Aristotle Comprehensive Complexity Score Research Articles

Comparison of risk stratification scoring system as a predictor of mortality and morbidity in congenital heart disease patients requiring surgery.

Risk stratification systems have been important in reducing morbidity and mortality among congenital heart disease (CHD) patients requiring cardiac surgery. Multiple risk stratification scoring systems have been developed, including Aristotle Basic Complexity Score (ABC), Aristotle Comprehensive Complexity Score (ACC), Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery (STS-EACTS), and Risk Adjustment in Congenital Heart Surgery (RACHS-1). This study aims to access the superior risk stratification scoring system model in predicting mortality and morbidity. The authors used Embase, PubMed, Scopus, and ProQuest as the primary databases for searching and included studies from hand searching. The area under the receiver operating characteristic curve was compared. A total of 11 articles were included in this review. The AUC of ABC for predicting mortality ranges from 0.59 to 0.71, and morbidity ranges from 0.673 to 0.743. The AUC of ACC score for predicting mortality ranges from 0.704 to 0.87, and a study revealed the AUC of morbidity is 0.730. The AUC of RACHS-1 for predicting mortality ranges from 0.68 to 0.782. The AUC of STS-EACTS for predicting mortality ranges from 0.739 to 0.8 and 0.732 for predicting morbidity. ABC, ACC, RACHS-1, and STS-EACTS have acceptable to excellent discriminatory ability in predicting mortality and morbidity among CHD patients requiring cardiac surgery.

Is the combination of conventional ultrafiltration and modified ultrafiltration superior to modified ultrafiltration in pediatric open-heart surgery?

ABSTRACT Background: Cardiopulmonary bypass (CPB) during open-heart surgery is associated with increased body fluids as a consequence of hemodilution due to the use of CPB. Ultrafiltration (UF) is a method used to decrease the body fluid volume on CPB. Aims and Objectives: This study aimed to compare the effects of combined conventional UF (CUF) and modified UF (MUF) versus MUF on the clinical outcomes of pediatric patients undergoing open-heart surgery for congenital heart disease. Materials and Methods: This was a prospective, single-center, randomized, and double-blinded clinical study that involved 74 pediatric patients undergoing open-heart surgery on CPB. Patient management was standardized. Preoperative Aristotle comprehensive complexity level, ultrafiltrate volumes, hematocrit, hemodynamic data, transesophageal echocardiographically (TEE) determined ejection fraction (EF), fractional area change (FAC), temperature drift, arterial oxygenation, time of extubation, ventilation, comparison of inotropic drugs, postoperative chest tube drainage, cardiac care unit (CCU), and hospital length of stay (LOS) were recorded in both groups. The analysis was conducted using SPSS-23.0, IBM, Armonk, NY, USA. Results: There was no mortality in both groups. Technical difficulties prevented the completion of MUF in two patients out of 37 in the CUF + MUF group. In this study, there were 43.26% of females and 56.75% of males, with a median age of 439 days, a mean weight of 9.98 kg, and an Aristotle Comprehensive Complexity score of level 2. Group CUF + MUF had a greater ultrafiltrate volume of 122 ± 39.7 ml (P = 0.036). The duration of ventilatory support was 11.2 ± 6.4 h versus 34.4 ± 5.7 h (P = 0.013), average CCU LOS was 4.3 ± 3.5 days versus 7.2 ± 3.6 days (P = 0.008), and chest tube drain in the first 48 h was 89.76 ± 34.82 ml versus 106.65 ± 47.29 ml (P = 0.029) in groups CUF + MUF and MUF, respectively. Inotropic infusion requirements were significantly lower in the CUF + MUF group compared to the MUF group. EF and FAC were 14% and 5% higher at 45 min in group CUF + MUF, respectively. Conclusions: The advantage of combining CUF and MUF over MUF is the significant improvement in the hemodynamic status of patients, which significantly decreases the duration of mechanical ventilation, average CCU LOS, inotrope requirements after surgery, and chest tube drain in the first 48 h.

First Harvest of Pediatric and Congenital Heart Surgery Multicenter Database in Turkey: Novel Application of Real-Time Online Reporting.

A new congenital heart surgery database (CKCV) with real-time online reporting function was recently developed in Turkey. All standard international parameters were used, but Aristotle Comprehensive Complexity score was modified. In this study, the first analysis of the CKCV Database is reported. The CKCV Database included 2307 procedures from 12 centers between January 2018 and March 2020. All parameters, including 10 real-time online reports, which represent the number of centers, number and mortality rates of all procedures, number of extracorporeal membrane oxygenation (ECMO) and results, details of postoperative complications, age-group statistics, analysis for priority status, mean intensive care and hospital stay durations of the procedures, results of Aristotle Basic, Modified Aristotle Comprehensive (MACC) and Society of Thoracic Surgeons-European Association (STAT) Score Categories, comparison of centers were analyzed. Most common 10 procedures were ventricular septal defect (VSD) repair (n = 273), tetralogy of Fallot (TOF) repair (n = 243), atrial septal defect (ASD) repair (n = 181), complete AVSD repair (n = 95), cavopulmonary anastomosis (n = 81), systemic to pulmonary shunt (n = 79), modified Fontan (n = 71), subaortic resection, (n = 66) PA banding (n = 66), and arterial switch operation (n = 66). Cardiopulmonary bypass was used in 84.6% of the procedures. Overall mortality rate was 6.0%. A total of 618 major and 570 minor complications were observed in 333 and 412 patients, respectively. According to six MACC categories, number of the patients and mortality rates were I (293; 0.3%); II (713; 1.4%); III (601; 3.3%); IV (607; 12%); V (84; 35.7%); and VI (9; 55.6%), respectively. Analysis of five STAT Categories showed 0.7, 3.8, 5.4, 14.9, and 54.7% mortality rates. CKCV Database has a great potential for nationwide quality improvement studies. Users could instantly analyze and compare their results to national and international aggregate data using a real-time online reporting function. This is the first multicenter congenital database study in Turkey.

Impacto sobre la función ventricular izquierda del cierre quirúrgico de ductus arterioso persistente en recién nacidos de menos de 1.500 g

Introduction and objectivesPatent ductus arteriosus (PDA) ligation in premature infants causes changes in the circulatory system that affects the immature myocardium of the patients. The objective of the study was to analyse the response of left ventricle to PDA ligation, according to pre-operative and post-operative echocardiograph parameters. MethodA retrospective analysis was performed on all patients (n=100) with less than 1500g birth weight undergoing PDA surgical ligation in this hospital during a five year period.Data were collected on the clinical characteristics, pre-operative medical management, echocardiography, surgical intervention, and in-hospital stay and Neonatal Intensive Care Unit (NICU) stay. The assessment of operative risk was made by calculating the Aristotle comprehensive complexity score (ACCS). The preoperative echocardiography data were obtained 24hours before the intervention and 24hours after surgery. Characteristics of the patent ductus arteriosus, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic dimension (LVEDD) were assessed. ResultsThe mean gestational age and birth weight was 26.1±1.8 weeks and 823.5±191.9g, respectively. The mean ACCS was 14.02±2.48 (range, 9 to 20). The median age at surgery was 15.5 days (IQR, 11 to 21). Nineteen patients (19%) died during admission. No echocardiography variable was significant in the univariate analysis for mortality.The pre-postoperative correlation for echocardiography values showed a significant decrease in post-intervention values for LVEF (P=.0001) and LVEDD (P=.001). The analysis by subgroups according to weight at the time of the intervention showed significant differences for LVEDD in patients with more than 820g (P=.002), but not in those of equal or less than 820g (P=.311). ConclusionsPreterm infants have a worse management of the volume overload produced by the DAP because of myocardial immaturity. The surgical closure of the DAP causes a decrease in the preload that in these patients is reflected in a worse adaptation to volume changes after surgery in direct relation with the weight at the time of the intervention. Patients with less weight at PDA surgical ligation were more likely to have a worse management to load changes after operation.

Bilateral Pulmonary Artery Banding before Norwood Procedure: Survival of High-Risk Patients

This study reports midterm results of high-risk patients with hypoplastic left ventricle treated with initial bilateral pulmonary artery banding (PAB) before secondary Norwood procedure (NP). Retrospective study of 17 patients admitted between July 2012 and February 2017 who underwent this treatment strategy because diagnosis or clinical status was associated with high risk for NP. Survival was compared with that of patients who underwent primary NP. Mean Aristotle comprehensive complexity score for NP would have been 19.7 ± 2.6. Risk factors included obstructed pulmonary venous return (n = 9), body weight < 2.5 kg (n = 7), total anomalous pulmonary venous connection (n = 3), and necrotizing enterocolitis (n = 1). Ten patients had a score ≥ 19.5. Early survival after PAB was 82.4% (14/17). NP was performed in 14 patients after improvement of clinical condition at a median age of 56 days and a weight ≥2,500 g. There was no 30-day mortality, but one interstage death. One patient died later after Glenn operation. One-year survival after primary PAB followed by NP was 70.6 ± 11.1%. During the same period, 35 patients with overall lower risk factors underwent primary NP; early postoperative survival and 1-year survival were 88.6 ± 5.4% and 68.6 ± 7.8%, respectively. There was no significant difference in survival between the two groups (p = 0.83) despite higher risk in the secondary Norwood group (p <0.0001). PAB before NP in high-risk patients constituted salvage management. Primary PAB provided enough time for stabilization and control of most risk factors. It allowed midterm survival equivalent to the survival after primary NP in lower risk neonates.

Analysis of congenital heart surgery results: A comparison of four risk scoring systems.

This study aims to evaluate the surgical results of our clinic according to presumption systems of Risk Adjustment in Congenital Heart Surgery, Aristotle Basic Complexity score, Aristotle Comprehensive Complexity score, and Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories and to compare the efficiency of these systems in predicting morbidity and mortality. In the study, classification and the risk scoring were performed with the four different systems for 1,950 patients (1,038 males, 912 females; mean age 5.5 months; range, 1 day to 18 years) who were administered congenital heart surgery between 1 October 2012 and 31 December 2016. The hospital mortality and morbidity were calculated for each category from the four models. The discriminatory ability of the models was determined by calculating the area under the receiver operating characteristic curve and the receiver operating characteristic curves of the four models were compared. Median weight of the patients was 7.2 kg (range, 1.8-80 kg). Among the patients, 53% were males and 47.5% were younger than one year of age. Of totally 1,950 operations, mortality was observed in 149 (7.6%) and morbidity was observed in 541 (27.7%). Areas under the receiver operating characteristic curve for mortality were 0.803, 0.795, 0.729, and 0.712 for the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories, Aristotle Comprehensive Complexity, Risk Adjustment in Congenital Heart Surgery, and Aristotle Basic Complexity scores, respectively. Areas under the receiver operating characteristic curve for morbidity were 0.732, 0.731, 0.730, and 0.685 for the Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories, Risk Adjustment in Congenital Heart Surgery, Aristotle Comprehensive Complexity, and Aristotle Basic Complexity scores, respectively. Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories, Risk Adjustment in Congenital Heart Surgery, Aristotle Basic Complexity, and Aristotle Comprehensive Complexity score systems were effective in predicting the morbidities and mortalities of patients who underwent congenital heart surgery and evaluating the performance of the surgical centers. Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery mortality categories were on the forefront due to high feasibility and performance. Aristotle Basic Complexity score system had the lowest performance. Combinations of systems will provide the most benefit during evaluation of results.

Escala de riesgo Aristóteles como factor predictor de mortalidad en el cierre quirúrgico de persistencia de ductus arterioso en prematuros

Introduction and objectivesPatent ductus arteriosus is a very common diagnosis in pre-term infants. Surgical closure is a therapeutic option. An attempt is made to identify pre-operative risk factors for mortality, and the usefulness of the Aristotle score to predict mortality. MethodA retrospective analysis was conducted on all patients under 1500g birth weight undergoing surgical closure at our hospital between January 2008 and December 2013. Perioperative data were collected, and a logistic regression model was used for analysis. ResultsOf the 100 patients reviewed, 59 were male infants, and the mean gestational age and birth weight was 26.1±1.8 weeks and 823.5±191.9g, respectively. The mean Aristotle Comprehensive Complexity Score was 14.02±2.48. The median age at surgery was 15.5 days, and 19 (19%) patients died while in hospital.In the multivariate analysis for mortality, patients with a higher Aristotle Comprehensive Complexity Score (OR 2.8 (95% confidence interval, 1.73-4.59); P=.0001) had a higher mortality. Among the risk factors, the Aristotle Comprehensive Complexity Score showed the largest area under curve (0.904) in the receiver-operating curve analysis. The group with a greater than or equal to 15 score had a higher risk of mortality. ConclusionsMortality associated with surgical closure of patent ductus arteriosus is related to prematurity status of the patient not to surgery itself. Aristotle Comprehensive Complexity Score is the most useful independent predictor of mortality. The patient group with greater than or equal to 15 score had an increased risk of in-hospital mortality. In this selected sub-group, a conservative treatment might be the best option.

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

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. 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. 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.

Retuning mortality risk prediction in paediatric cardiac surgery: the additional role of early postoperative metabolic and respiratory profile.

The existing risk stratification scores for paediatric patients undergoing cardiac surgery include the Aristotle Basic Complexity (ABC) Score, the Risk Adjustment in Congenital Heart Surgery-1 (RACHS-1) Score and the Aristotle Comprehensive Complexity (ACC) Score. They are all based on the nature of the surgical operation (ABC and RACHS-1 Scores) with possible adjustment for a number of patient conditions (ACC Score). The present study investigates if the early postoperative parameters may be used to improve the preoperative mortality risk prediction. A retrospective study on 1392 consecutive patients aged ≤12 years old, undergoing cardiac surgery with cardiopulmonary bypass and without a residual right-to-left shunt was conducted. The ABC Score and metabolic and respiratory postoperative parameters at arrival in the intensive care unit were tested for association and discriminative power for operative mortality. The ABC yielded a c-statistic of 0.746. Additional independent predictors of operative mortality were postoperative hypoxia [Formula: see text] and arterial blood lactates. In a multivariable model including the ABC Score, postoperative hypoxia and arterial blood lactates remained independently associated with operative mortality. A modified ABC Score was created, consisting of the ABC Score plus 1.5 points in case of postoperative hypoxia plus 1 point per each 1 mmol/l of arterial blood lactates. The new model was significantly (P = 0.043) more discriminative than the ABC Score, with a c-statistic of 0.803. Early postoperative respiratory and metabolic parameters increased the accuracy and discrimination of the ABC Score. An external validation is needed to confirm our results.

Comparison of risk scoring systems in congenital heart surgery

Hacettepe University Faculty of Medicine Department of Cardiovascular Surgery; data of 413 patients under 18 years old who had congenital heart surgery were evaluated between 01.01.2011-30.10.2012 and risk scorings were made by "RACHS-1 (Risk Adjustment in Congenital Heart Surgery)", "Aristotle Basic Complexity Score (ABS)" and "Aristotle Comprehensive Complexity Score (ACS)" systems used in evaluation of the risk of mortality and morbidity in (ACS)" systems used in evaluation of the risk of mortality and morbidity in congenital heart surgery. Data obtained were compared by Mann-Whitney U test and how effective these systems were in evaluating mortality and morbidity and their superiorities over each other were examined. Following the research, it was observed that all three systems were effective in evaluating mortality and morbidity; the most successful of them in foreseeing the event was the ACS system, ACS system was followed by RACHS-1 system and ABS system was the most incapable of these in foreseeing the event. It was seen that in detecting time related mortality, rating of these tests changed, RACHS-1 system detected the time related mortality best. It was also seen that with RACHS-1 system, a previously evaluated concept, it was possible to determine morbidity.

Common arterial trunk: current implementation of the primary and staged repair strategies.

In this study, we report our experience on the primary and staged surgical approaches for common arterial trunk (CAT) repair. Between August 2003 and February 2015, 16 consecutive patients underwent CAT repair in our institution. Two different approaches have been followed: group 'primary repair' (PR) consists of patients suitable for straightforward CAT repair, who underwent surgery electively at 1-3 months of age (n = 13); group 'staged repair' (SR) consists of critically ill neonates with CAT and poor preoperative status or coexisting interrupted aortic arch (n = 3). They underwent staged CAT repair with aortic arch repair and right ventricular-to-pulmonary artery (RV-PA) shunt within the neonatal period, followed by an intracardiac repair later in infancy. Median age at initial surgical treatment was 8 days (range: 7-21 days) in group SR and 34 days (range: 14-91 days) in group PR (P = 0.03). Mean Aristotle Comprehensive Complexity score was 11 ± 0.6 (range: 11-13) in group PR and 18 ± 3.1 (range: 15-21) in group SR (P < 0.01). Follow-up was completed with a median duration of 3.6 years (range: 8 months to 11 years). There was neither early nor late mortality in both groups. In group SR, the median interval to second stage surgery was 216 days (range: 216-260 days). Seven patients (54%) in group PR required reoperation for RV-PA conduit failure (n = 4), truncal valve repair/replacement (n = 2) or both (n = 1). After initial surgery, Kaplan-Meier freedom from reoperation after 1, 2 and 8 years was 77 ± 12, 68 ± 13 and 20 ± 17% in group PR, and 0% in group SR (log-rank P < 0.01). Although all patients in group SR required reoperation to complete the anatomical correction (second stage procedure), there was no surgical reintervention of truncal valve and aortic arch thereafter. Routine elective CAT repair could be safely performed at 1-3 months of age. However, neonatal CAT repair could be associated with a higher mortality especially in the presence of an interrupted aortic arch. In such cases, a staged CAT repair seems to be associated with favourable postoperative course and improved hospital survival, despite the inevitable need for reoperation, which can be performed at a relatively low risk.

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.

Negative pressure therapy for post-sternotomy wound infections in young children

Post-sternotomy wound infection remains a significant morbidity in congenital and paediatric cardiac surgery. However, the techniques used for this complication in children are not optimal in terms of mortality, morbidity and the use of medical resources. Negative pressure therapy is an effective modality in the treatment in adults, but reports of its use in children are limited. This study evaluated the use of negative pressure therapy in young children for post-sternotomy wound infections. From October 2004 to June 2012, 15 consecutive cases of post-sternotomy wound infections in patients ≤6 years of age were managed with negative pressure therapy, and these patients were followed up for ≥12 months after wound closure. The median Aristotle comprehensive complexity score was 9.9 ± 4.0. The infection was identified at a median of 16 days after surgery, and the procedure was performed within 24 h of diagnosis. No additional surgical procedures were applied. No cases of hospital mortality or second surgery for infection control occurred. The median duration until wound closure was 25 days (range: 5-92 days). Further, no patient showed sternal instability at treatment termination. During the mean follow-up period of 45.8 ± 31.3 months after wound closure, no admission occurred for infection recurrence. According to a multivariable analysis, the infection depth and patient weight significantly lengthened treatment duration (P = 0.008 and 0.046, respectively). Negative pressure therapy is an effective treatment modality for wound infections in paediatric cardiac surgery and results in low morbidity, mortality and medical resource use.

The Aristotle Score Predicts Mortality After Surgery of Patent Ductus Arteriosus in Preterm Infants

Outcomes after surgical ligation of patent ductus arteriosus (PDA) in preterm infants are often complicated by prematurity associated comorbidities. The Aristotle comprehensive complexity score (ACCS) has been proposed as a useful tool for complexity adjustment in the analysis of outcome after congenital heart surgery. The aims of this study were to define preoperative risk factors for mortality and to demonstrate the usefulness of ACCS to predict mortality after surgical ligation of PDA in the preterm. Included were 49 preterm babies (≤35 weeks of gestation) who had surgical ligation of PDA between May 2009 and July 2012. Median gestational age was 27.6 weeks (range, 23 to 35 weeks) and median birth weight was 1,040 g (range, 520 to 2,280 g). Median age at operation was 15 days (range, 4 to 44 days) and median weight was 1,120 g (range, 400 to 2,880 g). Initial oral ibuprofen was ineffective in 24 patients and contraindicated in 25. All surgical ligations were done at bedside in the neonatal intensive care unit. Preoperative clinical and laboratory profiles were reviewed and ACCS was derived. Eight of 49 patients (16.3%) died at a median of 14 days (range, 2 to 73 days) after PDA ligation. Patients who had contraindications for oral ibuprofen (odds ratio [OR] 8.94; p=0.049), coagulopathy (OR 12.13; p=0.025), renal dysfunction (OR 28.88; p=0.003), intraventricular hemorrhage greater than grade II or seizure (OR 34.00; p=0.002), and ACCS points (OR 29.594; p<0.05) were significantly associated with an increased risk for mortality. Among the risk factors, ACCS showed the largest area under curve (0.991) by receiver-operating characteristic curve analysis. Optimal cutoff value of ACCS for mortality were 15 or greater, with sensitivity of 87.5%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 97.6%. The ACCS, especially for procedure-independent complexity factors, is a useful tool to predict mortality after ligation of PDA in preterm infants.

Editorial Comment: Re: Evaluation of the Aristotle complexity models in adult patients with congenital heart disease

With an increasing number of adult congenital heart (GUCH) surgery patients, a suitable risk stratification model should be available for outcome evaluation, but it would tend to be incomplete due to the very heterogeneous and often complex patient groups with multiple measured as well as unmeasured risk factors. The paper by Horer et al .[ 1] contained valuable data concerning the procedural factors associated with early death and the complications following GUCH surgery. In addition to identifying the associations between early death and procedural factors, the authors looked for associations between items contained within the Aristotle comprehensive complexity (ACC) score. They commented that some of the items in the ACC ‘did not achieve statistical significance’ in terms of an association with early death, putting this down to the low prevalence of these factors within the dataset or to the small number of deaths. However, the lack of inclusion of complex patients who were not offered high-risk surgical options might skew the analysis. A third possibility is the lack of an association between all items in the ACC (developed primarily for paediatric cardiac patients) and early death in adult patients. Having found that the ACC score had a fairly good discrimination in the GUCH patient population, the authors discussed the appropriateness of the ACC for predicting outcome. Some care is required here. The authors talked of predictive accuracy, but no assessment of the accuracy of ACC was presented. To be very clear, discrimination (the extent to which a model can discern between low-risk and high-risk cases) is not a measure of predictive accuracy for individual patients or patient sub-groups. As we may remember, the Aristotle score was not created to predict mortality [2]. The score would give an average value of mortality for a given paediatric cardiac procedure which every centre or surgeon could use for performance evaluation. The authors also commented on the potential utility of adding diagnostic information such as ‘univentricular status’ to augment procedural information in risk stratification schemes such as the ACC. We certainly see the value in this and have recently completed an analysis of the UK Central Cardiac Audit Database (CCAD) to develop a risk model for paediatric cardiac surgery that incorporates such information on diagnosis [3]. In risk modelling for paediatric cardiac surgery, the trend is towards systems based on the analysis of data rather than expert opinion [4]. Nevertheless, the authors’ vision of their work stimulating the collection and publication of larger series of data is one we fully endorse.

Evaluation of the Aristotle complexity models in adult patients with congenital heart disease†

The adult congenital heart disease (CHD) population has surpassed the paediatric CHD population. Half of all mortality caused by CHD occurs in adulthood; in some patients, it occurs during surgery. We sought to assess the potential risk factors for adverse outcome after cardiac operations in adults with CHD, and to evaluate the predictive power of the Aristotle score models for hospital mortality. Procedure-dependent and independent factors, as well as the outcome factors of all consecutive patients aged 16 or more who underwent surgery for CHD between 2005 and 2008 at our institution were evaluated according to the European Association for Cardio-Thoracic Surgery Congenital Database nomenclature. An Aristotle basic complexity (ABC) and an Aristotle comprehensive complexity (ACC) score were assigned to each operation. The discriminatory power of the scores was assessed using the area under the receiver operating characteristics (AuROC) curve. During 542 operations, 773 procedures were performed. The early mortality rate was 2.4%, and the early complication rate was 53.7%. Tricuspid valve replacement (P = 0.009), mitral valve replacement (P < 0.001), elevated lung resistances (P = 0.002), hypothyroidism (P = 0.002) and redosternotomy (P = 0.003) emerged as risk factors for 30-day mortality. Tricuspid valve replacement (P < 0.001), tricuspid valvuloplasty (P = 0.006), mitral valve replacement (P = 0.003), shunt implantation (P = 0.009), surgical ablation (P = 0.024), myocardial dysfunction (P = 0.014), elevated lung resistances (P = 0.004), hypothyroidism (P = 0.002) and redosternotomy (P < 0.001) emerged as risk factors for complications. Mean ABC and ACC scores were 6.6 ± 2.3, and 9.0 ± 3.7, respectively. The AuROCs of the ABC and the ACC scores for 30-day mortality were 0.663 (P = 0.044), and 0.755 (P = 0.002), respectively. The AuROCs of the ABC and the ACC scores for complications were 0.634 (P < 0.001), and 0.670 (P < 0.001), respectively. Surgery for adults with CHD can be performed with low early mortality. However, complications are frequent, especially in patients who require repeat operations for atrioventricular valve incompetence. The ACC score may be helpful to estimate the risk of early mortality.

A morbidity score for congenital heart surgery based on observed complications

The aim of this study was to develop a morbidity score based on observed postoperative complications after congenital heart surgery. Conditions or diseases that impair patients after congenital heart surgery or increase costs of hospital stay were called complications and attributed to scores ranging from 1 (mild) to 4 (severe) points, according to estimated severity or costliness. 'No complication' was assigned 0.5 points. From January to March 2011, scores for each observed 'complication' for every main (primary) surgical procedure were recorded and a morbidity score was calculated. In conformity with the Aristotle score methodology, if the sum of observed complication scores amounted to more than 5 points, a morbidity score of only 5 points was attributed. The estimated morbidity score was compared with the morbidity score attributed by the Aristotle basic complexity (ABC) score. One hundred and thirty-nine primary procedures were carried out. The mean ABC and Aristotle comprehensive complexity scores reached 8.31 ± 2.52 and 9.62 ± 3.47 points, respectively. Two patients died. No complication was detected after 46 procedures. Overall, there were 185 listed 'morbidity' conditions in connection with the other 93 surgical procedures, rendering a total score of 385 points. The most frequent event was 'mechanical ventilation 25-95 h': n = 39. The mean morbidity score was 2.14 ± 1.63. The morbidity scores ranged from 0.5 points (n = 46) to 5 points (n = 23) with a median of 2.0 points. The scores for 11 different procedures that were performed at least five times positively correlated with the corresponding Aristotle morbidity scores: Pearson's coefficient r = 0.75. But the morbidity score for bidirectional cavopulmonary anastomosis (3.14 ± 1.77) was higher than the corresponding Aristotle morbidity score (2.0). It was lower for 'conduit placement, right ventricle to pulmonary artery': 1.08 ± 0.97, versus 2.0, and for arterial switch operation: 2.08 ± 1.11, versus 3.0. The reported morbidity scores need to be tested on larger series and in different institutions. The introduced morbidity score has the potential to quantify postoperative complications accurately. Its estimation over time can facilitate the assessment of quality of congenital heart surgery. It will allow comparison of morbidity outcomes across institutions with different case-mixes.

Invited Commentary

Congenital heart surgery is currently performed with an operative mortality of 4% or less at many if not most centers in developed countries. Evaluation of the quality of outcomes for survivors (96% plus) is becoming increasingly important. Every procedure has associated morbidity. It ranges from minor inconvenience to prolonged hospitalization with major complications, suffering, and permanent disability. Some would say that death is the ultimate morbidity. An important economic aspect of this issue is resource utilization produced by increased morbidity. The article by Bojan and colleagues [1Bojan M. Gerelli S. Gioanni S. Pouard P. Vouhé P. Evaluation of a new tool for morbidity assessment in congenital cardiac Surgery.Ann Thorac Surg. 2011; 92: 2200-2205Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar] compares the Aristotle Comprehensive Complexity Score (ACCS), the only rating system that includes morbidity, with actual outcomes previously suggested by our group. Both complications and resources used are applied to develop a morbidity index from a single institutional experience over 27 months. The correlation with ACCS was relatively high for all measurements examined. Because there was no incidence of renal failure requiring chronic dialysis, the correlation of the ACCS with the requirement for temporary dialysis was analyzed and found to be very high. It is suggested that this complication be included in the evaluation of morbidity. When ACCS was developed, the amount of available outcome data was limited. Therefore a group of congenital heart surgeons devised the scores using subjective probability, basically expert opinion. The goal moving forward is to revise the scores using actual outcome data. The mortality portion has been addressed at the procedure level [2O'Brien S.M. Clarke D.R. Jacobs J.P. et al.An empirically based tool for analyzing mortality associated with congenital heart surgery.J Thorac Cardiovasc Surg. 2009; 138: 1139-1153Abstract Full Text Full Text PDF PubMed Scopus (475) Google Scholar]. Hopefully the more difficult job of revising the morbidity portion will soon be accomplished. In the future, modification of the comprehensive score is desired so that individual patient factors are considered. This will require an enormous amount of data. In addition, as the specialty evolves further modifications will be needed. Perhaps software can be developed that will use The Society of Thoracic Surgeons/European Association for Cardio-Thoracic Surgery (STS/EACTS) databases to automatically update the scores as additional data are accumulated. Evaluation of a New Tool for Morbidity Assessment in Congenital Cardiac SurgeryThe Annals of Thoracic SurgeryVol. 92Issue 6PreviewTo 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. Full-Text PDF

Invited Commentary

Invited Commentary

Persistent Institutional Difficulties in Surgery for Transposition of the Great Arteries in Guatemala: Analysis With the Aristotle Basic and Comprehensive Scores

Background. Neonates with complex congenital cardiac lesions are largely inadequately managed in Guatemala. Methods. Between 1997 and 2009, 79 patients who underwent operations for transposition of the great arteries were identified; 51 (63.3%) had an arterial switch operation (ASO) and 28 (36%) an atrial switch operation (ATSO). The Aristotle Basic Complexity score (ABC score) and the Aristotle Comprehensive Complexity score (ACC score) have been used to aid in the evaluation of quality of care associated with pediatric cardiac surgery by adjusting for operative complexity. Results. In-hospital mortality was 47% for the ASO and 25% for the ATSO group; 36.7% were beyond 1 month of age and many exhibited increased preoperative risk factors. The mean ABC score was 9.75 ± 0.89 and the ACC score was 12.12 ± 2.7, with a mean 2.36-point increase (P < .05). Comparing survivors and nonsurvivors with both scores, significant differences were identified (ABC: P < .04 and ACC: P < .02). Conclusion. During this 13-year period, a low volume of surgery for transposition of the great arteries (TGA) was performed at our institution with a relatively high surgical mortality. Many patients with TGA in Guatemala are either never referred for surgery or referred late. Strategies to improve outcomes for neonates with TGA in Guatemala must include increases in early diagnosis countrywide and prompt referral to our unit. Based on the larger number of neonates with TGA that would be referred to our center, we anticipate that this strategy should substantially improve surgical outcomes and favor overall team-related skills.