Abstract 10384: Validation of a Simple Score to Determine Risk of Hospital Mortality After the Norwood Procedure
Background: The NIH/NHLBI Pediatric Heart Network Single Ventricle Reconstruction (SVR) trial identified risk factors for hospital mortality after the Norwood procedure. However, the ability to quantify pre-operative risk remains elusive. This study aimed to develop an accurate and clinically feasible score to assess the risk of hospital mortality in neonates undergoing the Norwood procedure. Methods: All patients (n = 549) in the publically available SVR database were included in the analysis. Patients were randomly divided into a derivation (75%) and validation (25%) cohort. Pre-operative patient, center, and surgeon-related covariates found to be associated with mortality upon univariate analysis (p < 0.2) were included in the initial multivariable logistic regression model. The final model was derived by including only variables independently associated with mortality (p < 0.05). A risk score was then developed using relative magnitudes of the covariates’ odds ratio. The score was then tested in the validation cohort. Results: A 20-point risk score using 6 variables (see Table) was developed. The derivation and validation cohorts did not differ in age, sex, mortality, and the score covariates. Mean score in derivation and validation cohort were 5.2 ± 3.2 and 5.6 ± 3.5, p = 0.35, respectively. In weighted regression analysis, model predicted risk of mortality correlated closely with actual rates of mortality in the derivation (R 2 = 0.87, p < 0.01) and validation cohorts (R 2 = 0.82, p 10). Patients were classified as low (score 0-5), medium (6-10), or high risk (>10). Mortality differed significantly between risk groups in the derivation (6% vs. 22% vs. 77%, p < 0.01) and validation (4% vs. 30% vs. 53%, p < 0.01) cohorts. Conclusion: This mortality score is accurate in determining risk of hospital mortality in neonates undergoing the Norwood operation. The score has the potential to be used in clinical practice to aid in risk assessment prior to surgery.