Association of Postnatal Opioid Exposure and 2-Year Neurodevelopmental Outcomes in Infants Undergoing Cardiac Surgery.

BACKGROUND: Opioids are commonly used to provide analgesia during and after congenital heart surgery. The effects of exposure to opioids on neurodevelopment in neonates and infants are not well understood. OBJECTIVES: This study sought to evaluate the associations between cumulative opioid exposure (measured in morphine mg equivalent) over the first year of life and 2-year neurodevelopmental outcomes (Bayley Scales of Infant and Toddler Development-Third/Fourth Edition [Bayley-III/IV] cognitive, language, and motor scores). METHODS: A single-center retrospective cohort study of infants undergoing congenital heart surgery was performed. Adjustment for measurable confounders was performed through multivariable linear regression. RESULTS: A total of 526 subjects were studied, of whom 32% underwent Society for Thoracic Surgeons-European Association for Cardio-Thoracic Surgery category 4 or 5 operations. In unadjusted analyses, higher total exposure to opioids was associated with worse scores across all 3 Bayley-III/IV domain scores (all P < 0.05). After adjustment for measured confounders, greater opioid exposure was associated with lower Bayley-III/IV scores (cognitive: ß = -1.0 per log-transformed morphine mg equivalents, P = 0.04; language: ß = -1.2, P = 0.04; and motor: ß = -1.1, P = 0.02). Total hospital length of stay, prematurity, genetic syndromes, and worse neighborhood socioeconomic status (represented either by Social Vulnerability Index or Childhood Opportunity Index) were all associated with worse Bayley-III/IV scores across all domains (all P < 0.05). CONCLUSIONS: Greater postnatal exposure to opioids was associated with worse neurodevelopmental outcomes across cognitive, language, and motor domains, independent of other less modifiable factors. This finding should motivate research and efforts to explore reduction in opioid exposure while preserving quality cardiac intensive care.

Health-Related Quality of Life After Neonatal Treatment of Symptomatic Tetralogy of Fallot: Insights from the Congenital Cardiac Research Collaborative.

To evaluate the association between initial management strategy of neonatal symptomatic Tetralogy of Fallot (sTOF) and later health-related quality of life (HRQOL) outcomes. We performed a multicenter, cross-sectional evaluation of a previously assembled cohort of infants with sTOF who underwent initial intervention at ≤ 30 days of age, between 2005 and 2017. Eligible patients' parents/guardians completed an age-appropriate Pediatric Quality of Life Inventory, a Pediatric Quality of Life Inventory Cardiac Module Heart Disease Symptoms Scale, and a parental survey. The association between treatment strategy and HRQOL was evaluated, and the entire sTOF cohort was compared to published values for the healthy pediatric population and to children with complex congenital heart disease and other chronic illness. The study cohort included 143 sTOF subjects, of which 59 underwent a primary repair, and 84 had a staged repair approach. There was no association between initial management strategy and lower HRQOL. For the entire cohort, in general, individual domain scores decreased as age sequentially increased. Across domain measurements, mean scores for the sTOF cohort were significantly lower than the healthy pediatric population and comparable to those with other forms of complex CHD and other chronic health conditions. The presence of a genetic syndrome was significantly associated with a poor HRQOL (p = 0.003). Initial treatment strategy for sTOF was not associated with differences in late HRQOL outcomes, though the overall HRQOL in this sTOF cohort was significantly lower than the general population, and comparable to others with chronic illness.

Cumulative Radiation Exposure and Lifetime Cancer Risk in Patients With Tetralogy of Fallot Requiring Early Intervention.

Background: Neonates with tetralogy of Fallot and symptomatic cyanosis (sTOF) require early intervention, utilizing either a staged repair (SR) or primary repair (PR) approach. They are exposed to several sources of low-dose ionizing radiation, which may contribute to increased cancer risk. Objectives: The purpose of this study was to compare cumulative radiation exposure and associated lifetime attributable risk (LAR) of cancer between treatment strategies in sTOF. Methods: Neonates with sTOF who underwent SR or PR from 2012 to 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Radiation exposure from all radiologic studies prior to 18 months of age was converted to organ-equivalent doses and projected LAR of cancer incidence using the National Cancer Institute dosimetry tools. Results: There were 242 neonates from 8 centers, including patients with 146 SR and 96 PR. Cumulative total effective dose was significantly higher for SR (median 8.3 mSv, IQR: 3.0-17.4 mSv) than PR (2.1 mSv, IQR: 0.8-8.5 mSv; P < 0.001). Cumulative organ-level doses were significantly higher in SR compared to PR. Regardless of treatment strategy, LARs were higher in females compared to males. Among organs with median exposure >1 mGy in females, the LAR was highest for breast in SR (mean 1.9/1,000 patients). The highest proportion of cancers attributable to radiation exposure was projected for thyroid cancer in females undergoing SR (7.3%). Conclusions: Cumulative radiation exposure and LARs were higher among those undergoing SR compared to PR. This will be an important factor to consider in determining the preferred neonatal treatment strategy and should substantiate efforts to reduce radiation exposure in this vulnerable population.

Intubation and Lower Saturation in the Delivery Room are Associated with Balloon Atrial Septostomy in Neonates with Transposition of the Great Arteries.

OBJECTIVE: To identify delivery room (DR) characteristics of patients with transposition of the great arteries (TGA) who underwent preoperative balloon atrial septostomy (BAS). STUDY DESIGN: Retrospective cohort study of all patients with prenatally diagnosed TGA delivered at our center between 2013 and 2023 who underwent arterial switch operation during the newborn admission. RESULTS: A total of 168 patients were included (median gestational age 39.5 weeks, 64% male, 33% with ventricular septal defect, 8% with aortic arch hypoplasia). BAS was performed in 84 patients (50%). Patients who underwent BAS had higher proportion of intubation in the DR (87% vs 33%, P < .001), lower maximum oxygen saturation in the first 10 minutes (64% vs 74%, P < .001) and 20 minutes (71% vs 81%, P < .001) of life, and lower maximum oxygen saturation at any point in the DR (79% vs 87%, P < .001). Adjusting for confounders (ventricular septal defect, aortic arch anomaly, 5-minute Apgar, birth weight), intubation in the DR (aOR 9.5, 95% CI 3.9, 25.0) and lower maximum oxygen saturation in the DR (aOR 0.9, 95% CI 0.8, 0.9) were independently associated with BAS. By receiver operating characteristic analysis, a maximum oxygen saturation of less than 86% at any time point in the DR discriminated for BAS with a specificity of 0.88, sensitivity of 0.70, and area under the curve of 0.82. CONCLUSIONS: Intubation and lower oxygen saturation in the DR are independently associated with BAS in patients with TGA born at our center. A maximum DR saturation of less than 86% best discriminates patients who undergo BAS in our population.

Pulmonary Artery Wedge Pressure Can Underestimate Direct Pulmonary Vein Pressure in Pediatric Pulmonary Vein Stenosis.

Background: Pulmonary artery wedge pressure (PAWP) can underestimate directly measured pulmonary vein pressure (PVP) as demonstrated in animal studies and human case reports. This concept has not been validated in a larger cohort of pediatric patients with pulmonary vein stenosis (PVS). Methods: Pediatric patients who underwent cardiac catheterization for PVS at a single center from January 1, 2018, to March 31, 2023, were retrospectively reviewed. Mismatch between the PAWP and directly measured PVP or LA pressure was defined as >3 mm Hg. Preintervention angiography was reviewed and percent stenosis calculated. Results: Twenty-six patients met inclusion criteria; 51 lower pulmonary veins (34 left, 17 right) from 42 catheterizations were evaluated. Significant PVS (≥30% stenosis) was seen in 38/51 (75%) veins, and 9/51 (18%) veins had no angiographic narrowing (0% stenosis). PAWP-PVP mismatch occurred in 37/51 (73%) veins with a median difference of 8 mm Hg (IQR, 6-12). Of these, PAWP was equal to LA pressure in 26 instances, all of which had significant PVS (median % stenosis 54 [IQR, 45-60]). Six of the cases with PAWP-PVP mismatch, PVS (range, 41%-70% stenosis), and no PAWP-LA mismatch reported both a proximal and distal segmental PAWP. In all 6 instances, there was no distal PAWP-PVP mismatch (median difference 1 mm Hg [range, 0-3]). Conclusions: In this single-center study of pediatric patients with PVS, PAWP significantly underestimated directly measured PVP in lower pulmonary veins. Balloon wedge or end hole catheter position in a distal lobar segment may more accurately estimate the PVP.

Outcomes Associated with Giant Coronary Artery Aneurysms after Kawasaki Disease: A Single-Center United States Experience.

OBJECTIVES: To determine the long-term outcomes among a cohort of patients with Kawasaki disease (KD) and a history of giant coronary artery aneurysms (CAAs) at a single US center. STUDY DESIGN: Medical records for all patients with KD and giant CAAs at a pediatric academic institution were reviewed. Primary outcomes included major adverse cardiovascular events (MACE) and normalization of CA luminal diameter, using Kaplan-Meier analyses. RESULTS: There were 60 patients with KD and giant CAAs identified between 1989 and 2023. The majority of patients were male (71.7%) with a median age at diagnosis of 0.9 years (range, 0.2-13.3 years). Patients were followed for a median of 11 years, up to 34.5 years. MACE occurred in 13 patients (21.7%) at a median of 1.4 years (range, 0.04-22.6 years) after KD diagnosis. The 10-, 20-, and 30-year MACE-free rates were 75%, 75%, and 60%. Patients with maximal CA z scores of ≥20 or bilateral CAA were more likely to have MACE. During follow-up, 26.7% of CAA regressed to a normal luminal diameter at a median of 3.6 years (range, 0.6-12.0 years). The 10-, 20- and 30-year likelihood of CA regression to normal luminal diameter was 36%, 46%, and 46%. CONCLUSIONS: Over 30 years, MACE occurred in nearly 22% of patients, more often in those with bilateral CAA or CA z scores of ≥20. Despite regression to a normal luminal diameter in >25% of CAAs, patients with a history of KD-associated giant CAA require ongoing surveillance for cardiac complications, even years after the initial disease.

Incidence, Management, and Outcomes of Pulmonary Embolism at Tertiary Pediatric Hospitals in the United States.

Background: Pediatric pulmonary embolism (PE) is rare and potentially life-threatening. Though thrombolysis and thrombectomy are increasingly used in adult PE, trends in pediatric treatment and outcomes remain incompletely described. Objectives: The purpose of this study was to describe the incidence of PE, proportion of cases treated with anticoagulation alone, systemic thrombolysis, and directed therapy (local thrombolysis and thrombectomy), clinical outcomes, and total costs. Methods: A multicenter observational study was performed using administrative data from the Pediatric Health Information System database to study PE treated at U.S. pediatric hospitals from 2015 to 2021. Outcomes by treatment were evaluated using multivariable generalized linear mixed effects models. Results: Of 3,136 subjects, 70% were at least 12 years of age, and 46% were male. Sixty-two percent had at least 1 comorbidity, and congenital heart disease of any kind was the most prevalent (20%). Eighty-eight percent of subjects received anticoagulation alone, 7% received systemic thrombolysis, and 5% received directed therapy. Overall in-hospital mortality was 7.5%. Treatment approach did not change over time (P = 0.98). After adjusting for patient characteristics, directed therapy was associated with a lower risk of mortality (adjusted percentage -3%, [95% CI: -5% to 0%]) than anticoagulation alone. Systemic thrombolysis was associated with a greater total cost of hospitalization ($113,043 greater [95% CI: $62,866, $163,219]). Length of hospital stay did not differ by treatment. Conclusions: Pediatric patients with PE have a high incidence of underlying chronic disease. Anticoagulation alone remains the mainstay of treatment, with thrombolysis and thrombectomy rarely being used. Given the relative rarity of pediatric PE, additional research requiring innovative study designs is paramount.

Outcomes of Neonates Born with Symptomatic Tetralogy of Fallot and Absent Ductus Arteriosus.

OBJECTIVE: To test the hypothesis that neonates with symptomatic tetralogy of Fallot (TOF) and absent ductus arteriosus (ADA) have worse clinical outcomes compared with those with a ductus arteriosus (DA), and that this difference is driven by those born with ADA and with critically deficient pulmonary blood flow (CDPBF). STUDY DESIGN: We performed a retrospective, multicenter cohort study of neonates who underwent intervention for symptomatic TOF comparing death and reintervention between subjects with and without a DA identified on fetal echocardiogram or on echocardiogram performed in the first postnatal day. Exclusion criteria were as follows: inability to define DA status, collaterals supplying pulmonary blood flow, atrioventricular septal defect, and absent pulmonary valve. We defined CDPBF as undergoing a procedure to augment pulmonary blood flow on the date of birth or extracorporeal membrane oxygenation prior to such a procedure. RESULTS: The study cohort included 519 patients, among whom 11% had ADA. Patients with ADA were more likely to have a genetic syndrome and had smaller branch pulmonary artery size. In analyses adjusting for center, interventional treatment strategy, genetic syndrome, and minimum branch pulmonary artery size, ADA was associated with higher mortality risk (adjusted hazard ratio of 2.37 (95% CI: 1.07,5.27; P = .034). Seven patients had CDPBF (1.3% of the entire cohort and 12% of patients with ADA). CONCLUSIONS: A minority of symptomatic TOF neonates have ADA, which is associated with higher adjusted mortality risk compared with those with a DA. CDPBF appears to be a rare but important entity in this population.

Effect of patient factors, center, and era on Fontan timing: An observational study using the Pediatric Health Information Systems Database.

BACKGROUND: There are no consensus guidelines defining optimal timing for the Fontan operation, the last planned surgery in staged palliation for single-ventricle heart disease. OBJECTIVES: Identify patient-level characteristics, center-level variation, and secular trends driving Fontan timing. METHODS: A retrospective observational study of subjects who underwent Fontan from 2007 to 2021 at centers in the Pediatric Health Information Systems database was performed using linear mixed-effects modeling in which age at Fontan was regressed on patient characteristics and date of operation with center as random effect. RESULTS: We included 10,305 subjects (40.4% female, 44% non-white) at 47 centers. Median age at Fontan was 3.4 years (IQR 2.6-4.4). Hypoplastic left heart syndrome (-4.4 months, 95%CI -5.5 to -3.3) and concomitant conditions (-2.6 months, 95%CI -4.1 to -1.1) were associated with younger age at Fontan. Subjects with technology-dependence (+4.6 months, 95%CI 3.1-6.1) were older at Fontan. Black (+4.1 months, 95%CI 2.5-5.7) and Asian (+8.3 months, 95%CI 5.4-11.2) race were associated with older age at Fontan. There was significant variation in Fontan timing between centers. Center accounted for 10% of variation (ICC 0.10, 95%CI 0.07-0.14). Center surgical volume was not associated with Fontan timing (P = .21). Operation year was associated with age at Fontan, with a 3.1 month increase in age for every 5 years (+0.61 months, 95%CI 0.48-0.75). CONCLUSIONS: After adjusting for patient-level characteristics there remains significant inter-center variation in Fontan timing. Age at Fontan has increased. Future studies addressing optimal Fontan timing are warranted.

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.

Calculating Relative Lung Perfusion Using Fluoroscopic Sequences and Image Analysis: The Fluoroscopic Flow Calculator.

BACKGROUND: Maldistribution of pulmonary blood flow in patients with congenital heart disease impacts exertional performance and pulmonary artery growth. Currently, measurement of relative pulmonary perfusion can only be performed outside the catheterization laboratory. We sought to develop a tool for measuring relative lung perfusion using readily available fluoroscopy sequences. METHODS: A retrospective cohort study was conducted on patients with conotruncal anomalies who underwent lung perfusion scans and subsequent cardiac catheterizations between 2011 and 2022. Inclusion criteria were nonselective angiogram of pulmonary vasculature, oblique angulation ≤20°, and an adequate view of both lung fields. A method was developed and implemented in 3D Slicer's SlicerHeart extension to calculate the amount of contrast that entered each lung field from the start of contrast injection and until the onset of levophase. The predicted perfusion distribution was compared with the measured distribution of pulmonary blood flow and evaluated for correlation, accuracy, and bias. RESULTS: In total, 32% (79/249) of screened studies met the inclusion criteria. A strong correlation between the predicted flow split and the measured flow split was found (R2=0.83; P<0.001). The median absolute error was 6%, and 72% of predictions were within 10% of the true value. Bias was not systematically worse at either extreme of the flow distribution. The prediction was found to be more accurate for either smaller and younger patients (age 0-2 years), for right ventricle injections, or when less cranial angulations were used (≤20°). In these cases (n=40), the prediction achieved R2=0.87, median absolute error of 5.5%, and 78% of predictions were within 10% of the true flow. CONCLUSIONS: The current study demonstrates the feasibility of a novel method for measuring relative lung perfusion using conventional angiograms. Real-time measurement of lung perfusion at the catheterization laboratory has the potential to reduce unnecessary testing, associated costs, and radiation exposure. Further optimization and validation is warranted.

Trends in Ductus Arteriosus Stent Versus Blalock-Taussig-Thomas Shunt Use and Comparison of Cost, Length of Stay, and Short-Term Outcomes in Neonates With Ductal-Dependent Pulmonary Blood Flow: An Observational Study Using the Pediatric Health Information Systems Database.

BACKGROUND: The modified Blalock-Taussig-Thomas shunt is the gold standard palliation for securing pulmonary blood flow in infants with ductal-dependent pulmonary blood flow. Recently, the ductus arteriosus stent (DAS) has become a viable alternative. METHODS AND RESULTS: This was a retrospective multicenter study of neonates ≤30 days undergoing DAS or Blalock-Taussig-Thomas shunt placement between January 1, 2017 and December 31, 2020 at hospitals reporting to the Pediatric Health Information Systems database. We performed generalized linear mixed-effects modeling to evaluate trends in intervention and intercenter variation, propensity score adjustment and inverse probability weighting with linear mixed-effects modeling to analyze length of stay and cost of hospitalization, and generalized linear mixed modeling to analyze differences in 30-day outcomes. There were 1874 subjects (58% male, 61% White) from 45 centers (29% DAS). Odds of DAS increased with time (odds ratio [OR] 1.23, annually, P<0.01 [95% CI, 1.10-1.38]) with significant intercenter variation (median OR, 3.81 [95% CI, 2.74-5.91]). DAS was associated with shorter hospital length of stay (ratio of geometric means, 0.76 [95% CI, 0.63-0.91]), shorter intensive care unit length of stay (ratio of geometric means, 0.77 [95% CI, 0.61-0.97]), and less expensive hospitalization (ratio of geometric means, 0.70 [95% CI, 0.56-0.87]). Intervention was not significantly associated with odds of 30-day transplant-free survival (OR,1.18 [95% CI, 0.70-1.99]) or freedom from catheter reintervention (OR, 1.02 [95% CI, 0.65-1.58]), but DAS was associated with 30-day freedom from composite adverse outcome (OR, 1.51 [95% CI, 1.11-2.05]). CONCLUSIONS: Use of DAS is increasing, but there is variability across centers. Though odds of transplant-free survival and reintervention were not significantly different after DAS, and DAS was associated with shorter length of stay and lower in-hospital costs.

Neurocognitive function and health-related quality of life in adolescents and young adults with CHD with pulmonary valve dysfunction.

BACKGROUND: Neurocognitive impairment and quality of life are two important long-term challenges for patients with complex CHD. The impact of re-interventions during adolescence and young adulthood on neurocognition and quality of life is not well understood. METHODS: In this prospective longitudinal multi-institutional study, patients 13-30 years old with severe CHD referred for surgical or transcatheter pulmonary valve replacement were enrolled. Clinical characteristics were collected, and executive function and quality of life were assessed prior to the planned pulmonary re-intervention. These results were compared to normative data and were compared between treatment strategies. RESULTS: Among 68 patients enrolled from 2016 to 2020, a nearly equal proportion were referred for surgical and transcatheter pulmonary valve replacement (53% versus 47%). Tetralogy of Fallot was the most common diagnosis (59%) and pulmonary re-intervention indications included stenosis (25%), insufficiency (40%), and mixed disease (35%). There were no substantial differences between patients referred for surgical and transcatheter therapy. Executive functioning deficits were evident in 19-31% of patients and quality of life was universally lower compared to normative sample data. However, measures of executive function and quality of life did not differ between the surgical and transcatheter patients. CONCLUSION: In this patient group, impairments in neurocognitive function and quality of life are common and can be significant. Given similar baseline characteristics, comparing changes in neurocognitive outcomes and quality of life after surgical versus transcatheter pulmonary valve replacement will offer unique insights into how treatment approaches impact these important long-term patient outcomes.

Current Trends in Invasive Closure of Patent Ductus Arteriosus in Very Low Birth Weight Infants in United States Children's Hospitals, 2016-2021.

OBJECTIVE: To describe the current practices in invasive patent ductus arteriosus (PDA) closure (surgical ligation or transcatheter occlusion) in very low birth weight (VLBW) infants and changes in patient characteristics and outcomes from 2016 to 2021 among US children's hospitals. STUDY DESIGN: We evaluated a retrospective cohort of VLBW infants (birth weight 400-1499 g and gestational age 22-31 weeks) who had invasive PDA closure within 6 months of age from 2016 to 2021 in children's hospitals in the Pediatric Health Information System. Changes in patient characteristics and outcomes over time were evaluated using generalized linear models and generalized linear mixed models. RESULTS: 2418 VLBW infants (1182 surgical ligation; 1236 transcatheter occlusion) from 42 hospitals were included. The proportion of infants receiving transcatheter occlusion increased from 17.2% in 2016 to 84.4% in 2021 (P < .001). In 2021, 28/42 (67%) hospitals had performed transcatheter occlusion in > 80% of their VLBW infants needing invasive PDA closure, compared with only 2/42 (5%) in 2016. Although median postmenstrual age (PMA) at PDA closure did not change for the overall cohort, PMA at transcatheter occlusion decreased from 38 weeks in 2016 to 31 weeks by 2020, P < .001. Among those infants not intubated prior to PDA closure, extubation within 3 days postprocedure increased over time (yearly adjusted odds ratios of 1.26 [1.08-1.48]). Length of stay and mortality did not change over time. CONCLUSION: We report rapid adoption of transcatheter occlusion for PDA among VLBW infants in US children's hospitals over time. Transcatheter occlusions were performed at younger PMA over time.

Coil Embolization of a Ruptured Mycotic Coronary Artery Aneurysm in a Pediatric Patient.

Mycotic coronary artery aneurysms are rare but have a high risk of mortality. Traditional management is surgical, but percutaneous intervention can be performed in patients with high surgical risk. In this report, we describe a case of mycotic coronary aneurysm in a pediatric patient successfully managed with percutaneous coil embolization. (Level of Difficulty: Advanced.).

Association of Interstage Monitoring Era and Likelihood of Hemodynamic Compromise at Intervention for Recoarctation Following the Norwood Operation.

Background Intensive monitoring has been associated with a lower death rate between the Norwood operation and superior cavopulmonary connection, possibly due to early identification and effective treatment of residual anatomic lesions like recoarctation before lasting harm occurs. Methods and Results Neonates undergoing a Norwood operation and receiving interstage care at a single center between January 1, 2005, and September 18, 2020, were studied. In those with recoarctation, we evaluated association of era ([1] preinterstage monitoring, [2] a transitional phase, [3] current era) and likelihood of hemodynamic compromise (progression to moderate or greater ventricular dysfunction/atrioventricular valve regurgitation, initiation/escalation of vasoactive/respiratory support, cardiac arrest preceding catheterization, or interstage death with recoarctation on autopsy). We also analyzed whether era was associated with technical success of transcatheter recoarctation interventions, major adverse events, and transplant-free survival. A total of 483 subjects were studied, with 22% (n=106) treated for recoarctation during the interstage period. Number of catheterizations per Norwood increased (P=0.005) over the interstage eras, with no significant change in the proportion of subjects with recoarctation (P=0.36). In parallel, there was a lower likelihood of hemodynamic compromise in subjects with recoarctation that was not statistically significant (P=0.06), with a significant difference in the proportion with ventricular dysfunction at intervention (P=0.002). Rates of technical success, procedural major adverse events, and transplant-free survival did not differ (P>0.05). Conclusions Periods with interstage monitoring were associated with increased referral for catheterization but also reduced likelihood of ventricular dysfunction (and a suggestion of lower likelihood of hemodynamic compromise) in subjects with recoarctation. Further study is needed to guide optimal interstage care of this vulnerable population.