title: Performance of contemporary surgical risk scores for mitral valve surgery.
abstract: BACKGROUND
  Risk stratification for mitral valve repair or replacement (MVR) is important in the decision-making for treating several mitral valve disease but is rarely studied. We compared the prognostic utility of EuroSCORE, EuroSCORE II, and Society of Thoracic Surgeons (STS) Score for MVR.
  
  
  METHODS
  The three scores were retrospectively calculated for consecutive patients undergoing isolated MVR at Auckland City Hospital during 2005-2012 and their discrimination and calibration for mortality and morbidities assessed.
  
  
  RESULTS
  There were 408 patients (mitral valve repair 48.1% and replacement 51.9%) followed-up for 6.0 ± 2.6 years. The operative mortality was 2.5%. Mean EuroSCORE, EuroSCORE II, and STS Score were 7.6%, 3.4%, and 3.5%. C-statistics were 0.844, 0.817, and 0.850 for operative mortality. Hosmer-Lemeshow test p values were 0.076, 0.541, and 0.306, and Brier scores 0.0246, 0.0035, and 0.0075, respectively, for operative mortality. The numerically highest c-statistic for predicting complications include EuroSCORE for return to the operating room (c = 0.673); EuroSCORE II for stroke (c = 0.669) and mediastinitis (c = 0.801); and STS for renal failure (c = 0.828), ventilation >24 hours (c = 0.789), and composite morbidity (c = 0.732). The individual STS complication models for MVR had a numerically higher c-statistic only for stroke (c = 0.737).
  
  
  CONCLUSIONS
  All scores discriminated mortality and most morbidities after MVR, although EuroSCORE over-estimated operative mortality. The STS Score was the best overall predictor of mortality and morbidity in the MVR cohort.
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.|Department of Medicine, University of Auckland, Auckland, New Zealand.
authors.forename: Tom Kai Ming
authors.initials: TK
authors.lastname: Wang
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
authors.forename: Sophie
authors.initials: S
authors.lastname: Harmos
authors.affiliation: Department of Medicine, University of Auckland, Auckland, New Zealand.
authors.forename: Greg D
authors.initials: GD
authors.lastname: Gamble
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
authors.forename: Tharumenthiran
authors.initials: T
authors.lastname: Ramanathan
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.|Department of Medicine, University of Auckland, Auckland, New Zealand.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Ruygrok
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D013997:Time Factors
keywords: cardiac surgery; mitral valve; risk modeling