Association Between Past and Present Operative Mortality in Congenital Heart Surgery: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: Mortality after congenital heart surgery is an important metric across benchmarking, quality, and reporting initiatives. All rely on estimates from prior years, and how well these reflect current outcomes is unclear. METHODS: Index operations from The Society of Thoracic Surgeons Congenital Database (2014-2019) were included. Adjusted operative mortality in "past" 4-year and 1-year intervals vs the most recent year ("present") was evaluated using Bayesian hierarchical logistic regression with results presented as odds ratios and 95% credible intervals (CrI). RESULTS: Among 115,699 operations (106 hospitals), overall present observed mortality was 2.5%. Regression to the mean was evident, and individual hospital's present vs past adjusted mortality were only weakly correlated (-0.11 vs past 1-year data, 0.22 vs past 4-year data). A significant relationship was found between past and present mortality only for the group of hospitals in the highest mortality quartile, most prominent for past 4-year data (adjusted odds ratio vs lowest mortality quartile, 2.04; 95% CrI, 1.44-2.80). The proportion of present hospital mortality variation explained by past mortality quartile was 52% (95% CrI, 20%-90%) using past 4-year data and only 27% (95% CrI, 92%-83%) using past 1-year data. Overall 66% of hospitals changed mortality quartiles from past to present (30% by ≥2 quartiles). CONCLUSIONS: Past mortality relates to present primarily for groups of hospitals at the extremes, with past 4-year data more informative than past 1-year data. For individual hospitals, past may differ from present, regression to the mean is common, and many change quartiles. Past mortality should be used thoughtfully and not as the sole factor informing present decision making.

Recommendations for Centers Performing Pediatric Heart Surgery in the United States.

Care and outcomes for the more than 40,000 patients undergoing pediatric and congenital heart surgery in the United States annually are known to vary widely. While consensus recommendations have been published across numerous fields as one mechanism to promote a high level of care delivery across centers, it has been more than two decades since the last pediatric heart surgery recommendations were published in the United States. More recent guidance is lacking, and collaborative efforts involving the many disciplines engaged in caring for these children have not been undertaken to date. The present initiative brings together professional societies spanning numerous care domains and congenital cardiac surgeons, pediatric cardiologists, nursing, and other healthcare professionals from diverse programs around the country to develop consensus recommendations for United States centers. The focus of this initial work is on pediatric heart surgery, and it is recommended that future efforts focus in detail on the adult congenital population. We describe the background, rationale, and methodology related to this collaborative effort, and recommendations put forth for Essential Care Centers (essential services necessary for any program), and Comprehensive Care Centers (services to optimize comprehensive and high-complexity care), encompassing structure, process, and outcome metrics across 14 domains.

Recommendations for centers performing pediatric heart surgery in the United States.

Care and outcomes for the more than 40,000 patients undergoing pediatric and congenital heart surgery in the United States annually are known to vary widely. While consensus recommendations have been published across numerous fields as one mechanism to promote a high level of care delivery across centers, it has been more than two decades since the last pediatric heart surgery recommendations were published in the United States. More recent guidance is lacking, and collaborative efforts involving the many disciplines engaged in caring for these children have not been undertaken to date. The present initiative brings together professional societies spanning numerous care domains and congenital cardiac surgeons, pediatric cardiologists, nursing, and other healthcare professionals from diverse programs around the country to develop consensus recommendations for United States centers. The focus of this initial work is on pediatric heart surgery, and it is recommended that future efforts focus in detail on the adult congenital population. We describe the background, rationale, and methodology related to this collaborative effort, and recommendations put forth for Essential Care Centers (essential services necessary for any program), and Comprehensive Care Centers (services to optimize comprehensive and high-complexity care), encompassing structure, process, and outcome metrics across 14 domains.

Recommendations for Centers Performing Pediatric Heart Surgery in the United States.

Care and outcomes for the more than 40,000 patients undergoing pediatric and congenital heart surgery in the United States annually are known to vary widely. While consensus recommendations have been published across numerous fields as one mechanism to promote a high level of care delivery across centers, it has been more than two decades since the last pediatric heart surgery recommendations were published in the United States. More recent guidance is lacking, and collaborative efforts involving the many disciplines engaged in caring for these children have not been undertaken to date. The present initiative brings together professional societies spanning numerous care domains and congenital cardiac surgeons, pediatric cardiologists, nursing, and other healthcare professionals from diverse programs around the country to develop consensus recommendations for United States centers. The focus of this initial work is on pediatric heart surgery, and it is recommended that future efforts focus in detail on the adult congenital population. We describe the background, rationale, and methodology related to this collaborative effort, and recommendations put forth for Essential Care Centers (essential services necessary for any program), and Comprehensive Care Centers (services to optimize comprehensive and high-complexity care), encompassing structure, process, and outcome metrics across 14 domains.

Contemporary Relationship Between Hospital Volume and Outcomes in Congenital Heart Surgery.

BACKGROUND: Studies examining the volume-outcome relationship in congenital heart surgery (CHS) are more than a decade old. Since then, mortality has declined, and case-mix adjustment has evolved. We determined the current relationship between hospital CHS volume and outcomes. METHODS: Patients aged ≤18 years undergoing index operations in The Society of Thoracic Surgeons-Congenital Heart Surgery Database (2017-2020) were included. Associations between annual hospital volume and case-mix-adjusted operative mortality, major complications, failure to rescue (FTR), and postoperative length of stay (PLOS) were assessed using Bayesian hierarchical models, overall, by The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category, and for the Norwood procedure. RESULTS: Across 101 centers (76,714 index operations), median annual volume was 144 operations/y. Operative mortality was 2.7%. Lower-volume hospitals had higher mortality, with an apparent transition zone at ∼190 operations/y (95% credible interval [CrI], 115-450 operations/y), below which a sustained uptick in the estimated odds of death occurred. Odds of death compared with a 450 operations/y reference were 50 operations/y (odds ratio [OR], 1.84; 95% CrI, 1.41-2.37), 100 operations/y (OR, 1.37; 95% CrI, 1.08-1.71), 200 operations/y (OR, 0.92; 95% CrI, 0.1-1.18), 300 operations/y (OR, 0.89; 95% CrI, 0.76-1.04). The volume-outcome effect was more apparent for STAT 4 to 5 than STAT 1 to 3 operations. In the overall cohort, PLOS and complications were similar across hospital volumes, whereas FTR rates were higher at lower-volume hospitals. Lower-volume hospitals had worse outcomes after the Norwood procedure, most notably mortality and FTR. CONCLUSIONS: Hospital volume is associated with mortality and FTR after CHS. The relationship is strongest for high-risk operations. These data can inform ongoing initiatives to improve CHS care.

Age at surgery and outcomes following neonatal cardiac surgery: An analysis from the Pediatric Cardiac Critical Care Consortium.

OBJECTIVE: The optimal timing for neonatal cardiac surgery is a potentially modifiable factor that may affect outcomes. We studied the relationship between age at surgery (AAS) and outcomes across multiple hospitals, focusing on neonatal operations where timing appears is not emergency. METHODS: We studied neonates ≥37 weeks' gestation and ≥2.5 kg admitted to a treating hospital on or before day of life 2 undergoing selected index cardiac operations. The impact of AAS on outcomes was evaluated across the entire cohort and a standard risk subgroup (ie, free of preoperative mechanical ventilation, mechanical circulatory support, or other organ failure). Outcomes included mortality, major morbidity (ie, cardiac arrest, mechanical circulatory support, unplanned cardiac reintervention, or neurologic complication), and postoperative cardiac intensive care unit and hospital length of stay. Post hoc analyses focused on operations undertaken between day of life 2 and 7. RESULTS: We studied 2536 neonates from 47 hospitals. AAS from day of life 2 through 7 was not associated with risk adjusted mortality or major morbidity among the entire cohort and the standard risk subgroup. Older AAS, although associated with modest increases in postoperative cardiac intensive care unit and hospital length of stay in the entire cohort, was not associated with hospital length of stay in the standard risk subgroup. CONCLUSIONS: Among select nonemergency neonatal cardiac operations, AAS between day of life 2 and 7 was not found to be associated with risk adjusted mortality or major morbidity. Although delays in surgical timing may modestly increase preoperative resource use, studies of AAS and outcomes not evident at the time of discharge are needed.

Variation in Case-Mix Across Hospitals: Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database was queried to document variation of patient characteristics, procedure types, and programmatic case-mix. METHODS: All index cardiac operations in patients less than 18 years of age in the STS Congenital Heart Surgery Database (July 2016 to June 2020) were eligible for inclusion except patients weighing ≤2.5 kg undergoing isolated patent ductus arteriosus closure. At the hospital level, we describe variations in patient and procedural characteristics known from previous analyses to be associated with outcomes. We also report variations across hospitals of programmatic case-mix. RESULTS: Data were analyzed from 117 sites (90 322 total operations, 87 296 total index cardiac operations eligible for STAT [STS-European Association for Cardio-Thoracic Surgery] 2020 Mortality Score). The median annual total index cardiac operations eligible for STAT 2020 Mortality Score per hospital was 157 (interquartile range [IQR], 94-276). Wide variability was documented in total annual index cardiac operations eligible for STAT 2020 Mortality Score per hospital (ratio 90th/10th percentile = 9.01), operations in neonates weighing <2.5 kg (ratio 90th/10th percentile = 4.09), operations in patients with noncardiac anatomic abnormalities (ratio 90th/10th percentile = 3.46), and operations in patients with preoperative mechanical ventilation (ratio 90th/10th percentile = 3.97). At the hospital level, the median percentage of all index cardiac operations in STAT 2020 Mortality Category 5 was 3.7% (IQR, 1.7%-4.9%), the median percentage of all index cardiac operations in STAT 2020 Mortality Category 4 or 5 was 24.4% (IQR, 19.0%-28.4%), the median hospital-specific mean STAT Mortality Category was 2.39 (IQR, 2.20-2.47), and the median hospital-specific mean STAT Mortality Score was 0.86 (IQR, 0.73-0.91). CONCLUSIONS: Substantial variation of patient characteristics, procedure types, and case-mix exists across pediatric and congenital cardiac surgical programs. Knowledge about programmatic case-mix augments data about indirectly standardized programmatic observed-to-expected (O/E) mortality. Indirectly standardized O/E ratios do not provide a complete description of a given pediatric and congenital cardiac surgical program. The indirectly standardized programmatic O/E ratios associated with a given program apply only to its specific case-mix of patients and may represent a quite different case-mix than that of another program.

Reevaluating Congenital Heart Surgery Center Performance Using Operative Mortality.

BACKGROUND: The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) provides observed-to-expected (O/E) operative mortality ratios to more than 100 congenital heart centers in North America. We compared the current approach for estimating O/E ratios to approaches incorporating information on diagnosis as moderators of procedures, other unused risk factors, and additional variation in confidence interval construction to characterize center performance. METHODS: Bayesian additive regression trees (BART) and lasso models linked operative mortality to diagnosis-procedure categories, procedure-specific risk factors, and syndromes/abnormalities. Bootstrapping accounted for variation in the STS-CHSD (STS bootstrap) and lasso CIs. We compared O/E estimates, interquartile range of CI widths, and concordance of center performance categorizations (worse-than-, as-, or better-than-expected mortality) of the new approaches to the STS-CHSD. RESULTS: In 110 surgical centers including 98,822 surgical operative encounters, there were 2818 (2.85%) operative mortalities (center range, 0.37%-10%). Compared with the STS-CHSD, BART- and lasso-estimated O/E ratios varied more and had narrower confidence intervals (interquartile range of confidence interval: STS-CHSD = 1.11, STS bootstrap = 0.98; lasso = 0.80; BART = 0.96). Concordance of performance categorization with the STS-CHSD ranged from 84% (lasso) to 91% (STS Bootstrap); more than 70% of discordant centers improved categories. Discordant centers had smaller volumes, fewer operative mortalities, and treated more patients with congenital lung abnormalities. CONCLUSIONS: Relative to the STS-CHSD, up to 16% of hospitals changed performance categories, most improving performance. Given the significance of quality reports for congenital heart centers, inclusion of additional risk factors and unaddressed variation should be considered.

Mortality Prediction After Cardiac Surgery in Children: An STS Congenital Heart Surgery Database Analysis.

BACKGROUND: The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (CHSD) provides risk-adjusted operative mortality rates to approximately 120 North American congenital heart centers. Optimal case-mix adjustment methods for operative mortality risk prediction in this population remain unclear. METHODS: A panel created diagnosis-procedure combinations of encounters in the CHSD. Models for operative mortality using the new diagnosis-procedure categories, procedure-specific risk factors, and syndromes or abnormalities included in the CHSD were estimated using Bayesian additive regression trees and least absolute shrinkage and selector operator (lasso) models. Performance of the new models was compared with the current STS CHSD risk model. RESULTS: Of 98 825 operative encounters (69 063 training; 29 762 testing), 2818 (2.85%) STS-defined operative mortalities were observed. Differences in sensitivity, specificity, and true and false positive predicted values were negligible across models. Calibration for mortality predictions at the higher end of risk from the lasso and Bayesian additive regression trees models was better than predictions from the STS CHSD model, likely because of the new models' inclusion of diagnosis-palliative procedure variables affecting <1% of patients overall but accounting for 27% of mortalities. Model discrimination varied across models for high-risk procedures, hospital volume, and hospitals. CONCLUSIONS: Overall performance of the new models did not differ meaningfully from the STS CHSD risk model. Adding procedure-specific risk factors and allowing diagnosis to modify predicted risk for palliative operations may augment model performance for very high-risk surgical procedures. Given the importance of risk adjustment in estimating hospital quality, a comparative assessment of surgical program quality evaluations using the different models is warranted.

Evolving Cost-Quality Relationship in Pediatric Heart Surgery.

BACKGROUND: For the more than 40,000 children in the United States undergoing congenital heart surgery annually, the relationship between hospital quality and costs remains unclear. Prior studies report conflicting results and clinical outcomes have continued to improve over time. We examined a large contemporary cohort, aiming to better inform ongoing initiatives seeking to optimize health care value in this population. METHODS: Clinical information (The Society of Thoracic Surgeons Congenital Database) was merged with standardized cost data (Pediatric Health Information Systems) for children undergoing heart surgery from 2010 to 2015. In-hospital cost variability was analyzed using Bayesian hierarchical models adjusted for case-mix. Quality metrics examined included in-hospital mortality, postoperative complications, postoperative length of stay (PLOS), and a composite. RESULTS: Overall, 32 hospitals (n = 45,315 patients) were included. Median adjusted cost per case varied across hospitals from $67,700 to $51,200 in the high vs low cost tertile (ratio 1.32; 95% credible interval, 1.29 to 1.35), and all quality metrics also varied across hospitals. Across cost tertiles, there were no significant differences in the quality metrics examined, with the exception of PLOS. The PLOS findings were driven by high-risk The Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery categories 4 and 5 cases (adjusted median length of stay 16.8 vs 14.9 days in high vs low cost tertile [ratio 1.13, 1.05 to 1.24]), and intensive care unit PLOS. CONCLUSIONS: Contemporary congenital heart surgery costs vary across hospitals but were not associated with most quality metrics examined, highlighting that performance in one area does not necessarily convey to others. Cost variability was associated with PLOS, particularly related to intensive care unit PLOS and high-risk cases. Care processes influencing PLOS may provide targets for value-based initiatives in this population.

Successful Reduction of Postoperative Chest Tube Duration and Length of Stay After Congenital Heart Surgery: A Multicenter Collaborative Improvement Project.

Background Congenital heart disease practices and outcomes vary significantly across centers, including postoperative chest tube (CT) management, which may impact postoperative length of stay (LOS). We used collaborative learning methods to determine whether centers could adapt and safely implement best practices for CT management, resulting in reduced postoperative CT duration and LOS. Methods and Results Nine pediatric heart centers partnered together through 2 learning networks. Patients undergoing 1 of 9 benchmark congenital heart operations were included. Baseline data were collected from June 2017 to June 2018, and intervention-phase data were collected from July 2018 to December 2019. Collaborative learning methods included review of best practices from a model center, regular data feedback, and quality improvement coaching. Center teams adapted CT removal practices (eg, timing, volume criteria) from the model center to their local resources, practices, and setting. Postoperative CT duration in hours and LOS in days were analyzed using statistical process control methodology. Overall, 2309 patients were included. Patient characteristics did not differ between the study and intervention phases. Statistical process control analysis showed an aggregate 15.6% decrease in geometric mean CT duration (72.6 hours at baseline to 61.3 hours during intervention) and a 9.8% reduction in geometric mean LOS (9.2 days at baseline to 8.3 days during intervention). Adverse events did not increase when comparing the baseline and intervention phases: CT replacement (1.8% versus 2.0%, P=0.56) and readmission for pleural effusion (0.4% versus 0.5%, P=0.29). Conclusions We successfully lowered postoperative CT duration and observed an associated reduction in LOS across 9 centers using collaborative learning methodology.

Updating an Empirically Based Tool for Analyzing Congenital Heart Surgery Mortality.

OBJECTIVES: STAT Mortality Categories (developed 2009) stratify congenital heart surgery procedures into groups of increasing mortality risk to characterize case mix of congenital heart surgery providers. This update of the STAT Mortality Score and Categories is empirically based for all procedures and reflects contemporary outcomes. METHODS: Cardiovascular surgical operations in the Society of Thoracic Surgeons Congenital Heart Surgery Database (January 1, 2010 - June 30, 2017) were analyzed. In this STAT 2020 Update of the STAT Mortality Score and Categories, the risk associated with a specific combination of procedures was estimated under the assumption that risk is determined by the highest risk individual component procedure. Operations composed of multiple component procedures were eligible for unique STAT Scores when the statistically estimated mortality risk differed from that of the highest risk component procedure. Bayesian modeling accounted for small denominators. Risk estimates were rescaled to STAT 2020 Scores between 0.1 and 5.0. STAT 2020 Category assignment was designed to minimize within-category variation and maximize between-category variation. RESULTS: Among 161,351 operations at 110 centers (19,090 distinct procedure combinations), 235 types of single or multiple component operations received unique STAT 2020 Scores. Assignment to Categories resulted in the following distribution: STAT 2020 Category 1 includes 59 procedure codes with model-based estimated mortality 0.2% to 1.3%; Category 2 includes 73 procedure codes with mortality estimates 1.4% to 2.9%; Category 3 includes 46 procedure codes with mortality estimates 3.0% to 6.8%; Category 4 includes 37 procedure codes with mortality estimates 6.9% to 13.0%; and Category 5 includes 17 procedure codes with mortality estimates 13.5% to 38.7%. The number of procedure codes with empirically derived Scores has grown by 58% (235 in STAT 2020 vs 148 in STAT 2009). Of the 148 procedure codes with empirically derived Scores in 2009, approximately one-half have changed STAT Category relative to 2009 metrics. The New STAT 2020 Scores and Categories demonstrated good discrimination for predicting mortality in an independent validation sample (July 1, 2017-June 30, 2019; sample size 46,933 operations at 108 centers) with C-statistic = 0.791 for STAT 2020 Score and 0.779 for STAT 2020 Category. CONCLUSIONS: The updated STAT metrics reflect contemporary practice and outcomes. New empirically based STAT 2020 Scores and Category designations are assigned to a larger set of procedure codes, while accounting for risk associated with multiple component operations. Updating STAT metrics based on contemporary outcomes facilitates accurate assessment of case mix.

Association between Z-score for birth weight and postoperative outcomes in neonates and infants with congenital heart disease.

OBJECTIVE: We hypothesized that infants with fetal growth restrictions have increased mortality and morbidity after congenital heart disease surgery. METHODS: The study included patients in The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2016) who underwent cardiac surgery at a corrected gestational age of ≤44 weeks. Patients were classified as severely (birth weight Z-score -4 to -2), moderately (Z-score -2 to -1), and mildly growth restricted (Z-score -1.0 to -0.5) and compared with a reference population (Z-score 0-0.5). Multivariable logistic regression clustering on center was used to evaluate the association of birth weight Z-score with operative mortality and postoperative complications and its interaction with gestational age was assessed. RESULTS: In 25,244 patients, operative mortality was 8.6% and major complications occurred in 19.4%. Compared with the reference group, the adjusted odds ratio (AOR) of mortality was increased in infants with severe (AOR, 2.4; 95% confidence interval [CI], 2.0-3.0), moderate (AOR, 1.7; 95% CI, 1.4-2.0), and mild growth restriction (AOR, 1.4; 95% CI, 1.2-1.6). The AOR for major postoperative complications was increased for severe (AOR, 1.4; 95% CI, 1.2-1.7) and moderate growth restriction (AOR, 1.2; 95% CI, 1.1-1.4). There was significant interaction between birth weight Z-score and gestational age (P = .007). CONCLUSIONS: Even birth weight Z-scores slightly below average are independent risk factors for mortality and morbidity in infants who undergo cardiac surgery. The strongest association between poor fetal growth and operative mortality exists in early-term infants. These novel findings might account for some of the previously unexplained variation in cardiac surgical outcomes.

Theoretical Model for Delivery of Congenital Heart Surgery in the United States.

BACKGROUND: Over 150 hospitals perform congenital heart surgery (CHS) in the United States. Many hospitals are close together, with a median patient travel distance of 38.5 miles. We began with a theoretical blank slate and used objective methodology guided by population density and volume thresholds to estimate the optimal number and locations of hospitals to provide CHS in the United States. METHODS: Guided by published data, we estimated the number of CHS operations in the United States in to be 32,500 per year. We distributed patients geographically based on population density. Metropolitan Statistical Areas (population centers and surrounding areas with close economic/social ties) were used as potential hospital locations. Patients were assigned to the closest hospital location such that all hospitals had a CHS volume of ≥300 operations. RESULTS: We estimated 57 hospitals could serve the contiguous United States. Median theoretical hospital volume after regionalization was 451 operations (interquartile range, 366-648). Median patient travel distance was 35.1 miles. Some patients (6396/31,895, 20%) traveled more than 100 miles. CONCLUSIONS: Our model suggests the United States could be served by approximately 100 fewer CHS hospitals than currently exist. With hospitals optimally placed, patient travel burden would decrease. This model serves as a platform to improve care delivery by regionalization of CHS.

Spillover of Early Extubation Practices From the Pediatric Heart Network Collaborative Learning Study.

OBJECTIVES: The Pediatric Heart Network Collaborative Learning Study used collaborative learning strategies to implement a clinical practice guideline that increased rates of early extubation after infant repair of tetralogy of Fallot and coarctation of the aorta. We assessed early extubation rates for infants undergoing cardiac surgeries not targeted by the clinical practice guideline to determine whether changes in extubation practices spilled over to care of other infants. DESIGN: Observational analyses of site's local Society of Thoracic Surgeons Congenital Heart Surgery Database and Pediatric Cardiac Critical Care Consortium Registry. SETTING: Four Pediatric Heart Network Collaborative Learning Study active-site hospitals. PATIENTS: Infants undergoing ventricular septal defect repair, atrioventricular septal defect repair, or superior cavopulmonary anastomosis (lower complexity), and arterial switch operation or isolated aortopulmonary shunt (higher complexity). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Aggregate outcomes were compared between the 12 month pre-clinical practice guideline and 12 months after study completion (Follow Up). In infants undergoing lower complexity surgeries, early extubation increased during Follow Up compared with Pre-Clinical Practice Guideline (30.2% vs 18.8%, p = 0.006), and hours to initial postoperative extubation decreased. We observed variation in these outcomes by surgery type, with only ventricular septal defect repair associated with a significant increase in early extubation during Follow Up compared with Pre-Clinical Practice Guideline (47% vs 26%, p = 0.006). Variation by study site was also seen, with only one hospital showing an increase in early extubation. In patients undergoing higher complexity surgeries, there was no difference in early extubation or hours to initial extubation between the study eras. CONCLUSIONS: We observed spillover of extubation practices promoted by the Collaborative Learning Study clinical practice guideline to lower complexity operations not included in the original study that was sustainable 1 year after study completion, though this effect differed across sites and operation subtypes. No changes in postoperative extubation outcomes following higher complexity surgeries were seen. The significant variation in outcomes by site suggests that center-specific factors may have influenced spillover of clinical practice guideline practices.