INTRODUCTION: Observational studies have demonstrated an association between use of digoxin and reduced interstage mortality after Norwood operation for hypoplastic left heart syndrome (HLHS). Digoxin use has increased significantly but remains variable between different hospitals, independent of case-mix. Instrumental variable analyses have the potential to overcome unmeasured confounding, the major limitation of previous observational studies and to generate an estimate of the attributable benefit of treatment with digoxin.

METHODS: A cohort of neonates with HLHS born from 1/1/2007 to 12/31/2021 who underwent Norwood operation at Pediatric Health Information Systems Database hospitals and survived >14 days after operation were studied. Using hospital-specific, 6-month likelihood of administering digoxin as an instrumental variable, analyses adjusting for both unmeasured confounding (using the instrumental variable) and measured confounders with multivariable logistic regression were performed.

RESULTS: The study population included 5,148 subjects treated at 47 hospitals of which 63% were male and 46% non-Hispanic white. Of these, 44% (n=2,184) were prescribed digoxin. Treatment with digoxin was associated with superior 1-year transplant-free survival in unadjusted analyses (85% vs. 82%, p=0.02). This survival benefit persisted in an instrumental-variable analysis (OR: 0.71, 95% CI: 0.54-0.94, p=0.01), which can be converted to an absolute risk reduction of 5% (number needed to treat of 20).

CONCLUSION: In this observational study of patients with HLHS after Norwood using instrumental variable techniques, a significant benefit in one-year transplant-free survival attributable to digoxin was demonstrated. In the absence of clinical trial data, this should encourage the use of digoxin in this vulnerable population.

BACKGROUND: Lymphatic embolization therapy has proven effective for Fontan failure from plastic bronchitis or protein-losing enteropathy but not when multiple lymphatic compartments are involved; furthermore, embolization does not alter the underlying pathophysiology of lymphatic dysfunction. A technique for transcatheter thoracic duct decompression (TDD), rerouting the thoracic duct to the pulmonary venous atrium to treat multicompartment lymphatic failure is described and early outcomes presented.

METHODS: Initially covered stents were used to channel the innominate vein flow inside of the cavopulmonary pathway into the pulmonary venous atrium. A modified approach was developed where covered stents redirected innominate vein directly to the left atrium via an extravascular course. Baseline and follow-up data on all patients undergoing TDD were reviewed.

RESULTS: Twelve patients underwent TDD between March 2018 and February 2021 at a median age of 12 (range: 2-22) years. Lymphatic failure occurred in median of 3 compartments per patient (protein-losing enteropathy, ascites, pleural effusions, plastic bronchitis); 10 patients had lymphatic embolizations before TDD. TDD method was intra-Fontan tunnel in 4, direct approach in 7, and other in 1. There were no major procedural complications; 6 patients underwent subsequent procedures, most commonly to treat endoleaks. Lymphatic failure resolved in 6 patients, improved in 2, and was unchanged in 4 at 6 (range: 1-20) months follow-up. One patient died after TDD from Fontan failure.

CONCLUSIONS: TDD is a promising new treatment for the failing Fontan physiology from multicompartment lymphatic failure. Additional work is needed to refine the technique and define optimal candidates.

BACKGROUND: Concern regarding aortic erosion has focused attention on the retro-aortic rim in patients undergoing device closure of atrial septal defects (ASD), but its effect on early outcomes is not well studied.

METHODS: A multicenter retrospective cohort study of patients undergoing device occlusion of ASD between 1/2011-10/2014 was performed, using data from the IMproving Pediatric and Adult Congenital Treatment Registry. Subjects were divided between those with retro-aortic rim <5 and ≥5 mm. Primary outcomes were technical failure and major early adverse events. Case times were measured as surrogates of technical complexity. The effect of deficient retro-aortic rim on primary outcomes was assessed using hierarchical logistic regression, adjusting for other suspected covariates and assessing whether they represent independent risk factors RESULTS: 1,564 subjects (from 77 centers) were included, with deficient retro-aortic rim present in 40%. Technical failure occurred in 91 subjects (5.8%) and a major early adverse event in 64 subjects (4.1%). Adjusting for known covariates, the presence of a deficient retro-aortic rim was not significantly associated with technical failure (OR: 1.3, 95% CI: 0.9-2.1) or major early adverse event (OR: 0.7, 95% CI: 0.4-1. 2). Total case (P = 0.01) and fluoroscopy time (P = 0.02) were greater in subjects with deficient rim, but sheath time was not significantly different (P = 0.07). Additional covariates independently associated with these outcomes were identified.

CONCLUSION: Deficient retro-aortic rim was highly prevalent but not associated with increased risk of technical failure or early adverse events. Studies with longer follow-up are necessary to assess other outcomes, including device erosion. © 2016 Wiley Periodicals, Inc.

OBJECTIVES: The authors sought to study variation in the practice of balloon aortic (BAV) and pulmonary valvuloplasty (BPV).

BACKGROUND: The IMPACT (IMProving Adult and Congenital Treatment) registry provides an opportunity to study practice variation in transcatheter interventions for congenital heart disease.

METHODS: The authors studied BAV and BPV in the IMPACT registry from January 1, 2011, to September 30, 2015, using hierarchical multivariable models to measure hospital-level variation in: 1) the distribution of indications for intervention; and 2) in cases with "high resting gradient" as the indication, consistency with published guidelines.

RESULTS: A total of 1,071 BAV cases at 60 hospitals and 2,207 BPV cases at 75 hospitals were included. The indication for BAV was high resting gradient in 82%, abnormal stress test or electrocardiogram (2%), left ventricular dysfunction (11%), and symptoms (5%). Indications for BPV were high resting gradient in 82%, right-left shunt (6%), right ventricular dysfunction (7%), and symptoms (5%). No association between hospital characteristics and distribution of indications was demonstrated. Among interventions performed for "high resting gradient," there was significant adjusted hospital-level variation in the rates of cases performed consistently with guidelines. For BAV, significant differences were seen across census regions, with hospitals in the East and South more likely to practice consistently than those in the Midwest and West (p = 0.005). For BPV, no association was found between hospital factors and rates of consistent practice, but there was significant interhospital variation (median rate ratio: 1.4; 95% confidence interval: 1.2 to 1.6; p < 0.001).

CONCLUSIONS: There is measurable hospital-level variation in the practice of BAV and BPV. Further research is necessary to determine whether this affects outcomes or resource use.

OBJECTIVE: To compare management strategies for neonates <2.5 kg with tetralogy of Fallot and symptomatic cyanosis who either undergo staged repair (SR) (initial palliation followed by later complete repair) or primary repair (PR).

METHODS: Consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing <2.5 kg at initial intervention and between 2005 and 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Primary outcome was mortality and secondary outcomes included component (eg, initial palliation, complete repair, or primary repair) and cumulative (SR: initial palliation followed by later complete repair) hospital and intensive care unit lengths of stay, durations of ventilation, inotrope use, cardiopulmonary bypass time, procedural complications, and reintervention. Outcomes were compared with propensity score adjustments with PR as the reference group.

RESULTS: The cohort included 76 SR (initial palliation: 53 surgical and 23 transcatheter) and 44 PR patients. The observed risk of overall mortality was similar between SR and PR groups (15.8% vs 18.2%: P = .735). The adjusted hazard of mortality remained similar between groups overall (hazard ratio, 0.59; 95% confidence interval, 0.26-1.36; P = .214), as well as during short-term (<4 months: hazard ratio, 0.37; 95% confidence interval, 0.13-1.09; P = .071) and midterm (>4 months: hazard ratio, 1.32; 95% confidence interval, 0.30-5.79; P = .717) follow-up. Reintervention in the first 18 months was common in both groups (53.2% vs 48.4%; hazard ratio, 1.69; 95% confidence interval, 0.96-2.28; P = .072). Adjusted procedural complications and neonatal morbidity burden were overall lower in the SR group. Cumulative secondary outcome burdens largely favored the PR group.

CONCLUSIONS: In this study comparing SR and PR treatment strategies for neonates with tetralogy of Fallot and symptomatic cyanosis and weight <2.5 kg, mortality and reintervention burden was highly independent of treatment strategy. Other potential advantages were observed with each approach.

BACKGROUND: Recent data have demonstrated that overall mortality and adverse events are not significantly different for primary repair (PR) and staged repair (SR) approaches to management of neonates with symptomatic tetralogy of Fallot (sTOF). Cost data can be used to compare the relative value (cost for similar outcomes) of these approaches and are a potentially more sensitive measure of morbidity.

OBJECTIVES: This study sought to compare the economic costs associated with PR and SR in neonates with sTOF.

METHODS: Data from a multicenter retrospective cohort study of neonates with sTOF were merged with administrative data to compare total costs and cost per day alive over the first 18 months of life in a propensity score-adjusted analysis. A secondary analysis evaluated differences in department-level costs.

RESULTS: In total, 324 subjects from 6 centers from January 2011 to November 2017 were studied (40% PR). The 18-month cumulative mortality (P = 0.18), procedural complications (P = 0.10), hospital complications (P = 0.94), and reinterventions (P = 0.22) did not differ between PR and SR. Total 18-month costs for PR (median $179,494 [IQR: $121,760-$310,721]) were less than for SR (median: $222,799 [IQR: $167,581-$327,113]) (P < 0.001). Cost per day alive (P = 0.005) and department-level costs were also all lower for PR. In propensity score-adjusted analyses, PR was associated with lower total cost (cost ratio: 0.73; P < 0.001) and lower department-level costs.

CONCLUSIONS: In this multicenter study of neonates with sTOF, PR was associated with lower costs. Given similar overall mortality between treatment strategies, this finding suggests that PR provides superior value.

Quality improvement efforts have focused on reducing interstage mortality for infants with hypoplastic left heart syndrome (HLHS). In 1/2016, two publications reported that use of digoxin was associated with reduced interstage mortality. The degree to which these findings have affected real world practice has not been evaluated. The discharge medications of neonates with HLHS undergoing Norwood operation between 1/2007 and 12/2018 at Pediatric Health Information Systems Database hospitals were studied. Mixed effects models were calculated to evaluate the hypothesis that the likelihood of digoxin prescription increased after 1/2016, adjusting for measurable confounders with furosemide and aspirin prescription measured as falsification tests. Interhospital practice variation was measured using the median odds ratio. Over the study period, 6091 subjects from 45 hospitals were included. After adjusting for measurable covariates, discharge after 1/2016 was associated with increased odds of receiving digoxin (OR 3.9, p < 0.001). No association was seen between date of discharge and furosemide (p = 0.26) or aspirin (p = 0.12). Prior to 1/2016, the likelihood of receiving digoxin was decreasing (OR 0.9 per year, p < 0.001), while after 1/2016 the rate has increased (OR 1.4 per year, p < 0.001). However, there remains significant interhospital variation in the likelihood of receiving digoxin even after adjusting for known confounders (median odds ratio = 3.5, p < 0.0001). Following publication of studies describing an association between digoxin and improved interstage survival, the likelihood of receiving digoxin at discharge increased without similar changes for furosemide or aspirin. Despite concerted efforts to standardize interstage care, interhospital variation in pharmacotherapy in this vulnerable population persists.

OBJECTIVES: The objective of this study was to assess contemporary use of operator directed sedation (ODS) and anesthesiologist care (AC) in the pediatric/congenital cardiac catheterization laboratory (PCCL), specifically evaluating whether the use of operator-directed sedation was associated with increased risk of major adverse events.

BACKGROUND: The safety of ODS relative to AC during PCCL procedures has been questioned.

METHODS: A multicenter, retrospective cohort study was performed studying procedures habitually performed with ODS or AC at IMPACT (Improving Adult and Congenital Treatment) registry hospitals using ODS for ≥5% of cases. The risks for major adverse events (MAE) for ODS and AC cases were compared, adjusted for case mix. Current recommendations were evaluated by comparing the ratio of observed to expected MAE for cases in which ODS was inappropriate (inconsistent with those guidelines) with those for similar risk AC cases, as well as those in which ODS or AC was appropriate.

RESULTS: Of the hospitals submitting data to IMPACT, 28 of 101 met inclusion criteria. Of the 7,042 cases performed using ODS at these centers, 88% would be inappropriate. Use of ODS was associated with lower likelihood of MAE both in observed results (p < 0.0001) and after adjusting for case-mix (odds ratio: 0.81; p = 0.006). Use of AC was also associated with longer adjusted fluoroscopy and procedure times (p < 0.0001 for both). The observed/expected ratio for ODS cases with high pre-procedural risk (inappropriate for ODS) was significantly lower than that for AC cases with comparable pre-procedural risk. Across a range of pre-procedural risks, there was no stratum in which risk for MAE was lower for AC than ODS.

CONCLUSIONS: Across a range of hospitals, ODS was used safely and with improved efficiency. Clinical judgment better identified cases in which ODS could be used than pre-procedural risk score. This should inform future guidelines for the use of ODS and AC in the catheterization laboratory.

<p><strong>BACKGROUND: </strong>We sought to characterize short- and long-term outcomes following superior cavopulmonary connection (SCPC) in children eligible for inclusion of antegrade pulmonary blood flow (APBF) in the SCPC circuit, exploring whether maintaining APBF was associated with outcomes.</p>

<p><strong>METHODS: </strong>This was a retrospective cohort study of patients with single ventricle heart disease and APBF who underwent SCPC at our center between 1/1/00 and 9/30/17. Patients were divided into two groups: APBF eliminated (APBF (-)), and APBF maintained (APBF (+)) at the time of SCPC.</p>

<p><strong>RESULTS: </strong>Of 149 patients, 108 (72.5%) were in APBF (-) and 41 (27.5%) were in APBF (+). Of those in APBF (+), 5 (12.2%) subsequently had APBF eliminated after SCPC. Patients in APBF (+) had a higher prevalence of chest tube duration &gt; 10 days and underwent more interventions during the post-SCPC hospitalization (1.9% v. 12%, p=0.008 for both), but had shorter surgical support times at SCPC (p&lt;0.0001). There were no differences in post-SCPC intensive care unit or hospital lengths of stay82 patients (76%) in APBF (-) and 22 patients (54%) in APBF (+) underwent Fontan completion during the study period. Patients in APBF (+) had a greater weight gain from SCPC to Fontan [6.7 (1.8-22) v. 8.15 (4.4-20.6) kg, p=0.012] and a shorter hospital length of stay after Fontan [9 (4-107) v. 7.5 (4-14) days, p=0.044].</p>

<p><strong>CONCLUSIONS: </strong>Short term morbidity associated with maintaining APBF at the time of SCPC is modest, but longer-term outcomes suggest potential benefits in those in whom APBF can be successfully maintained.</p>

<p>Protein-losing enteropathy (PLE) is a rare but potentially devastating complication of single-ventricle physiology after the Fontan operation. Although abnormal bone mineral density (BMD) is a known complication of chronic disease and congenital heart disease, no reports have described BMD in patients with PLE. This study investigated a cross-sectional sample of children and young adults with a confirmed diagnosis of PLE. Serum levels of 25(OH)D, calcium, total protein, and albumin were recorded from the first outpatient encounter with each subject. Corrected calcium (cCa) was calculated from the serum calcium and albumin levels. Dual-energy X-ray absorptiometry (DXA) was used to measure BMD, and z-scores were generated using appropriate software. DXA results were available for 12 patients (eight males and four females). The age at DXA ranged from 7.2 to 25.2 years. The mean z-score was -1.73 standard deviation (SD) for the entire cohort, with 42 % z-scores below -2 SDs. Serum 25(OH)D levels were abnormal in 58 % of the patients. There was a positive correlation between cCa and DXA z-score and a negative correlation between total protein and DXA z-score. Patients receiving corticosteroid therapy had a significantly lower DXA z-score than those not receiving corticosteroids (-3.15 vs. -0.31; p = 0.02). Children with PLE are at risk for abnormal BMD compared with age- and sex-matched control subjects. In the study cohort, corticosteroid exposure, a marker of disease severity, appeared to be associated with decreased BMD. Routine bone health screening is warranted for children with PLE, particularly those receiving corticosteroid therapy.</p>