Kevin D. Hill

Cumulative Radiation Exposure and Cancer Risk Estimation in Children With Heart Disease

Background— Children with heart disease are frequently exposed to imaging examinations that use ionizing radiation. Although radiation exposure is potentially carcinogenic, there are limited data on cumulative exposure and the associated cancer risk. We evaluated the cumulative effective dose of radiation from all radiation examinations to estimate the lifetime attributable risk of cancer in children with heart disease. Methods and Results— Children ⩽6 years of age who had previously undergone 1 of 7 primary surgical procedures for heart disease at a single institution between 2005 and 2010 were eligible for the study. Exposure to radiation-producing examinations was tabulated, and cumulative effective dose was calculated in millisieverts. These data were used to estimate lifetime attributable risk of cancer above baseline using the approach of the Committee on Biological Effects of Ionizing Radiation VII. The cohort included 337 children exposed to 13 932 radiation examinations. Conventional radiographs represented 92% of examinations, whereas cardiac catheterization and computed tomography accounted for 81% of cumulative exposure. Overall median cumulative effective dose was 2.7 mSv (range, 0.1–76.9 mSv), and the associated lifetime attributable risk of cancer was 0.07% (range, 0.001%–6.5%). Median lifetime attributable risk of cancer ranged widely depending on surgical complexity (0.006%–1.6% for the 7 surgical cohorts) and was twice as high in females per unit exposure (0.04% versus 0.02% per 1-mSv effective dose for females versus males, respectively; P<0.001). Conclusions— Overall radiation exposures in children with heart disease are relatively low; however, select cohorts receive significant exposure. Cancer risk estimation highlights the need to limit radiation dose, particularly for high-exposure modalities.

Variation in Congenital Heart Surgery Costs Across Hospitals

BACKGROUND: A better understanding of costs associated with common and resource-intense conditions such as congenital heart disease has become increasingly important as children’s hospitals face growing pressure to both improve quality and reduce costs. We linked clinical information from a large registry with resource utilization data from an administrative data set to describe costs for common congenital cardiac operations and assess variation across hospitals. METHODS: Using linked data from The Society of Thoracic Surgeons and Pediatric Health Information Systems Databases (2006–2010), estimated costs/case for 9 operations of varying complexity were calculated. Between-hospital variation in cost and associated factors were assessed by using Bayesian methods, adjusting for important patient characteristics. RESULTS: Of 12 718 operations (27 hospitals) included, median cost/case increased with operation complexity (atrial septal defect repair, [

Cause, timing, and location of death in the Single Ventricle Reconstruction trial

25 499] to Norwood operation, [

Gestational Age at Birth and Outcomes After Neonatal Cardiac Surgery An Analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database

165 168]). Significant between-hospital variation (up to ninefold) in adjusted cost was observed across operations. Differences in length of stay (LOS) and complication rates explained an average of 28% of between-hospital cost variation. For the Norwood operation, high versus low cost hospitals had an average LOS of 50.8 vs 31.8 days and a major complication rate of 50% vs 25.3%. High volume hospitals had lower costs for the most complex operations. CONCLUSIONS: This study establishes benchmarks for hospital costs for common congenital heart operations and demonstrates wide variability across hospitals related in part to differences in LOS and complication rates. These data may be useful in designing initiatives aimed at both improving quality of care and reducing cost.

The Society of Thoracic Surgeons Congenital Heart Surgery Database: 2016 Update on Outcomes and Quality.

OBJECTIVES The Single Ventricle Reconstruction trial randomized 555 subjects with a single right ventricle undergoing the Norwood procedure at 15 North American centers to receive either a modified Blalock-Taussig shunt or right ventricle-to-pulmonary artery shunt. Results demonstrated a rate of death or cardiac transplantation by 12 months postrandomization of 36% for the modified Blalock-Taussig shunt and 26% for the right ventricle-to-pulmonary artery shunt, consistent with other publications. Despite this high mortality rate, little is known about the circumstances surrounding these deaths. METHODS There were 164 deaths within 12 months postrandomization. A committee adjudicated all deaths for cause and recorded the timing, location, and other factors for each event. RESULTS The most common cause of death was cardiovascular (42%), followed by unknown cause (24%) and multisystem organ failure (7%). The median age at death for subjects dying during the 12 months was 1.6 months (interquartile range, 0.6 to 3.7 months), with the highest number of deaths occurring during hospitalization related to the Norwood procedure. The most common location of death was at a Single Ventricle Reconstruction trial hospital (74%), followed by home (13%). There were 29 sudden, unexpected deaths (18%), although in retrospect, 12 were preceded by a prodrome. CONCLUSIONS In infants with a single right ventricle undergoing staged repair, the majority of deaths within 12 months of the procedure are due to cardiovascular causes, occur in a hospital, and within the first few months of life. Increased understanding of the circumstances surrounding the deaths of these single ventricle patients may reduce the high mortality rate.

Assessment of Pulmonary Hypertension in the Pediatric Catheterization Laboratory: Current Insights From the Magic Registry

Background— Gestational age at birth is a potentially important modifiable risk factor in neonates with congenital heart disease. We evaluated the relationship between gestational age and outcomes in a multicenter cohort of neonates undergoing cardiac surgery, focusing on those born at early term (ie, 37–38 weeks’ gestation). Methods and Results— Neonates in the Society of Thoracic Surgeons Congenital Heart Surgery Database who underwent cardiac surgery between 2010 and 2011 were included. Multivariable logistic regression was used to evaluate the association of gestational age at birth with in-hospital mortality, postoperative length of stay, and complications, adjusting for other important patient characteristics. Of 4784 included neonates (92 hospitals), 48% were born before 39 weeks’ gestation, including 31% at 37 to 38 weeks. Compared with a 39.5-week gestational age reference level, birth at 37 weeks’ gestational age was associated with higher in-hospital mortality, with an adjusted odds ratio (95% confidence interval) of 1.34 (1.05–1.71; P =0.02). Complication rates were higher and postoperative length of stay was significantly prolonged for those born at 37 and 38 weeks’ gestation (adjusted P <0.01 for all). Late-preterm births (34–36 weeks’ gestation) also had greater mortality and postoperative length of stay (adjusted P ≤0.003 for all). Conclusions— Birth during the early term period of 37 to 38 weeks’ gestation is associated with worse outcomes after neonatal cardiac surgery. These data challenge the commonly held perception that delivery at any time during term gestation is equally safe and appropriate and question the related practice of elective delivery of fetuses with complex congenital heart disease at early term. # CLINICAL PERSPECTIVE {#article-title-35}Background— Gestational age at birth is a potentially important modifiable risk factor in neonates with congenital heart disease. We evaluated the relationship between gestational age and outcomes in a multicenter cohort of neonates undergoing cardiac surgery, focusing on those born at early term (ie, 37–38 weeks’ gestation). Methods and Results— Neonates in the Society of Thoracic Surgeons Congenital Heart Surgery Database who underwent cardiac surgery between 2010 and 2011 were included. Multivariable logistic regression was used to evaluate the association of gestational age at birth with in-hospital mortality, postoperative length of stay, and complications, adjusting for other important patient characteristics. Of 4784 included neonates (92 hospitals), 48% were born before 39 weeks’ gestation, including 31% at 37 to 38 weeks. Compared with a 39.5-week gestational age reference level, birth at 37 weeks’ gestational age was associated with higher in-hospital mortality, with an adjusted odds ratio (95% confidence interval) of 1.34 (1.05–1.71; P=0.02). Complication rates were higher and postoperative length of stay was significantly prolonged for those born at 37 and 38 weeks’ gestation (adjusted P<0.01 for all). Late-preterm births (34–36 weeks’ gestation) also had greater mortality and postoperative length of stay (adjusted P⩽0.003 for all). Conclusions— Birth during the early term period of 37 to 38 weeks’ gestation is associated with worse outcomes after neonatal cardiac surgery. These data challenge the commonly held perception that delivery at any time during term gestation is equally safe and appropriate and question the related practice of elective delivery of fetuses with complex congenital heart disease at early term.

Variation in Prenatal Diagnosis of Congenital Heart Disease in Infants

The Society of Thoracic Surgeons Congenital Heart Surgery Database is the largest congenital and pediatric cardiac surgical clinical data registry in the world. It is the platform for all activities of The Society of Thoracic Surgeons related to the analysis of outcomes and the improvement of quality in this subspecialty. This article summarizes current aggregate national outcomes in congenital and pediatric cardiac surgery and reviews related activities in the areas of quality measurement, performance improvement, and transparency. The reported data about aggregate national outcomes are exemplified by an analysis of 10 benchmark operations performed from January 2011 to December 2014 and documenting overall discharge mortality (interquartile range among programs with more than 9 cases): off-bypass coarctation, 1.0% (0.0% to 0.9%); ventricular septal defect repair, 0.7% (0.0% to 1.1%); tetralogy of Fallot repair, 1.0% (0.0% to 1.7%); complete atrioventricular canal repair, 3.2% (0.0% to 6.5%); arterial switch operation, 2.7% (0.0% to 5.6%); arterial switch operation plus ventricular septal defect, 5.3% (0.0% to 6.7%); Glenn/hemiFontan, 2.1% (0.0% to 3.8%); Fontan operation, 1.4% (0.0% to 2.4%); truncus arteriosus repair, 9.6% (0.0 % to 11.8%); and Norwood procedure, 15.6% (10.0% to 21.4%).

Surgeon and Center Volume Influence on Outcomes After Arterial Switch Operation: Analysis of the STS Congenital Heart Surgery Database

Objectives: To assess protocols, demographics, and hemodynamics in pediatric patients undergoing catheterization for pulmonary hypertension (PH). Background: Pediatric specific data is limited on PH. Methods: Review of the Mid‐Atlantic Group of Interventional Cardiology (MAGIC) collaboration PH registry dataset. Results: Between November 2003 and October 2008, seven institutions submitted data from 177 initial catheterizations in pediatric patients with suspected PH. Pulmonary arterial hypertension associated with congenital heart disease (APAH‐CHD) (n = 61, 34%) was more common than idiopathic PAH (IPAH) (n = 36, 20%). IPAH patients were older with higher mean pulmonary arterial pressures (mPAP) (P < 0.01). Oxygen lowered mPAP in patients with IPAH (P < 0.01) and associated PAH not related to congenital heart disease (APAH‐non CHD) (P < 0.01). A synergistic effect was seen with inhaled Nitric Oxide (iNO) (P < 0.01). Overall 9/30 (29%) patients with IPAH and 8/48 (16%) patients with APAH‐non CHD were reactive to vasodilator testing. Oxygen lowered pulmonary vascular resistance index (PVRI) in patients with APAH‐CHD (P < 0.01). There was no additive effect with iNO but a subset of patients required iNO to lower PVRI below 5 WU·m2. General anesthesia (GA) lowered systemic arterial pressure (P < 0.01) with no difference between GA and procedural sedation on mPAP or PVRI. Adverse events were rare (n = 7) with no procedural deaths. Conclusions: Pediatric patients with PH demonstrate a higher incidence of APAH‐CHD and neonatal specific disorders compared to adults. Pediatric PH patients may demonstrate baseline mPAP < 40 mm Hg but > 50% systemic illustrating the difficulty in applying adult criteria to children with PH. Catheterization in children with PH is relatively safe.

Intervention for Recoarctation in the Single Ventricle Reconstruction Trial Incidence, Risk, and Outcomes

BACKGROUND AND OBJECTIVE: Prenatal diagnosis allows improved perioperative outcomes for fetuses with certain forms of congenital heart disease (CHD). Variability in prenatal diagnosis has been demonstrated in other countries, leading to efforts to improve fetal imaging protocols and access to care, but has not been examined across the United States. The objective was to evaluate national variation in prenatal detection across geographic region and defect type in neonates and infants with CHD undergoing heart surgery. METHODS: Cardiovascular operations performed in patients ≤6 months of age in the United States and included in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2006–2012) were eligible for inclusion. Centers with >15% missing prenatal diagnosis data were excluded from the study. Prenatal diagnosis rates were compared across geographic location of residence and defect type using the χ2 test. RESULTS: Overall, the study included 31 374 patients from 91 Society of Thoracic Surgeons Congenital Heart Surgery Database participating centers across the United States. Prenatal detection occurred in 34% and increased every year, from 26% (2006) to 42% (2012). There was significant geographic variation in rates of prenatal diagnosis across states (range 11.8%–53.4%, P < .0001). Significant variability by defect type was also observed, with higher rates for lesions identifiable on 4-chamber view than for those requiring outflow tract visualization (57% vs 32%, P < .0001). CONCLUSIONS: Rates of prenatal CHD detection in the United States remain low for patients undergoing surgical intervention, with significant variability between states and across defect type. Additional studies are needed to identify reasons for this variation and the potential impact on patient outcomes.

Percutaneous Vascular Stent Implantation as Treatment for Central Vascular Obstruction Due to Fibrosing Mediastinitis

BACKGROUND The relative impact of center volume and of surgeon volume on early outcomes after the arterial switch operation (ASO) is incompletely understood. METHODS Neonates in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2005-2012) undergoing ASO for transposition of the great arteries were included in the analysis. Multivariable logistic regression with adjustment for patient factors and ventricular septal defect closure was used to evaluate relationships between annual center and surgeon volume and a composite end point (in-hospital mortality or major complications). RESULTS The study included 2,357 patients (84 centers, 155 surgeons). Median annual ASO center volume was 4 (range, 1 to 18). Median annual surgeon volume was 2 (range, 0.1 to 11). In-hospital mortality was 3.4%; 14.7% had major morbidity and 15.5% met the composite end point. Analyzed individually, lower center and surgeon volumes were each associated with the composite end point (odds ratios for centers with 2 versus 10 cases/y, 1.92; 95% confidence interval, 1.23 to 2.99); odds ratios for surgeons with 1 versus 6 cases/y, 2.16; 95% confidence interval, 1.42 to 3.26). When analyzed together, the addition of surgeon volume to the center volume models attenuated but did not completely mitigate the association of center volume with outcome (relative attenuation of odds ratio = 31%). Addition of center volume to surgeon volume models attenuated the association of surgeon volume with outcome to a lesser degree (relative attenuation of odds ratio = 11%). CONCLUSIONS Center and surgeon volume each influence early outcomes after ASO; however, surgeon volume appears to play a more prominent role. Surgeon and center ASO volume should be considered in the context of initiatives to improve outcomes from ASO for transposition of the great arteries.