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

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

Melody® pulmonary valve implantation in two teenage patients with congenitally corrected transposition of the great arteries status after Senning atrial switch operation.

The Melody® transcatheter pulmonary valve system was developed for placement within right ventricle-to-pulmonary artery conduits in patients with CHD for treatment of stenosis or regurgitation, providing an alternative to open-heart surgery. Abnormal systemic venous connections altering the catheter course to the right ventricle-to-pulmonary artery conduit may present a challenge to Melody® valve implantation. We present two such cases, in which the Melody® valve was successfully implanted in teenage patients with congenitally corrected transposition of the great arteries after Senning atrial switch operation. Despite the abnormal catheter course, the right ventricle-to-pulmonary artery was approachable via the right femoral vein allowing for deployment of the Melody® valve in the appropriate position. This suggests that systemic vein-to-left atrium baffles are not prohibitive of Melody® valve implantation. This is an important implication considering the substantial population of ageing patients with CHD who have undergone atrial switch. Melody® valve implantation can be considered as a viable option for treatment of these patients if they develop right ventricle-to-pulmonary artery conduit failure.

Dual-Axis Rotational Angiography is Safe and Feasible to Detect Coronary Allograft Vasculopathy in Pediatric Heart Transplant Patients: A Single-Center Experience.

Coronary allograft vasculopathy (CAV) is the leading cause of graft failure in pediatric heart transplant recipients, also adding to mortality in this patient population. Coronary angiography is routinely performed to screen for CAV, with conventional single-plane or bi-plane angiography being utilized. Dual-axis rotational coronary angiography (RA) has been described, mostly in the adult population, and may offer reduction in radiation dose and contrast volume. Experience with this in the pediatric population is limited. This study describes a single-institution experience with RA for screening for CAV in pediatric patients. The catheterization database at our institution was used to identify pediatric heart transplant recipients having undergone RA to screen for CAV. Procedural data including radiation dose, fluoroscopy time, contrast volume, and procedure time were collected for each catheterization. The number of instances in which RA was not successful, ECG changes were present, and CAV was detected were also collected for each catheterization. A total of 97 patients underwent 345 catheterizations utilizing RA. Median radiation dose-area product per kilogram was found to be 341.7 (mGy cm(2)/kg), total air kerma was 126.8 (mGy), procedure time was 69 min, fluoroscopy time was 9.9 min, and contrast volume was 13 ml. A total of 17 (2 %) coronary artery injections out of 690 could not be successfully imaged using RA. A total of 14 patients had CAV noted at any point, 10 of whom had progressive CAV. Electrocardiographic changes were documented in a total of 10 (3 %) RA catheterizations. Procedural characteristics did not differ between serial catheterizations. RA is safe and feasible for CAV screening in pediatric heart transplant recipients while offering coronary imaging in multiple planes compared to conventional angiography.

Implementation of Methodology for Quality Improvement in Pediatric Cardiac Catheterization: A Multi-center Initiative by the Congenital Cardiac Catheterization Project on Outcomes-Quality Improvement (C3PO-QI).

The Congenital Cardiac Catheterization Project on Outcomes (C3PO) launched in 2007 as a multi-center collaborative to establish standardized and comparable metrics for pediatric cardiac catheterization procedures. The limitations of larger registries at the time led to the development of the next phase in 2013, C3PO-Quality Improvement (C3PO-QI), focusing on instituting QI initiatives within the field. The objective of this manuscript is to provide a detailed overview of C3PO-QI and report data on case characteristics and outcome metrics being explored. C3PO-QI was designed to cultivate institutional collaboration during implementation of its initiatives. A database and website were developed to support data entry and on-demand reporting. The registry prospectively captures pediatric cardiac catheterization data among 15 hospitals. The present study includes case demographic data (n) and quality metric reporting by case type, age, and radiation dose variables. This dataset includes 13,135 cases entered into the database between 1/1/2014 and 12/31/2015. Interventional cases make up the highest percentage by case mix distribution (48 %), and patients <1 years make up the highest percentage by age distribution (26 %). The ratio of diagnostic and interventional procedures performed changes by age group. Application of QI metric shows all procedure types surpassing metric goals. Large volume data collection, such as in C3PO-QI, allows for meaningful interpretation of data. C3PO-QI is uniquely poised to deliver fast-paced changes in the field. Although the project initiatives are specific to pediatric cardiac catheterization, the implementation of the project and utilization of real-time reporting is generalizable to other specialties and multi-center collaboratives.

Balloon valvuloplasty for congenital aortic stenosis: Multi-center safety and efficacy outcome assessment.

OBJECTIVE: To describe contemporary outcomes of balloon aortic valvuloplasty (BAVP) performed in 22 US centers. BACKGROUND: BAVP constitutes first-line therapy for congenital aortic stenosis (cAS) in many centers. METHODS: We used prospectively-collected data from two active, multi-institutional, pediatric cardiac catheterization registries. Acute procedural success was defined, for purposes of this review, as a residual peak systolic gradient≤35 mm Hg and no more than mild aortic regurgitation (AR) for patients with isolated cAS. For patients with mixed aortic valve disease, a residual peak systolic gradient≤35 mm Hg without worsening of AR was considered successful outcome. RESULTS: In 373 patients with a median age of 8 months (1 day to 40 years of age) peak systolic gradient had a median of 59 [50, 71] mm Hg pre-BAVP and 22 [15, 30] mm Hg post-BAVP (P<0.001). Procedural success was achieved in 160 patients (71%). The factors independently associated with procedural success were: first time intervention (OR=2.0 (1.0, 4.0) P=0.04), not-prostaglandin dependent, (OR=3.5 (1.5, 8.1); P=0.003), and isolated cAS (absence of AR) (OR=2.1 (1.1-3.9); P=0.03). Twenty percent of patients experienced adverse events, half of which were of high severity. There was no procedural mortality. Neonatal status was the only factor associated with increased risk of high severity adverse events (OR 3.7; 95% CI 1.5-9.0). CONCLUSION: In the current era, BAVP results in procedural success (gradient reduction with minimal increase in AR) in 71% of patients treated at US centers where BAVP is considered first-line therapy relative to surgery.

Absorbable metal stents for vascular use in pediatric cardiology: progress and outlook.

The past five years have yielded impressive advancements in fully absorbable metal stent technology. The desired ultimate ability for such devices to treat a vascular stenosis without long-term device-related complications or impeding future treatment continues to evoke excitement in clinicians and engineers alike. Nowhere is the need for fully absorbable metal stents greater than in patients experiencing vascular anomalies associated with congenital heart disease (CHD). Perhaps not surprisingly, commercially available absorbable metal stents have been implanted in pediatric cardiology patients with conditions ranging from pulmonary artery and vein stenosis to coarctation of the aorta and conduit/shunt reconstructions. Despite frequent short term procedural success, device performance has missed the mark with the commercially available devices not achieving degradation benchmarks for given applications. In this review we first provide a general overview detailing the theory of absorbable metal stents, and then review recent clinical use in CHD patients since the release of current-generation absorbable metal stents around 2019. We also discuss the challenges and our center's experience associated with the use of absorbable metal stents in this pediatric population. Lastly, we present potential directions for future engineering endeavors to mitigate existing challenges.

Congenital right internal mammary artery to portal vein arteriovenous malformation.

Neonatal cases of systemic artery to portal venous system arteriovenous malformations (AVMs) can present unique challenges in terms of diagnosis, management, and treatment. Prompt identification of these AVMs is necessary for minimizing long-term sequelae and optimizing prognosis. Our report describes the diagnosis and successful endovascular coil embolization of a congenital right internal mammary artery (IMA) to portal vein AVM in a young infant initially presenting during routine fetal screening with an incidentally discovered congenital thoracic vascular abnormality.

sVEGFR1 Is Enriched in Hepatic Vein Blood-Evidence for a Provisional Hepatic Factor Candidate?

Background: Pulmonary arteriovenous malformations (PAVMs) are common sequelae of palliated univentricular congenital heart disease, yet their pathogenesis remain poorly defined. In this preliminary study, we used paired patient blood samples to identify potential hepatic factor candidates enriched in hepatic vein blood. Methods: Paired venous blood samples were collected from the hepatic vein (HV) and superior vena cava (SVC) from children 0 to 10 years with univentricular and biventricular congenital heart disease (n = 40). We used three independent protein analyses to identify proteomic differences between HV and SVC blood. Subsequently, we investigated the relevance of our quantified protein differences with human lung microvascular endothelial assays. Results: Two independent protein arrays (semi-quantitative immunoblot and quantitative array) identified that soluble vascular endothelial growth factor receptor 1 (sVEGFR1) is significantly elevated in HV serum compared to SVC serum. Using ELISA, we confirmed the previous findings that sVEGFR1 is enriched in HV serum (n = 24, p < 0.0001). Finally, we studied the quantified HV and SVC serum levels of sVEGFR1 in vitro. HV levels of sVEGFR1 decreased tip cell selection (p = 0.0482) and tube formation (fewer tubes [p = 0.0246], shorter tube length [p = 0.0300]) in vitro compared to SVC levels of sVEGFR1. Conclusions: Based on a small heterogenous cohort, sVEGFR1 is elevated in HV serum compared to paired SVC samples, and the mean sVEGFR1 concentrations in these two systemic veins cause pulmonary endothelial phenotypic differences in vitro. Further research is needed to determine whether sVEGFR1 has a direct role in pulmonary microvascular remodeling and PAVMs in patients with palliated univentricular congenital heart disease.

Ventricular Fibrillation and Myocardial Depression Following Pulmonary Valve Replacement in Tetralogy of Fallot With an Intramural Coronary Artery and Coronary Artery Compression by Chest Tube.

We describe the case of a 10-year-old male with a history of repaired Tetralogy of Fallot and known intramural right coronary artery (RCA) who presented for bioprosthetic pulmonary valve replacement. The operation was complicated by postoperative ventricular fibrillation arrest. Selective coronary angiography revealed external compression of the mid-RCA by a mediastinal chest tube that improved immediately upon removal of the tube. Ultimately, the patient required additional unroofing of the intramural coronary for full recovery. This case highlights the need to thoroughly investigate malignant ventricular dysrhythmias following pediatric cardiac surgery and to rule out coronary insufficiency, which may be due to both extrinsic and/or intrinsic lesions.

Hepatic Vein Blood Increases Lung Microvascular Angiogenesis and Endothelial Cell Survival-Toward an Understanding of Univentricular Circulation.

To improve our understanding of pulmonary arteriovenous malformations in univentricular congenital heart disease, our objective was to identify the effects of hepatic vein and superior vena cava constituents on lung microvascular endothelial cells independent of blood flow. Paired blood samples were collected from the hepatic vein and superior vena cava in children 0-10 years old undergoing cardiac catheterization. Isolated serum was subsequently used for in vitro endothelial cell assays. Angiogenic activity was assessed using tube formation and scratch migration. Endothelial cell survival was assessed using proliferation (BrdU incorporation, cell cycle analysis) and apoptosis (caspase 3/7 activity, Annexin-V labeling). Data were analyzed using Wilcoxon signed-rank test and repeated measures analysis. Upon incubating lung microvascular endothelial cells with 10% patient serum, hepatic vein serum increases angiogenic activity (tube formation, P = 0.04, n = 24; migration, P< 0.001, n = 18), increases proliferation (BrdU, P < 0.001, n = 32; S-phase, P = 0.04, n = 13), and decreases apoptosis (caspase 3/7, P < 0.001, n = 32; Annexin-V, P = 0.04, n = 12) compared to superior vena cava serum. Hepatic vein serum regulates lung microvascular endothelial cells by increasing angiogenesis and survival in vitro. Loss of hepatic vein serum signaling in the lung microvasculature may promote maladaptive lung microvascular remodeling and pulmonary arteriovenous malformations.

Cardiac Arrest Secondary to Traumatic Aortopulmonary Window During Transcatheter Pulmonary Valve Implantation in Supported Ross.

We present a patient with a supported Ross procedure and severe pulmonary homograft stenosis who developed cardiac arrest while undergoing transcatheter pulmonary valve replacement and was found to have a large iatrogenic aortopulmonary window. Cardiopulmonary resuscitation was initiated followed by covered stent placement, extracorporeal membrane oxygenation support, and ultimately emergent surgery with a good outcome. (Level of Difficulty: Advanced.).

Pediatric heart failure therapy with beta-adrenoceptor antagonists.

Management of chronic heart failure in pediatrics has been altered by the adult literature showing improvements in mortality and hospitalization rates with the use of beta-adrenoceptor antagonists (beta-blockers) for routine therapy of all classes of ischemic and non-ischemic heart failure. Many pediatric heart failure specialists have incorporated these agents into their routine management of pediatric heart failure related to dilated cardiomyopathy or ventricular dysfunction in association with congenital heart disease. Retrospective and small prospective case series have shown encouraging improvements in cardiac function and symptoms, but interpretation has been complicated by the high rate of spontaneous recovery in pediatric patients. A recently completed pediatric double-blind, randomized, placebo-controlled clinical trial showed no difference between placebo and two doses of carvedilol over a 6-month period of follow-up, with significant improvement of all three groups over the course of evaluation. Experience with adults has suggested that only certain beta-blockers, including carvedilol, bisoprolol, nebivolol, and metoprolol succinate, should be used in the treatment of heart failure and that patients with high-grade heart failure may derive the most benefit. Other studies surmise that early or prophylactic use of these medications may alter the risk of disease progression in some high-risk subsets, such as patients receiving anthracyclines or those with muscular dystrophy. This article reviews these topics using experience as well as data from all the recent pediatric studies on the use of beta-blockers to treat congestive heart failure, especially when related to systolic ventricular dysfunction.

Acute Success of Balloon Aortic Valvuloplasty in the Current Era: A National Cardiovascular Data Registry Study.

OBJECTIVES: The aim of this study was to evaluate practice patterns and outcomes of a contemporary group of patients undergoing balloon aortic valvuloplasty (BAV) for congenital aortic stenosis (AS). BACKGROUND: BAV is the most common treatment for isolated congenital AS. METHODS: Within the IMPACT (Improving Pediatric and Adult Congenital Treatments) Registry, all BAV procedures performed between January 2011 and March 2015 were identified. Procedures were separated into those performed for critical versus noncritical AS. Outcomes were stratified into optimal, adequate, and inadequate, with optimal and adequate outcomes defining "successful" procedures. Multivariate logistic regression was used to identify patient and procedural characteristics associated with unsuccessful BAV. Mortality and adverse events rates were compared across patient cohorts. RESULTS: Of the 1,026 isolated BAV procedures captured in IMPACT, 718 (70%) were "successful." Success rates were 70.9% for noncritical AS (n = 916) and 62.7% for critical AS (n = 110). Multivariate analysis revealed that prior cardiac catheterization, mixed valve disease, baseline aortic valve gradient >60 mm Hg, baseline aortic insufficiency greater than mild, presence of a trainee, and multiple balloon inflations were associated with unsuccessful BAV in the noncritical AS cohort. There were no factors associated with unsuccessful procedures in the critical AS group. No procedural deaths occurred, but 2.4% of patients did not survive to hospital discharge. Adverse events occurred in 15.8% of all cases and were more frequent in procedures performed for critical AS (30.0% vs. 14.1%; p < 0.001). CONCLUSIONS: BAV is an effective treatment for congenital AS with low rates of mortality and adverse events. Patients with critical AS have a higher risk for procedure-related adverse events.

Practice Variation in Single-Ventricle Patients Undergoing Elective Cardiac Catheterization: A Report from the Congenital Cardiac Catheterization Project on Outcomes (C3PO).

OBJECTIVE: The objective of this study was to investigate variation in practice surrounding elective cardiac catheterization in patients with single-ventricle (SV) congenital heart disease. DESIGN: Patient and procedural characteristics and outcomes during SV catheterization were collected prospectively from eight centers using a web-based registry (Congenital Cardiac Catheterization Project on Outcomes). We attempted to identify a population of elective procedures by limiting the cohort in case type and timing. Cases were then stratified by stage of SV palliation (pre-bidirectional cavopulmonary anastomosis [pre-BCPA], pre-Fontan and post-Fontan) and limited by age. Subcohort analysis was performed by mode of airway management (assisted vs. spontaneous ventilation). Institutional variation was assessed. RESULTS: Between 2/2007 and 6/2010, 1459 (10.1%) of 14 467 cases in the registry met the inclusion and exclusion criteria, including 326 pre-BCPA, 571 pre-Fontan and 562 post-Fontan procedures. Median patient age was 0.4 (interquartile range 0.3, 0.5), 2.6 (1.0, 3.4) and 9.6 (5.2, 15.4) years and weight was 5.6 (4.8, 6.4), 12.2 (10.5, 14), and 26.3 (16.6, 51.8) kg in the pre-BCPA, pre-Fontan and post-Fontan cohorts, respectively. Cases were more commonly diagnostic in the pre-BCPA cohort (57%) whereas they were more commonly interventional in the pre-Fontan (69%) and post-Fontan (77%) cohorts. At least one adverse event (AE) occurred in 210 cases (14.4%) overall, including 20% of pre-BCPA, 11% of pre-Fontan and 14% of post-Fontan catheterizations. Mode of airway management was associated with statistically significant, but clinically small differences in hemodynamic measures in the pre- and post-Fontan cohorts, but not in the pre-BCPA group. Considerable practice variation exists across centers with variability in airway management, AE rate, case type, interventions performed and fluoroscopy time, in all SV cohorts. CONCLUSIONS: Elective catheterization in SV patients, frequently performed with intervention, is common among US congenital cardiac centers. However, important variation in practice exists during these procedures in SV patients, at all stages of palliation.

Safety of percutaneous patent ductus arteriosus closure: an unselected multicenter population experience.

BACKGROUND: The technique and safety of transcatheter patent ductus arteriosus (PDA) closure have evolved during the past 20 years. We sought to report a multicenter experience of PDA closure with a focus on the rate of adverse events (AE) and a review of institutional practice differences. METHODS AND RESULTS: Outcome data on transcatheter PDA closure were collected at 8 centers prospectively using a multicenter registry (Congenital Cardiac Catheterization Project on Outcome Registry). Between February 2007 and June 2010, 496 PDA closures were recorded using a device in 338 (68%) or coils in 158 (32%). Most patients had an isolated PDA (90%). Fifty percent of patients were between 6 months and 3 years old, with only 40 patients (8%) <6 months old. Median minimum PDA diameter was 2.5 mm (range 1 to 12 mm; IQR 2 to 3 mm) for device closure and 1 mm (range 0.5 to 6 mm; IQR 1 to 2 mm) for coil closure (P<0.001). A device rather than coil was used in patients <3 years, weight <11 kg, and with a PDA minimum diameter >2 mm (all P<0.001). Three of 8 centers exclusively used a device for PDAs with a diameter >1.5 mm. In 9% of cases (n=46), an AE occurred; however, only 11 (2%) were classified as high severity. Younger age was associated with a higher AE rate. Coil-related AEs were more common than device-related AEs (10% versus 2%, P<0.001). CONCLUSIONS: PDA closure in the present era has a very low rate of complications, although these are higher in younger children. Technical intervention-related events were more common in coil procedures compared with device procedures. For PDAs ≤2.5 mm in diameter, institutional differences in preference for device versus coil exist.

Catheterization for Congenital Heart Disease Adjustment for Risk Method (CHARM).

OBJECTIVES: This study sought to develop a method to adjust for case mix complexity in catheterization for congenital heart disease to allow equitable comparisons of adverse event (AE) rates. BACKGROUND: The C3PO (Congenital Cardiac Catheterization Project on Outcomes) has been prospectively collecting data using a Web-based data entry tool on all catheterization cases at 8 pediatric institutions since 2007. METHODS: A multivariable logistic regression model with high-severity AE outcome was built using a random sample of 75% of cases in the multicenter cohort; the models were assessed in the remaining 25%. Model discrimination was assessed by the C-statistic and calibration with Hosmer-Lemeshow test. The final models were used to calculate standardized AE ratios. RESULTS: Between August 2007 and December 2009, 9,362 cases were recorded at 8 pediatric institutions of which high-severity events occurred in 454 cases (5%). Assessment of empirical data yielded 4 independent indicators of hemodynamic vulnerability. Final multivariable models included procedure type risk category (odds ratios [OR] for category: 2 = 2.4, 3 = 4.9, 4 = 7.6, all p < 0.001), number of hemodynamic indicators (OR for 1 indicator = 1.5, ≥2 = 1.8, p = 0.005 and p < 0.001), and age <1 year (OR: 1.3, p = 0.04), C-statistic 0.737, and Hosmer-Lemeshow test p = 0.74. Models performed well in the validation dataset, C-statistic 0.734. Institutional event rates ranged from 1.91% to 7.37% and standardized AE ratios ranged from 0.61 to 1.41. CONCLUSIONS: Using CHARM (Catheterization for Congenital Heart Disease Adjustment for Risk Method) to adjust for case mix complexity should allow comparisons of AE among institutions performing catheterization for congenital heart disease.

Ventricular remodeling and survival are more favorable for myocarditis than for idiopathic dilated cardiomyopathy in childhood: an outcomes study from the Pediatric Cardiomyopathy Registry.

BACKGROUND: Myocarditis is a cause of a new-onset dilated cardiomyopathy phenotype in children, with small studies reporting high rates of recovery of left ventricular (LV) function. METHODS AND RESULTS: The presenting characteristics and outcomes of children with myocarditis diagnosed clinically and with biopsy confirmation (n=119) or with probable myocarditis diagnosed clinically or by biopsy alone (n=253) were compared with children with idiopathic dilated cardiomyopathy (n=1123). Characteristics at presentation were assessed as possible predictors of outcomes. The distributions of time to death, transplantation, and echocardiographic normalization in the biopsy-confirmed myocarditis and probable myocarditis groups did not differ (P≥0.5), but both groups differed significantly from the idiopathic dilated cardiomyopathy group (all P≤0.003). In children with myocarditis, lower LV fractional shortening z-score at presentation predicted greater mortality (hazard ratio, 0.85; 95% confidence interval, 0.73 to 0.98; P=0.03) and greater LV posterior wall thickness predicted transplantation (hazard ratio, 1.17; 95% confidence interval, 1.02 to 1.35; P=0.03). In those with decreased LV fractional shortening at presentation, independent predictors of echocardiographic normalization were presentation with an LV end-diastolic dimension z-score >2 (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58; P<0.001) and greater septal wall thickness (hazard ratio, 1.16; 95% confidence interval, 1.01 to 1.34; P=0.04). CONCLUSIONS: Children with biopsy-confirmed or probable myocarditis had similar proportions of death, transplantation, and echocardiographic normalization 3 years after presentation and better outcomes than those of children with idiopathic dilated cardiomyopathy. In children with myocarditis who had impaired LV ejection at presentation, rates of echocardiographic normalization were greater in those without LV dilation and in those with greater septal wall thickness at presentation. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005391.

Importance of totally anomalous pulmonary venous connection and postoperative pulmonary vein stenosis in outcomes of heterotaxy syndrome.

Historically, outcomes of patients with heterotaxy syndrome and congenital heart disease have been poor. Published series include patients treated over many decades or focus on specific patient/operative subgroups. This study was performed to evaluate midterm outcomes and determine anatomic risk factors for death in patients with all types of heterotaxy syndrome treated after 1985. We reviewed all infants with heterotaxy born between 1985 and 1997, presenting to one institution at <6 months age, followed for > or =5 years. Of 102 study patients (46 with asplenia phenotype, 56 with polysplenia phenotype), 48 (47%) died at a median age of 0.6 months, 12 without intervention. Survivors were followed for a median of 12.8 years (5-21.7 years). Independent predictors of mortality included obstructed totally anomalous pulmonary venous connection (TAPVC) (OR, 7.8; 95% CI, 1.9-32.9; p = 0.005), mild or greater atrioventricular (AV) valve regurgitation at presentation (OR, 3.5; 95% CI, 1.0-12.1; p = 0.03), and common AV canal (OR, 3.1; 95% CI, 1.1-8.5; p = 0.03). Sixteen patients developed pulmonary vein stenosis at a median age of 2 months, with 5 (31%) alive at follow-up. In patients with TAPVC, the mean indexed sum of pulmonary vein diameters was lower among patients who died than in survivors (42.3 +/- 8.3 vs 49.5 +/- 10.1 mm/m2; p = 0.02). Mortality remains high among patients with heterotaxy treated in the modern surgical era, particularly those with obstructed TAPVC. Pulmonary vein stenosis is common after repair of TAPVC in patients with heterotaxy, may be diagnosed beyond infancy, and is associated with poor outcomes.