of PPM in transcatheter pulmonic valve implantation (TPVI) has not been studied. Based on the narrowest valve stent diameters in two views of fluoroscopy, internal geometric orifice area (GOA) of the valve stent was calculated and indexed by body surface area (BSA), deriving iGOA. To define PPM in TPVI, receiver operating characteristics (ROC) curve analysis for iGOA for predicting significant residual right ventricular outflow tract (RVOT) gradient was used to derive the optimal cut-off value of iGOA. Our cohort were divided into 2 groups: PPM versus non-PPM. The clinical data were compared between 2 groups. TPVI was performed using Melody valve in 101 patients. Significant RVOT residual pressure gradient (≥ 15 mmHg) was observed in 31 patients (39.6%). Over a mean follow up periods of 6.9 ± 2.7 years, 22 patients (21.8%) required repeat interventions (16 transcatheter, 11 surgical, and both in 5 patients). Based on the ROC analysis, the best cut-off value of iGOA was 1.25 cm2/m2 (area under the curve 0.873, p < 0.001) to define PPM. PPM was present in 42 patients (42%). On the Kaplan-Meier survival analysis, PPM was associated with the need of repeat intervention (p = 0.02). In conclusion, in TPVI, PPM was a strong predictor for the need of re-intervention. Considering PPM, target diameter of valve stent would depend on the patient body size and should be taken into account for optimal outcome of TPVI.

Outcomes in Young Adults With Tetralogy of Fallot and Pulmonary Annular Preserving or Transannular Patch Repairs.

BACKGROUND: Early surgical tetralogy of Fallot (ToF) repair involved patching across the pulmonic annulus (transannular patch [TAP] repair), which resulted in severe pulmonic regurgitation. Long-term outcome improvements were anticipated with modifications that preserved the pulmonic annulus (annulus-preserving [AP] repair). The objective of the present study was to evaluate the need for late reintervention in adults with AP repair and those with TAP repair. METHODS: We conducted a retrospective review of adults (born 1981-1996) with childhood intracardiac ToF repairs at a tertiary care center. The primary cardiovascular outcome was need for reintervention after primary intracardiac repair of ToF. Secondary outcomes included a composite of death, heart failure, and ventricular arrhythmias. RESULTS: Two hundred thirty adults were included: 104 with AP repair and 126 with TAP repair. The median age at last follow up was 25 years (interquartile range [IQR] 20-28) and the median follow-up duration was 7.9 years (IQR 3.5-12). Reintervention of any type was significantly more common in the TAP group during both childhood and adulthood (72.2% TAP vs 20.2% AP, HR 5.5, 95% CI 3.4-9.0; P < 0.001). Pulmonary valve replacement (PVR) was almost 6 times more likely in adults with TAP repair (65.1% TAP vs 16.3% AP, HR 5.7, 95% CI 3.4-9.7; P < 0.001). CONCLUSIONS: Patients who had AP ToF repair had significantly fewer late reinterventions compared with TAP repair, with the majority of reinterventions due to PVR. More long-term follow-up is required.

Congenital right ventricular diverticulum formed by pulmonary regurgitative jet flow in a fetus with tetralogy of Fallot and absent pulmonary valve.

Congenital ventricular diverticulum is a rare anomaly with an unclear pathology. Here, we report a male fetus at 24 weeks of gestation, diagnosed with right ventricular diverticulum associated with tetralogy of Fallot and absent pulmonary valve. The diverticulum was located at the anterosuperior wall of the right ventricle and faced into the massive pulmonary regurgitation flow jet. Intrauterine fetal death from heart failure resulted at 26 weeks of gestation. An autopsy revealed significant subendocardial fibrosis in the diverticular wall without inflammatory cell infiltration. Clinical and pathologic features suggested that the regurgitative blood flow contributed to the formation of the right ventricular diverticulum.

The behavior of residual pulmonary artery gradient after arterial switch operation: A longitudinal data analysis.

OBJECTIVE: The arterial switch operation (ASO) is the standard treatment for the transposition of the great arteries. The timely variation in the residual pressure gradient across the pulmonary arteries is ill-defined. This study is aimed to study the progressive changes in the pressure gradient across the pulmonary valve and pulmonary arteries after ASO. METHODS: All eligible patients for this study who underwent ASO between 2000 and 2019 were reviewed. Transthoracic echocardiography was used to estimate the peak pressure gradient across the pulmonary artery and its branches. The primary outcome was the total peak pressure gradient (TPG) which is the sum of peak pressure gradients across the main pulmonary artery and pulmonary artery branches. Furthermore, longitudinal data analyses with mixed-effect modeling were used to determine the independent predictors for the changes in the pressure gradient. RESULTS: Three hundred and nine patients were included in the study. Over a 17-year follow-up, the freedom from pulmonary stenosis reintervention was 95% (16 out of the 309 patients underwent reintervention = 5%). The longitudinal data analyses of serial 1844 echocardiographic studies for the included patients revealed that the TPG recorded in the first postoperative echocardiogram across pulmonary valve, right and left pulmonary artery branches was the most significant predictor for reintervention. CONCLUSION: The total peak gradient measured in the first postoperative echocardiogram is the most important predictor for reintervention. We propose that a total peak gradient in the first postoperative echocardiography of 55 mm Hg or more is a predictor for reintervention.

Right ventricular strain in repaired Tetralogy of Fallot with regards to pulmonary valve replacement.

PURPOSE: To assess right ventricular (RV) myocardial strain both globally and segmentally through feature-tracking cardiac magnetic resonance (CMR) in patients with Tetralogy of Fallot (ToF), with regards to pulmonary valve replacement (PVR). METHODS: After Ethics Committee approval, we retrospectively included 46 consecutive ToF patients who had two CMR examinations performed at our institution between March 2014 and June 2019. We divided patients into those who had not undergone PVR between the two CMR examinations (Group-0), and those who had (Group-1). Ventricular volumes were quantified on cine sequences, and strain was calculated through feature-tracking, using the previously traced segmentations. RV longitudinal and radial strain were assessed both globally and separately for the septum and free wall. Variations were normalized for intercurrent years, differences were appraised with t-tests or Mann-Whitney U. RESULTS: 30 patients belonged to Group-0 and 16 to Group-1. Median age was 22 years (interquartile range [IQR] 17-29 years) in Group-0, and 21 years (IQR 16-29 years) in Group-1. No significant differences were reported in RV strain between groups (p ≥ 0.254) except for RV septal radial strain, significantly higher (p = 0.010) in Group-0 (24.2 %, IQR 10.1-52.4 %) than in Group-1 (6.0 %, IQR -3.3-23.3 %) at the second CMR. Both global and segmental RV strains decreased over time in both groups, and yearly variations did not differ significantly (p ≥ 0.081) between groups. CONCLUSIONS: While PVR performed at the appropriate timing eases the burden on the RV allowing for a reduction in volumes, RV strain seems to continuously deteriorate as in patients who do not undergo PVR.

A Novel Right Ventricular Volume and Pressure Loaded Piglet Heart Model for the Study of Tricuspid Valve Function.

Heart conditions in which the tricuspid valve (TV) faces either increased volume or pressure stressors are associated with premature valve failure. Mechanistic studies to improve our understanding of the underlying pathophysiology responsible for the development of premature TV failure are lacking. Due to the inability to conduct these studies in humans, an animal model is required. In this manuscript, we describe the protocols for a novel chronic recovery infant piglet heart model for the study of changes in the TV when placed under combined volume and pressure stress. In this model, volume loading of the right ventricle and the TV is achieved through the disruption of the pulmonary valve. Then pressure loading is accomplished through the placement of a pulmonary artery band. The success of this model is assessed at four weeks post intervention surgery through echocardiography, intracardiac pressure measurement, and pathologic examination of the heart specimens.

SAPIEN S3 valve deployment in the pulmonary position using the gore DrySeal sheath to protect the tricuspid valve.

BACKGROUND: Tricuspid valve injury can occur during implantation of a SAPIEN valve in the pulmonary position. We describe our experience using a long Gore DrySeal (GDS) sheath to protect the tricuspid valve during advancement of the Commander delivery system. METHODS: Retrospective single center review of all patients who underwent placement of a SAPIEN valve in the right ventricular outflow tract between January 2016 and April 2020. Patients were divided into two groups: delivery of the valve using standard technique (Group I), and with the use of a GDS (Group II), for comparison. RESULTS: There were 48 patients in total: 25 in Group I and 23 in Group II. In Group II, the first 10 patients had a 29 mm S3 placed through a 26 French (Fr), 65 cm GDS. We then performed additional crimping of the S3 onto the balloon after the balloon catheter was withdrawn to position the valve on the balloon outside the body. Subsequently, seven had a 29 mm S3 placed through a 24 Fr GDS, and four had a 26 mm S3 placed through a 22 Fr GDS including one weighing 16 kg. Two had a 23 mm S3 placed through a 22Fr GDS as the 20Fr GDS was not available in our lab. Severe tricuspid valve injury occurred in 2/25 (8%) of Group I patients and 0/23 of Group II patients. CONCLUSION: Use of a long GDS may protect the tricuspid valve from injury during implantation of the S3 valve in the pulmonary position, and is technically feasible in smaller patients.

Influence of Pulmonary Valve Function Preservation Technique for Tetralogy of Fallot Repair on Right Ventricular Performance in Children.

BACKGROUND: Right ventricular (RV) ejection fraction may remain normal or even high despite significant impairment of RV myocardial performance in cases of total repair for tetralogy of Fallot (TOF). The aim of this study is to evaluate the influence of pulmonary valve function preservation (PVFP) versus monocuspid transannular patch augmentation (MTAPA) surgical strategies for Fallot repair on postoperative RV performance. METHODS: This retrospective study enrolled all patients (N = 480) who had TOF repaired at our center over a period of 7 years (March 2012 to January 2019). Group I included 377 patients (78.5%) who underwent TOF repair with MTAPA, and group II included 103 patients (21.5%) who underwent TOF repair with PVFP, which included all patients with pulmonary valve sparing with limited sub- or supravalvular patch. Patients' preoperative and postoperative echocardiography and other parameters (ventilation time, intensive care unit [ICU] stay duration, and RV myocardial performance index [RVMPI]) were recorded to evaluate RV function. RESULTS: We observed a significant statistical difference in the postoperative course between groups I and II, with excellent midterm outcomes for group II. A remarkable significant improvement of RVMPI took place in group II versus group I (P < .0001), as well as a significant decline in pulmonary regurgitation progression (P < .0001). The immediate postoperative RVMPI in group I (0.79 ± 0.63) versus that in group II (0.36 ± 0.17) was significantly higher (P < .0001), as was the late postoperative RVMPI (group I, 0.64 ± 0.25; group II, 0.49 ± 0.17; P < 0001). The postoperative RV outflow tract was decreased in group II versus group I. Group II had a significantly shorter duration on mechanical ventilation and in the ICU and less need for inotropes. CONCLUSION: We conclude that TOF repair patients have excellent RV myocardial performance with the PVFP surgical strategy in comparison with MTAPA.

Outcomes After Transcatheter Reintervention for Dysfunction of a Previously Implanted Transcatheter Pulmonary Valve.

OBJECTIVES: The aim of this analysis was to evaluate outcomes following transcatheter reintervention for degenerated transcatheter pulmonary valves (TPVs). BACKGROUND: TPV replacement (TPVR) with the Melody valve demonstrated sustained relief of right ventricular outflow tract (RVOT) obstruction and pulmonary regurgitation. METHODS: All patients who underwent TPVR with a Melody valve as part of 3 Medtronic-sponsored prospective multicenter studies were included. Transcatheter reinterventions included balloon dilation of the previously implanted Melody valve, placement of a bare-metal stent within the implanted TPV, or placement of a new TPV in the RVOT (TPV-in-TPV). Indications for reintervention, decisions to reintervene, and the method of reintervention were at physician discretion. All patients provided written informed consent to participate in the trials, and each trial was approved by local or central Institutional Review Boards or ethics committees at participating sites. RESULTS: A total of 309 patients who underwent TPVR were discharged from the implantation hospitalization with Melody valves in place. Transcatheter reintervention on the TPV was performed in 46 patients. The first transcatheter reintervention consisted of TPV-in-TPV in 28 patients (median 6.9 years [quartile 1 to quartile 3: 5.2 to 7.8 years] after TPVR), simple balloon dilation of the implanted Melody valve in 17 (median 4.9 years [quartile 1 to quartile 3: 4.0 to 6.0 years] after TPVR), and bare-metal stent placement alone in 1 (4.4 years after TPVR). There were no major procedural complications. Overall, 4-year freedom from explant and from any later RVOT reintervention after the first reintervention were 83% and 60%, respectively. Freedom from repeat RVOT reintervention was longer in patients undergoing TPV-in-TPV than balloon dilation (71% vs. 46% at 4 years; p = 0.027). CONCLUSIONS: TPV-in-TPV can be an effective and durable treatment for Melody valve dysfunction. Although balloon dilation of the Melody valve was also acutely effective at reducing RVOT obstruction, the durability of this therapy was limited in this cohort compared with TPV-in-TPV.

Munich Comparative Study: Prospective Long-Term Outcome of the Transcatheter Melody Valve Versus Surgical Pulmonary Bioprosthesis With Up to 12 Years of Follow-Up.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) has become an important treatment of right ventricular outflow tract dysfunction. Studies directly comparing the long-term outcome of PPVI with the Melody valve to surgical pulmonary valve replacement (SPVR) are lacking. METHODS: All patients treated with PPVI with the Melody valve and SPVR between January 2006 and December 2018 in our center were enrolled into a database and investigated with a standard follow-up protocol. The current study compares the outcomes in means of survival, reinterventions, infectious endocarditis, and performance of the valves. RESULTS: The study included 452 patients, of whom 241 were treated with PPVI with the Melody valve and 211 patients with SPVR with different types of valves. Median follow-up time was 5.4 years (3 months to 12.5 years), and the total observation was 2449 patient-years. Estimated survival after 10 years was 94% in the Melody group and 92% in the SPVR group (P=0.47). There was no difference in the estimated survival free of surgery on the implanted valve at 10 years (Melody, 87%, versus SPVR, 87%; P=0.54) or in the survival with the originally implanted pulmonary valve (Melody group, 80%; SPVR group, 73%; P=0.46) between both groups. The annualized incidence of infective endocarditis was 1.6% in the Melody group and 0.5% in the SPVR group, and the estimated survival free of endocarditis did not differ significantly between groups (Melody group, 82%; SPVR group, 86%; P=0.082). Survival free of valve replacement because of infective endocarditis was comparable between both groups (Melody, 88%; SPVR, 88%; P=0.35). CONCLUSIONS: PPVI with the Melody valve and SPVR provides similar survival, freedom of reinterventions, and infective endocarditis with or without the need of replacement of the pulmonary valve. Being less invasive, PPVI should be considered a method for treatment for patients with dysfunctional right ventricular outflow tracts.

Three-Year Outcomes From the Harmony Native Outflow Tract Early Feasibility Study.

BACKGROUND: The Harmony transcatheter pulmonary valve (TPV) was designed for treatment of postoperative pulmonary valve regurgitation in patients with repaired right ventricular outflow tracts. METHODS: The Native TPV EFS (Early Feasibility Study) is a prospective, multicenter, nonrandomized feasibility study. Three-year outcomes are reported. RESULTS: Of 20 implanted patients, 17 completed 3-year follow-up (maximum: 4.1 years). There were no deaths and 2 early explants. One patient did not complete the 3-year visit. In patients with available 3-year echocardiographic data, 1 had a mild paravalvular leak and the rest had none/trace; 1 patient had mild pulmonary valve regurgitation and the remainder had none/trace. The 3-year mean right ventricular outflow tract echocardiographic gradient was 15.7±5.5 mm Hg. Radiographically, no late frame fractures or erosions were identified. At 2 years, 2 patients presented with an increased echocardiographic outflow gradient (1 mixed lesion with moderate/severe pulmonary valve regurgitation). Computed tomography scans identified neointimal tissue ingrowth within the stent frame in both patients, and they were treated successfully with a transcatheter valve-in-valve procedure (Melody TPV). Additional follow-up computed tomography scans performed at 3.2±0.5 years after implant were obtained in 16 patients and revealed luminal tissue thickening at the inflow and outflow portion of the frame with no significant alteration of the valve housing. CONCLUSIONS: Three-year results from the Native TPV EFS revealed stable Harmony TPV device position, good valve function in most, and the absence of moderate/severe paravalvular leak and significant late frame fractures. Two patients developed significant neointimal proliferation requiring valve-in-valve treatment, while all others had no clinically significant right ventricular outflow tract obstruction. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01762124.

The snared wire technique for Sapien valve implantation in the pulmonary position.

OBJECTIVES: Description of the snared wire technique (SWT) to facilitate the delivery of the Sapien valve in pulmonary position, and comparison with standard delivery technique. BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) with the Sapien delivery system has proven to be challenging. Therefore, alternative strategies for facilitating its delivery in this position are needed. METHODS: Retrospective analysis of patients who underwent TPVR with or without the new SWT. The SWT was chosen as an elective strategy when the anatomy was judged to be challenging for TPVR (planned SWT) or as a rescue strategy when a standard delivery failed (rescue SWT). RESULTS: From February 2018 to January 2020, 84 patients underwent TPVR with a Sapien S3 valve using either a standard delivery (n = 63, 75%) or a SWT (n = 21, 25%). Fifteen patients underwent a planned SWT, six patients underwent a rescue SWT after failure of a standard delivery. All planned SWT cases were successful and, compared to the standard delivery group, no significant differences were found in terms of time to valve-deployment, fluoroscopy time, procedure time, or frequency of complications. Rescue SWT cases had longer fluoroscopy time (p = .05), longer time to valve-deployment (p = .0001), and higher frequency of complications (p = .002) including tricuspid valve injury (p = .0004), but allowed the operator to successfully implant the valve into the desired location. CONCLUSIONS: Even in the most challenging anatomies, the SWT represents a feasible and effective alternative strategy for TPVR with the Sapien valve that should be considered when other techniques have failed.

Left Anterior Mini-Incision for Pulmonary Valve Replacement Following Tetralogy of Fallot Repair.

Pulmonary insufficiency is a known complication following Tetralogy of Fallot repair. With over 90% of patients now surviving to adulthood, surgeons are once again faced with the question of when, and more importantly, how to reintervene. We developed a novel approach to pulmonary valve replacement in this population through a 5-cm left anterior mini-incision. The incision is optimized for exposing and operating on the right ventricular outflow tract and the main pulmonary artery in patients with a history of median sternotomy. Early outcomes are reassuring, and we believe our approach is a safe and reliable alternative to median sternotomy within this patient population, with the ability to quickly convert intraoperatively when needed.

Assessment of right ventricular function by isovolumic acceleration of pulmonary and tricuspid annulus in surgically repaired tetralogy of Fallot.

Assessment of right ventricular (RV) function is quite important in patients with surgically corrected tetralogy of Fallot (TOF). However, quantitative assessment of RV function remains challenging, mainly because of the complex RV geometry. This prospective study investigated isovolumic acceleration (IVA), a parameter of myocardial systolic function not influenced by either preload or afterload, using tissue Doppler imaging. We evaluated IVA measured on pulmonary annulus (PA-IVA) and tricuspid annulus (TA-IVA), because we considered that PA-IVA and TA-IVA correspond with systolic function of the RV outflow tract (RVOT) and RV basal function, respectively. Thirty-nine patients with surgically repaired TOF (TOF group) and 40 age-matched healthy children (control group) were enrolled in this study. No significant difference was seen between TA-IVA (2.5 ±â€…0.8 m/s2) and PA-IVA (2.4 ±â€…0.8 m/s2) in the control group. In the TOF group, PA-IVA (1.0 ±â€…0.5 m/s2) was significantly lower than TA-IVA (1.3 ±â€…0.6 m/s2, p < 0.05). Both TA-IVA and PA-IVA were significantly lower in the TOF group than in the control group (p < 0.05 each). We concluded that PA-IVA offers a useful index to assess RVOT function in TOF patients. J. Med. Invest. 67 : 145-150, February, 2020.

Transcatheter pulmonary valve replacement in pediatric patients.

INTRODUCTION: Right ventricular outflow tract (RVOT) dysfunction is common among individuals with congenital heart disease (CHD). Surgical intervention often carries prohibitive risks due to the need for sequential pulmonary valve (PV) replacements throughout their life in the majority of cases. Transcatheter pulmonary valve replacement (tPVR) is one of the most exciting recent developments in the treatment of CHD and has evolved to become an attractive alternative to surgery in patients with RVOT dysfunction. AREAS COVERED: In this review, we examine the pathophysiology of RVOT dysfunction, indications for tPVR, and the procedural aspect. Advancements in clinical application and valve technology will also be covered. EXPERT OPINION: tPVR is widely accepted as an alternative to surgery to address RVOT dysfunction, but still significant numbers of patients with complex RVOT morphology deemed not suitable for tPVR. As the technology continues to evolve, new percutaneous valves will allow such complex RVOT patient to benefit from tPVR.

Impact of right atrium dimension on adverse outcome after pulmonary valve replacement in repaired Tetralogy of Fallot patients.

The hemodynamic impact of residual pulmonary regurgitation (PR) in repaired Tetralogy of Fallot (rTOF) has been well demonstrated. However, markers driving the decision making process to indicate the ideal timing of pulmonary valve replacement (PVR) are still uncertain. Furthermore, very few studies have included the right atrium (RA) dilatation as a preoperative risk factor for post-PVR clinical adverse outcome. The aim of this study was to investigate the impact of pre-PVR right atrial dilation on adverse outcomes in rTOF. We retrospectively reviewed from our CMR database all rTOF patients who underwent CMR study before and after PVR. Detailed clinical and surgical history were collected, in addition to imaging data. The composite primary and secondary post-PVR end points were also recorded. The study cohort consisted of 41 patients (mean age at PVR repair 27.4 ± 10 years). As expected, end-diastolic and end-systolic right ventricle (RV) volumes significantly decreased after PVR (p < 0.001). The RV reverse remodeling, defined by ΔRVEDVi and ΔRVESVi, was associated with both pre-PVR RVEDVi and RVESVi. The higher the pre-PVR RV volumes, more the RV reverse remodeling will be obtained post-surgery. Patients who experienced an adverse outcome were older at pre-PVR, they had a higher Nt-ProBNP, worse VO2/kg/min, more significant tricuspid regurgitation and more dilated RA. The association with the RA dilatation persists and becomes even more significant if we exclude patients who had tricuspid repair beside RVOT surgical reconstruction. Besides RV volumes and function, RA dimensions may play a pivotal role in the decision making of TOF patients.