Abstract 9972: Do Risk Models Accurately Predict the Coronary Artery Bypass Graft Mortality Risk in Patients of Southeast Asian Origin?
Introduction: Cardiac surgery risk models have been developed based on predominantly Caucasian populations. This study is conducted to validate and evaluate these models for Southeast Asian patients.
Methods: We analyzed a prospectively collected dataset of 1769 patients who underwent isolated CABG between 2009 and 2013 in an academic medical center: National University Heart Center, Singapore. Patients were scored by six risk models (Additive EuroSCORE, Logistic EuroSCORE, EuroSCORE II, Society of Thoracic Surgeons (STS), Northern New England Cardiovascular Disease Study Group, and Parsonnet). Discriminatory power was compared using ROC and C-statistics. Goodness of fit test was used to assess model calibration.
Results: The overall observed mortality was 2.48% (n=44). C-statistics showed fair discriminatory power for all six risk scores, with STS (C-statistic 0.774, 95% CI 0.697 - 0.851) and EuroSCORE II (C-statistic 0.766, 95% CI 0.690 - 0.843) having the highest values. The optimal thresholds using Youden’s method were: STS threshold 1.33%, sensitivity 79.55%, specificity 68.04%; EuroSCORE II threshold 5.23%, sensitivity 54.55%, specificity 86.14%. Calibration testing revealed that only the STS (p=0.156) and EuroSCORE II (p=0.352) had a good fit with our data. However, EuroSCORE II and STS over-predict and under-predict mortality in high risk patients respectively.
Conclusion: The STS and EuroSCORE II have the best predictive value for patients of Southeast Asian origin and can provide our surgeons with a suitable benchmark for outcome tracking. Inaccurate predictions for high-risk patients may be improved with recalibration.
Author Disclosures: S. Liang: None. Y. Lim: None. R. Ma: None. K. Yow: None. J. Eng: None. B. Li: None. C. Lee: None. T. Kofidis: None. K. Teoh: None. O. Ooi: None. H. Luo: None.
- © 2015 by American Heart Association, Inc.