title: Is it possible to simplify risk stratification scores for patients with ST-segment elevation myocardial infarction undergoing primary angioplasty?
abstract: BACKGROUND
  There are several risk scores for stratification of patients with ST-segment elevation myocardial infarction (STEMI), the most widely used of which are the TIMI and GRACE scores. However, these are complex and require several variables. The aim of this study was to obtain a reduced model with fewer variables and similar predictive and discriminative ability.
  
  
  METHODS
  We studied 607 patients (age 62 years, SD=13; 76% male) who were admitted with STEMI and underwent successful primary angioplasty. Our endpoints were all-cause in-hospital and 30-day mortality. Considering all variables from the TIMI and GRACE risk scores, multivariate logistic regression models were fitted to the data to identify the variables that best predicted death.
  
  
  RESULTS
  Compared to the TIMI score, the GRACE score had better predictive and discriminative performance for in-hospital mortality, with similar results for 30-day mortality. After data modeling, the variables with highest predictive ability were age, serum creatinine, heart failure and the occurrence of cardiac arrest. The new predictive model was compared with the GRACE risk score, after internal validation using 10-fold cross validation. A similar discriminative performance was obtained and some improvement was achieved in estimates of probabilities of death (increased for patients who died and decreased for those who did not).
  
  
  CONCLUSIONS
  It is possible to simplify risk stratification scores for STEMI and primary angioplasty using only four variables (age, serum creatinine, heart failure and cardiac arrest). This simplified model maintained a good predictive and discriminative performance for short-term mortality.
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal. Electronic address: ana_timoteo@yahoo.com.
authors.forename: Ana Teresa
authors.initials: AT
authors.lastname: Timóteo
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal.
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Papoila
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal.
authors.forename: João Pedro
authors.initials: JP
authors.lastname: Lopes
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal.
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Oliveira
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal.
authors.forename: Maria Lurdes
authors.initials: ML
authors.lastname: Ferreira
authors.affiliation: Cardiology Department, Santa Marta Hospital, Centro Hospitalar de Lisboa Central, EPE, Lisbon, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Cruz Ferreira
mesh_terms: D017130:Angioplasty; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*
keywords: Acute coronary syndromes; Prognosis; Prognóstico; Risk scores; Scores de risco; Síndromas coronárias agudas