Twenty years of experience with intraoperative pulmonary artery stenting.

OBJECTIVES: To describe our 20-year experience with intraoperative pulmonary artery (PA) stent placement and evaluate long-term patient outcomes, specifically the need and risk factors for reintervention. BACKGROUND: Intraoperative PA stent placement is an alternative to surgical patch arterioplasty and percutaneous angioplasty or stent placement to treat branch PA stenosis. METHODS: We performed a retrospective review of all intraoperative PA stents placed at our institution from 1994-2013. Patient and stent characteristics and outcome data were collected. Risk factors associated with reintervention were identified using univariate cox regression analysis. RESULTS: Eighty-one PA stents were placed in 68 patients. The procedural complication rate was 4.4%. During a median follow-up period of 6 years (interquartile range [IQR] 0.9-12.7), 30 patients (44%) underwent reintervention on the stented PA with a median time to first reintervention of 2.6 years (IQR 0.7-4.4 years). The first reintervention was surgical in 30% and catheter-based in 70%. Risk factors for reintervention included age < 18 months (Hazard ratio [HR] 2.97, P = 0.005) and body surface area < 0.47 m2 (HR 3.20, P = 0.003) at the time of stent implantation, and the presence of multiple aortopulmonary collaterals in patients with tetralogy of Fallot (HR 4.61, P = 0.003). CONCLUSIONS: Intraoperative PA stent implantation is a safe and effective alternative to percutaneous stent implantation and offers several advantages, including the ability to implant adult-size stents in small patients while avoiding injury to peripheral vessels, to position stents to facilitate future percutaneous stent redilation, and to access the PAs directly, which eliminates radiation exposure. © 2017 Wiley Periodicals, Inc.

The Society of Thoracic Surgeons Congenital Heart Surgery Database: 2017 Update on Outcomes and Quality.

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 report 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 2012 to December 2015. This analysis documents the overall aggregate operative mortality (interquartile range among all participating programs) for the following procedural groups: off-bypass coarctation repair, 1.3% (0.0% to 1.8%); ventricular septal defect repair, 0.6% (0.0% to 0.9%); tetralogy of Fallot repair, 1.1% (0.0% to 1.4%); complete atrioventricular canal repair, 3.0% (0.0% to 4.7%); arterial switch operation, 2.7% (0.0% to 4.1%); arterial switch operation and ventricular septal defect repair, 5.3% (0.0% to 6.7%); Glenn/hemi-Fontan, 2.5% (0.0% to 4.5%); Fontan operation, 1.2% (0.0% to 1.2%); truncus arteriosus repair, 9.4% (0.0% to 16.7%); and Norwood procedure, 15.7% (8.9% to 25.0%).

Functional Status and Quality of Life in Survivors of Extracorporeal Membrane Oxygenation After the Norwood Operation.

BACKGROUND: Infants who require extracorporeal membrane oxygenation (ECMO) support after a Norwood operation are at increased risk for early and late death compared with patients who do not require ECMO post-Norwood. Little is known about the effect that ECMO post-Norwood has on functional status and quality of life among long-term survivors. METHODS: We prospectively evaluated functional status and health-related quality of life in 12 surviving patients (cases) and 19 corresponding patients (controls) from a previous retrospective case-control assessment of long-term survival in patients requiring ECMO post-Norwood. Functional status was assessed with the Vineland Adaptive Behavior Scale-II, and health-related quality of life was assessed with the Pediatric Quality of Life Inventory (PedsQL) core and cardiac modules. RESULTS: There were no differences in demographics, extracardiac or genetic anomalies, or age at follow-up assessment between ECMO cases and non-ECMO controls. The Vineland Adaptive Behavior Scale-II scores were comparable between groups, with both groups demonstrating function in the normal range in all four domains tested. The only difference in PedsQL scores between cases and controls was perceived physical appearance, which was lower among ECMO survivors by both patient and proxy report. PedsQL scores of both groups were comparable to published scores for patients with single-ventricle congenital heart disease but generally lower than scores for the healthy population. CONCLUSIONS: The requirement for ECMO support after a Norwood operation does not appear to significantly affect functional status or quality of life among the subset of patients who achieve long-term survival.

Out of many, one: integrating data in the paediatric cardiovascular environment.

Large volumes of data and multiple computing platforms are now universal components of paediatric cardiovascular medicine, but are in a constant state of evolution. Often, multiple sets of related data reside in disconnected "silos", resulting in clinical, administrative, and research activities that may be duplicative, inefficient, and at times inaccurate. Comprehensive and integrated data solutions are needed to facilitate these activities across congenital heart centres. We describe methodology, key considerations, successful use cases, and lessons learnt in developing an integrated data platform across our congenital heart centre.

Critical Care Nursing's Impact on Pediatric Patient Outcomes.

BACKGROUND: Previous studies have demonstrated the effect of adult nursing skill mix, staffing ratios, and level of education on patient deaths, complication rates, and failure to rescue (FTR). To date, only one known study had examined the effect of nursing experience and education on postoperative pediatric cardiac operations. METHODS: Nursing survey data were linked to The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database for patients undergoing cardiac operations (2010 to 2011). Logistic regression models were used to estimate associations of nursing education and years of clinical experience with in-hospital mortality rates, complication rates, and FTR. Generalized estimating equations and robust standard error estimates were used to account for within-center correlation of outcomes. RESULTS: Among 15,463 patients (29 hospitals), the in-hospital mortality rate was 2.8%, postoperative complications occurred in 42.4%, and the FTR rate was 6.4%. After covariate adjustment, pediatric critical care units with a higher proportion of nurses with a Bachelor of Science degree or higher had lower odds of complication (odds ratio for 10% increase, 0.85; 95% confidence interval, 0.76 to 0.96; p = 0.009). Units with a higher proportion of nurses with more than 2 years of experience had lower mortality rates (odds ratio for 10% increase, 0.92; 95% confidence interval, 0.85 to 0.99; p = 0.025). CONCLUSIONS: This is the first study to demonstrate that higher levels of nursing education and experience are significantly associated with fewer complications after pediatric cardiac operations and aligns with our previous findings on their association with reduced deaths. These results provide data for pediatric hospital leaders and reinforce the importance of organization-wide mentoring strategies for new nurses and retention strategies for experienced nurses.

Hyperoxia Is Associated With Poor Outcomes in Pediatric Cardiac Patients Supported on Venoarterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: Patients who require venoarterial extracorporeal membrane oxygenation because of cardiac failure frequently have supranormal blood oxygen tensions (hyperoxia). Recent studies have suggested worse outcomes in patients with hyperoxia after resuscitation from cardiac or respiratory arrests, presumably because of oxidative stress. There are limited data regarding the effect of hyperoxia on outcomes in pediatric patients on venoarterial extracorporeal membrane oxygenation. DESIGN: Retrospective chart review. SETTING: Pediatric cardiothoracic ICU. PATIENTS: Cardiac surgery patients less than 1 year old requiring venoarterial extracorporeal membrane oxygenation in the postoperative period from 2007 to 2013. MEASUREMENTS AND MAIN RESULTS: In 93 infants (median time on extracorporeal membrane oxygenation, 5 d), mortality at 30 days post surgery (primary outcome) was 38%. Using a receiver operating characteristic curve, a mean PaO2 of 193 mm Hg in the first 48 hours of extracorporeal membrane oxygenation was determined to have good discriminatory ability with regard to 30-day mortality. Univariate analysis identified a mean PaO2 greater than 193 mm Hg (p = 0.001), longer cardiopulmonary bypass times (p = 0.09), longer duration of extracorporeal membrane oxygenation (p < 0.0001), and higher extracorporeal membrane oxygenation pump flows (p = 0.052) as possible risk factors for 30-day mortality. In multivariable analysis controlling for the variables listed above, a mean PaO2 greater than 193 mm Hg remained an independent risk factor for mortality (p = 0.03). In addition, a mean PaO2 greater than 193 mm Hg was associated with the need for renal dialysis (p = 0.02) but not with neurologic injury (p = 0.41) during the hospitalization. CONCLUSIONS: In infants with congenital heart disease who are placed on venoarterial extracorporeal membrane oxygenation postoperatively, hyperoxia (defined as a mean PaO2 > 193 mm Hg in the first 48 hr of extracorporeal membrane oxygenation) was an independent risk factor for 30-day mortality after surgery. Future studies are needed to delineate the causative or associative role of hyperoxia with outcomes, especially in children with baseline cyanosis who may be more susceptible to the effects of oxidative stress.

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

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%).

Risk Factors for Interstage Mortality Following the Norwood Procedure: Impact of Sociodemographic Factors.

Interstage mortality remains significant for patients undergoing staged palliation for hypoplastic left heart syndrome and other related single right ventricle malformations (HLV). The purpose of this study was to identify factors related to demographics, socioeconomic position, and perioperative course associated with post-Norwood hospital discharge, pre-stage 2, interstage mortality (ISM). Medical record review was conducted for patients with HLV, born from 1/2000 to 7/2009 and discharged alive following the Norwood procedure. Sociodemographic and perioperative factors were reviewed. Patients were determined to have ISM if they died between Norwood procedure hospital discharge and stage 2 palliation. Univariable and multivariable logistic regressions were performed to identify risk factors associated with ISM. A total of 273 patients were included in the analysis; ISM occurred in 32 patients (12%). Multivariable analysis demonstrated that independent risk factors for interstage mortality included teen mothers [adjusted odds ratio (AOR) 6.6, 95% confidence interval (CI) 1.9-22.5], single adult caregivers (AOR 4.1, 95% CI 1.2-14.4), postoperative dysrhythmia (AOR 2.7, 95% CI 1.1-6.4), and longer ICU stay (AOR 2.7, 95% CI 1.2-6.1). Anatomic and surgical course variables were not associated with ISM in multivariable analysis. Patients with HLV are at increased risk of ISM if born to a teen mother, if they lived in a home with only one adult caregiver, suffered a postoperative dysrhythmia, or experienced a prolonged ICU stay. These risk factors are identifiable, and thus these infants may be targeted for interventions to reduce ISM.

Epidemiology of Stroke in Pediatric Cardiac Surgical Patients Supported With Extracorporeal Membrane Oxygenation.

BACKGROUND: Stroke is a common complication of extracorporeal membrane oxygenation (ECMO), and pediatric cardiac surgical patients may be at higher risk. Epidemiology and risk factors for stroke in these patients are not well characterized. METHODS: We analyzed pediatric (<18 years) cardiac ECMO cases in the Extracorporeal Life Support Organization Registry from 2002 to 2013. Cardiac surgical patients were identified, and procedures were stratified according to The Society of Thoracic Surgeons morbidity categories. The primary outcome was any stroke (hemorrhagic or infarction) identified by neuroimaging. Risk factors were identified through multivariable logistic regression. RESULTS: We analyzed 3,517 cardiac surgical patients; 81% with cyanotic disease, and 57% in high-risk categories from The Society of Thoracic Surgeons (categories 4 and 5). Overall, 12% experienced stroke while receiving ECMO, and those with stroke had greater in-hospital mortality (72% versus 51%; p < 0.0001). In multivariable analysis, neonatal status (adjusted odds ratio, 1.8; 95% confidence interval, 1.3 to 2.4), lower weight-for-age z score (adjusted odds ratio, 1.1 for each 1-point decrease; 95% confidence interval, 1.04 to 1.25), and longer ECMO duration (upper quartile [≥ 167 hours] adjusted odds ratio, 1.4; 95% confidence interval, 1.1 to 1.8) were independently associated with increased stroke risk, whereas cyanotic disease, The Society of Thoracic Surgeons category, and bypass time were not. CONCLUSIONS: This multicenter analysis demonstrates that pediatric cardiac surgical patients on ECMO are at high risk of stroke; younger or underweight patients and those with longer ECMO duration are at greatest risk, independent of procedural complexity. Future study is necessary to determine how anticoagulation or other clinical practices can be modified to reduce stroke incidence.

Impact of Patient Characteristics on Hospital-Level Outcomes Assessment in Congenital Heart Surgery.

BACKGROUND: Accurate hospital outcome measures in congenital heart surgery are important to multiple initiatives. While methods have been developed to account for differences in procedural case-mix, characteristics patients bring into the operation that may also vary across hospitals and influence outcome have received less attention. We evaluated the impact of these characteristics in a large cohort. METHODS: Patients undergoing congenital heart surgery at centers participating in The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010 to 2013) with adequate data quality were included. Variation across hospitals in important patient characteristics was examined, and hospital operative mortality rates were compared with and without adjustment for patient characteristics. RESULTS: Overall, 86 centers (52,224 patients) were included. There was greater than twofold variation across hospitals for nearly all patient characteristics examined. For example, the proportion of a center's surgical population comprised of neonates ranged from 12.8% to 26.6% across hospitals; the proportion with a non-cardiac anomaly ranged from 0.7% to 5.0%. When hospital mortality rankings were evaluated based on "standard" (adjustment for differences in procedural case-mix alone) versus "full" models (adjustment for both differences in procedural case-mix and patient characteristics), 14.0% changed their ranking for mortality by 20 or greater positions, 34.9% of centers changed which mortality quartile they were classified in, and 14.0% changed their statistical classification (statistically higher, lower, or same-as-expected mortality). CONCLUSIONS: Characteristics of patients undergoing congenital heart surgery vary across centers and impact hospital outcomes assessment. Methods to assess outcomes and relative performance should account for these characteristics.

Quality-Cost Relationship in Congenital Heart Surgery.

BACKGROUND: There is an increasing focus on optimizing health care quality and reducing costs. The care of children undergoing heart surgery requires significant investment of resources, and it remains unclear how costs of care relate to quality. We evaluated this relationship across a multicenter cohort. METHODS: Clinical data from The Society of Thoracic Surgeons Database were merged with cost data from the Pediatric Health Information Systems Database for children undergoing heart surgery (2006 to 2010). Hospital-level costs were modeled using Bayesian hierarchical methods adjusting for case-mix, and hospitals were categorized into cost tertiles. The primary quality metric evaluated was in-hospital mortality. RESULTS: Overall, 27 hospitals (30,670 patients) were included. Median adjusted cost per case was $82,360 and varied fivefold across hospitals, while median adjusted mortality was 3.4% and ranged from 2.4% to 5.0% across hospitals. Overall, hospitals in the lowest cost tertile had significantly lower adjusted mortality rates compared with the middle and high cost tertiles (2.5% vs 3.8% and 3.5%, respectively, both p < 0.001). When assessed at the individual hospital level, most (75%) but not all hospitals in the lowest cost tertile were also in the lowest mortality tertile. Similar relationships were seen across the spectrum of surgical complexity. Lower cost hospitals also had shorter length of stay and trends toward fewer major complications. CONCLUSIONS: Lowest cost hospitals generally deliver the highest quality care for children undergoing heart surgery, although there is some variation in this relationship. This information is important in the design of initiatives aiming to optimize health care value in this population.

Left ventricular retraining: theory and practice.

Congenitally corrected transposition of the great arteries or l-transposition of the great arteries is characterized by discordance of both the atrioventricular and ventriculoarterial connections. Physiologic repair of associated conditions, whereby the morphologic right ventricle remains the systemic ventricle, has resulted in unsatisfactory long-term outcomes due to the development of right ventricular failure and tricuspid valve regurgitation. While intuitively attractive, anatomic repair also has inherent challenges and risks, particularly for those patients who present late and require left ventricular retraining. Although early and intermediate-term outcomes for anatomic repair have been encouraging, longer-term follow-up has demonstrated concern for late left ventricular dysfunction in this subgroup of patients. Continued monitoring of this challenging patient population will clarify late outcomes and inform clinical management in the future.

Abdominal cardiac devices in pediatric and congenital heart disease: a practice model transition.

BACKGROUND: Abdominal cardiac implantable electronic device maintenance procedures are traditionally performed by cardiac surgeons. The University of Michigan Congenital Heart Center transitioned from this practice model to one in which electrophysiologists perform the majority of these procedures. This study presents the outcomes of these procedures during this transition. METHODS: Retrospective cohort study of all patients undergoing abdominal device maintenance procedure, inclusive of generator change, removal, or placement with preexisting leads from January 2005 to July 2013. Procedures involving epicardial lead placement were excluded. The primary outcome was major complications defined as any intraoperative complication, the requirement of an additional operative intervention, or hospitalization for device-related infection. RESULTS: There were 113 procedures on 93 patients. Of these, 84 (74%) procedures were on patients with congenital heart disease. Cardiac surgeons performed 54 (48%) procedures and electrophysiologists performed 59 (52%). Mean age was 16 ± 11 years. The groups were similar regarding age and proportion with congenital heart disease (CHD). Major complications occurred in 3 (5.5%) cardiac surgeon procedures and 2 (3.4%) electrophysiologist procedures. There is no difference in the risk of major complications between groups (P = .59). CONCLUSION: This 8.5-year period encompassed a practice model transition from cardiac surgeon-performed abdominal device procedures to primarily electrophysiologist-performed abdominal device procedures. There was no difference in the risk of complications between services. This suggests that electrophysiologist-performed abdominal cardiac device maintenance procedures are a viable practice model, provided there is support and collaboration from the cardiac surgery service.

The role of home monitoring in interstage management of infants following the Norwood procedure.

Although outcomes for infants with complex single ventricle heart defects have steadily improved in recent decades, there is still a significant risk for mortality and morbidity during the interstage period between stage 1 Norwood hospitalization discharge and stage 2 palliation. Home monitoring programs, which involve parental surveillance of daily weight and oxygen saturations during the interstage period, have been shown to significantly improve survival rates. This article describes the potential risk factors or causes of interstage mortality and reviews the role of home monitoring in early detection and potential prevention of adverse outcomes.

Long-Term Survival and Reintervention After the Ross Procedure Across the Pediatric Age Spectrum.

BACKGROUND: There are limited data regarding long-term outcomes after the Ross procedure in children. We evaluated mortality and reintervention in a large pediatric cohort. METHODS: A retrospective analysis of all patients aged younger than 18 years who underwent the Ross procedure at our institution (1991 to 2013) was conducted. Kaplan-Meier curves and Cox proportion hazard models were used to evaluate long-term outcomes and associated risk factors. RESULTS: Included were 240 consecutive patients undergoing a Ross/Ross-Konno procedure: 18% infants, 48% children, and 33% adolescents. Infants were more likely to have complex left heart disease (p = 0.005). Overall survival to hospital discharge was 96%; infants had the highest mortality (18%). Long-term survival status was known for 99.6% (median follow-up, 10.7 years). Overall 15-year survival was 87% (lowest in infants, 72%; p = 0.003). Reintervention status was known in 87%. Overall 15-year freedom from any left ventricular outflow tract reintervention was 59%; 85% still had their autograft valve at the latest follow-up. Left ventricular outflow tract reintervention was uncommon in infants (n = 2). Overall 15-year freedom from right ventricular outflow tract reintervention was 53%, and was lower in infants (19%) than in children (51%) and adolescents (76%; p < 0.0001). CONCLUSIONS: Outcomes after the Ross procedure in children vary by age. Infants more commonly have complex left heart disease and experience higher mortality but have excellent long-term autograft durability. Children and adolescents have higher rates of left ventricular outflow tract reintervention, whereas infants are at highest risk of right ventricular outflow tract reintervention.

Hemorrhagic complications in pediatric cardiac patients on extracorporeal membrane oxygenation: an analysis of the Extracorporeal Life Support Organization Registry.

OBJECTIVES: To determine the prevalence of and risk factors for hemorrhagic complications in children with cardiac disease requiring extracorporeal membrane oxygenation. DESIGN: Retrospective review of the Extracorporeal Life Support Organization Registry (2002-2013). SETTING: Participating Extracorporeal Life Support Organization centers. PATIENTS: Patients less than 18 years old on extracorporeal membrane oxygenation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 21,845 patients requiring extracorporeal membrane oxygenation during the study period, 8,905 (41%) had cardiac disease, and 79% of whom (6,995) had cardiac surgery. Hemorrhagic complications occurred in 8,480 patients (39% of overall cohort), with higher rates in cardiac versus noncardiac patients (49% vs 32%; p < 0.0001) related to cannulation and surgical site bleeding. Cardiac surgical patients had higher rates of hemorrhage compared with cardiac medical patients (57% vs 38%; p < 0.0001), and cardiac patients with hemorrhage had higher extracorporeal membrane oxygenation mortality compared with those without (42% vs 22% in medical patients and 34% vs 20% in surgical patients; both p < 0.0001). In multivariable analysis in both the cardiac medical and surgical groups, hemorrhage risk was higher in children greater than 1 year old and in patients with longer extracorporeal membrane oxygenation duration. Additional independent risk factors for hemorrhage in cardiac surgical patients included pre-extracorporeal membrane oxygenation mediastinal exploration (odds ratio, 3.6; 95% CI, 2.1-6.3), Society of Thoracic Surgeons morbidity category 4-5 (odds ratio, 1.2; 95% CI, 1.03-1.5), cannulation less than 24 hours after surgery (odds ratio, 1.6; 95% CI, 1.3-1.9), and longer cardiopulmonary bypass time (≥ 282 min [upper quartile]; odds ratio, 1.5; 95% CI, 1.3-1.9). CONCLUSIONS: In this large, multicenter analysis, hemorrhagic complications occurred in nearly half of children with heart disease on extracorporeal membrane oxygenation and were associated with a significant mortality risk. Several factors were associated with hemorrhagic complications in cardiac surgical patients including pre-extracorporeal membrane oxygenation mediastinal exploration, greater surgical complexity, early postoperative cannulation, and longer bypass times. Whether these risks can be mitigated by modifying or delaying systemic anticoagulation requires further investigation.

Measuring hospital performance in congenital heart surgery: administrative versus clinical registry data.

BACKGROUND: In congenital heart surgery, hospital performance has historically been assessed using widely available administrative data sets. Recent studies have demonstrated inaccuracies in case ascertainment (coding and inclusion of eligible cases) in administrative versus clinical registry data; however, it is unclear whether this impacts assessment of performance on a hospital level. METHODS: Merged data from The Society of Thoracic Surgeons (STS) database (clinical registry) and the Pediatric Health Information Systems (PHIS) database (administrative data set) for 46,056 children undergoing cardiac operations (2006-2010) were used to evaluate in-hospital mortality for 33 hospitals based on their administrative versus registry data. Standard methods to identify/classify cases were used: Risk Adjustment in Congenital Heart Surgery, version 1 (RACHS-1) in the administrative data and STS-European Association for Cardiothoracic Surgery (STAT) methodology in the registry. RESULTS: Median hospital surgical volume based on the registry data was 269 cases per year; mortality was 2.9%. Hospital volumes and mortality rates based on the administrative data were on average 10.7% and 4.7% lower, respectively, although this varied widely across hospitals. Hospital rankings for mortality based on the administrative versus registry data differed by 5 or more rank positions for 24% of hospitals, with a change in mortality tertile classification (high, middle, or low mortality) for 18% and a change in statistical outlier classification for 12%. Higher volume/complexity hospitals were most impacted. Agency for Healthcare Quality and Research (AHRQ) methods in the administrative data yielded similar results. CONCLUSIONS: Inaccuracies in case ascertainment in administrative versus clinical registry data can lead to important differences in assessment of hospital mortality rates for congenital heart surgery.