title: Society of Thoracic Surgeons 2008 cardiac risk models predict in-hospital mortality of heart valve surgery in a Chinese population: a multicenter study.
abstract: OBJECTIVE
  The Society of Thoracic Surgeons 2008 cardiac surgery risk models have been developed for heart valve surgery with and without coronary artery bypass grafting. The aim of our study was to evaluate the performance of Society of Thoracic Surgeons 2008 cardiac risk models in Chinese patients undergoing single valve surgery and the predicted mortality rates of those undergoing multiple valve surgery derived from the Society of Thoracic Surgeons 2008 risk models.
  
  
  METHODS
  A total of 12,170 patients underwent heart valve surgery from January 2008 to December 2011. Combined congenital heart surgery and aortal surgery cases were excluded. A relatively small number of valve surgery combinations were excluded. The final research population included the following isolated heart valve surgery types: aortic valve replacement, mitral valve replacement, and mitral valve repair. The following combined valve surgery types were included: mitral valve replacement plus tricuspid valve repair, mitral valve replacement plus aortic valve replacement, and mitral valve replacement plus aortic valve replacement and tricuspid valve repair. Evaluation was performed by using the Hosmer-Lemeshow test and C-statistics.
  
  
  RESULTS
  Data from 9846 patients were analyzed. The Society of Thoracic Surgeons 2008 cardiac risk models showed reasonable discrimination and poor calibration (C-statistic, 0.712; P = .00006 in Hosmer-Lemeshow test). Society of Thoracic Surgeons 2008 models had better discrimination (C-statistic, 0.734) and calibration (P = .5805) in patients undergoing isolated valve surgery than in patients undergoing multiple valve surgery (C-statistic, 0.694; P = .00002 in Hosmer-Lemeshow test). Estimates derived from the Society of Thoracic Surgeons 2008 models exceeded the mortality rates of multiple valve surgery (observed/expected ratios of 1.44 for multiple valve surgery and 1.17 for single valve surgery).
  
  
  CONCLUSIONS
  The Society of Thoracic Surgeons 2008 cardiac surgery risk models performed well when predicting the mortality for Chinese patients undergoing valve surgery. The Society of Thoracic Surgeons 2008 models were suitable for single valve surgery in a Chinese population; estimates of mortality for multiple valve surgery derived from the Society of Thoracic Surgeons 2008 models were less accurate.
authors.affiliation: Department of Cardiac and Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China; Department of Cardiac and Thoracic Surgery, No 252 Hospital, Baoding, Hebei, China.
authors.forename: Lv
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Cardiac and Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Fang-Lin
authors.initials: FL
authors.lastname: Lu
authors.affiliation: Department of Cardiac and Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Cardiac and Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Meng-Wei
authors.initials: MW
authors.lastname: Tan
authors.affiliation: Department of Cardiac and Thoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China. Electronic address: zhiyunx@hotmail.com.
authors.forename: Zhi-yun
authors.initials: ZY
authors.lastname: Xu
mesh_terms: D000368:Aged; D044466:Asian People; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality*; D002681:China / Q000453:epidemiology; D003661:Decision Support Techniques; D005260:Female; D006349:Heart Valve Diseases / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality; D006351:Heart Valves / Q000601:surgery*; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012955:Societies, Medical; D016896:Treatment Outcome