Seminal Postoperative Complications and Mode of Death After Pediatric Cardiac Surgical Procedures

BACKGROUND

Understanding the seminal complications leading to death after pediatric cardiac surgical procedures may provide opportunities to reduce mortality. This study analyzed all deaths at two pediatric cardiac surgical programs and developed a method to identify the seminal complications and modes of death.

METHODS

Trained nurses abstracted all cases of in-hospital mortality meeting inclusion criteria from each site over 5 years (2008 to 2012). Complication definitions were consistent with those of a multicenter clinical registry. An adjudication committee assigned a seminal complication in each case (the complication initiating the cascade of events leading to death). Seminal complications were grouped into categories to designate "mode of death." The epidemiology of seminal complications and of mode of death was described.

RESULTS

In 191 subjects, low cardiac output syndrome (71% of all subjects), cardiac arrest (52%), and arrhythmia (48%) were the most common complications. The committee assigned low cardiac output syndrome (30%), failure to separate from bypass (16%), and cardiac arrest (12%) most frequently as seminal complications. Seminal complications occurred a median 2 hours (interquartile range [IQR], 0 to 35 hours) postoperatively. Patients experienced a median of seven (IQR, 3 to 12) additional complications before death at a median of 15 days (IQR, 4 to 46). Systemic circulatory failure was the most common mode of death (51%), followed by inadequate pulmonary blood flow (13%) and cardiac arrest (12%).

CONCLUSIONS

Seminal complications occurred early postoperatively, and systemic circulatory failure was the most common mode of death. Our classification system is likely scalable for subsequent multicenter analysis to understand cause-specific mortality variation across hospitals and to drive quality improvement.

Congenital Heart Surgery Case Mix Across North American Centers and Impact on Performance Assessment

BACKGROUND

Performance assessment in congenital heart surgery is challenging due to the wide heterogeneity of disease. We describe current case mix across centers, evaluate methodology inclusive of all cardiac operations versus the more homogeneous subset of Society of Thoracic Surgeons benchmark operations, and describe implications regarding performance assessment.

METHODS

Centers (n = 119) participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2010 through 2014) were included. Index operation type and frequency across centers were described. Center performance (risk-adjusted operative mortality) was evaluated and classified when including the benchmark versus all eligible operations.

RESULTS

Overall, 207 types of operations were performed during the study period (112,140 total cases). Few operations were performed across all centers; only 25% were performed at least once by 75% or more of centers. There was 7.9-fold variation across centers in the proportion of total cases comprising high-complexity cases (STAT 5). In contrast, the benchmark operations made up 36% of cases, and all but 2 were performed by at least 90% of centers. When evaluating performance based on benchmark versus all operations, 15% of centers changed performance classification; 85% remained unchanged. Benchmark versus all operation methodology was associated with lower power, with 35% versus 78% of centers meeting sample size thresholds.

CONCLUSIONS

There is wide variation in congenital heart surgery case mix across centers. Metrics based on benchmark versus all operations are associated with strengths (less heterogeneity) and weaknesses (lower power), and lead to differing performance classification for some centers. These findings have implications for ongoing efforts to optimize performance assessment, including choice of target population and appropriate interpretation of reported metrics.

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%).

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.

Clinical Epidemiology of Extubation Failure in the Pediatric Cardiac ICU: A Report From the Pediatric Cardiac Critical Care Consortium

OBJECTIVE

To describe the clinical epidemiology of extubation failure in a multicenter cohort of patients treated in pediatric cardiac ICUs.

DESIGN

Retrospective cohort study using prospectively collected clinical registry data.

SETTING

Pediatric Cardiac Critical Care Consortium registry.

PATIENTS

All patients admitted to the CICU at Pediatric Cardiac Critical Care Consortium hospitals.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis of all mechanical ventilation episodes in the registry from October 1, 2013, to July 31, 2014. The primary outcome of extubation failure was reintubation less than 48 hours after planned extubation. Repeated-measures analysis using generalized estimating equations to account for within patient and center correlation was performed to identify risk factors for extubation failure. Adjusted extubation failure rates for each hospital were calculated using logistic regression controlling for patient factors. Of 1,734 mechanical ventilation episodes (1,478 patients at eight hospitals) ending in a planned extubation, there were 100 extubation failures (5.8%). In multivariable analysis, only longer duration of mechanical ventilation was significantly associated with extubation failure (p = 0.01); the failure rate was 4% when ventilated less than 24 hours, 9% after 24 hours, and 13% after 7 days. For 503 patients intubated and extubated in the cardiac operating room, 15 patients (3%) failed extubation within 48 hours (12 within 24 hr). Case-mix-adjusted extubation failure rates ranged from 1.1% to 9.8% across hospitals. Patients failing extubation had greater median cardiac ICU length of stay (15 vs 3 d; p < 0.001) and in-hospital mortality (7.9 vs 1.2%; p < 0.001).

CONCLUSIONS

Though extubation failure is uncommon overall, there may be opportunities to improve extubation readiness assessment in patients ventilated more than 24 hours. These data suggest that extubation in the operating room after cardiac surgery can be done with a low failure rate. We observed variation in extubation failure rates across hospitals, and future investigation must elucidate the optimal strategies of high-performing centers to reduce ventilation time while limiting extubation failures.

Estimating Mortality Risk for Adult Congenital Heart Surgery: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

BACKGROUND

Adjustment for case mix is critical to accurate outcomes analysis in congenital heart surgery. Established tools encompass all age groups and are not specific to the growing population of adults undergoing congenital heart operations. We derived an empirically based adult congenital heart surgery (ACHS) mortality score.

METHODS

In-hospital mortality was analyzed for the 152 most common procedures/procedural groups in adults 18 years of age and older in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) (2000-2013). Procedure-specific adult mortality rate estimates were calculated using Bayesian methods adjusting for small denominators for procedures with 30 cases or more (N = 52). Each procedural group was assigned an ACHS mortality score ranging from 0.1 to 3.0 based on the estimated mortality rate. Discrimination was assessed using the c-index in a separate validation sample.

RESULTS

A total of 12,513 procedures (116 centers) were analyzed. Overall unadjusted mortality was 1.8%. Significant differences in mortality rates in adults compared with all ages were seen for several procedures, including Ebstein's repair (0.7% versus 4.9%; p = 0.003) and Fontan operations (6.8% versus 1.4%; p < 0.01). The procedure with the lowest model-based estimate of mortality and accompanying ACHS mortality score was atrial septal defect repair (0.2%, 0.1), and the highest was Fontan revision (9.7%, 3.0). The c-index for the ACHS mortality score was 0.809 versus 0.777 for the "non-age-specific" Society of Thoracic Surgeons-European Association for Cardio-thoracic Surgery (STAT) mortality score applied to adults.

CONCLUSIONS

Risk estimation based on the aggregate of all age groups is suboptimal when analyzing outcomes specifically among adults. An empirically based ACHS mortality score can facilitate case-mix adjustment by providing accurate estimation of mortality risk for adults.

The Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model: Part 2-Clinical Application

BACKGROUND

The empirically derived 2014 Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model incorporates adjustment for procedure type and patient-specific factors. The purpose of this report is to describe this model and its application in the assessment of variation in outcomes across centers.

METHODS

All index cardiac operations in The Society of Thoracic Surgeons Congenital Heart Surgery Database (January 1, 2010, to December 31, 2013) were eligible for inclusion. Isolated patent ductus arteriosus closures in patients weighing less than or equal to 2.5 kg were excluded, as were centers with more than 10% missing data and patients with missing data for key variables. The model includes the following covariates: primary procedure, age, any prior cardiovascular operation, any noncardiac abnormality, any chromosomal abnormality or syndrome, important preoperative factors (mechanical circulatory support, shock persisting at time of operation, mechanical ventilation, renal failure requiring dialysis or renal dysfunction (or both), and neurological deficit), any other preoperative factor, prematurity (neonates and infants), and weight (neonates and infants). Variation across centers was assessed. Centers for which the 95% confidence interval for the observed-to-expected mortality ratio does not include unity are identified as lower-performing or higher-performing programs with respect to operative mortality.

RESULTS

Included were 52,224 operations from 86 centers. Overall discharge mortality was 3.7% (1,931 of 52,224). Discharge mortality by age category was neonates, 10.1% (1,129 of 11,144); infants, 3.0% (564 of 18,554), children, 0.9% (167 of 18,407), and adults, 1.7% (71 of 4,119). For all patients, 12 of 86 centers (14%) were lower-performing programs, 67 (78%) were not outliers, and 7 (8%) were higher-performing programs.

CONCLUSIONS

The 2014 Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model facilitates description of outcomes (mortality) adjusted for procedural and for patient-level factors. Identification of low-performing and high-performing programs may be useful in facilitating quality improvement efforts.

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.

Variation in Prenatal Diagnosis of Congenital Heart Disease in Infants

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 χ(2) 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.

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.

Contemporary Outcomes of Surgical Repair of Total Anomalous Pulmonary Venous Connection in Patients With Heterotaxy Syndrome

BACKGROUND

Total anomalous pulmonary venous connection (TAPVC) is prevalent in patients with atriovisceral heterotaxy. Although functionally univentricular heart defects are common in heterotaxy syndromes, the extent to which this association influences overall risk for TAPVC repair is undefined. This study examines multiinstitutional experience with TAPVC repair in infants with heterotaxy using a national clinical registry.

METHODS

The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) (2002-2012) was queried for patients with heterotaxy syndrome who underwent TAPVC repair, with or without concomitant procedures at age of 90 days or younger. The cohort was divided into single ventricle (SV) and non-single ventricle (non-SV) groups based on STS-CHSD codes. Patient characteristics and in-hospital outcomes were described.

RESULTS

Sixty-five centers reported 261 TAPVC repair operations (females, 115 [44%]; median [interquartile range] age and weight, 7 days [3-19 days] and 3.1 kg [2.7-3.5 kg]). Overall, 180 (69%) patients were identified with asplenia or right atrial isomerism, and 167 (64%) had SV diagnoses. Discharge mortality was 38%. Postoperatively, the median length of stay was 18 days (7-32 days), 20 (8%) patients required extracorporeal membrane oxygenation support, and 11 (4%) had reoperation for pulmonary vein stenosis. Mortality was higher for patients with SV defects (SV, 43% versus non-SV, 30%; p = 0.03). Length of stay, postoperative extracorporeal membrane oxygenation, and reoperation for pulmonary vein stenosis was similar between SV and non-SV groups. Overall, there was no difference in mortality for patients undergoing concomitant systemic-to-pulmonary artery shunt (p = 0.134) or surgery within 48 hours of birth (p = 0.876).

CONCLUSIONS

Total anomalous pulmonary venous connection repair in heterotaxy patients carries a high mortality risk, particularly with functionally univentricular physiology. These multiinstitutional data serve as an important benchmark and may be useful for risk stratification and counseling.

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.

Adverse cardiac events in children with Williams syndrome undergoing cardiovascular surgery: An analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database

OBJECTIVE

Patients with Williams syndrome (WS) undergoing cardiac surgery are at risk for major adverse cardiac events (MACE). Prevalence and risk factors for such events have not been well described. We sought to define frequency and risk of MACE in patients with WS using a multicenter clinical registry.

METHODS

We identified cardiac operations performed in patients with WS using the Society of Thoracic Surgeons Congenital Heart Surgery Database (2000-2012). Operations were divided into 4 groups: isolated supravalvular aortic stenosis, complex left ventricular outflow tract (LVOT), isolated right ventricular outflow tract (RVOT), and combined LVOT/RVOT procedures. The proportion of patients with MACE (in-hospital mortality, cardiac arrest, or postoperative mechanical circulatory support) was described and the association with preoperative factors was examined.

RESULTS

Of 447 index operations (87 centers), median (interquartile range) age and weight at surgery were 2.4 years (0.6-7.4 years) and 10.6 kg (6.5-21.5 kg), respectively. Mortality occurred in 20 patients (5%). MACE occurred in 41 patients (9%), most commonly after combined LVOT/RVOT (18 out of 87; 21%) and complex LVOT (12 out of 131; 9%) procedures, but not after isolated RVOT procedures. Odds of MACE decreased with age (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.98-0.99), weight (OR, 0.97; 95% CI, 0.93-0.99), but increased in the presence of any preoperative risk factor (OR, 2.08; 95% CI, 1.06-4.00), and in procedures involving coronary artery repair (OR, 5.37; 95% CI, 2.05-14.06).

CONCLUSIONS

In this multicenter analysis, MACE occurred in 9% of patients with WS undergoing cardiac surgery. Demographic and operative characteristics were associated with risk. Further study is needed to elucidate mechanisms of MACE in this high-risk population.

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.

Linking the congenital heart surgery databases of the Society of Thoracic Surgeons and the Congenital Heart Surgeons' Society: part 2--lessons learned and implications

PURPOSE

A link has been created between the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) and the Congenital Heart Surgeons' Society Database (CHSS-D). Five matrices have been created that facilitate the automated identification of patients who are potentially eligible for the five active CHSS studies using the STS-CHSD. These matrices are now used to (1) estimate the denominator of patients eligible for CHSS studies and (2) compare "eligible and enrolled patients" to "potentially eligible and not enrolled patients" to assess the generalizability of CHSS studies.

METHODS

The matrices were applied to 40 consenting institutions that participate in both the STS-CHSD and the CHSS to (1) estimate the denominator of patients that are potentially eligible for CHSS studies, (2) estimate the completeness of enrollment of patients eligible for CHSS studies among all CHSS sites, (3) estimate the completeness of enrollment of patients eligible for CHSS studies among those CHSS institutions participating in each CHSS cohort study, and (4) compare "eligible and enrolled patients" to "potentially eligible and not enrolled patients" to assess the generalizability of CHSS studies. The matrices were applied to all participants in the STS-CHSD to identify patients who underwent frequently performed operations and compare "eligible and enrolled patients" to "potentially eligible and not enrolled patients" in following five domains: (1) age at surgery, (2) gender, (3) race, (4) discharge mortality, and (5) postoperative length of stay. Completeness of enrollment was defined as the number of actually enrolled patients divided by the number of patients identified as being potentially eligible for enrollment.

RESULTS

For the CHSS Critical Left Ventricular Outflow Tract Study (LVOTO) study, for the Norwood procedure, completeness of enrollment at centers actively participating in the LVOTO study was 34%. For the Norwood operation, discharge mortality was 15% among 227 enrolled patients and 16% among 1768 nonenrolled potentially eligible patients from the 40 consenting institutions. Median postoperative length of stay was 31 days and 26 days for these enrolled and nonenrolled patients. For the CHSS anomalous aortic origin of a coronary artery (AAOCA) study, for AAOCA repair, completeness of enrollment at centers actively participating in the AAOCA study was 40%.

CONCLUSION

Determination of the denominator of patients eligible for CHSS studies and comparison of "eligible and enrolled patients" to "potentially eligible and not enrolled patients" provides an estimate of the extent to which patients in CHSS studies are representative of the overall population of eligible patients; however, opportunities exist to improve enrollment.

Survey of nongovernmental organizations providing pediatric cardiovascular care in low- and middle-income countries

BACKGROUND

Nearly 90% of the children with heart disease in low- and middle-income countries (LMICs) cannot access cardiovascular (CV) services. Limitations include inadequate financial, human, and infrastructure resources. Nongovernmental organizations (NGOs) have played crucial roles in providing clinical services and infrastructure supports to LMICs CV programs; however, these outreach efforts are dispersed, inadequate, and lack coordination.

METHODS

A survey was sent to members of the World Society for Pediatric and Congenital Heart Society and PediHeart.

RESULTS

A clearinghouse was created to provide information on NGO structures, geographic reach, and scope of services. The survey identified 80 NGOs supporting CV programs in 92 LMICs. The largest outreach efforts were in South and Central America (42%), followed by Africa (18%), Europe (17%), Asia (17%), and Asia-Western Pacific (6%). Most NGOs (51%) supported two to five outreach missions per year. The majority (87%) of NGOs provided education, diagnostics, and surgical or catheter-based interventions. Working jointly with LMIC partners, 59% of the NGOs performed operations in children and infants; 41% performed nonbypass neonatal operations. Approximately a quarter (26%) reported that partner sites do not perform interventions in between missions.

CONCLUSIONS

Disparity and inadequacy in pediatric CV services remain an important problem for LMICs. A global consensus and coordinated efforts are needed to guide strategies on the development of regional centers of excellence, a global outcome database, and a CV program registry. Future efforts should be held accountable for impacts such as growth in the number of independent LMIC programs as well as reduction in mortality and patient waiting lists.

Stage 1 hybrid palliation for hypoplastic left heart syndrome--assessment of contemporary patterns of use: an analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

OBJECTIVE

Hybrid palliation is an alternative to Norwood stage 1 for the initial management of hypoplastic left heart syndrome. Contemporary multicenter hybrid use and institutional/patient factors associated with hybrid use relative to the Norwood have not been evaluated. We describe hybrid use in relation to institutional volume, patient factors, and short-term outcomes.

METHODS

Infants aged 60 days or less listed in The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2012) undergoing initial palliation of hypoplastic left heart syndrome were included. Annual institutional hybrid use rates were calculated: [hybrid procedures/(Norwood + hybrid + transplant procedures)]. In-hospital outcomes for primary hybrid and primary Norwood were compared and stratified by high (defined as ≥50%) versus low (defined as ≤10%) institutional hybrid use.

RESULTS

Of 1728 patients (100 centers), most (n = 1496, 87%) underwent an index Norwood; 232 patients (13%) underwent an index hybrid procedure. Preoperative patient risk factors were more prevalent in patients undergoing the hybrid procedure. Only 13 of 100 institutions were high hybrid users, and these tended to have lower annual hypoplastic left heart syndrome index case volume. Unadjusted in-hospital mortality was higher for the hybrid compared with the Norwood procedure (30% vs 16%; P < .001). In-hospital mortality for the hybrid procedure was not associated with hybrid use (26% among institutions with low use vs 28% among institutions with high use). However, centers with high hybrid use had higher mortality after the Norwood (43%) compared with centers with low hybrid use (16%).

CONCLUSIONS

Few centers currently select the hybrid procedure for most infants with hypoplastic left heart syndrome. Although unadjusted in-hospital hybrid mortality is higher than Norwood mortality, potential risk factors are more prevalent among hybrid cases. Institutions with higher hybrid use have lower hypoplastic left heart syndrome case volume and higher Norwood mortality.

Variability in noncardiac surgical procedures in children with congenital heart disease

BACKGROUND

The purpose of this study was to examine the volume and variability of noncardiac surgeries performed in children with congenital heart disease (CHD) requiring cardiac surgery in the first year of life.

METHODS

Patients who underwent cardiac surgery by 1 year of age and had a minimum 5-year follow-up at 22 of the hospitals contributing to the Pediatric Health Information System database between 2004 and 2012 were included. Frequencies of noncardiac surgical procedures by age 5 years were determined and categorized by subspecialty. Patients were stratified according to their maximum RACHS-1 (Risk Adjustment in Congenital Heart Surgery) category. The proportions of patients across hospitals who had a noncardiac surgical procedure for each subspecialty were compared using logistic mixed effects models.

RESULTS

8857 patients underwent congenital heart surgery during the first year of life, 3621 (41%) of whom had 13,894 noncardiac surgical procedures by 5 years. Over half of all procedures were in general surgery (4432; 31.9%) or otolaryngology (4002; 28.8%). There was significant variation among hospitals in the proportion of CHD patients having noncardiac surgical procedures. Compared to children in the low risk group (RACHS-1 categories 1-3), children in the high-risk group (categories 4-6) were more likely to have general, dental, orthopedic, and thoracic procedures.

CONCLUSIONS

Children with CHD requiring cardiac surgery frequently also undergo noncardiac surgical procedures; however, considerable variability in the frequency of these procedures exists across hospitals. This suggests a lack of uniformity in indications used for surgical intervention. Further research should aim to better standardize care for this complex patient population.

Epidemiology and outcomes after in-hospital cardiac arrest after pediatric cardiac surgery

BACKGROUND

Multicenter data regarding cardiac arrest in children undergoing heart operations are limited. We describe epidemiology and outcomes associated with postoperative cardiac arrest in a large multiinstitutional cohort.

METHODS

Patients younger than 18 years in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2007 through 2012) were included. Patient factors, operative characteristics, and outcomes were described for patients with and without postoperative cardiac arrest. Multivariable models were used to evaluate the association of center volume with cardiac arrest rate and mortality after cardiac arrest, adjusting for patient and procedural factors.

RESULTS

Of 70,270 patients (97 centers), 1,843 (2.6%) had postoperative cardiac arrest. Younger age, lower weight, and presence of preoperative morbidities (all p < 0.0001) were associated with cardiac arrest. Arrest rate increased with procedural complexity across common benchmark operations, ranging from 0.7% (ventricular septal defect repair) to 12.7% (Norwood operation). Cardiac arrest was associated with significant mortality risk across procedures, ranging from 15.4% to 62.3% (all p < 0.0001). In multivariable analysis, arrest rate was not associated with center volume (odds ratio, 1.06; 95% confidence interval, 0.71 to 1.57 in low- versus high-volume centers). However, mortality after cardiac arrest was higher in low-volume centers (odds ratio, 2.00; 95% confidence interval, 1.52 to 2.63). This association was present for both high- and low-complexity operations.

CONCLUSIONS

Cardiac arrest carries a significant mortality risk across the stratum of procedural complexity. Although arrest rates are not associated with center volume, lower-volume centers have increased mortality after cardiac arrest. Further study of mechanisms to prevent cardiac arrest and to reduce mortality in those with an arrest is warranted.

The importance of patient-specific preoperative factors: an analysis of the society of thoracic surgeons congenital heart surgery database

BACKGROUND

The most common forms of risk adjustment for pediatric and congenital heart surgery used today are based mainly on the estimated risk of mortality of the primary procedure of the operation. The goals of this analysis were to assess the association of patient-specific preoperative factors with mortality and to determine which of these preoperative factors to include in future pediatric and congenital cardiac surgical risk models.

METHODS

All index cardiac operations in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) during 2010 through 2012 were eligible for inclusion. Patients weighing less than 2.5 kg undergoing patent ductus arteriosus closure were excluded. Centers with more than 10% missing data and patients with missing data for discharge mortality or other key variables were excluded. Rates of discharge mortality for patients with or without specific preoperative factors were assessed across age groups and were compared using Fisher's exact test.

RESULTS

In all, 25,476 operations were included (overall discharge mortality 3.7%, n=943). The prevalence of common preoperative factors and their associations with discharge mortality were determined. Associations of the following preoperative factors with discharge mortality were all highly significant (p<0.0001) for neonates, infants, and children: mechanical circulatory support, renal dysfunction, shock, and mechanical ventilation.

CONCLUSIONS

Current STS-CHSD risk adjustment is based on estimated risk of mortality of the primary procedure of the operation as well as age, weight, and prematurity. The inclusion of additional patient-specific preoperative factors in risk models for pediatric and congenital cardiac surgery could lead to increased precision in predicting risk of operative mortality and comparison of observed to expected outcomes.