Assessing the State of Training in Congenital Interventional Cardiology: A Global Survey of Program Directors.

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.

Catheterization for Congenital Heart Disease Adjustment for Risk Method II.

BACKGROUND: Current metrics used to adjust for case mix complexity in congenital cardiac catheterization are becoming outdated due to the introduction of novel procedures, innovative technologies, and expanding patient subgroups. This study aims to develop a risk adjustment methodology introducing a novel, clinically meaningful adverse event outcome and incorporating a modern understanding of risk. METHODS: Data from diagnostic only and interventional cases with defined case types were collected for patients ≤18 years of age and ≥2.5 kg at all Congenital Cardiac Catheterization Project on Outcomes participating centers. The derivation data set consisted of cases performed from 2014 to 2017, and the validation data set consisted of cases performed from 2019 to 2020. Severity level 3 adverse events were stratified into 3 tiers by clinical impact (3a/b/c); the study outcome was clinically meaningful adverse events, severity level ≥3b (3bc/4/5). RESULTS: The derivation data set contained 15 224 cases, and the validation data set included 9462 cases. Clinically meaningful adverse event rates were 4.5% and 4.2% in the derivation and validation cohorts, respectively. The final risk adjustment model included age <30 days, Procedural Risk in Congenital Cardiac Catheterization risk category, and hemodynamic vulnerability score (C statistic, 0.70; Hosmer-Lemeshow P value, 0.83; Brier score, 0.042). CONCLUSIONS: CHARM II (Congenital Heart Disease Adjustment for Risk Method II) risk adjustment methodology allows for equitable comparison of clinically meaningful adverse events among institutions and operators with varying patient populations and case mix complexity performing pediatric cardiac catheterization.

Augmented Reality Visualization of 3D Rotational Angiography in Congenital Heart Disease: A Comparative Study to Standard Computer Visualization.

Augmented reality (AR) visualization of 3D rotational angiography (3DRA) provides 3D representations of cardiac structures with full visualization of the procedural environment. The purpose of this study was to evaluate the feasibility of converting 3DRAs of congenital heart disease patients to AR models, highlight the workflow for 3DRA optimization for AR visualization, and assess physicians' perceptions of their use. This single-center study prospectively evaluated 30 retrospectively-acquired 3DRAs that were converted to AR, compared to Computer Models (CM). Median patient age 6.5 years (0.24-38.8) and weight 20.6 kg (3.4-107.0). AR and CM quality were graded highly. RV pacing was associated with higher quality of both model types (p = 0.02). Visualization and identification of structures were graded as "very easy" in 81.1% (n = 73) and 67.8% (n = 61) of AR and CM, respectively. Fifty-nine (66%) grades 'Agreed' or 'Strongly Agreed' that AR models provided superior appreciation of 3D relationships; AR was found to be least beneficial in visualization of aortic arch obstruction. AR models were thought to be helpful in identifying pathology and assisting in interventional planning in 85 assessments (94.4%). There was significant potential seen in the opportunity for patient/family counseling and trainee/staff education with AR models. It is feasible to convert 3D models of 3DRAs into AR models, which are of similar image quality as compared to CM. AR models provided additional benefits to visualization of 3D relationships in most anatomies. Future directions include integration of interventional simulation, peri-procedural counseling of patients and families, and education of trainees and staff with AR models.

Safety and Short-Term Outcomes for Infants < 2.5 kg Undergoing PDA Device Closure: A C3PO Registry Study.

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% of cases with a 1.7% incidence of level 4/5 AEs, including one periprocedural mortality. Neither failed device placement nor adverse events were significantly associated with patient age, weight or institutional volume. Higher incidence of adverse events associated with patients who had non-cardiac problems (p = 0.017) and cases with multiple devices attempted (p = 0.064). Transcatheter PDA closure in small infants can be performed with excellent short-term outcomes and safety across institutions with variable case volume.

Occult Diastolic Dysfunction and Adverse Clinical Outcomes in Adolescents and Young Adults With Fontan Circulation.

Background In Fontan circulation, diastolic dysfunction portends a worse clinical outcome but may be concealed during routine assessment. Invasive evaluation with rapid volume expansion (RVE) can identify patients with occult diastolic dysfunction (ODD). We sought to evaluate the association between ODD and adverse clinical outcomes at medium-term follow-up. Methods and Results We conducted a single-center observational study of patients with Fontan circulation who underwent clinical catheterization with RVE from 2012 to 2017. ODD was defined as post-RVE end-diastolic pressure ≥15 mm Hg. A composite adverse clinical outcome included mortality, cardiac transplant, ventricular assist device, plastic bronchitis, protein-losing enteropathy, arrhythmia, stroke/thrombus, or cardiac-related hospital admission. Proportional hazards regression was used to compare the ODD-positive and ODD-negative groups for risk of the composite adverse clinical outcome. Eighty-nine patients with Fontan circulation (47% female patients) were included at a median age of 14 years. ODD was identified in 31%. Fontan duration was longer in the ODD group (P=0.001). The composite adverse clinical outcome occurred more frequently in the ODD group (52 versus 26%, P=0.03) during a median follow-up duration of 2.9 years after catheterization. ODD (hazard ratio [HR], 2.68 [95% CI, 1.28-5.66]; P=0.02) and Fontan duration (HR, 1.07 [95% CI, 1.02-1.12]; P=0.003) were associated with the composite adverse clinical outcome. When stratified by Fontan duration, ODD remained significantly associated with the hazard of adverse clinical outcomes in patients with a Fontan duration ≥10 years (HR, 2.57 [95% CI, 1.03-6.57]; P=0.04). Conclusions Cardiac catheterization with rapid volume expansion reveals a significant incidence of ODD, which relates to Fontan duration. ODD is associated with an increased hazard of adverse clinical outcomes during medium-term follow-up, especially in patients with longer Fontan duration. ODD may portend a worse prognosis in Fontan circulation.

Feasibility of intraprocedural augmented reality visualisation of 3D rotational angiography in congenital cardiac catheterisation.

Three-dimensional rotational angiography has become a mainstay of congenital cardiac catheterisation. Augmented reality is an exciting and emerging technology that allows for interactive visualisation of 3D holographic images in the user's environment. This case series reports on the feasibility of intraprocedural augmented reality visualisation of 3D rotational angiography in five patients with CHD.

Changes in Practice/Outcomes of Pediatric/Congenital Catheterization in Response to the First Wave of COVID.

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.

Data-driven computational models of ventricular-arterial hemodynamics in pediatric pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a complex disease involving increased resistance in the pulmonary arteries and subsequent right ventricular (RV) remodeling. Ventricular-arterial interactions are fundamental to PAH pathophysiology but are rarely captured in computational models. It is important to identify metrics that capture and quantify these interactions to inform our understanding of this disease as well as potentially facilitate patient stratification. Towards this end, we developed and calibrated two multi-scale high-resolution closed-loop computational models using open-source software: a high-resolution arterial model implemented using CRIMSON, and a high-resolution ventricular model implemented using FEniCS. Models were constructed with clinical data including non-invasive imaging and invasive hemodynamic measurements from a cohort of pediatric PAH patients. A contribution of this work is the discussion of inconsistencies in anatomical and hemodynamic data routinely acquired in PAH patients. We proposed and implemented strategies to mitigate these inconsistencies, and subsequently use this data to inform and calibrate computational models of the ventricles and large arteries. Computational models based on adjusted clinical data were calibrated until the simulated results for the high-resolution arterial models matched within 10% of adjusted data consisting of pressure and flow, whereas the high-resolution ventricular models were calibrated until simulation results matched adjusted data of volume and pressure waveforms within 10%. A statistical analysis was performed to correlate numerous data-derived and model-derived metrics with clinically assessed disease severity. Several model-derived metrics were strongly correlated with clinically assessed disease severity, suggesting that computational models may aid in assessing PAH severity.

Cardiac Magnetic Resonance to Predict Coronary Artery Compression in Transcatheter Pulmonary Valve Implantation Into Conduits.

OBJECTIVES: The aim of this study was to evaluate the accuracy of cardiac magnetic resonance (CMR) in predicting coronary artery (CA) compression during transcatheter pulmonary valve implantation (TPVi). BACKGROUND: TPVi is a widely available option to treat dysfunctional right ventricle (RV)-to-pulmonary artery (PA) conduits, but CA compression is an absolute contraindication. CMR can evaluate coronary anatomy, but its utility in predicting CA compression is not well established. METHODS: After Institutional Review Board approval was obtained, all patients at 9 centers with attempted TPVi in RV-PA conduits and recent CMR (≤12 months) were analyzed. A core laboratory reviewed all CMR studies for the shortest orthogonal distance from a CA to the conduit, the shortest distance from a CA to the most stenotic area of the conduit, and subjective assessment of CA compression risk. RESULTS: Among 231 patients, TPVi was successful in 198 (86%); in 24 (10%), balloon testing precluded implantation (documented CA compression or high risk). Distance to the RV-PA conduit ≤2.1 mm (area under the curve [AUC]: 0.70) and distance to most stenotic area ≤13.1 mm (AUC: 0.69) predicted CA compression. Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with CA compression when controlling for abnormal coronary anatomy or degree of conduit calcification. CONCLUSIONS: CMR can help predict the risk for CA compression during TPVi in RV-PA conduits but cannot completely exclude CA compression. CMR may assist in patient selection and counseling families prior to TPVi, although balloon testing remains essential.

Interpreting Quality Improvement When Introducing New Technology: A Collaborative Experience in ASD Device Closures.

The objective of this study was to evaluate the impact of the regular introduction of new technologies into interventional cardiac catheterization procedures, in this case new atrial septal defect (ASD) closure devices, while conducting a multi-center collaborative initiative to reduce radiation usage during all procedures. Data were collected prospectively by 8 C3PO institutions between January 1, 2014 and December 31, 2017 for ASD device closure procedures in the cardiac catheterization lab during a quality improvement (QI) initiative aimed at reducing patient radiation exposure. Radiation exposure was measured in dose area product per body weight (µGy*m2/kg). Use of proposed practice change strategies at the beginning and end of the QI intervention period was assessed. Radiation exposure was summarized by institution and by initial type of device used for closure. This study included 602 ASD device closures. Without changes in patient characteristics, total fluoroscopy duration, or number of digital acquisitions, median radiation exposure decreased from 37 DAP/kg to 14 DAP/kg from 2014 to 2017. While all individual centers decreased overall median DAP/kg, the use of novel devices for ASD closure correlated with a temporary period of worsening institutional radiation exposure and increased fluoroscopy time. The introduction of new ASD closure devices resulted in increased radiation exposure during a QI project designed to reduce radiation exposure. Therefore, outcome assessment must be contextualized in QI projects, hospital evaluation, and public reporting, to acknowledge the expected variation during innovation and introduction of novel therapies.

Procedural Risk in Congenital Cardiac Catheterization (PREDIC3T).

Background Advancements in the field, including novel procedures and multiple interventions, require an updated approach to accurately assess patient risk. This study aims to modernize patient hemodynamic and procedural risk classification through the creation of risk assessment tools to be used in congenital cardiac catheterization. Methods and Results Data were collected for all cases performed at sites participating in the C3PO (Congenital Cardiac Catheterization Project on Outcomes) multicenter registry. Between January 2014 and December 2017, 23 119 cases were recorded in 13 participating institutions, of which 88% of patients were <18 years of age and 25% <1 year of age; a high-severity adverse event occurred in 1193 (5.2%). Case types were defined by procedure(s) performed and grouped on the basis of association with the outcome, high-severity adverse event. Thirty-four unique case types were determined and stratified into 6 risk categories. Six hemodynamic indicator variables were empirically assessed, and a novel hemodynamic vulnerability score was determined by the frequency of high-severity adverse events. In a multivariable model, case-type risk category (odds ratios for category: 0=0.46, 1=1.00, 2=1.40, 3=2.68, 4=3.64, and 5=5.25; all P≤0.005) and hemodynamic vulnerability score (odds ratio for score: 0=1.00, 1=1.27, 2=1.89, and ≥3=2.03; all P≤0.006) remained independent predictors of patient risk. Conclusions These case-type risk categories and the weighted hemodynamic vulnerability score both serve as independent predictors of patient risk for high-severity adverse events. This contemporary procedure-type risk metric and weighted hemodynamic vulnerability score will improve our understanding of patient and procedural outcomes.

Acute and short-term haemodynamic impact of transcatheter pulmonary valve implantation on left ventricular systolic and diastolic function.

OBJECTIVES: Assess the acute and short-term haemodynamic impact of transcatheter pulmonary valve implantation on left ventricular systolic and diastolic function stratified by pre-transcatheter pulmonary valve implantation physiology. BACKGROUND: Transcatheter pulmonary valve implantation is a widely available option to treat residual or recurrent pulmonary stenosis and pulmonary insufficiency. Transcatheter pulmonary valve implantation acutely increases pulmonary artery size and diastolic pressure in patients with pulmonary insufficiency and acute pulmonary edema has been reported after transcatheter pulmonary valve implantation, possibly related to acute left ventricular volume loading. However, the impact of transcatheter pulmonary valve implantation on left ventricular diastolic function has not been established. METHODS: Patients who underwent transcatheter pulmonary valve implantation from 2010 to 2017 at our centre were grouped by indication for transcatheter pulmonary valve implantation as pulmonary stenosis, pulmonary insufficiency, or mixed disease. Separate analysis was performed on those who underwent transcatheter pulmonary valve implantation for pulmonary stenosis versus pulmonary insufficiency or mixed disease. Intracardiac haemodynamics immediately before and after transcatheter pulmonary valve implantation and echocardiographic assessment of left ventricular systolic and diastolic function at baseline, 1-day post transcatheter pulmonary valve implantation, and 1-year post transcatheter pulmonary valve implantation were compared between groups. RESULTS: In 102 patients who underwent transcatheter pulmonary valve implantation, the indication was pulmonary stenosis in 29 (28%), pulmonary insufficiency in 28 (29%), and mixed disease in 44 (43%). There were no significant differences in left ventricular systolic or diastolic function between groups at baseline, immediately after transcatheter pulmonary valve implantation, or 1-year post implantation. The mean pulmonary artery wedge pressure increased equally across groups. CONCLUSIONS: While patients with pulmonary insufficiency likely have acute left ventricular volume loading following transcatheter pulmonary valve implantation, this does not appear to be haemodynamically significant as transcatheter pulmonary valve implantation was not associated with measurable changes in left ventricular systolic or diastolic function acutely or 1-year post implantation.

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.

Differences in Pulmonary and Systemic Flow Measurements by Cardiac Magnetic Resonance vs Cardiac Catheterization and Relation to Collateral Flow in Single Ventricle Patients.

Both cardiac magnetic resonance (CMR) and cardiac catheterization (cath) may assess patients with single ventricle physiology prior to stage II or Fontan palliation. However, development of significant aortopulmonary collaterals may invalidate assumptions of the Fick method. We compared CMR and cath flow measurements and evaluated the relation to collateral flow. This single-center study included all pre-stage II and pre-Fontan patients between 2010 and 2017 with CMR and cath within 1 month. Pulmonary (Qp) and systemic flow (Qs) by cath were calculated by Fick method. CMR Qp was calculated by total pulmonary venous flow, and Qs by total vena caval flow. Collateral flow by CMR was the difference of pulmonary vein and pulmonary artery flow. In 26 studies (16 pre-stage II and 10 pre-Fontan) in 21 patients, collateral flow was higher in pre-Fontan patients (1.8 ± 0.6 vs 0.9 ± 0.8 L/min/m2, p = 0.01). Overall, CMR and cath had good agreement for Qs and Qp:Qs, with moderate correlation (r = 0.44, p = 0.02 for Qs, r = 0.48, p = 0.02 for Qp:Qs). In pre-Fontan but not in pre-stage II patients, CMR had higher Qp (mean difference - 1.71 L/min/m2) and Qp:Qs (mean difference - 0.36). The underestimation of cath Qp correlated with amount of collateral flow (r = - 0.47, p = 0.02). Neither cath nor CMR flow measurements correlated with outcomes in this small cohort. In conclusion, collaterals lead to systematically higher Qp and Qp:Qs measurements by CMR vs cath in single ventricle patients. Measurements may not be used interchangeably, with potential clinical significance in estimating pulmonary vascular resistance. Further study is necessary to evaluate possible relation to clinical outcomes.

Differences in Cost of Care by Palliation Strategy for Infants With Ductal-Dependent Pulmonary Blood Flow.

BACKGROUND: In infants with ductal-dependent pulmonary blood flow, initial palliation with patent ductus arteriosus (PDA) stent or modified Blalock-Taussig (BT) shunt have comparable mortality but discrepant length of stay, procedural complication rates and reintervention burdens, which may influence cost. The relative economic impact of these palliation strategies is unknown. METHODS AND RESULTS: Retrospective study of infants with ductal-dependent pulmonary blood flow palliated with PDA stent (n=104) or BT shunt (n=251) from 2008 to 2015 at 4 centers of the Congenital Catheterization Research Collaborative. Inflation-adjusted inpatient hospital costs were calculated for first year of life using Pediatric Health Information System data. Costs derived from outpatient catheterizations not in Pediatric Health Information System were imputed. Costs were compared using propensity score-adjusted multivariable models, to account for baseline differences between groups. After propensity score adjustment, first year of life costs were significantly lower in PDA stent ($215 825 [190 644-244 333]) than BT shunt ($249 855 [230 693-270 609]) patients ( P=0.05). After addition of imputed costs, first year of life costs were not significantly different between PDA stent ($226 403 [200 274-255 941]) and BT shunt ($252 072 [232 955-272 759]) groups ( P=0.15). Patient characteristics associated with higher costs included: younger gestational age, genetic syndrome, noncardiac diagnoses, procedural complications, extracorporeal membrane oxygenation, duration of ventilation, intensive care unit and hospital length of stay and reintervention ( P≤0.02 for all). CONCLUSIONS: In this first multicenter comparative cost study of PDA stent or BT shunt as palliation for infants with ductal-dependent pulmonary blood flow, adjusted for baseline differences, PDA stent was associated with lower to equivalent costs over the first year of life. Combined with previous evidence suggesting clinical noninferiority, these findings suggest that PDA stent provides competitive health care value.