Predictive value of different scoring systems for early postoperative mortality in patients with a second coronary artery bypass grafting

Abstract

Background Coronary artery bypass graft (CABG) has been developed over many years. Recently, an increasing number of patients need a second surgery for relapse of symptoms. In consideration of the high surgical risk, accurate preoperative evaluation is needed. The aim of the study was to assess the predictive value of three different risk scoring system for early postoperative mortality rate in patients with redo-CABG. Methods Seventy-seven patients who underwent redo-CABG in Fu Wai Hospital from January 1997 to June 2013 were enrolled. All patients were retrospectively scored for early postoperative mortality rate using EuroSCORE, STS score and SinoSCORE. Overall expected mortality rates were compared with observed mortality rates. Discrimination was evaluated using receiver operating characteristic (ROC) curves and area under a ROC curve (AUC). Results Four patients died after a redo-CABG 5%. The mortality rates predicted by EuroSCORE, STS score and SinoSCORE were 5.0%, 2.2% and 1.4%, respectively. The AUC of the three kinds of score were 0.465, 0.543 and 0.528, respectively, indicating a poor correlation between the observed and predicted mortality rates. Conclusion The predictive value of EuroSCORE, STS score and SinoSCORE is poor for early postoperative mortality rate in patients with redo-CABG.