Comparative Study of Earlier EuroSCORE and EuroSCORE II Model Among CABG Patients: A Cohort Study in Bangladesh Population

Abstract

Objective: The European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) is an updated version of the original EuroSCORE. The goal of this analysis was to compare EuroSCORE II and additive and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) in predicting early mortality after coronary artery bypass surgery in a single center of Bangladesh.Methods: A prospective consecutive series of 400 adults who underwent coronary artery bypass surgery between January 2014 and December 2016 was studied in National Heart Foundation Hospital & Research Institute. The newly developed EuroSCORE II was applied in this sample and compared to the additive and logistic version of the models. Validity was assessed on the basis of its calibration (using the Hosmer-Lemeshow test) and its discrimination using the receiver operating characteristic curve (ROC) and the association between observed and predicted mortality were performed using the one proportion Z test. Results:The Hosmer-Lemeshow test showed that the model calibration was satisfactory (p = 0.738 in EuroSCORE II, p = 0.114 in additive method and p = 0.645 in logistic method), and area under ROC curve 0.972 in EuroSCORE II, 0.903 in additive model and 0.915 in logistic model. Hospital overall observed early mortality was 1.25%. EuroSCORE II predicted mortality 1.3% [95% confidence interval (CI) 0.49-3.10] having p value 0.860, additive EuroSCORE predicted mortality is 4.3% [95% confidence interval (CI) 2.53-6.78], having p value 0.001, and mortality prediction my logistic EuroSCORE 2.2% [95% confidence interval (CI) 1.00-4.16], having p value 0.112. Conclusion:EuroSCORE II is better calibrated than the previous model. Mortality prediction by the EuroSCORE II is not very different from observed early mortality in CABG patients in National Heart Foundation Hospital and Research Institute.