Constantine Mavroudis

An empirically based tool for analyzing mortality associated with congenital heart surgery

OBJECTIVE Analysis of congenital heart surgery results requires a reliable method of estimating the risk of adverse outcomes. Two major systems in current use are based on projections of risk or complexity that were predominantly subjectively derived. Our goal was to create an objective, empirically based index that can be used to identify the statistically estimated risk of in-hospital mortality by procedure and to group procedures into risk categories. METHODS Mortality risk was estimated for 148 types of operative procedures using data from 77,294 operations entered into the European Association for Cardiothoracic Surgery (EACTS) Congenital Heart Surgery Database (33,360 operations) and the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (43,934 patients) between 2002 and 2007. Procedure-specific mortality rate estimates were calculated using a Bayesian model that adjusted for small denominators. Each procedure was assigned a numeric score (the STS-EACTS Congenital Heart Surgery Mortality Score [2009]) ranging from 0.1 to 5.0 based on the estimated mortality rate. Procedures were also sorted by increasing risk and grouped into 5 categories (the STS-EACTS Congenital Heart Surgery Mortality Categories [2009]) that were chosen to be optimal with respect to minimizing within-category variation and maximizing between-category variation. Model performance was subsequently assessed in an independent validation sample (n = 27,700) and compared with 2 existing methods: Risk Adjustment for Congenital Heart Surgery (RACHS-1) categories and Aristotle Basis Complexity scores. RESULTS Estimated mortality rates ranged across procedure types from 0.3% (atrial septal defect repair with patch) to 29.8% (truncus plus interrupted aortic arch repair). The proposed STS-EACTS score and STS-EACTS categories demonstrated good discrimination for predicting mortality in the validation sample (C-index = 0.784 and 0.773, respectively). For procedures with more than 40 occurrences, the Pearson correlation coefficient between a procedures STS-EACTS score and its actual mortality rate in the validation sample was 0.80. In the subset of procedures for which RACHS-1 and Aristotle Basic Complexity scores are defined, discrimination was highest for the STS-EACTS score (C-index = 0.787), followed by STS-EACTS categories (C-index = 0.778), RACHS-1 categories (C-index = 0.745), and Aristotle Basic Complexity scores (C-index = 0.687). When patient covariates were added to each model, the C-index improved: STS-EACTS score (C-index = 0.816), STS-EACTS categories (C-index = 0.812), RACHS-1 categories (C-index = 0.802), and Aristotle Basic Complexity scores (C-index = 0.795). CONCLUSION The proposed risk scores and categories have a high degree of discrimination for predicting mortality and represent an improvement over existing consensus-based methods. Risk models incorporating these measures may be used to compare mortality outcomes across institutions with differing case mixes.

Fontan Conversion To Cavopulmonary Connection And Arrhythmia Circuit Cryoablation

OBJECTIVES We review our surgical experience patients with atriopulmonary Fontan operations who had obstructive or arrhythmia indications for conversion to total cavopulmonary artery connections, arrhythmia circuit cryoablation, and placement of atrial antitachycardia pacemaker. METHODS Fourteen patients (mean age 14 +/- 4 years) had conversion to total cavopulmonary artery connection 8 +/- 3 years after the original atriopulmonary Fontan operation primarily for atrial arrhythmias in 11, obstructive lesions in 2, and bradycardia with cyanosis in 1. Arrhythmia circuit cryoablation was performed on 11 patients and 10 had atrial antitachycardia pacemakers. Preoperative functional New York Heart Association class was IV in 9, III in 4, and II in 1. RESULTS One patient had brain death (7%) presumably caused by resternotomy complications despite an excellent hemodynamic result. Another required reoperation for a maldeployed clamshell device after attempted fenestration closure. Average length of stay was 10 +/- 3 days; chest tubes were removed on day 7 +/- 3. There were no long-term deaths (mean follow-up 1.7 years, range 5 months to 5 years). Postoperative arrhythmias occurred in five patients, three of whom had successful termination by antitachycardia pacemaker and two who had pharmacologic control of their respective junctional ectopic and slow atrial tachycardia. All patients have improved to New York Heart Association class I or II. CONCLUSIONS Total cavopulmonary artery conversion in association with arrhythmia circuit cryoablation and atrial antitachycardia pacemaker placement can be accomplished with low morbidity and mortality, oftentimes resulting in dramatic increases in functional class and control of life-threatening arrhythmias.

Contemporary Patterns of Management of Tetralogy of Fallot: Data From The Society of Thoracic Surgeons Database

BACKGROUND The Society of Thoracic Surgeons Database was queried to ascertain current trends in management of tetralogy of Fallot (TOF) and to determine the prevalence of various surgical techniques. METHODS The study population (n = 3059 operations) was all index operations in 2002-2007, age 0-18 years with Primary Diagnosis of TOF, and Primary Procedure TOF repair or palliation. Patients with Pulmonary Atresia, Absent Pulmonary Valve, and Atrioventricular Canal were excluded. RESULTS 294 patients had initial palliation, including 178 neonates. 2534 patients had repair of TOF as the initial operation (primary repair), including 154 neonates. 217 patients had repair of TOF after prior palliation. Of patients who had primary repair (n = 2534), 975 had repair at 3 to 6 months, 614 at 6 months to 1 year, 492 at 1 to 3 months, and 154 at 0 to 30 days. Of patients who had repair following prior palliation (n = 217), 65 had repair in the first 6 months of life, 111 at 6 months to 1 year, and only 41 (18.9%) at more than 1 year of age. Type of repair: Of 2534 primary repairs, 581 (23%) had no ventriculotomy, 571 (23%) had nontransanular patch, 1329 (52%) had transanular patch, and 53 (2%) had right ventricle to pulmonary artery conduits. Of repairs after prior palliation (n = 217), 20 (9%) had no ventriculotomy, 30 (14%) had nontransanular patch, 144 (66%) had transanular patch, and 24 (11%) had conduits. Discharge mortality (95% confidence interval; CI) was 22 of 294 (7.5%; CI: 4.7%-11.1%) for initial palliation, 33 of 2534 (1.3%; CI: 0.9%-1.8%) for primary repair, and 2 of 217 (0.9%; CI: 0.1%-3.3%) for secondary repair. For neonates, discharge mortality was 11 of 178 (6.2%; CI: 3.1%-10.8%) for palliation and 12 of 154 (7.8%; CI: 4.1%-13.2%) for primary repair. CONCLUSIONS Primary repair in the first year of life is the most prevalent strategy. Despite contemporary awareness of the late consequences of pulmonary insufficiency, ventriculotomy with transanular patch remains the most prevalent technique, both for primary repair and for repair following palliation.

Variation in Outcomes for Benchmark Operations: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

BACKGROUND We evaluated outcomes for common operations in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSDB) to provide contemporary benchmarks and examine variation between centers. METHODS Patients undergoing surgery from 2005 to 2009 were included. Centers with greater than 10% missing data were excluded. Discharge mortality and postoperative length of stay (PLOS) among patients discharged alive were calculated for 8 benchmark operations of varying complexity. Power for analyzing between-center variation in outcome was determined for each operation. Variation was evaluated using funnel plots and Bayesian hierarchical modeling. RESULTS Eighteen thousand three hundred seventy-five index operations at 74 centers were included in the analysis of 8 benchmark operations. Overall discharge mortality was: ventricular septal defect (VSD) repair = 0.6% (range, 0% to 5.1%), tetralogy of Fallot (TOF) repair = 1.1% (range, 0% to 16.7%), complete atrioventricular canal repair (AVC) = 2.2% (range, 0% to 20%), arterial switch operation (ASO) = 2.9% (range, 0% to 50%), ASO + VSD = 7.0% (range, 0% to 100%), Fontan operation = 1.3% (range, 0% to 9.1%), truncus arteriosus repair = 10.9% (0% to 100%), and Norwood procedure = 19.3% (range, 0% to 100%). Funnel plots revealed that the number of centers characterized as outliers were VSD = 0, TOF = 0, AVC = 1, ASO = 3, ASO + VSD = 1, Fontan operation = 0, truncus arteriosus repair = 4, and Norwood procedure = 11. Power calculations showed that statistically meaningful comparisons of mortality rates between centers could be made only for the Norwood procedure, for which the Bayesian-estimated range (95% probability interval) after risk-adjustment was 7.0% (3.7% to 10.3%) to 41.6% (30.6% to 57.2%). Between-center variation in PLOS was analyzed for all operations and was larger for more complex operations. CONCLUSIONS This analysis documents contemporary benchmarks for common pediatric cardiac surgical operations and the range of outcomes among centers. Variation was most prominent for the more complex operations. These data may aid in quality assessment and quality improvement initiatives.

Congenital Heart Surgery Nomenclature and Database Project: overview and minimum dataset

The International Congenital Heart Surgery Nomenclature and Database Project was organized for the purpose of standardizing nomenclature and reporting strategies that would establish the foundations for an international database. Worldwide representatives met for a series of conferences, at which time, issues of nomenclature were discussed and debated. Authors were chosen to review the various congenital heart diagnoses and reflect the mediated debate that followed. Manuscripts were prepared that reviewed the appropriate extant nomenclature, made recommendations for an inclusive rather than an exclusive method of reporting, and determined a hierarchical database scheme that would allow several levels of reporting based on the data input. This manuscript outlines two datasets for an international congenital heart surgery database, a minimum dataset and a comprehensive dataset. The comprehensive dataset includes all the imagined variables, in a hierarchical scheme, which are detailed enough to generate risk stratification analyses. The minimum dataset will include data points that would create an essential dataset, which would be mandatory for data sharing and would lend itself to basic interpretation of trends. The minimum dataset has four drop-down menus for short lists of: (1) noncardiac abnormalities/general preoperative risk factors, (2) diagnoses, (3) procedures, and (4) complications, from which clinicians can choose for entry into the minimum dataset. There was universal agreement for these datasets and short lists by the assembled members of the Society of Thoracic Surgeons-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. The datasets and short lists were also unanimously approved by the Congenital Heart Surgery Committee of The European Association for Cardiothoracic Surgery and adopted by the European Congenital Heart Surgeons Foundation.

Congenital Heart Surgery Nomenclature and Database Project: vascular rings, tracheal stenosis, pectus excavatum

The extant nomenclature for vascular rings, tracheal stenosis, and pectus deformities is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Vascular rings are subclassified as double aortic arch, right arch/left ligamentum, pulmonary artery sling, and innominate compression. Tracheal stenosis is subclassified as congenital complete tracheal rings (localized or long-segment) or acquired postintubation types. Pectus deformities are subclassified as pectus excavatum and carinatum (mild, moderate, severe). A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Congenital Heart Surgery Nomenclature and Database Project: patent ductus arteriosus, coarctation of the aorta, interrupted aortic arch

The extant nomenclature for patent ductus arteriosus (PDA), coarctation of the aorta (CoAo), and interrupted aortic arch (IAA) is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. PDA is subclassified by origin, insertion, and patient weight. CoAo is subclassified into isolated CoAo, CoAo with ventricular septal defect, and CoAo with complex intracardiac anomalies. IAA is subclassified into anatomic types A, B, and C based on the location of the interruption. A comprehensive database set is presented which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Congenital heart surgery nomenclature and database project

In 1998, the first report of the Society of Thoracic Surgery (STS) National Congenital Heart Surgery Database defined clinical features for 18 congenital heart disease categories, providing a significant amount of important information and pinpointing database strengths and weaknesses. Following this report, the STS Congenital Heart Surgery Committee, working with the European Association of Cardio-Thoracic Surgery and the European Congenital Heart Surgeons Foundation, initiated the International Congenital Heart Surgery and Nomenclature Database Project. To standardize nomenclature and reporting strategies and establish a foundation for an international congenital heart surgery database. The project’s first report was published in the Annals of Thoracic Surgery in April 2000. The current report outlines modifications to the minimal dataset and diagnosis and procedure short lists.

Coarctation of the Aorta: Midterm Outcomes of Resection With Extended End-to-End Anastomosis

BACKGROUND We began using the technique of resection with extended end-to-end anastomosis for infants and children with coarctation of the aorta in 1991. The purpose of this review is to evaluate the midterm outcomes of this technique, specifically determining the incidence of and risk factors for transcatheter or surgical reintervention. METHODS A retrospective analysis of the cardiac surgery database was performed to identify all patients who had a diagnosis of coarctation of the aorta with or without ventricular septal defect and had resection with extended end-to-end anastomosis from 1991 to 2007. Perioperative course and follow-up with physical examination, echocardiogram, and cardiology evaluation were obtained. RESULTS From 1991 through 2007, 201 patients had repair of coarctation of the aorta with resection with extended end-to-end anastomosis. The median age was 23 days, and the median weight was 4.0 kg. Surgical approach was by left thoracotomy in 157 patients (78%) with a mean cross-clamp time of 18 +/- 4 minutes. Median sternotomy approach was used in 44 patients (22%) to repair a hypoplastic transverse aortic arch (n = 16) or because of associated ventricular septal defect (n = 28) with a mean circulatory arrest time of 14 +/- 9 minutes. Early mortality occurred in 4 patients (2.0%). Three patients (1.5%) required early arch revision: 2 intraoperatively and 1 on postoperative day 1. Follow-up data were available for 182 patients (91%) with a mean follow-up of 5.0 +/- 4.3 years (908 patient-years). Reinterventions (n = 8; 4.0%) included three balloon angioplasties and five reoperations; 75% of the reinterventions occurred in the first postoperative year. Hypoplastic transverse aortic arch was not a risk factor for reintervention (p = 0.36), but was a risk factor for mortality (p = 0.039). Aberrant right subclavian artery was the only risk factor for recoarctation (p = 0.007). CONCLUSIONS Repair of coarctation of the aorta with resection with extended end-to-end anastomosis has a low early mortality, effectively addresses transverse arch hypoplasia, and at midterm follow-up has a low rate of reintervention for recurrent coarctation.

Pediatric coronary artery bypass for Kawasaki, congenital, post arterial switch, and iatrogenic lesions

BACKGROUND Pediatric coronary artery bypass (PCAB) has been recently employed for expanding indications to treat acquired, congenital, post arterial switch, and other iatrogenic pediatric coronary artery problems. METHODS Between 1987 and 1998, 3 infants and 13 children (n = 16, mean age 6.1 years, range 2 months-18 years) underwent one or more internal thoracic artery (ITA) to coronary artery (CA) bypass grafts for Kawasaki disease (n = 4), congenital lesions (n = 3), post arterial switch (n = 4), and other iatrogenic obstructions (n = 5). Proximal left main CA arterioplasty was performed concurrently with ITA-CA bypass in 4 patients. RESULTS Survival is 93.8%. All bypass grafts in surviving patients are patent 2 months-11 years postoperation. The 11 elective patients are well (NYHA I-II). The 5 emergent operations were performed in 2 infants and 3 adolescents who had poor ventricular function prior to ITA-CA bypass due to iatrogenic injuries in 3, congenital critical left main stenosis in 1, and intraoperative iatrogenic coronary injury in 1. The 3 adolescents fared worse, resulting in death in the first, cardiac transplantation in the second, and full recovery in the third. The 2 infants have steadily improving ventricular function. CONCLUSIONS ITA-CA bypass can be successfully performed in infants and children for expanding elective and life-saving indications with excellent results. Poor preoperative ventricular function often persists, especially in those older children with iatrogenic injuries, and may result in death or cardiac transplantation.