Risk stratification in paediatric open-heart surgery.

OBJECTIVE The aims of this study were to identify independent risk factors for mortality following paediatric open-heart surgery and to develop risk models for use in clinical audit based on identified risk factors. The study also tests the validity of the recently proposed Risk Adjustment in Congenital Heart Surgery (RACHS-1) method of risk stratification as applied to open-heart operations. METHODS A multiple logistic regression analysis was performed on all patients less than 18 years of age undergoing open-heart surgery at a single institution over a 3-year period. Preoperative and operative variables included for analysis were age at operation, weight, sex, American Society of Anaesthesiology (ASA) grade, RACHS-1 risk category, preoperative haemoglobin, bypass time, temperature, cross-clamp time, circulatory arrest time, blood transfusion on bypass and surgeon. The outcome measure was in-hospital death. RESULTS 1085 consecutive open-heart cases were identified. There were 51 in-hospital deaths (4.7%). Variables identified as being independently significant risk factors for in-hospital death were age (P = 0.0002), RACHS-1 risk category (P < 0.0001), and bypass time. Based on these three variables, a risk model was constructed to predict mortality. The area under the receiver-operating-characteristic (ROC) curve for this model was 0.86. A second model was constructed ignoring bypass time. In this model, the significance of the 'preoperative' risk factors was (P = 0.0003) for age and (P < 0.0001), for RACHS-1 risk category. The area under the ROC curve was 0.81 for the second model. CONCLUSIONS This study identifies age at operation, RACHS-1 risk category and bypass time as highly significant risk factors for mortality after paediatric open-heart surgery. It validates the RACHS-1 risk stratification method as applied to the subset of open-heart surgery, whilst accepting the limitations of such a system. The risk models formulated permit risk prediction and allow for analysis of surgical results. Such risk-adjustment is important when assessing performance and comparing outcomes amongst individuals or institutions.

[1]  F. Lacour-Gayet,et al.  Risk stratification theme for congenital heart surgery. , 2002, Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual.

[2]  Tom Treasure,et al.  Risk-adjusted sequential probability ratio tests: applications to Bristol, Shipman and adult cardiac surgery. , 2003, International journal for quality in health care : journal of the International Society for Quality in Health Care.

[3]  Bradley G Hammill,et al.  Validation of European System for Cardiac Operative Risk Evaluation (EuroSCORE) in North American cardiac surgery. , 2002, European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.

[4]  K. Gauvreau,et al.  Center-specific differences in mortality: preliminary analyses using the Risk Adjustment in Congenital Heart Surgery (RACHS-1) method. , 2002, The Journal of thoracic and cardiovascular surgery.

[5]  C. Mavroudis,et al.  Congenital heart disease outcome analysis: methodology and rationale. , 2002, The Journal of thoracic and cardiovascular surgery.

[6]  A. Bernstein,et al.  A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. , 1989, Circulation.

[7]  K. Gauvreau,et al.  Regional Racial and Ethnic Differences in Mortality for Congenital Heart Surgery in Children May Reflect Unequal Access to Care , 2003, Pediatric Cardiology.

[8]  G. Coffman,et al.  In-hospital mortality for surgical repair of congenital heart defects: preliminary observations of variation by hospital caseload. , 1995, Pediatrics.

[9]  J. Monro,et al.  Assessment of mortality rates for congenital heart defects and surgeons' performance. , 2001, The Annals of thoracic surgery.

[10]  J. Daley,et al.  Risk factors for prolonged length of stay after major elective surgery. , 1999, Annals of surgery.

[11]  Nicky Best,et al.  Comparison of UK paediatric cardiac surgical performance by analysis of routinely collected data 1984–96: was Bristol an outlier? , 2001, The Lancet.

[12]  K. Jenkins,et al.  Risk of Death for Medicaid Recipients Undergoing Congenital Heart Surgery , 2003, Pediatric Cardiology.

[13]  M. Irwin,et al.  The ASA Physical Status Classification: Inter-observer Consistency , 2002, Anaesthesia and intensive care.

[14]  S Gallivan,et al.  Mortality rates after surgery for congenital heart defects in children and surgeons' performance , 2000, The Lancet.

[15]  M. Jacobs,et al.  Preoperative risk-of-death prediction model in heart surgery with deep hypothermic circulatory arrest in the neonate. , 2000, The Journal of thoracic and cardiovascular surgery.

[16]  Laura P Coombs,et al.  The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models. , 2003, The Annals of thoracic surgery.

[17]  A. Flahault,et al.  Pulmonary complications following lung resection: a comprehensive analysis of incidence and possible risk factors. , 2000, Chest.

[18]  Kimberlee Gauvreau,et al.  Consensus-based method for risk adjustment for surgery for congenital heart disease. , 2002, The Journal of thoracic and cardiovascular surgery.

[19]  E. Hannan,et al.  Pediatric cardiac surgery: the effect of hospital and surgeon volume on in-hospital mortality. , 1998, Pediatrics.

[20]  S Gallivan,et al.  Early identification of divergent performance in congenital cardiac surgery. , 2001, European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.