The Aristotle Comprehensive Complexity Score Predicts Mortality and Morbidity After Congenital Heart Surgery

Enhancing the Classification of Congenital Heart Defects for Outcome Association Studies in Birth Defects Registries

INTRODUCTION

Traditional strategies for grouping congenital heart defects (CHDs) using birth defect registry data do not adequately address differences in expected clinical consequences between different combinations of CHDs. We report a lesion-specific classification system for birth defect registry-based outcome studies.

METHODS

For Core Cardiac Lesion Outcome Classifications (C-CLOC) groups, common CHDs expected to have reasonable clinical homogeneity were defined. Criteria based on combinations of Centers for Disease and Control-modified British Pediatric Association (BPA) codes were defined for each C-CLOC group. To demonstrate proof of concept and retention of reasonable case counts within C-CLOC groups, Texas Birth Defect Registry data (1999-2017 deliveries) were used to compare case counts and neonatal mortality between traditional vs. C-CLOC classification approaches.

RESULTS

C-CLOC defined 59 CHD groups among 62,262 infants with CHDs. Classifying cases into the single, mutually exclusive C-CLOC group reflecting the highest complexity CHD present reduced case counts among lower complexity lesions (e.g., 86.5% of cases with a common atrium BPA code were reclassified to a higher complexity group for a co-occurring CHD). As expected, C-CLOC groups had retained larger sample sizes (i.e., representing presumably better-powered analytic groups) compared to cases with only one CHD code and no occurring CHDs.

DISCUSSION

This new CHD classification system for investigators using birth defect registry data, C-CLOC, is expected to balance clinical outcome homogeneity in analytic groups while maintaining sufficiently large case counts within categories, thus improving power for CHD-specific outcome association comparisons. Future outcome studies utilizing C-CLOC-based classifications are planned.

Outcomes of Prophylactic Peritoneal Dialysis Catheter Insertion in Children Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

The objective of this Prospective Register of Systematic Reviews (CRD42022384192) registered systematic review and meta-analysis was to determine whether prophylactic peritoneal dialysis (PD) catheter insertion at the time of pediatric cardiac surgery is associated with improved short-term outcomes.

DATA SOURCES

Databases search of the MEDLINE, EMBASE, CINAHL, and Cochrane Library completed in April 2021 and updated October 2023.

STUDY SELECTION

Two reviewers independently completed study selection, data extraction, and bias assessment. Inclusion criteria were randomized controlled trials (RCTs) and observational studies of children (≤ 18 yr) undergoing cardiac surgery with cardiopulmonary bypass. We evaluated use of prophylactic PD catheter versus not.

DATA EXTRACTION

The primary outcome was in-hospital mortality, as well as secondary short-term outcomes. Pooled random-effect meta-analysis odds ratio with 95% CI are reported.

DATA SYNTHESIS

Seventeen studies met inclusion criteria, including four RCTs. The non-PD catheter group received supportive care that included diuretics and late placement of PD catheters in the ICU. Most study populations included children younger than 1 year and weight less than 10 kg. Cardiac surgery was most commonly used for arterial switch operation. In-hospital mortality was reported in 13 studies; pooled analysis showed no association between prophylactic PD catheter placement and in-hospital mortality. There were mixed results for ICU length of stay and time to negative fluid balance, with some studies showing shortened duration associated with use of prophylactic PD catheter insertion and others showing no difference. Overall, the studies had high risk for bias, mainly due to small sample size and lack of generalizability.

CONCLUSIONS

In this meta-analysis, we have failed to demonstrate an association between prophylactic PD catheter insertion in children and infants undergoing cardiac surgery and reduced in-hospital mortality. Other relevant short-term outcomes, including markers of fluid overload, require further study.

Second harvest of Congenital Heart Surgery Database in Türkiye: Current outcomes

Background

This second harvest of the Congenital Heart Surgery Database intended to compare current results with international databases.

Methods

This retrospective study examined a total of 4007 congenital heart surgery procedures from 15 centers in the Congenital Heart Surgery Database between January 2018 and January 2023. International diagnostic and procedural codes were used for data entry. STAT (Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery) mortality scores and categories were used for comparison of the data. Surgical priority status was modified from American Society of Anesthesiologist guidelines. Centers that sent more than 5 cases to the database were included to the study.

Results

Cardiopulmonary bypass and cardioplegic arrest were performed in 2,983 (74.4%) procedures. General risk factors were present in 22.6% of the patients, such as genetic anomaly, syndrome, or prematurity. Overall, 18.9% of the patients had preoperative risk factors (e.g., mechanical ventilation, renal failure, and sepsis). Of the procedures, 610 (15.2%) were performed on neonates, 1,450 (36.2%) on infants, 1,803 (45%) on children, and 144 (3.6%) on adults. The operative timing was elective in 56.5% of the patients, 34.4% were urgent, 8% were emergent, and 1.1% were rescue procedures. Extracorporeal membrane oxygenation support was used in 163 (4%) patients, with a 34.3% survival rate. Overall mortality in this series was 6.7% (n=271). Risk for mortality was higher in patients with general risk factors, such as prematurity, low birth weight neonates, and heterotaxy syndrome. Mortality for patients with preoperative mechanical ventilation was 17.5%. Pulmonary hypertension and preoperative circulatory shock had 11.6% and 10% mortality rates, respectively. Mortality for patients who had no preoperative risk factor was 3.9%. Neonates had the highest mortality rate (20.5%). Intensive care unit and hospital stay time for neonates (median of 17.8 days and 24.8 days, respectively) were also higher than the other age groups. Infants had 6.2% mortality. Hospital mortality was 2.8% for children and 3.5% for adults. Mortality rate was 2.8% for elective cases. Observed mortality rates were higher than expected in the fourth and fifth categories of the STAT system (observed, 14.8% and 51.9%; expected, 9.9% and 23.1%; respectively).

Conclusion

For the first time, outcomes of congenital heart surgery in Türkiye could be compared to the current world experience with this multicenter database study. Increased mortality rate of neonatal and complex heart operations could be delineated as areas that need improvement. The Congenital Heart Surgery Database has great potential for quality improvement of congenital heart surgery in Türkiye. In the long term, participation of more centers in the database may allow more accurate risk adjustment.

Predicting the risk of infant mortality for newborns operated for congenital heart defects: A population-based cohort (EPICARD) study of two post-operative predictive scores

BACKGROUND

Whereas no global severity score exists for congenital heart defects (CHD), risk (Risk Adjusted Cardiac Heart Surgery-1: RACHS-1) and/or complexity (Aristotle Basic Complexity: ABC) scores have been developed for those who undergo surgery. Population-based studies for assessing the predictive ability of these scores are lacking.

OBJECTIVE

To assess the predictive ability of RACHS-1 and ABC scores for the risk of infant mortality using population-based cohort (EPICARD) data for newborns with structural CHD.

METHODS

The study population comprised 443 newborns who underwent curative surgery. We assessed the predictive ability of each score alone and in conjunction with an a priori selected set of predictors of infant mortality. Statistical analysis included logistic regression models for which we computed model calibration, discrimination (ROC), and a rarely used but clinically meaningful measure of variance explained (Tjur's coefficient of discrimination).

RESULTS

The risk of mortality increased with increasing RACHS-1 and the ABC scores and models based on both scores had adequate calibration. Model discrimination was higher for the RACHS-1-based model (ROC 0.68, 95% CI, 0.58-0.79) than the ABC-based one (ROC 0.59, 95% CI, 0.49-0.69), P = 0.03. Neither score had the good predictive ability when this was assessed using Tjur's coefficient.

CONCLUSIONS

Even if the RACHS-1 score had better predictive ability, both scores had low predictive ability using a variance-explained measure. Because of this limitation and the fact that neither score can be used for newborns with CHD who do not undergo surgery, it is important to develop new predictive models that comprise all newborns with structural CHD.

Adverse Outcomes Prediction for Congenital Heart Surgery: A Machine Learning Approach

OBJECTIVE

Risk assessment tools typically used in congenital heart surgery (CHS) assume that various possible risk factors interact in a linear and additive fashion, an assumption that may not reflect reality. Using artificial intelligence techniques, we sought to develop nonlinear models for predicting outcomes in CHS.

METHODS

We built machine learning (ML) models to predict mortality, postoperative mechanical ventilatory support time (MVST), and hospital length of stay (LOS) for patients who underwent CHS, based on data of more than 235,000 patients and 295,000 operations provided by the European Congenital Heart Surgeons Association Congenital Database. We used optimal classification trees (OCTs) methodology for its interpretability and accuracy, and compared to logistic regression and state-of-the-art ML methods (Random Forests, Gradient Boosting), reporting their area under the curve (AUC or c-statistic) for both training and testing data sets.

RESULTS

Optimal classification trees achieve outstanding performance across all three models (mortality AUC = 0.86, prolonged MVST AUC = 0.85, prolonged LOS AUC = 0.82), while being intuitively interpretable. The most significant predictors of mortality are procedure, age, and weight, followed by days since previous admission and any general preoperative patient risk factors.

CONCLUSIONS

The nonlinear ML-based models of OCTs are intuitively interpretable and provide superior predictive power. The associated risk calculator allows easy, accurate, and understandable estimation of individual patient risks, in the theoretical framework of the average performance of all centers represented in the database. This methodology has the potential to facilitate decision-making and resource optimization in CHS, enabling total quality management and precise benchmarking initiatives.

Family-Centered Care at Pediatric Cardiac Intensive Care Units in Germany and the Relationship With Parent and Infant Well-Being: A Study Protocol

Rationale and Aim: Infants with Congenital Heart Disease (CHD) are at risk for neurodevelopmental delays, emotional, social and behavioral difficulties. Hospitalization early in life and associated stressors may contribute to these challenges. Family-centered Care (FCC) is a health care approach that is respectful of and responsive to the needs and values of a family and has shown to be effective in improving health outcomes of premature infants, as well as the mental well-being of their parents. However, there is limited empirical data available on FCC practices in pediatric cardiology and associations with parent and infant outcomes. Methods and Analysis: In this cross-sectional study, we will explore FCC practices at two pediatric cardiac intensive care units in Germany, assess parent satisfaction with FCC, and investigate associations with parental mental well-being and parenting stress, as well as infant physical and mental well-being. We will collect data of 280 infants with CHD and their families. Data will be analyzed using multivariate statistics and multilevel modeling. Implications and Dissemination: The study protocol was approved by the medical ethics committees of both partner sites and registered with the German registry for clinical trials (NR DRKS00023964). This study serves as a first step to investigate FCC practices in a pediatric cardiology setting, providing insight into the relationship between FCC and parent and infant outcomes in a population of infants with CHD. Results will be disseminated in peer-reviewed journals.

Preoperative miRNA-208a as a Predictor of Postoperative Complications in Children with Congenital Heart Disease Undergoing Heart Surgery

Major perioperative cardiovascular events are important causes of morbidity in pediatric patients with congenital heart disease who undergo reparative surgery. Current preoperative clinical risk assessment strategies have poor accuracy for identifying patients who will sustain adverse events following heart surgery. There is an ongoing need to integrate clinical variables with novel technology and biomarkers to accurately predict outcome following pediatric heart surgery. We tested whether preoperative levels of miRNAs-208a can serve as such a biomarker. Serum samples were obtained from pediatric patients immediately before heart surgery. MiRNA-208a was quantified by RQ-PCR. Correlations between the patient's clinical variables and miRNA levels were tested. Lower levels of preoperative miRNA-208a correlated with and could predict the appearance of postoperative cardiac and inflammatory complications. MiRNA-208a may serve as a biomarker for the prediction of patients who are at risk to develop complications following surgery for the repair of congenital heart defects.

Risk stratification models for congenital heart surgery in children: Comparative single-center study

OBJECTIVE

Three scores have been proposed to stratify the risk of mortality for each cardiac surgical procedure: The RACHS-1, the Aristotle Basic Complexity (ABC), and the STS-EACTS complexity scoring model. The aim was to compare the ability to predict mortality and morbidity of the three scores applied to a specific population.

DESIGN

Retrospective, descriptive study.

SETTING

Pediatric and neonatal intensive care units in a referral hospital.

PATIENTS

Children under 18 years admitted to the intensive care unit after surgery.

INTERVENTIONS

None.

OUTCOME MEASURES

Demographic, clinical, and surgical data were assessed. Morbidity was considered as prolonged length of stay (LOS > 75 percentile), high respiratory (>72 hours of mechanical ventilation), and high hemodynamic support (inotropic support >20).

RESULTS

One thousand and thirty-seven patients were included, in which 205 were newborns (18%). The category 2 was the most frequent in the three scores: In RACHS-1, ABC, 44.9%, and STS-EACTS, 40.8%. Newborns presented significant higher categories. Children required cardiopulmonary bypass in more occasions (P < .001) but the times of bypass and aortic cross-clamp were significantly higher in newborns (P < .001 and P = .016). Thirty-two patients died (2.8%). A quarter of patients had a prolonged LOS, 17%, a high respiratory support, and 7.1%, a high hemodynamic support. RACHS-1 (AUC 0.760) and STS-EACTS (AUC 0.763) were more powerful for predicting mortality and STS-EACTS for predicting prolonged LOS (AUC 0.733) and the need for high respiratory support (AUC 0.742).

CONCLUSIONS

STS-EACTS seems to stratify better risk of mortality, prolonged LOS, and need for respiratory support after surgery.

Intravenous morphine versus intravenous paracetamol after cardiac surgery in neonates and infants: a study protocol for a randomized controlled trial

BACKGROUND

Morphine is worldwide the analgesic of first choice after cardiac surgery in children. Morphine has unwanted hemodynamic and respiratory side effects. Therefore, post-cardiac surgery patients may potentially benefit from a non-opioid drug for pain relief. A previous study has shown that intravenous (IV) paracetamol is effective and opioid-sparing in children after major non-cardiac surgery. The aim of the study is to test the hypothesis that intermittent IV paracetamol administration in children after cardiac surgery will result in a reduction of at least 30% of the cumulative morphine requirement.

METHODS

This is a prospective, multi-center, randomized controlled trial at four level-3 pediatric intensive care units (ICUs) in the Netherlands and Belgium. Children who are 0-36 months old will be randomly assigned to receive either intermittent IV paracetamol or continuous IV morphine up to 48 h post-operatively. Morphine will be available as rescue medication for both groups. Validated pain and sedation assessment tools will be used to monitor patients. The sample size (n = 208, 104 per arm) was calculated in order to detect a 30% reduction in morphine dose; two-sided significance level was 5% and power was 95%.

DISCUSSION

This study will focus on the reduction, or replacement, of morphine by IV paracetamol in children (0-36 months old) after cardiac surgery. The results of this study will form the basis of a new pain management algorithm and will be implemented at the participating ICUs, resulting in an evidence-based guideline on post-operative pain after cardiac surgery in infants who are 0-36 months old.

TRIAL REGISTRATION

Dutch Trial Registry ( www.trialregister.nl ): NTR5448 on September 1, 2015. Institutional review board approval (MEC2015-646), current protocol version: July 3, 2017.

Cardiac surgery in adults with high-surgical complexity CHD: results of a network collaborative programme

BACKGROUND

Adults with CHD often exhibit complex cardiac abnormalities, whose management requires specific clinical and surgical expertise. To enable easier access of these patients to highly specialised care, we implemented a collaborative programme that incorporates medical and surgical specialists belonging to both paediatric and adult cardiovascular institutions.

OBJECTIVES

The objective of this study was to review the experience gained and to analyse the surgical outcome of major cardiac surgery.

METHODS

We retrospectively reviewed all consecutive patients admitted for major cardiac surgery using our network between January, 2010 and December, 2013. Analysis of surgical outcome was performed in patients selected for major cardiac surgery with cardiopulmonary bypass. Early and late outcomes were evaluated.

RESULTS

Out of a total of 433 inward patients, 86 were selected for surgery. The median age was 25.5 years, -64 patients (74.4%) had previously undergone heart surgery, and -55 patients (64%) had been subjected to at least one sternotomy. Abnormalities of the left ventricular and right ventricular outflow tract were the most frequent (37.2% and 30.2%, respectively), and despite high-surgical complexity only one death occurred (in-hospital mortality 1.1%). On a median follow-up time of 4 years no deaths and no heart-failure events have occurred; one patient underwent further cardiac surgery programmed at the time of discharge.

CONCLUSIONS

Low mortality and morbidity rates can be obtained in high-surgical complexity adults with CHD populations when paediatric and adult cardiac specialists operate in the same multidisciplinary environment.

Clinical feasibility of pre-operative neurodevelopmental assessment of infants undergoing open heart surgery

AIM

Assessing the neurodevelopmental status of infants with congenital heart disease before surgery provides a means of identifying those at heightened risk of developmental delay. This study aimed to investigate factors impacting clinical feasibility of pre-operative neurodevelopmental assessment of infants undergoing early open heart surgery.

METHODS

Infants who underwent open heart surgery prior to 4 months of age participated in this cross-sectional study. The Test of Infant Motor Performance and Prechtl's Assessment of General Movements were undertaken on infants pre-operatively. When assessments could not be undertaken, reasons were ascribed to either infant or environmental circumstances. Demographic data and Aristotle scores were compared between groups of infants who did or did not undergo assessment. Binary logistic regression was used to explore associations.

RESULTS

A total of 60 infants participated in the study. Median gestational age was 38.78 weeks (interquartile range: 36.93-39.72). Of these infants, 37 (62%) were unable to undergo pre-operative assessment. Twenty-four (40%) could not complete assessment due to infant-related factors and 13 (22%) due to environmental-related factors. For every point increase in the Aristotle Patient-Adjusted Complexity score, the infants likelihood of being unable to undergo assessment increased by 35% (odds ratio: 0.35; 95% confidence interval: 1.03-1.77, P = 0.03).

CONCLUSION

Over half of the infants undergoing open heart surgery were unable to complete pre-operative neurodevelopmental assessment. The primary reason for this was infant-related medical instability. Findings suggest further research is warranted to investigate whether the Aristotle Patient-Adjusted Complexity score might serve as an indicator to inform developmental surveillance with this medically fragile cohort.

Impact of Viral Respiratory Pathogens on Outcomes After Pediatric Cardiac Surgery

OBJECTIVES

Viral respiratory infection is commonly considered a relative contraindication to elective cardiac surgery. We aimed to determine the frequency and outcomes of symptomatic viral respiratory infection in pediatric cardiac surgical patients.

DESIGN

Retrospective cohort study of children undergoing cardiac surgery. Symptomatic children were tested using a multiplex Polymerase Chain Reaction (respiratory virus polymerase chain reaction) panel capturing nine respiratory viruses. Tests performed between 72 prior to and 48 hours after PICU admission were included. Mortality, length of stay in PICU, and intubation duration were investigated as outcomes.

SETTING

Tertiary PICU providing state-wide pediatric cardiac services.

PATIENTS

Children less than 18 years admitted January 1, 2008 to November 29, 2014 for cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Respiratory virus polymerase chain reaction was positive in 73 (4.2%) of 1,737 pediatric cardiac surgical admissions, including 13 children with multiple viruses detected. Commonly detected viruses included rhino/enterovirus (48%), adenovirus (32%), parainfluenza virus 3 (10%), and respiratory syncytial virus (3%). Pediatric Index of Mortality 2, Aristotle scores, and cardiopulmonary bypass times were similar between virus positive and negative/untested cohorts. Respiratory virus polymerase chain reaction positive patients had a median 2.0 days greater PICU length of stay (p < 0.001) and longer intubation duration (p < 0.001). Multivariate analysis adjusting for age, Aristotle score, cardiopulmonary bypass duration, and need for preoperative PICU admission confirmed that virus positive patients had significantly greater intubation duration and PICU length of stay (p < 0.001). Virus positive patients were more likely to require PICU admission greater than 4 days (odds ratio, 3.5; 95% CI, 1.9-6.2) and more likely to require intubation greater than 48 hours (odds ratio, 2.5; 95% CI, 1.4-4.7). There was no difference in mortality. No association was found between coinfection and outcomes.

CONCLUSIONS

Pediatric cardiac surgical patients with a respiratory virus detected at PICU admission had prolonged postoperative recovery with increased length of stay and duration of intubation. Our results suggest that postponing cardiac surgery in children with symptomatic viral respiratory infection is appropriate, unless the benefits of early surgery outweigh the risk of prolonged ventilation and PICU stay.

Mortality Following Congenital Heart Surgery in Adults Can Be Predicted Accurately by Combining Expert-Based and Evidence-Based Pediatric Risk Scores

Objectives:

Currently, there are few specific risk stratification models available to predict mortality following congenital heart surgery in adults. We sought to evaluate whether the predictive power of the common pediatric scores is applicable for adults. In addition, we evaluated a new grown-ups with congenital heart disease (GUCH) score specifically designed for adults undergoing congenital heart surgery.

Methods and Results:

Data of all consecutive patients aged 18 years or more, who underwent surgery for congenital heart disease (CHD) between 2004 and 2013 at our institution, were collected. We evaluated the Aristotle Basic Complexity (ABC), the Aristotle Comprehensive Complexity (ACC), the Risk Adjustment in Congenital Heart Surgery (RACHS-1), and the Society of Thoracic Surgeons (STS)–European Association for Cardiothoracic Surgery (EACTS) scores. The proposed GUCH score consists of the STS-EACTS score, the procedure-dependent and -independent factors of the ACC score, and age. The discriminatory power of the scores was assessed using the area under the receiver–operating characteristics curve (c-index). A total of 830 operations were evaluated. Hospital mortality was 2.9%. C-indexes were 0.67, 0.80, 0.62, 0.78, and 0.84 for the ABC, ACC, RACHS-1, STS-EACTS, and GUCH mortality scores, respectively.

Conclusion:

The evidence-based EACTS-STS score outperforms the expert-based ABC score. The expert-based ACC score is superior to the evidence-based EACTS-STS score since comorbidities are considered. Our proposed GUCH score outperforms all other scores since it integrates the advantages of the evidence-based EACTS-STS score for procedures and the expert-based ACC score for comorbidities. Evidence-based scores for adults with CHD should include comorbidities and patient ages.

Weight-for-age standard score - distribution and effect on in-hospital mortality: A retrospective analysis in pediatric cardiac surgery

OBJECTIVE

To study the distribution of weight for age standard score (Z score) in pediatric cardiac surgery and its effect on in-hospital mortality.

INTRODUCTION

WHO recommends Standard Score (Z score) to quantify and describe anthropometric data. The distribution of weight for age Z score and its effect on mortality in congenital heart surgery has not been studied.

METHODS

All patients of younger than 5 years who underwent cardiac surgery from July 2007 to June 2013, under single surgical unit at our institute were enrolled. Z score for weight for age was calculated. Patients were classified according to Z score and mortality across the classes was compared. Discrimination and calibration of the for Z score model was assessed. Improvement in predictability of mortality after addition of Z score to Aristotle Comprehensive Complexity (ACC) score was analyzed.

RESULTS

The median Z score was -3.2 (Interquartile range -4.24 to -1.91] with weight (mean±SD) of 8.4 ± 3.38 kg. Overall mortality was 11.5%. 71% and 52.59% of patients had Z score < -2 and < -3 respectively. Lower Z score classes were associated with progressively increasing mortality. Z score as continuous variable was associated with O.R. of 0.622 (95% CI- 0.527 to 0.733, P < 0.0001) for in-hospital mortality and remained significant predictor even after adjusting for age, gender, bypass duration and ACC score. Addition of Z score to ACC score improved its predictability for in-hosptial mortality (δC - 0.0661 [95% CI - 0.017 to 0.0595, P = 0.0169], IDI- 3.83% [95% CI - 0.017 to 0.0595, P = 0.00042]).

CONCLUSION

Z scores were lower in our cohort and were associated with in-hospital mortality. Addition of Z score to ACC score significantly improves predictive ability for in-hospital mortality.

The RACHS-1 risk category can be a predictor of perioperative recovery in Asian pediatric cardiac surgery patients

PURPOSE

The Risk Adjustment for Congenital Heart Surgery (RACHS-1) classification was originally designed to facilitate the prediction of in-hospital mortality for pediatric cardiac surgery patients. However, there have been few reports on clinical outcomes predicted by the RACHS-1 category, especially in an Asian population. The aim of this study was to determine whether RACHS-1 classification can predict patient outcomes.

METHODS

A total of 580 pediatric cardiac surgery procedures performed from January 2005 to December 2009 were retrospectively classified into the six RACHS-1 categories. The association between RACHS-1 category and clinical outcomes, including length of catecholamine requirement, mechanical ventilation time, intensive care unit stay, and in-hospital mortality, were examined.

RESULTS

The frequencies of RACHS-1 categories in the study population were: category 1, 10.7 %; category 2, 36.7 %; category 3, 42.8 %; category 4, 6.6 %; category 5, 0.0 %; category 6, 3.3 %. There was a significant linear correlation between RACHS-1 category and in-hospital mortality (r = 0.96, p < 0.001). Kaplan-Meier analysis demonstrated that length of catecholamine infusion, mechanical ventilation time, and ICU stay were significantly different (p < 0.05) in the different RACHS-1 categories, except for those between category 4 and 6 (p = 0.09).

CONCLUSIONS

Based on the results of our analysis, we conclude that the RACHS-1 stratification system can predict in-hospital mortality and patient outcomes in patients undergoing pediatric cardiac surgery.

The impact of gestational age on resource utilization after open heart surgery for congenital cardiac disease from birth to 1 year of age

The impact of gestational age on perioperative morbidity was examined using a novel construct, the resource utilization index (RUI). The medical records of subjects from birth to 1 year of age entered into a pediatric cardiothoracic surgery database from a major academic medical center between 2007 and 2011 were reviewed. The hypothesis tested was that infants born at 37-38 weeks (early-term infants) experience greater resource utilization after open heart surgery than those born at 39 completed weeks and that this association can be observed until 1 year of age. The results support the premise that resource utilization increases linearly with declining gestational age among infants at 0-12 months who undergo cardiac surgery. Five of the six variables comprising the RUI showed statistically significant linear associations with gestational age in the predicted direction. Multivariate linear regression analysis showed that gestational age was a significant predictor of an increased RUI composite. Further investigation is needed to test the concept and to expand on these findings.

Evaluation of a new tool for morbidity assessment in congenital cardiac surgery

BACKGROUND

To date, no instrument to assess morbidity in congenital cardiac surgery has been validated. In the Aristotle system, morbidity is accounted for by a subjective assessment of length of intensive care unit stay. A previously published Morbidity Index (MI), still in development, has been derived from objective data. The present study aims to assess the feasibility and utility of the MI at a single institution and its association with the Aristotle Comprehensive Complexity (ACC) score.

METHODS

Patients undergoing congenital cardiac surgery at our institution were enrolled retrospectively. The MI was calculated from the nonweighted sum of its components. The ability of the ACC to predict the components was estimated.

RESULTS

The MI increased more than length of stay across procedures with increasing complexity. Renal failure requiring long-term dialysis was not observed. A requirement for temporary dialysis, which is not an MI component, correlated well with the MI (r = 0.51, p < 0.001). The ACC was a good predictor for most components of the MI: length of intensive care unit stay 3 days or more, time to extubation, postoperative extracorporeal assistance, and, for temporary dialysis, with areas under the receiver operating characteristics curve of 0.67 (0.65, 0.70), 0.71 (0.68, 0.74) , 0.84 (0.75, 0.91), and 0.83 (0.77, 0.87) respectively.

CONCLUSIONS

Implementation of the MI in the Aristotle system will improve prediction of complications and long lengths of stay, making it a better morbidity indicator than length of intensive care unit stay. Requirement for temporary dialysis may be considered as an MI component.

Surgical management of congenital heart disease: contribution of the Aristotle complexity score to planning and budgeting in the German diagnosis-related groups system

Planning and budgeting for congenital heart surgery depend primarily on how closely reimbursement matches costs and on the number and complexity of the surgical procedures. Aristotle complexity scores for the year 2010 were correlated with hospital costs and with reimbursement according to the German diagnosis-related groups (DRG) system. Unit surgical performance was estimated as surgical performance (complexity score × hospital survival) times the number of primary procedures. This study investigated how this performance evolved during years 2006 to 2010. Hospital costs and reimbursements correlated highly with Aristotle comprehensive complexity levels (Spearman r = 1). Mean costs and reimbursement reached 35,050<euro> ± 32,665<euro> and 31,283<euro> ± 34,732<euro>, respectively, for an underfunding of 10.7%. Basic and comprehensive unit surgical performances were respectively 3036 ± 1009 and 3891 ± 1591 points in 2006. Both performances increased in sigmoid fashion to reach 3883 ± 1344 and 5335 ± 1314 points, respectively, in 2010. Top performances would be achieved in year 2011, and extrapolated costs would comprise about 19,434,094.92<euro> (95% confidence interval, 11,961,491.22-22,495,764.42<euro>). The current underfunding of congenital heart surgery needs correction. The Aristotle score can help to adjust reimbursement according to complexity of procedures. Unit surgical performance allows accurate budgeting in the current German DRG system.