A probabilistic neural twin for treatment planning in peripheral pulmonary artery stenosis.

The substantial computational cost of high-fidelity models in numerical hemodynamics has, so far, relegated their use mainly to offline treatment planning. New breakthroughs in data-driven architectures and optimization techniques for fast surrogate modeling provide an exciting opportunity to overcome these limitations, enabling the use of such technology for time-critical decisions. We discuss an application to the repair of multiple stenosis in peripheral pulmonary artery disease through either transcatheter pulmonary artery rehabilitation or surgery, where it is of interest to achieve desired pressures and flows at specific locations in the pulmonary artery tree, while minimizing the risk for the patient. Since different degrees of success can be achieved in practice during treatment, we formulate the problem in probability, and solve it through a sample-based approach. We propose a new offline-online pipeline for probabilistic real-time treatment planning which combines offline assimilation of boundary conditions, model reduction, and training dataset generation with online estimation of marginal probabilities, possibly conditioned on the degree of augmentation observed in already repaired lesions. Moreover, we propose a new approach for the parametrization of arbitrarily shaped vascular repairs through iterative corrections of a zero-dimensional approximant. We demonstrate this pipeline for a diseased model of the pulmonary artery tree available through the Vascular Model Repository.

Participation in Competitive Sports by Patients With Congenital Heart Disease: AHA/ACC and EAPC/ESC/AEPC Guidelines Comparison.

Sports participation in patients with congenital heart disease is an evolving subject. The American Heart Association/American College of Cardiology released a set of guidelines that advise the type and level of sports participation based primarily on anatomical defects with secondary consideration given to hemodynamic effects. Recently, the European Association of Preventive Cardiology/European Society of Cardiology/Association for European Paediatric and Congenital Cardiology offered a contrasting approach to sports participation that is based on hemodynamic and electrophysiological profiles of each patient, regardless of anatomical consideration. These guidelines are drastically different in their approaches but do have some similarities. In this review, we compare both documents, focusing on the aim, population, classification of sports, and the methodology of making recommendations. This review aims to assist practicing cardiologists in integrating the available published data and recommendations when counseling patients for sports participation.

Living to Tell the Tale: A First-Person Chronicle of the Development of the Fontan-Kreutzer Procedure.

The current surgical approach for patients with a single ventricle is the culmination of decades of dedicated research and groundbreaking innovation. From 1971 to the present day, a series of incremental advancements have significantly extended the life expectancy of these patients. Since the very beginning, Dr Guillermo Kreutzer and his team have pioneered different techniques with the ultimate goal of improving outcomes for these individuals. This is, narrated by him, the story of how it all began.

Persistent Patent Vertical Vein After Repair of Total Anomalous Pulmonary Venous Connection (TAPVR): A Rare Cause of Hypoxemia Post-Fontan Procedure.

Vertical vein (VV) ligation during total anomalous pulmonary venous return (TAPVR) repair is controversial. While some surgeons prefer ligation of the VV to prevent adverse sequelae of shunting across it and to promote flow through the newly created anastomosis, others leave it to serve as a "pop off valve" to the left heart structures, which are believed to be hypoplastic and noncompliant, presumably contributing to a more favorable post-operative outcome. We report two patients post-Fontan procedure, who underwent cardiac catheterization to explore the etiology of hypoxia and were found to have a persistent VV responsible for right to left shunting. Both patients underwent closure of the VV with improvement in the cyanosis and clinical course. These cases provide evidence supporting surgical ligation of the VV at the time of TAPVR repair, especially in patients with single ventricle.

Pulmonary Complications in Patients With Fontan Circulation: JACC Review Topic of the Week.

The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.

Surrogates of Muscle Mass on Cardiac MRI Correlate with Exercise Capacity in Patients with Fontan Circulation.

BACKGROUND: Sarcopenia is an increasingly recognized marker of frailty in cardiac patients. Patients with a history of congenital heart disease and Fontan procedure have a higher risk of developing progressive muscle wasting. Our objective was to determine if we could use routine cardiac MRI (CMR) for the surveillance of muscle wasting. METHODS: A retrospective study of all Fontan patients (n = 75) was conducted at our institution, with CMR performed from 2010 to 2022 and exercise stress testing performed within 12 months (4.3 ± 4.2 months). The skeletal muscle area (SMA) for the posterior paraspinal and anterior thoracic muscles were traced and indexed for body surface area (BSA). Patients were stratified by percentile into the upper and lower quartiles, and the two groups were compared. Multivariable regression was performed to control for sex and age. RESULTS: There was a significant positive association of both anterior (r = 0.34, p = 0.039) and paraspinal (r = 0.43, p = 0.007) SMA to peak VO2. Similarly, paraspinal but not anterior SMA was negatively associated with the VE/VCO2 (r = -0.45, p = 0.006). The upper quartile group had significantly more males (18/19 vs. 8/20; p = 0.0003) and demonstrated a significantly higher peak VO2 (32.2 ± 8.5 vs. 23.8 ± 4.7, p = 0.009), a higher peak RER (1.2 ± 0.1 vs. 1.1 ± 0.04, p = 0.007), and a significantly lower VE/VCO2 (32.9 ± 3.6 vs. 40.2 ± 6.2, p = 0.006) compared to the lowest quartile. The association of SMA to VO2 peak and VE/VCO2 was redemonstrated after controlling for sex and age. CONCLUSION: Thoracic skeletal muscle area may be an effective surrogate of muscle mass and is correlated to several measures of cardiorespiratory fitness post-Fontan. CMR would be an effective tool for the surveillance of sarcopenia in post-Fontan patients given its accessibility and routine use in these patients.

Occlusion of the os of the left coronary artery by dysplastic aortic valve tissue presenting as progressive mitral insufficiency and cardiac arrest.

Mitral regurgitation in the neonatal period is relatively rare. It can be secondary to a congenital malformation of the valve apparatus or mitral valve dysfunction and deformation secondary to myocardial dysfunction or volume load of the left ventricle. Less commonly, it can be due to coronary artery abnormalities leading to mitral valve papillary muscle ischaemia and subsequent dysfunction. Such coronary artery abnormalities include anomalous left coronary artery from pulmonary artery, left main coronary artery atresia, or a thromboembolic phenomenon. In this study, we describe a newborn with a dysplastic aortic valve causing obstruction of the os of the left coronary artery leading to progressive mitral insufficiency.

Cardiac MRI-Derived Inferior Vena Cava Cross-Sectional Area Correlates with Measures of Fontan-Associated Liver Disease.

There is currently no clear consensus on screening techniques to evaluate the presence or severity of Fontan-associated liver disease (FALD). Cardiac MRI (CMR) is used routinely for post-Fontan surveillance, but CMR-derived measures that relate to the severity of FALD are not yet defined. This was a cross-sectional single-center study of post-Fontan patients who underwent a CMR. CMR exams were re-analyzed by a single pediatric cardiologist. Surrogates of FALD included Gamma-Glutamyl Transferase (GGT), Fibrosis-4 laboratory score (FIB-4), and imaging findings. Findings consistent with cirrhosis on liver ultrasound included increased liver echogenicity and/or nodularity. Statistical analyses were performed to investigate potential relationships between CMR parameters and markers of FALD. Sixty-one patients were included. A larger inferior vena cava cross-sectional area (IVC-CSA) indexed to height was significantly associated with a higher FIB-4 score (Spearman's ρ = 0.28, p = 0.04), a higher GGT level (Spearman's ρ = 0.40, p = 0.02), and findings consistent with cirrhosis on liver ultrasound (OR 1.17, 95% CI: (1.01, 1.35), p = 0.04). None of the other CMR parameters were associated with markers of FALD. A larger indexed IVC-CSA was associated with higher systemic ventricle end-diastolic pressure (EDP) on cardiac catheterization (Spearman's ρ = 0.39, p = 0.018) as well as older age (Spearman's ρ = 0.46, p = < 0.001). Indexed IVC-CSA was the only CMR parameter that was associated with markers of FALD. This measure has the potential to serve as an additional non-invasive tool to improve screening strategies for FALD. Visual abstract summarizing the primary findings of this paper.

Virtual Transcatheter Interventions for Peripheral Pulmonary Artery Stenosis in Williams and Alagille Syndromes.

Background Despite favorable outcomes of surgical pulmonary artery (PA) reconstruction, isolated proximal stenting of the central PAs is common clinical practice for patients with peripheral PA stenosis in association with Williams and Alagille syndromes. Given the technical challenges of PA reconstruction and the morbidities associated with transcatheter interventions, the hemodynamic consequences of all treatment strategies must be rigorously assessed. Our study aims to model, assess, and predict hemodynamic outcomes of transcatheter interventions in these patients. Methods and Results Isolated proximal and "extensive" interventions (stenting and/or balloon angioplasty of proximal and lobar vessels) were performed in silico on 6 patient-specific PA models. Autoregulatory adaptation of the cardiac output and downstream arterial resistance was modeled in response to intervention-induced hemodynamic perturbations. Postintervention computational fluid dynamics predictions were validated in 2 stented patients and quantitatively assessed in 4 surgical patients. Our computational methods accurately predicted postinterventional PA pressures, the primary indicators of success for treatment of peripheral PA stenosis. Proximal and extensive treatment achieved median reductions of 14% and 40% in main PA systolic pressure, 27% and 56% in pulmonary vascular resistance, and 10% and 45% in right ventricular stroke work, respectively. Conclusions In patients with Williams and Alagille syndromes, extensive transcatheter intervention is required to sufficiently reduce PA pressures and right ventricular stroke work. Transcatheter therapy was shown to be ineffective for long-segment stenosis and pales hemodynamically in comparison with published outcomes of surgical reconstruction. Regardless of the chosen strategy, a virtual treatment planning platform could identify lesions most critical for optimizing right ventricular afterload.

Comparison of the investigational device exemption and post-approval trials of the Melody transcatheter pulmonary valve.

OBJECTIVE: We compared 5-year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post-approval study (PAS) and the investigational device exemption (IDE) trial. BACKGROUND: As a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a "real-world" environment. The 5-year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared. METHODS: The cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time-related outcomes and valve-related adverse events were compared between the two trials with Kaplan-Meier curves and log-rank testing. RESULTS: 167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both. CONCLUSIONS: Hemodynamic and time-related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real-world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post-approval studies as part of the regulatory process for Class III medical devices.

Transcatheter Intervention for Congenital Defects Involving the Great Vessels: JACC Review Topic of the Week.

Since the development of balloon angioplasty and balloon-expandable endovascular stent technology in the 1970s and 1980s, percutaneous transcatheter intervention has emerged as a mainstay of therapy for congenital heart disease (CHD) lesions throughout the systemic and pulmonary vascular beds. Congenital lesions of the great vessels, including the aorta, pulmonary arteries, and patent ductus arteriosus, are each amenable to transcatheter intervention throughout the lifespan, from neonate to adult. In many cases, on-label devices now exist to facilitate these therapies. In this review, we seek to describe the contemporary approach to and outcomes from transcatheter management of major CHD lesions of the great vessels, with a focus on coarctation of the aorta, single- or multiple-branch pulmonary artery stenoses, and persistent patent ductus arteriosus. We further comment on the future of transcatheter therapies for these CHD lesions.

Cangrelor PK/PD analysis in post-operative neonatal cardiac patients at risk for thrombosis.

Essentials An optimal therapeutic strategy has yet to be established to prevent early shunt thrombosis. A phase 1 study of cangrelor was performed in neonates after palliation of congenital heart disease. PD endpoint of >90% platelet inhibition in 60% of patients was achieved at 0.5 µg/kg/min dosing. No serious adverse events related to drug administration were observed, including bleeding. ABSTRACT: Background Systemic-to-pulmonary artery shunt thrombosis is a significant cause of early postoperative mortality in neonates after palliation of congenital heart disease. In the context of thromboprophylaxis, an optimal therapeutic strategy has yet to be established before aspirin administration. Cangrelor, a fast-acting, reversible P2Y12 inhibitor, may fill this unmet need. Objectives To evaluate the pharmacokinetics (PK), pharmacodynamics (PD), and safety of cangrelor in neonates undergoing stage 1 palliation. Methods This prospective, open-label, single-arm study evaluated two cangrelor dosing cohorts following placement of a systemic-to-pulmonary artery shunt, right ventricle-to-pulmonary artery shunt, or ductal stent. Drug concentrations and platelet reactivity, assessed by light transmission aggregometry and in microfluidic assays (MF), were measured. Results Twenty-two patients were consented and 15 received a 1-hour infusion of cangrelor at either 0.5 µg/kg/min (cohort 1) or 0.25 µg/kg/min (cohort 2). Whereas the primary PD endpoint was achieved at the higher dose (ie, reduction in maximal platelet aggregation by ≥90% in 60% of participants), only 29% of those in cohort 2 attained this goal. Comparable and statistically significant results were obtained in MF assays (P < .0001 vs. baseline). Drug levels during infusion were 3-fold higher in cohort 1 vs. cohort 2 (P < .001). Most participants (70%) had undetectable drug levels by 10 minutes postinfusion with full recovery in platelet function at 1 hour. No drug-related bleeding events occurred. Conclusions Favorable PK/PD properties of cangrelor 0.5 µg/kg/min dosing and safety profile warrant further evaluation in neonates following palliative cardiac procedures.

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.

Longitudinal Improvements in Radiation Exposure in Cardiac Catheterization for Congenital Heart Disease: A Prospective Multicenter C3PO-QI Study.

BACKGROUND: The C3PO-QI (Congenital Cardiac Catheterization Project on Outcomes - Quality Improvement), a multicenter registry launched in 2015, instituted quality improvement (QI) initiatives to reduce patient radiation exposure. Through regular collaboration, this initiative would allow for harmony among active participants, maximizing efforts and efficiency at achieving radiation best practices. This study sought to report these efforts with a detailed methodology for which institutions can target initiatives, reducing radiation exposure, and increasing patient safety. METHODS: Data were collected prospectively by 8 C3PO-QI institutions between January 1, 2015 and December 31, 2017. Radiation exposure was measured in dose area product per body weight (dose area product/kg; µGy*m2/kg) and reported by expected radiation exposure categories (REC) and institution for 40 published unique procedure types. Targeted interventions addressing selected strategic domains for radiation reduction were implemented in the pediatric catheterization labs of the C3PO-QI institutions. RESULTS: The study consisted of 15 257 unique cases. Median exposure (dose area product/kg) was decreased by 30% for all procedures. Dose area product/kg was reduced in all 3 REC, with the greatest improvement observed in REC I (REC I, -37%; REC II, -23%; REC III, -27%). Although the baseline radiation exposures and exact percent decrease varied across all C3PO-QI sites, each institution demonstrated improvements in radiation dose over time. These improvements occurred with the implementation of institution-specific QI interventions accelerated by participation in the C3PO-QI multicenter collaborative. CONCLUSIONS: Substantial radiation dose reductions can be achieved using targeted QI methodology and interventions. Participation in a multicenter QI collaborative may accelerate improvement across all centers due to enhanced engagement and shared learning between sites.

Adverse Events, Radiation Exposure, and Reinterventions Following Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) is associated with a risk of procedural serious adverse events (SAE) and exposure to ionizing radiation. OBJECTIVES: The purpose of this study was to define the risk of, and associations with, SAE and high-dose radiation exposure using large-scale registry data. METHODS: The analysis of the multicenter C3PO-QI registry was limited to patients who underwent TPVR from January 1, 2014, to December 31, 2016. SAE were defined as the occurrence of ≥1 moderate, major, or catastrophic events. Radiation dose was reported as dose area product adjusted for weight. Associations with outcome measures were explored in univariate and multivariable analyses. RESULTS: A total of 530 patients (59% male) underwent TPVR at a median age of 18.3 years (interquartile range [IQR]: 12.9 to 27.3 years) and weight of 58 kg (IQR: 43 to 77 kg) at 14 centers. Implant substrate included homograft (41%), bioprosthesis (30%), native right ventricular outflow tract (RVOT) (27%) and other (2%). TPVR indications were pulmonary insufficiency (28%), stenosis (23%), and mixed (49%). AE and SAE occurred in 26% and 13% of cases, respectively, including 1 mortality. SAE were more frequent in homograft conduit than other RVOT substrates, although SAE type and severity differed between implant substrates. Median radiation dose was 198 µGy·m2/kg (IQR: 94 to 350 µGy·m2/kg). Higher radiation dose was associated with older age, greater RVOT obstruction, and concomitant interventions (p < 0.001). During a median follow-up duration of 1 year, 13.3% underwent catheterization, surgery, or both, unrelated to infection. Younger age, smaller size, and hemodynamic and anatomic factors indicative of greater RVOT obstruction were associated with TPV reintervention. CONCLUSIONS: The incidence of SAE during TPVR in the C3PO-QI registry is high, but mortality is uncommon. Radiation dose is greater than for other congenital interventions and is associated with patient and procedural factors. Reintervention is common during early follow-up.

Mid-Term Valve-Related Outcomes After Transcatheter Tricuspid Valve-in-Valve or Valve-in-Ring Replacement.

BACKGROUND: Transcatheter aortic and pulmonary valves have been used to treat stenosis or regurgitation after prior surgical tricuspid valve (TV) replacement or repair. Little is known about intermediate-term valve-related outcomes after transcatheter tricuspid valve replacement (TTVR), including valve function, thrombus, and endocarditis. OBJECTIVES: The authors sought to evaluate mid-term outcomes in a large cohort of patients who underwent TTVR after surgical TV repair or replacement, with a focus on valve-related outcomes. METHODS: Patients who underwent TTVR after prior surgical TV replacement or repair were collected through an international registry. Time-related outcomes were modeled and risk factors assessed. RESULTS: Data were collected for 306 patients who underwent TTVR from 2008 through 2017 at 80 centers; 52 patients (17%) had a prior history of endocarditis. Patients were followed for a median of 15.9 months after implantation (0.1 to 90 months), with 64% of patients estimated to be alive without TV reintervention or a valve-related event at 3 years. The cumulative 3-year incidence of death, reintervention, and valve-related adverse outcomes (endocarditis, thrombosis, or significant dysfunction) were 17%, 12%, and 8%, respectively. Endocarditis was diagnosed in 8 patients 2 to 29 months after TTVR, for an annualized incidence rate of 1.5% per patient-year (95% confidence interval: 0.45% to 2.5%). An additional 8 patients were diagnosed with clinically relevant valve thrombosis, 3 in the short term, 2 within 2 months, and 3 beyond 6 months. Only 2 of these 8 patients received anticoagulant therapy before thrombus detection (p = 0.13 vs. patients without thrombus). Prior endocarditis was not a risk factor for reintervention, endocarditis, or valve thrombosis, and there was no difference in valve-related outcomes according to TTVR valve type. CONCLUSIONS: TV dysfunction, endocarditis, and leaflet thrombosis were uncommon after TTVR. Patients with prior endocarditis were not at higher risk for endocarditis or other adverse outcomes after TTVR, and endocarditis occurred with similar frequency in different valve types. Though rare, leaflet thrombosis is an important adverse outcome, and further study is necessary to determine the appropriate level of prophylactic therapy after TTVR.

Radiation Risk Categories in Cardiac Catheterization for Congenital Heart Disease: A Tool to Aid in the Evaluation of Radiation Outcomes.

To stratify diverse procedure types into categories with similar radiation exposure in cardiac catheterization for congenital heart disease. Radiation exposures for a comprehensive list of specific procedure types and stratification of outcomes based on radiation risk are not currently available. Data between January 2014 and December 2015 were collected on all cases performed at sites participating in C3PO-QI (Congenital Cardiac Catheterization Outcomes Project-Quality Improvement Initiative) and 9 centers were included. Using expert consensus, 40 unique procedure types were defined by diagnostic characteristics or the intervention(s) performed, and dose area product (DAP) per kilogram of body weight (µGy × m2/kg) was summarized. Using empiric and consensus methods, three radiation risk categories were created. A total of 11,735 cases were included for analysis. Thirteen (n = 7918) procedure types with median DAP/kg < 100 were categorized in the low radiation exposure category (median DAP/kg 39). The medium exposure category (n = 1807) consisted of 16 procedure types with median DAP/kg values ranging 100 to < 200 (overall median DAP/kg 131). Finally, the high radiation exposure category (n = 1073) consisted of 11 procedure types with median DAP/kg ≥ 200 (overall median DAP/kg of 231). The radiation exposure risk categories created in this multi-center dataset are a critical step towards the development of a robust risk adjustment methodology for radiation exposure in catheterization for congenital heart disease.

Endocarditis After Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Endocarditis has emerged as one of the most concerning adverse outcomes in patients with congenital anomalies involving the right ventricular outflow tract (RVOT) and prosthetic valves. OBJECTIVES: The aim of this study was to evaluate rates and potential risk factors for endocarditis after transcatheter pulmonary valve replacement in the prospective Melody valve trials. METHODS: All patients in whom a transcatheter pulmonary valve (TPV) was implanted in the RVOT as part of 3 prospective multicenter studies comprised the analytic cohort. The diagnosis of endocarditis and involvement of the TPV were determined by the implanting investigator. RESULTS: A total of 309 patients underwent transcatheter pulmonary valve replacement (TPVR) and were discharged with a valve in place. The median follow-up duration was 5.1 years, and total observation until study exit was 1,660.3 patient-years. Endocarditis was diagnosed in 46 patients (median 3.1 years after TPVR), and a total of 35 patients were reported to have TPV-related endocarditis (34 at the initial diagnosis, 1 with a second episode). The annualized incidence rate of endocarditis was 3.1% per patient-year and of TPV-related endocarditis was 2.4% per patient-year. At 5 years post-TPVR, freedom from a diagnosis of endocarditis was 89% and freedom from TPV-related endocarditis was 92%. By multivariable analysis, age ≤12 years at implant (hazard ratio: 2.3; 95% confidence interval: 1.2 to 4.4; p = 0.011) and immediate post-implant peak gradient ≥15 mm Hg (2.7; 95% confidence interval: 1.4 to 4.9; p = 0.002) were associated with development of endocarditis and with development of TPV-related endocarditis (age ≤12 years: 2.8; 95% confidence interval: 1.3 to 5.7; p = 0.006; gradient ≥15 mm Hg: 2.6; 95% confidence interval: 1.3 to 5.2; p = 0.008). CONCLUSIONS: Endocarditis is an important adverse outcome following TVPR in children and adults with post-operative congenital heart disease involving the RVOT. Ongoing efforts to understand, prevent, and optimize management of this complication are paramount in making the best use of TPV therapy. (Melody Transcatheter Pulmonary Valve [TPV] Study: Post Approval Study of the Original Investigational Device Exemption [IDE] Cohort; NCT00740870; Melody Transcatheter Pulmonary Valve Post-Approval Study; NCT01186692; and Melody Transcatheter Pulmonary Valve [TPV] Post-Market Surveillance Study; NCT00688571).

Hybrid Strategy for Neonates With Ductal-Dependent Systemic Circulation at High Risk for Norwood.

BACKGROUND: Hypoplastic left heart syndrome and other cardiac lesions with ductal-dependent systemic circulation continue to be challenging to manage, especially in high-risk (HR) populations (those with prematurity, multiple congenital anomalies, moderate to severe tricuspid regurgitation, hemodynamic instability, intact atrial septum). METHODS: A retrospective study on our institution's experience implementing a hybrid strategy as initial palliation in HR patients with ductal-dependent systemic circulation in HR patients undergoing Norwood versus hybrid procedure. From July 2004 to May 2008, 16 HR patients underwent stage I Norwood procedure. After implementation of a hybrid strategy in 2008, 24 HR patients underwent hybrid procedure from May 2008 to November 2015. RESULTS: There was no difference in gestational age, age at procedure, or hospital length of stay. The HR Hybrid group had lower mean weight (2.6 kg vs 3.1 kg, p = 0.026). Thirty-day mortality was lower in the HR Hybrid group (4% vs 31%, p = 0.019), although there was no difference in interstage mortality (17% vs 9%, p = 0.396). Catheter-based reintervention was more prevalent in the HR Hybrid group, but did not have a negative impact on survival. One-year transplant-free survival was similar (p = 0.416). HR Hybrid patients weighing less than 2.6 kg had higher overall survival (83% vs 25%, p = 0.013), as did patients who were premature (70% vs 0%, p = 0.003). CONCLUSIONS: In high-risk patients, the hybrid procedure appears to have lower 30-day mortality and may have a survival benefit in premature patients and those less than 2.6 kg. Long-term attrition in this high-risk population is ongoing regardless of early strategy.