Performance of The Society of Thoracic Surgeons 2008 Cardiac Risk Models for Major Postoperative Complications after Heart Valve Surgery in a Chinese Population: A Multicenter Study

Abstract

Background: To evaluate the performance of Society of Thoracic Surgeons (STS) 2008 cardiac surgery risk scores for postoperative complications in Chinese patients undergoing single valve surgery at multicenter institutions. 

Methods: From January 2009 through December 2012, 4493 consecutive patients older than 16 years who underwent single valve surgery at 4 cardiac surgical centers were collected and scored according to the STS 2008 risk scores. The final research population included the following isolated heart valve surgery types: aortic valve replacement, mitral valve replacement, and mitral valve repair. Calibration of the risk scores was assessed by the Hosmer–Lemeshow (H-L) test. Discrimination was tested by calculating the area under the receiver operating characteristic (ROC) curve. 

Results: The observed incidence rate for cerebrovascular accident (CVA), renal failure (RF), prolonged ventilation (Vent), reoperation (Reop), prolonged postoperative length of stay (PLOS), and short postoperative LOS (SLOS) was 0.90%, 1.32%, 4.18%, 2.43%, 3.64%, and 1.65%, respectively. The predicted incidence rate for CVA, RF, Vent, Reop, PLOS, and SLOS was 0.76%, 1.55%, 4.94%, 6.69%, 3.92%, and 2.54%, respectively. The STS 2008 risk scores give an accurate calibration for individual postoperative risk in CVA, RF, Vent, and PLOS (Hosmer–Lemeshow: P = .052, P = .474, P = .468, and P = .712, respectively). The area under the ROC curve of the STS 2008 risk scores for the above 4 postoperative complications were 0.714, 0.724, 0.727%, and 0.713, respectively.

Conclusion: The STS 2008 risk scores were suitable for major postoperative complications in patients undergoing single valve surgery, except for Reop and SLOS.