BACKGROUND:Two self-expanding transcatheter pulmonary valves (SETPVs), Harmony TPV (Medtronic) and Alterra Adaptive Prestent System with the Sapien 3 Valve (Edwards Lifesciences), treat pulmonary regurgitation in patients with a native or surgically repaired right ventricular outflow tract. Ventricular arrhythmias (VAs) are common after implantation. OBJECTIVES:The purpose of this study was to identify the incidence of and risk factors for VA in the first 6 months after SETPV implantation. METHODS:The multicenter SERVE registry included SETPV implantations at 25 U.S. CENTERS:VA was defined as nonsustained ventricular tachycardia (VT), sustained monomorphic VT, polymorphic VT, or >1% ventricular ectopy on Holter monitoring. RESULTS:A total of 513 SETPV implants (359 Harmony, 154 Alterra) were collected, with a median age of 28 years (Q1-Q3: 17-44 years) and no difference in baseline VA by valve type. Alterra patients were more likely (37%) than Harmony patients (26%; P = 0.014) to have VA during the procedural admission. At 6 months, predicted probability of VA burden decreased below baseline for Harmony patients (-6%; 95% CI: -10% to -2%; P < 0.001) and to baseline for Alterra (P = 0.53). CONCLUSIONS:This large multicenter registry study of the natural history of VA after SETPV implantation showed VA to be frequent during the procedural admission, with Alterra patients having more VA than Harmony patients. VA burden decreased to lower than baseline at 6 months in Harmony patients and to baseline in Alterra patients.

BACKGROUND:Coexisting coronary artery disease (CAD) and congenital heart disease (CHD) is rare in adults and poses complex management challenges requiring multidisciplinary coordination. CASE SUMMARY:A 79-year-old man with a history of CAD and stenting was referred for evaluation given worsening dyspnea. Coronary angiography revealed severe ostial left circumflex stenosis and moderate left main disease. In addition, computed tomography demonstrated a previously undiagnosed sinus venosus atrial septal defect with partial anomalous pulmonary venous return. Multidisciplinary evaluation at a partnering CHD program recommended staged percutaneous revascularization and transcatheter closure of the defect instead of surgical repair on cardiopulmonary bypass. The patient successfully underwent complex stenting of the CAD and subsequent transcatheter closure of the sinus venosus atrial septal defect with implantation of a 5.7-cm, 10-zig G-Armor covered stent within the superior vena cava. The procedures were well tolerated without complications, and the patient reported improvement in symptoms on follow-up evaluation. TAKE-HOME MESSAGES:Multidisciplinary percutaneous strategies can achieve effective revascularization and repair of complex coexisting CAD and CHD, avoiding high-risk surgical intervention. Growth in the complexity of CHD patients mandates expanded understanding of comprehensive percutaneous approaches. The hub-spoke model of adult CHD care can optimize treatment for these patients.

BACKGROUND:Disparities in congenital heart disease care exist between high-income and low- and middle-income countries (LMICs), likely extending to congenital cardiac catheterization (CCC). OBJECTIVES:This study compares patient characteristics and outcomes of CCC in the U.S.-based Congenital Cardiac Catheterization Project on Outcomes (C3PO) and the International Quality Improvement Collaborative-Congenital Heart Disease Catheterization Registry (IQIC-CHDCR) from LMICs. METHODS:The analysis included all CCC procedures recorded in C3PO (19 sites) and IQIC-CHDCR (19 sites) from 2019 to 2022. Patient and procedural characteristics, resource utilization, and outcomes were compared. RESULTS:A total of 28,957 C3PO and 6,485 IQIC-CHDCR cases were analyzed. Single ventricle patients accounted for 30% of C3PO and 13% of International Quality Improvement Collaborative (IQIC), with high-risk procedures (procedural risk in congenital cardiac catheterization 3-5) performed more frequently in C3PO (42% vs 23%). Median procedure duration was longer in C3PO (1.5 vs 0.8 hours). Clinically meaningful adverse event (CMAE) rates were higher in C3PO (3.9% vs 1.5%), though mortality was comparable (0.5% vs 0.7%). Risk-adjusted analysis showed a lower ratio in IQIC for both CMAE (0.50; 95% CI: 0.39-0.62) and severity level 4/5 events (0.71; 95% CI: 0.52-0.96). However, failure-to-rescue rates were higher in IQIC (7.1% vs 2.1%). CONCLUSIONS:The harmonized databases facilitated direct comparison of CCC practices, revealing more complex patients and resource-intensive procedures in C3PO, while the IQIC cohort demonstrated lower CMAE rates but a slightly higher mortality rate. These findings emphasize the need for further risk adjustment modeling for LMICs and identify areas to enhance global resource access and patient outcomes.

Background Technical success (TS) and procedural safety (PS) have been reported individually for transcatheter atrial septal defect (ASD) and patent ductus arteriosus (PDA) closures. A composite procedural performance (PP) metric as a patient-centered strategy has not been developed or studied. Methods A multicenter expert working group created PP metrics for ASD and PDA device closures as a composite of TS and PS. TS criteria were defined and categorized into 3 classes (optimal, satisfactory, and unsatisfactory). PS was defined using established adverse event (AE) definitions from the Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry. PP was divided into 3 outcome classes (I to III). Retrospective C3PO data were collected for all cases of isolated ASD and PDA closure from 2014 through 2017. Exclusion criteria included complex congenital heart disease, significant comorbidities, ASD patients with multiple defects or ≥2 deficient rims, and PDA patients weighing <6 kg or with pulmonary hypertension. Factors correlating with class III (suboptimal) PP were analyzed. Results A total of 542 ASD and 688 PDA closure cases were included. Most ASD cases (99%) had optimal or satisfactory TS while 1% had a high severity AE. Class III PP occurred in 2% of ASD cases, mostly due to new mitral valve insufficiency. There were no identified patient or procedural factors associated with class III PP for ASD closures. Optimal or satisfactory TS occurred in 98% of PDA cases, with high severity AEs in <1%. Class III PP occurred in 2% of PDA cases, predominantly due to new arch obstruction, and was associated with younger age (P < .001) and lower weight (P = .001). Conclusions This study introduces PP as a composite variable to comprehensively measure outcomes of standard-risk ASD and PDA device closure. The incorporation of both TS and PS aims to better reflect patient outcomes compared to individual measurements alone. PP may serve as a valuable tool for identifying areas for further investigation and quality improvement.

OBJECTIVE:We report a novel technique for percutaneous retrieval of an embolized umbilical arterial catheter lost within the aorta of a premature baby. KEY STEPS:Key steps include the following: immediate commencement of prostaglandin to maintain ductal patency; venous access with a 4-F sheath (sheath in femoral artery in an approximately 800-g patient is impossible, and alternatives are very high risk); careful traversal of right heart and prograde crossing of patent ductus arteriosus; small snare and 0.014-in wire inserted through the same 4-F catheter; snare wound around embolized line; wire directed through, then captured by snare (not typical lasso snare of line); finally, glide catheter, snare, wire, and captured line carefully pulled through the heart and into the 4-F prelude ideal sheath. POTENTIAL PITFALLS:Potential pitfalls include the following: heart perforation or damage to pulmonary and tricuspid valves, and instability during snare/retrieval. TAKE-HOME MESSAGE:Nontraditional use of a microsnare and wire through the same 4-F catheter via prograde approach can be used to retrieve embolized lines in the aorta in very preterm infants.

BACKGROUND:Neonates with hypoplastic left heart syndrome variants with an intact or highly restrictive atrial septum (HLH-IAS) require immediate postnatal intervention to survive. Emergent left atrial decompression (LAD) via a percutaneous or hybrid approach is standard, but the comparative effectiveness and outcomes of these approaches remain underexplored. METHODS:A multicenter retrospective analysis of all neonates with HLH-IAS who underwent LAD in the first 36 hours of life from January 2009 to March 2020 at 14 North American congenital cardiac programs was conducted. Patient and procedural characteristics and patient outcomes were compared between hybrid and percutaneous LAD. RESULTS:Among 128 patients with HLH-IAS, 105 (80%) underwent percutaneous LAD and 23 (17%) hybrid LAD. No significant differences were observed in preprocedural characteristics such as birth weight (3.1±0.6 versus 3.2±0.6 kg; P=0.453), presence of a baseline interatrial communication (66% versus 61%; P=0.659), interatrial communication gradient (14.4±6.9 versus 12.7±4.6 mm Hg; P=0.456), or lowest pH (7.13±0.14 versus 7.09±0.15; P=0.193). Hybrid LAD resulted in a shorter time from birth to procedure (120 versus 52 minutes; P=0.005) and to atrial septal defect creation (55 versus 29 minutes; P=0.002). All hybrid LAD were technically successful, although 11 (10%) percutaneous LAD were unsuccessful with 7 requiring conversion to surgical septectomy. There was a trend toward fewer serious adverse events with hybrid LAD (36% versus 17%; P=0.141). Most patients (67%) who underwent hybrid LAD had simultaneous pulmonary artery band placement and 21% of patients with percutaneous LAD required reoperation for pulmonary artery band. Long-term survival rates were comparably low between groups, with a 30% transplant-free survival at a median 8-month follow-up. CONCLUSIONS:In patients with HLH-IAS, hybrid LAD allows for faster atrial septal defect creation, has a higher technical success rate, and potentially fewer procedural serious adverse events compared with percutaneous LAD, alongside facilitating simultaneous pulmonary artery band. Our findings underscore the poor prognosis for patients with HLH-IAS despite intervention, highlighting the need for better treatment strategies.

Pulmonary vein stenosis (PVS) in pediatric patients, a condition requiring frequent transcatheter palliative interventions with high morbidity and mortality, necessitates development of a multicenter predictive model for clinically meaningful adverse events (CMAE). Patient and procedural data were collected for Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry cases with PVS interventions aged ≤18 years from 1/1/19 - 12/31/22. A multivariable logistic regression model predicting the primary outcome CMAE (severity levels 3bc/4/5) was built using a random sample of 75% of cases and validated with the remaining 25%. Model discrimination was assessed using the c-statistic and calibration using the Hosmer-Lemeshow test. The derivation dataset of 716 patients had an overall CMAE rate of 7.8%. Patient and procedural characteristics considered for model inclusion are shown in Table 1. The final multivariable model included male sex (odds ratio [OR] 1.74), genetic syndrome (OR 1.99), admission source (OR for medical unit 2.28; OR for step-down unit or ICU 2.07), case duration (OR for 120-209 minutes 2.05, OR for ≥210 minutes 3.18), and hemodynamic vulnerability score (OR for 1 point = 2.05, 2 points = 4.41, ≥3 points = 3.44). C-statistic 0.75, Hosmer-Lemeshow test p = 0.57. Important predictive features include hemodynamic vulnerability score, case duration as a marker for procedural complexity and admission source. Improved understanding of risk and future use of predictive modeling may allow for development of risk mitigation strategies to improve outcomes.

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 (RVGLS) 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%. RVGLS 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. RV EF was not associated with a significant change in RV or LV GLS (p=0.7). RV GLS showed the greatest improvement immediately after valve implantation. Higher pre-implantation RVSP was found to correlate with worse strain (p=0.001). Overall, average RV strain magnitude was higher when pre-implantation 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.

Current leadless pacemaker (LP) systems, which have been developed and used in patients with normal cardiac anatomy, are rare and technically even more challenging to implant in patients with congenital heart diseases, especially with univentricular physiology and Fontan palliation. We report two cases of percutaneous LP implantation in an adult and a child, respectively, highlighting the unconventional approaches, different challenges, and use of multimodality imaging in patients who underwent a Fontan operation.

BACKGROUND:Transverse aortic arch obstruction is a challenging lesion for which stent implantation provides a potentially important alternate therapy. The objectives were to evaluate the technical, procedural, and medium-to-long-term clinical outcomes of percutaneous stent implantation of transverse aortic arch obstruction. METHODS:This is a retrospective, multicenter study of transverse aortic arch stent implantation. Univariable and multivariable analyses were performed. RESULTS:Index catheterization included 187 stent implants in 146 patients. The median age is 14.3 years (interquartile range, 9.3-19), weight is 53 kg (30-69), and follow-up is 53 months (12-120). The most common stent design was open cell (n=90, 48%). Stents overlapped 142 arch vessels (37 carotid arteries) in 118 (81%) cases. Technical and procedural success rates were 100% and 88%, respectively. Lower weight (P=0.018), body surface area (P=0.013), and minimum-to-descending aortic diameter ratio (P<0.001) were associated with higher baseline aortic gradient. The residual gradient was inversely associated with implant and final dilation diameters (P<0.001). The combined incidence of aortic injury and stent-related complications was 14%. There were no reports of abnormal brain scans or stroke. Blood pressure cuff gradient, echocardiographic arch velocity, and hypertension rates improved within 1-year follow-up with increased antihypertensive medication use. Reintervention was reported in 60 (41%) patients at a median of 84 (22-148) months to first reintervention. On multivariable logistic regression, residual aortic gradient >10 mm Hg was associated with increased odds of reintervention at all time points when controlling for each final dilation diameter, weight, and minimum-to-descending aortic diameter ratio. CONCLUSIONS:Transverse aortic arch stent implantation has high rates of technical, procedural, and medium-to-long-term clinical success. Aortic gradient >10 mm Hg is associated with increased odds of reintervention at 1-year and most recent follow-ups. Open cell stent design was frequently used for its advantages in conformability, perfusion of arch vessels, low fracture rate, and the ability to perform effective angioplasty of side cells.

This study aimed to evaluate the current state of congenital interventional cardiology training worldwide, with a focus on case volumes, competency assessment, and the need for ongoing mentorship during early career stages. A survey was conducted among program directors (PDs) of congenital interventional training programs across the globe. The survey gathered data on training pathways, case volumes, types of procedures performed, trainee competency assessment, and the role of ongoing mentorship. Of the 79 PDs who completed the survey, it was observed that training pathways and case volumes varied significantly, particularly between the United States and other countries. Most PDs reported an annual laboratory case volume of >500 congenital cardiac cases, with most cases being interventional. While trainees demonstrated competency in simple procedures (diagnostic cases, simple ASD closure), complex interventions (such as patent ductus arteriosus closure in premature infants) require ongoing mentorship for graduates. PDs recommended a minimum case volume of 400 total cases for trainees, including 250 interventional cases. In addition to case volumes, assessing trainee competency was deemed important, with clinical reasoning, judgment, skillset, teamwork, and complication management being key areas of evaluation. The study highlights the variability in congenital interventional cardiology training and the need for ongoing mentorship during the early career years. External mentorship programs, facilitated by national and international societies, are proposed to provide critical support for early career interventionalists thus enhancing patient care for congenital heart disease. Ultimately, the findings of this survey may serve as a framework for future training standards and guidelines in this specialized field.

Objectives: Our goal was to conduct a hemodynamic analysis of a novel animal model of Fontan physiology. Poor late-term outcomes in Fontan patients are believed to arise from Fontan-induced hemodynamics, but the mechanisms remain poorly understood. Recent advances in surgical experimentation have resulted in the development of a chronic sheep model of Fontan physiology; however, detailed analysis of this model is lacking. Methods: We created a single-stage Fontan model in juvenile sheep with normal biventricular circulation. The superior vena cava was anastomosed to the main pulmonary artery, and the inferior vena cava was connected to the main pulmonary artery using an expanded polytetrafluoroethylene conduit. Longitudinal hemodynamics, including catheterization and magnetic resonance imaging were evaluated. Results: Four out of 12 animals survived, with the longest surviving animal living 3 years after single-stage Fontan. We showed a significant era effect regarding survival (1 out of 8 and subsequently 3 out of 4 animals surviving beyond 2 months) attributed in large part to the procedural learning curve. Key characteristics of Fontan hemodynamics, namely systemic venous hypertension and low normal cardiac output, were observed. However, recapitulation of passive human Fontan hemodynamics is affected by volume loading of the right ventricle given an anatomic difference in sheep azygous venous anatomy draining to the coronary sinus. Conclusions: A significant learning curve exists to ensure long-term survival and future surgical modifications, including banding of the main pulmonary artery and ligation of the azygous to coronary sinus connection are promising strategies to improve the fidelity of model hemodynamics. (JTCVS Open 2024;21:268-78)

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. (J Am Coll Cardiol Intv 2023;16:1917-1928)(c) 2023 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

ObjectiveAs COVID-19 continues to affect the global population, it is crucial to study the impact of the disease in vulnerable populations. This study of a diverse, international cohort aims to provide timely, experiential data on the course of disease in paediatric patients with congenital heart disease (CHD). MethodsData were collected by capitalising on two pre-existing CHD registries, the International Quality Improvement Collaborative for Congenital Heart Disease: Improving Care in Low- and Middle-Income Countries and the Congenital Cardiac Catheterization Project on Outcomes. 35 participating sites reported data for all patients under 18 years of age with diagnosed CHD and known COVID-19 illness during 2020 identified at their institution. Patients were classified as low, moderate or high risk for moderate or severe COVID-19 illness based on patient anatomy, physiology and genetic syndrome using current published guidelines. Association of risk factors with hospitalisation and intensive care unit (ICU) level care were assessed. ResultsThe study included 339 COVID-19 cases in paediatric patients with CHD from 35 sites worldwide. Of these cases, 84 patients (25%) required hospitalisation, and 40 (12%) required ICU care. Age <1 year, recent cardiac intervention, anatomical complexity, clinical cardiac status and overall risk were all significantly associated with need for hospitalisation and ICU admission. A multivariable model for ICU admission including clinical cardiac status and recent cardiac intervention produced a c-statistic of 0.86. ConclusionsThese observational data suggest risk factors for hospitalisation related to COVID-19 in paediatric CHD include age, lower functional cardiac status and recent cardiac interventions. There is a need for further data to identify factors relevant to the care of patients with CHD who contract COVID-19 illness.

To evaluate short-term procedural outcomes and safety for infants < 2.5 kg who underwent catheterization with intended patent ductus arteriosus (PDA) device closure in a multi-center registry, as performance of this procedure becomes widespread. A multi-center retrospective review was performed using data from the Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry. Data were collected for all intended cases of PDA closure in infants < 2.5 kg from April 2019 to December 2020 at 13 participating sites. Successful device closure was defined as device placement at the conclusion of the catheterization. Procedural outcomes and adverse events (AE) were described, and associations between patient characteristics, procedural outcomes and AEs were analyzed. During the study period, 300 cases were performed with a median weight of 1.0 kg (range 0.7–2.4). Successful device closure was achieved in 98.7

Cyanotic congenital heart disease (CCHD) due to one or more structural abnormalities causes insufficient blood oxygenation. Approximately 2 out of every 1000 infants are born with CCHD and palliative treatment for many patients involves shunting blood from the systemic to the pulmonary circuits, often through a modified Blalock-Taussig-Thomas shunt (BTTs). Synthetic vascular grafts typically used for BTTs have associated risks for intimal hyperplasia, thrombosis, and infection. Humacyte, Inc. has developed a 6mm diameter tissue-engineered blood vessel, the Human Acellular Vessel (HAV), currently being studied in adults suffering from vascular trauma, peripheral arterial disease, and renal failure requiring hemodialysis. In addition to restoring blood flow and providing arteriovenous access in these patients, the HAV has demonstrated the capacity for host cellular remodeling that transformed it into a native-like living tissue. Here the HAV production platform was modified to generate small diameter (3.5mm) vessels for preclinical evaluation. BTTs were placed from the right subclavian artery to the pulmonary artery in juvenile rhesus macaques. Post-operative imaging from 1 week to 6 months using angiography and MRI was used to confirm HAV patency, structure, and quantify blood flow. At explantation, the HAV and surrounding tissues were collected and processed for histological analyses. Results confirmed the feasibility of using the HAV BTTs, but also showed that all macaques had some immunological reactivity to the HAV human extracellular matrix in this xenogeneic animal model. Nonetheless, the HAV BTTs remained patent and performed well for up to six months in animals that had only mild host reactivity. HAV repopulation by host cells expressing smooth muscle and endothelial markers as well as the formation of neoadventitial tissue was also observed. These findings may support use of the HAV as a BTTs in CCHD and potentially other pediatric indications.

Objective: Pulmonary artery reconstruction during comprehensive stage 2 (CS2) procedure can be challenging. Since 2017, we have employed preemptive left pulmonary artery (LPA) stenting. We hypothesized that LPA stenting promotes adequate growth and without compromising Fontan candidacy. Herewith, we report our midterm results. Methods: From 2002 to 2020, 159 patients underwent CS2. Patients were divided as follows: no stent (n = 122; Group 1) and perioperative LPA stent (n = 37; Group 2). Group 2 was subdivided according to unplanned stent (n = 17; Group 2a) or preemptive stent (n = 20; Group 2b). Relevant perioperative data was reviewed. Nonparametric statistics were utilized. Results: Median age and weight at surgery and hospital length of stay after CS2 did not differ between groups. Median cardiopulmonary bypass and crossclamp times were significantly greater in Group 1 (265 vs 243 minutes [P = .021] and 46 vs 26 minutes [P = .008]). In-hospital mortality was similar between Groups 1 and 2 (9.0% vs 18.9%, respectively [P = .1348]). Group 2b demonstrated a superior survival compared to Group 2a (P = .0335) but not Group 1 (P > .9999). Preemptive stenting significantly increased median hilar LPA diameter at CS2 exit angiogram compared with no stenting (P < .0001). Groups 2a and 2b significantly increased the pre-Fontan diameter of the hilar LPA when compared with Group 1 (6.1 and 6.8 vs 5.7 mm, respectively [P < .0001]). A further 120 patients underwent Fontan operation (75%). Median follow-up for Groups 1 and 2 were 7.4 and 3.0 years, respectively. Conclusions: Perioperative LPA stenting during CS2 does not adversely affect pulmonary growth. Preemptive stenting seems advantageous for LPA growth in preparation for Fontan completion.

Data on the frequency and outcome of surgical interventions as a result of adverse events (AE) encountered in the pediatric and congenital cardiac catheterization laboratory are limited. This study analyzes the outcomes of specific types of AE that are most likely to require immediate surgical intervention. Data from the C3PO registry were analyzed to identify specific types of significant vascular/cardiac trauma or technical adverse events (stent/device/coil embolization/migration). The relationship between these AE and an "adverse outcome" (defined as either surgery, ECMO, or death) were analyzed. Between 01/2014 and 12/2017, 25,731 cases were entered into the C3PO registry. Vascular or cardiac trauma were observed in 92 cases (0.36% cases in C3PO), and technical adverse events were observed in 176 cases (0.68% cases in C3PO). The two highest procedure type risk categories (PREDIC3T) accounted for 61% of the cases in the cardiac/vascular trauma cohort, and 34% in the technical AE cohort. For vascular/cardiac trauma, 24 (26%) had an adverse outcome, with ECMO in 8 (9%), surgery in 19 (20%), and death in 9 (10%). For technical AE 25 (14%) had an adverse outcome, with ECMO in 3 (2%), surgery in 23 (13%), and death in 3 (2%). Survival after cardiac surgery secondary to an AE was 68% for cardiac/vascular trauma, and 96% for technical adverse events. RF perforation of the pulmonary valve was the procedure most likely to result in cardiac/vascular trauma (10%), with 57% of those having an adverse outcome. Atrial septal interventions accounted for 29% of all adverse outcomes in the cardiac/vascular trauma cohort. Non-elective or emergent cases were associated with a significantly higher incidence of an adverse outcome for both, cardiac/vascular trauma (OR 7.1) and technical adverse events (OR 2.7). Surgery within the last 30 days was associated with a significantly higher incidence of an adverse outcome for cardiac/vascular trauma only (OR 4.2). Significant cardiac/vascular trauma or stent/device/coil embolization/migration are rare, but high consequence AE. With appropriate surgical and ECMO backup, a high survival can be achieved. The potential need for and impact of immediate surgical backup seems to be higher for cardiac/vascular trauma (in particular after specific case types), than for device/coil migration/embolization, and as such case specific backup arrangements are required.

Background:The COVID-19 pandemic has posed tremendous stress on the health care system. Its effects on pediatric/congenital catheterization program practice and performance have not been described.Objectives:The purpose of this study was to evaluate how case volumes, risk-profile, and outcomes of pediatric/congenital catheterization procedures changed in response to the first wave of COVID-19 and after that wave.Methods:A multicenter retrospective observational study was performed using Congenital Cardiac Catheterization Project on Outcomes Registry (C3PO) data to study changes in volume, case mix, and outcomes (high-severity adverse events [HSAEs]) during the first wave of COVID (March 1, 2020, to May 31, 2020) in comparison to the period prior to (January 1, 2019, to February 28, 2020) and after (June 1, 2020, to December 31, 2020) the first wave. Multivariable analyses adjusting for case type, hemodynamic vulnerability, and age group were performed. Hospital responses to the first wave were captured with an electronic study instrument.Results:During the study period, 12,557 cases were performed at 14 C3PO hospitals (with 8% performed during the first wave of COVID and 32% in the postperiod). Center case volumes decreased from a median 32.1 cases/month (IQR: 20.7-49.0 cases/month) before COVID to 22 cases/month (IQR: 13-31 cases/month) during the first wave (P = 0.001). The proportion of cases with risk factors for HSAE increased during the first wave, specifically proportions of infants and neonates (P < 0.001) and subjects with renal insufficiency (P = 0.02), recent cardiac surgery (P < 0.001), and a higher hemodynamic vulnerability score (P = 0.02). The observed HSAE risk did not change significantly (P = 0.13). In multivariable analyses, odds of HSAE during the first wave of COVID (odds ratio: 0.75) appeared to be lower than that before COVID, but the difference was not significant (P = 0.09).Conclusions:Despite increased case-mix complexity, C3PO programs maintained, if not improved, their performance in terms of HSAE. Exploratory analyses of practice changes may inform future harm-reduction efforts.

Background Tissue-engineered vascular grafts (TEVGs) have the potential to advance the surgical management of infants and children requiring congenital heart surgery by creating functional vascular conduits with growth capacity. Methods Herein, we used an integrative computational-experimental approach to elucidate the natural history of neovessel formation in a large animal preclinical model; combining an in vitro accelerated degradation study with mechanical testing, large animal implantation studies with in vivo imaging and histology, and data-informed computational growth and remodeling models. Results Our findings demonstrate that the structural integrity of the polymeric scaffold is lost over the first 26 weeks in vivo, while polymeric fragments persist for up to 52 weeks. Our models predict that early neotissue accumulation is driven primarily by inflammatory processes in response to the implanted polymeric scaffold, but that turnover becomes progressively mechano-mediated as the scaffold degrades. Using a lamb model, we confirm that early neotissue formation results primarily from the foreign body reaction induced by the scaffold, resulting in an early period of dynamic remodeling characterized by transient TEVG narrowing. As the scaffold degrades, mechano-mediated neotissue remodeling becomes dominant around 26 weeks. After the scaffold degrades completely, the resulting neovessel undergoes growth and remodeling that mimicks native vessel behavior, including biological growth capacity, further supported by fluid–structure interaction simulations providing detailed hemodynamic and wall stress information. Conclusions These findings provide insights into TEVG remodeling, and have important implications for clinical use and future development of TEVGs for children with congenital heart disease.