title: [Proposed preoperative risk score for patients candidate to cardiac valve surgery].
abstract: BACKGROUND
  To establish a risk score for heart surgery allows the assessment of preoperative risk, informing the patient and defining care during the intervention.
  
  
  OBJECTIVE
  To assess preoperative risk factors for death in cardiac valve surgery and construct a simple risk model (score) for in-hospital mortality of patients candidate to surgery at Hospital São Lucas of Pontifícia Universidade Católica do Rio Grande do Sul (HSL-PUCRS).
  
  
  METHODS
  The study sample included 1,086 adult patients that underwent cardiac valve surgery between January 1996 and December 2007 at HSL-PUCRS. Logistic regression was used to identify risk and in-hospital mortality factors. The model was developed in 699 patients and its performance was tested in the remaining data (n = 387). The final model was created using the total study sample (n = 1,086).
  
  
  RESULTS
  Global mortality was 11.8%: 8.8% of elective cases and 63.8% of emergency cases. At the multivariate analysis, 9 variables remained independent predictors for the outcome: advanced age, surgical priority, female sex, ejection fraction < 45%, concomitant myocardial revascularization (CABG), pulmonary hypertension, NYHA functional class III or IV, creatinine levels (1.5 to 2.49 mg/dl and > 2.5 mg/dl or undergoing dialysis). The area under the ROC curve was 0.83 (95% CI: 0.78-0.86). The risk model showed good capacity for observed/predicted mortality: the Hosmer-Lemeshow test was x(2) = 5.61; p = 0.691 and r = 0.98 (Pearson's coefficient).
  
  
  CONCLUSIONS
  The variables predictive of in-hospital mortality allowed the construction of a simplified risk score for daily practice, which classifies the patient as having low, moderate, high, very high and extremely high preoperative risk.
authors.affiliation: Hospital São Lucas, Pontificia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brasil. guaragna@cardiol.br
authors.forename: João Carlos Vieira da Costa
authors.initials: JC
authors.lastname: Guaragna
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Bodanese
authors.forename: Fabiana Lucas
authors.initials: FL
authors.lastname: Bueno
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Goldani
mesh_terms: D000328:Adult; D000368:Aged; D017558:Elective Surgical Procedures / Q000401:mortality; D004630:Emergencies; D004812:Epidemiologic Methods; D005260:Female; D006349:Heart Valve Diseases / Q000401:mortality* / Q000601:surgery; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011300:Preoperative Care / Q000379:methods*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors