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.

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.

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.

Impact of pulmonary stenosis on right ventricular global longitudinal strain in repaired tetralogy of Fallot patients post transcatheter pulmonary valve replacement.

BACKGROUND: Mixed pulmonary disease with pulmonary regurgitation (PR) and stenosis (PS) in repaired tetralogy of Fallot (rTOF) can negatively impact ventricular health. Myocardial strain has been shown to be more sensitive at detecting occult ventricular dysfunction compared to right ventricular ejection fraction (RV EF). We hypothesize that rTOF patients with predominant PS will have lower RV global longitudinal strain (RV GLS) prior to and post-transcatheter pulmonary valve replacement (TPVR). METHODS: A retrospective cohort of rTOF patients who underwent cardiac magnetic resonance (CMR) and cardiac catheterization for right ventricular pressure (RVSP) measurement were analyzed at three time points: before valve implantation, at discharge and within 18 months post-TPVR. Patients were dichotomized into three groups based on RVSP: 0%-49%, 50%-74%, and >75%. RV GLS and left ventricular (LV) GLS by speckle tracking echocardiography (STE) were obtained from the apical 4-chamber using TomTec software (TOMTEC IS, Germany). RESULTS: Forty-eight patients were included. Every 14.3% increase in preimplantation RVSP above 28% was associated with an absolute magnitude 1% lower RV GLS (p = .001). Preimplantation RVSP when 75% or higher had 3.36% worse RV GLS than the lowest bin (p = .014). Overall, average RV strain magnitude was higher when preimplantation RVSP was less than 50% and had greater improvement over the three time points. Higher post implantation RVSP correlated with lower strain magnitude. CONCLUSION: Patients with significant PS (>50%) may benefit from earlier PVR and not depend solely on RV size and EF. Myocardial strain may be a more sensitive marker of function; however, larger, prospective studies are needed.

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.

Five-year follow-up after percutaneous pulmonary valve implantation using the Venus P-valve system for patients with pulmonary regurgitation and an enlarged native right ventricular outflow tract.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) with the self-expandable Venus P-valve system is a promising treatment for patients with pulmonary regurgitation (PR) and a native right ventricular outflow tract (RVOT). However, limited data is available regarding its midterm outcomes. This study assessed the midterm clinical and echocardiographic outcomes following Venus P-valve implantation. METHODS: From 2013 to 2018, 55 patients with moderate or severe PR after surgical RVOT repair with a transannular or RVOT patch were consecutively enrolled from six hospitals in China. Five-year clinical and echocardiographic outcomes were collected and evaluated. The primary endpoint was a freedom from all-cause mortality and reintervention. RESULTS: At 5 years, the primary endpoint was met for 96% of patients, corresponding to a freedom from all-cause mortality of 96% (95% confidence interval [CI]: 86%-99%) and freedom from reintervention of 98% (95% CI: 87%-100%). Endocarditis was reported in five patients (four patients within 1 year and one patient at 5 years) following PPVI. Transpulmonary gradient and stent orifice diameter remained stable compared to at discharge (p＞0.05). No paravalvular leak was reported while only 1 patient gradually increased to moderate PR during follow-up. Significant improvement of RV diameter and LVEF (p＜0.001) sustained over the 5-year follow-up, in consistent with remarked improved New York Heart Association(NYHA) functional class (p＜0.001). CONCLUSION: The 5-year results of the China VenusP Study demonstrated the midterm benefits of Venus P-valve implantation in the management of patients with severe PR with an enlarged native RVOT by providing sustained symptomatic and hemodynamic improvement.

Pulmonary Valve Replacement in Tetralogy of Fallot: Procedural Volume and Durability of Bioprosthetic Pulmonary Valves.

BACKGROUND: Robust data on changes in pulmonary valve replacement (PVR) procedural volume and predictors of bioprosthetic pulmonary valve (BPV) durability in patients with tetralogy of Fallot (TOF) are scarce. OBJECTIVES: This study sought to assess temporal trends in PVR procedural volume and BPV durability in a nationwide, retrospective TOF cohort. METHODS: Data were obtained from patient records. Robust linear regression was used to assess temporal trends in PVR procedural volume. Piecewise exponential additive mixed models were used to estimate BPV durability, defined as the time from implantation to redo PVR with death as a competing risk, and to assess risk factors for reduced durability. RESULTS: In total, 546 PVR were performed in 384 patients from 1976 to 2021. The annual number of PVR increased from 0.4 to 6.0 per million population (P < 0.001). In the last decade, the transcatheter PVR volume increased by 20% annually (P < 0.001), whereas the surgical PVR volume did not change significantly. The median BPV durability was 17 years (Q1: 10-Q3: 10 years-not applicable). There was no significant difference in the durability of different BPV after adjustment for confounders. Age at PVR (HR: 0.78 per 10 years from <1 year; 95% CI: 0.63-0.96; P = 0.02) and true inner valve diameter (9-17 mm vs 18-22 mm HR: 0.40; 95% CI: 0.22-0.73; P = 0.003 and 18-22 mm vs 23-30 mm HR: 0.59; 95% CI: 0.25-1.39; P = 0.23) were associated with reduced BPV durability in multivariate models. CONCLUSIONS: The PVR procedural volume has increased over time, with a greater increment in transcatheter than surgical PVR during the last decade. Younger patient age at PVR and a smaller true inner valve diameter predicted reduced BPV durability.

Right ventricular outflow tract obstruction associated with neointimal tissue accumulation and distortion of the Harmony TPV25 stent frame: Potential mechanisms and treatment.

BACKGROUND: The Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self-expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction. METHODS: We collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation. RESULTS: We describe six patients who underwent valve-in-valve implant for TPV25 obstruction (peak catheterization gradient peak 28-73 mmHg) 10-28 months after implant. In all cases, there was tissue accumulation within the inflow and valve-housing segments of the device and deformation of the self-expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve-in-valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation. DISCUSSION: The occurrence of short-term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve-in-valve implant using balloon expandable transcatheter valves.

Right ventricular dilatation score: a new assessment to right ventricular dilatation in adult patients with repaired tetralogy of Fallot.

BACKGROUND: Patients with repaired tetralogy of Fallot (rTOF) experience long-term chronic pulmonary valve regurgitation resulting in right ventricular (RV) dilatation. According to current guidelines, the evaluation of patients with rTOF for RV dilatation should be based on cardiac magnetic resonance (CMR). However, for many asymptomatic patients, routine CMR is not practical. Our study aims to identify screening methods for CMR based on echocardiographic data, with the goal of establishing a more practical and cheap method of screening for severity of RV dilatation in patients with asymptomatic rTOF. METHODS: Thirty two rTOF patients (mean age, 21(10.5) y, 21 males) with moderate to severe pulmonary regurgitation (PR) were prospectively recruited. Each patient received CMR and echocardiogram examination within 1 month prior to operation and collected clinical data, and then received echocardiogram examination at discharge and 3-6 months post-surgery. RESULTS: RV moderate-severe dilatation was defined as right ventricular end-diastolic volume index (RVEDVI) ≥ 160 ml/m2 or right ventricular end-systolic volume index (RVESVI) ≥ 80 ml/m2 in 15 of 32 patients (RVEDVI, 202.15[171.51, 252.56] ml/m2, RVESVI, 111.99 [96.28, 171.74] ml/m2). The other 17 (RVESDI, 130.19 [117.91, 139.35] ml/m2, RVESVI = 67.91 [63.35, 73.11] ml/m2) were defined as right ventricle mild dilatation, i.e., RVEDVI < 160 ml/m2 and RVESVI < 80 ml/m2, and the two parameters were higher than normal values. Compared with the RV mild dilatation group, patients of RV moderate-severe dilatation have worse cardiac function before surgery (right ventricular ejection fraction, 38.92(9.19) % versus 48.31(5.53) %, p < 0.001; Left ventricular ejection fraction, 59.80(10.26) versus 66.41(4.15), p = 0.021). Patients with RV moderate-severe dilatation faced longer operation time and more blood transfusion during operation (operation time, 271.53(08.33) min versus 170.53(72.36) min, p < 0.01; Intraoperative blood transfusion, 200(175) ml versus 100(50) ml, p = 0.001). Postoperative RV moderate-severe dilatation patients have poor short-term prognosis, which was reflected in a longer postoperative hospital stay (6.59 [2.12] days versus 9.80 [5.10] days, p = 0.024) and a higher incidence of hypohepatia (0[0] % versus 4[26.7] %, p = 0.023). Patients with RV dilatation score > 2.35 were diagnosed with RV moderate-severe dilatation (AUC = 0,882; Sensitivity = 94.1%; Specificity = 77.3%). CONCLUSIONS: RV moderate-severe dilatation is associated with worse preoperative cardiac function and short-term prognosis after PVR in rTOF patients with moderate to severe PR. The RV dilatation score is an effective screening method. When RV dilatation score > 2.35, the patient is indicated for further CMR examination and treatment.

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR. METHODS: Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve. RESULTS: Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis. CONCLUSIONS: Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

Rightward imbalanced pulmonary perfusion predicts better exercise stroke volume in children after Fallot repair.

BACKGROUND: Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known. AIM: To assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients. METHODS: We retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%. RESULTS: Normal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (ß=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (ß=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (ß=-0.283, 95% CI -0.495 to -0.072; P=0.006) and Fallot variant with pulmonary atresia (ß=-0.213, 95% CI -0.416 to -0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (ß=0.210, 95% CI 0.006 to 0.415; P=0.044). CONCLUSION: In addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.

1-Year Outcomes in a Pooled Cohort of Harmony Transcatheter Pulmonary Valve Clinical Trial Participants.

BACKGROUND: The Harmony transcatheter pulmonary valve (TPV) is the first U.S. Food and Drug Administration-approved device for severe pulmonary regurgitation (PR) in the native or surgically repaired right ventricular outflow tract (RVOT). OBJECTIVES: One-year safety and effectiveness of the Harmony TPV were evaluated in patients from the Harmony Native Outflow Tract Early Feasibility Study, Harmony TPV Pivotal Study, and Continued Access Study, representing the largest cohort to date of Harmony TPV recipients. METHODS: Eligible patients had severe PR by echocardiography or PR fraction ≥ 30% by cardiac magnetic resonance imaging and clinical indications for pulmonary valve replacement. The primary analysis included 87 patients who received a commercially available TPV22 (n = 42) or TPV25 (n = 45) device; 19 patients who received an early device iteration prior to its discontinuation were evaluated separately. RESULTS: In the primary analysis, median patient age at treatment was 26 years (IQR: 18-37 years) in the TPV22 group and 29 years (IQR: 19-42 years) in the TPV25 group. At 1 year, there were no deaths; 98% of TPV22 and 91% of TPV25 patients were free from the composite of PR, stenosis, and reintervention (moderate or worse PR, mean RVOT gradient >40 mmHg, device-related RVOT reoperation, and catheter reintervention). Nonsustained ventricular tachycardia occurred in 16% of patients. Most patients had none/trace or mild PR (98% of TPV22 patients, 97% of TPV25 patients). Outcomes with the discontinued device are reported separately. CONCLUSIONS: The Harmony TPV device demonstrated favorable clinical and hemodynamic outcomes across studies and valve types through 1 year. Further follow-up will continue to assess long-term valve performance and durability.

Impact of Right Ventricular Surface Area-to-Volume Ratio on Ventricular Remodeling After Pulmonary Valve Replacement.

Optimal reverse remodeling of the right ventricle (RV), a sentinel goal of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot, is not fully predicted by volume-based pre-PVR parameters. Our objectives were to characterize novel geometric RV parameters in patients receiving PVR and in controls, and to identify associations between these parameters and chamber remodeling post-PVR. Secondary analysis was performed on cardiac magnetic resonance (CMR) data from 60 patients enrolled in a randomized trial of PVR with and without surgical RV remodeling. 20 healthy age-matched subjects served as controls. The primary outcome was optimal post-PVR RV remodeling (end-diastolic volume index (EDVi) ≤ 114 ml/m2 and ejection fraction (EF) ≥ 48%) vs. suboptimal remodeling (EDVi ≥ 120 ml/m2 and EF ≤ 45%). RV geometry was markedly different at baseline in PVR patients compared with controls, with lower systolic surface area-to-volume ratio (SAVR) (1.16 ± 0.26 vs.1.44 ± 0.21 cm2/mL, p < 0.001) and lower systolic circumferential curvature (0.87 ± 0.27 vs. 1.07 ± 0.30 cm- 1, p = 0.007) but similar longitudinal curvature. In the PVR cohort, higher systolic SAVR was associated with higher RVEF both pre- and post-PVR (p < 0.001). Among PVR patients, 15 had optimal and 19 had suboptimal remodeling post-PVR. Multivariable modeling showed that among the geometric parameters, higher systolic SAVR (OR 1.68 per 0.1 cm2/mL increase; p = 0.049) and shorter systolic RV long-axis length (OR 0.92 per 0.1 cm increase; p = 0.035) were independently associated with optimal remodeling. Compared with controls, PVR patients have lower SAVR and lower circumferential but not longitudinal curvature. Higher pre-PVR systolic SAVR is associated with optimal remodeling post-PVR.

Surgical and transcatheter pulmonary valve replacement in patients with repaired tetralogy of Fallot: cardiac magnetic resonance imaging characteristics and morphology of right ventricular outflow tract.

BACKGROUND: Pulmonary valve replacement is recommended in patients with repaired tetralogy of Fallot based on cardiac magnetic resonance imaging (MRI) criteria. This procedure is performed by surgical or transcatheter approaches. OBJECTIVE: We aimed to investigate the differences in preprocedural MRI characteristics (volume, function, strain) and morphology of the right ventricular outflow tract and branch pulmonary arteries in patients for whom surgical or transcatheter pulmonary valve replacement was planned. MATERIALS AND METHODS: Cardiac MRI of 166 patients with tetralogy of Fallot were analyzed. Of these, 36 patients for whom pulmonary valve replacement was planned were included. Magnetic resonance imaging characteristics, right ventricular outflow tract morphology, branch pulmonary artery flow distribution and diameter were compared between surgical and transcatheter groups. Spearman correlation and Kruskal-Wallis tests were performed. RESULTS: Circumferential and radial MRI strain for the right ventricle were lower in the surgical group (P=0.045 and P=0.046, respectively). The diameter of the left pulmonary artery was significantly lower (P=0.021) and branch pulmonary artery flow and diameter ratio were higher (P=0.044 and P = 0.002, respectively) in the transcatheter group. There was a significant correlation between right ventricular outflow tract morphology and right ventricular end-diastolic volume index and global circumferential and radial MRI strain (P=0.046, P=0.046 and P= 0.049, respectively). CONCLUSION: Preprocedural MRI strain, right-to-left pulmonary artery flow, diameter ratio and morphological features of the right ventricular outflow tract were significantly different between the two groups. A transcatheter approach may be recommended for patients with branch pulmonary artery stenosis, since both pulmonary valve replacement and branch pulmonary artery stenting can be performed in the same session.

Outlet Ventricular Septal Defect: Impact of Surgery on the Late Aortic and Pulmonary Valve Functions.

This study retrospectively evaluated long-term post-operative aortic and pulmonary valve functions in outlet ventricular septal defects. We evaluated aortic regurgitation and pulmonary regurgitation using pre- and post-operative echocardiograms. Overall, 158 patients who underwent intracardiac repair due to outlet ventricular septal defects with aortic valve deformity or congestive heart failure were included. The median follow-up period was 7 years (interquartile range: 0-17 years), without deaths or pacemaker implantations. The age, weight, ventricular septal defect size, and mild aortic regurgitation at surgery were factors associated with post-operative residual aortic regurgitation. Mild pulmonary regurgitation was observed in 12%, 30%, and 40% of patients 5, 10, and 15 years after surgery, respectively. There were no significant differences in age and weight at which surgery was performed between patients with mild pulmonary regurgitation and those with less than mild pulmonary regurgitation. However, the number of sutures across the pulmonary valve was associated with post-operative pulmonary regurgitation (P < 0.01). As some patients with mild pre-operative aortic regurgitation may not improve even after surgery, early surgical intervention is necessary when aortic regurgitation appears. Some patients may develop post-operative pulmonary regurgitation in the long term, suggesting the need for careful follow-up.