title: Development and Validation of Predictive Models of Cardiac Mortality and Transplantation in Resynchronization Therapy.
abstract: BACKGROUND
  30-40% of cardiac resynchronization therapy cases do not achieve favorable outcomes.
  
  
  OBJECTIVE
  This study aimed to develop predictive models for the combined endpoint of cardiac death and transplantation (Tx) at different stages of cardiac resynchronization therapy (CRT).
  
  
  METHODS
  Prospective observational study of 116 patients aged 64.8 ± 11.1 years, 68.1% of whom had functional class (FC) III and 31.9% had ambulatory class IV. Clinical, electrocardiographic and echocardiographic variables were assessed by using Cox regression and Kaplan-Meier curves.
  
  
  RESULTS
  The cardiac mortality/Tx rate was 16.3% during the follow-up period of 34.0 ± 17.9 months. Prior to implantation, right ventricular dysfunction (RVD), ejection fraction < 25% and use of high doses of diuretics (HDD) increased the risk of cardiac death and Tx by 3.9-, 4.8-, and 5.9-fold, respectively. In the first year after CRT, RVD, HDD and hospitalization due to congestive heart failure increased the risk of death at hazard ratios of 3.5, 5.3, and 12.5, respectively. In the second year after CRT, RVD and FC III/IV were significant risk factors of mortality in the multivariate Cox model. The accuracy rates of the models were 84.6% at preimplantation, 93% in the first year after CRT, and 90.5% in the second year after CRT. The models were validated by bootstrapping.
  
  
  CONCLUSIONS
  We developed predictive models of cardiac death and Tx at different stages of CRT based on the analysis of simple and easily obtainable clinical and echocardiographic variables. The models showed good accuracy and adjustment, were validated internally, and are useful in the selection, monitoring and counseling of patients indicated for CRT.
authors.affiliation: Instituto do Coração, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Eduardo Arrais
authors.initials: EA
authors.lastname: Rocha
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Francisca Tatiana Moreira
authors.initials: FT
authors.lastname: Pereira
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: José Sebastião
authors.initials: JS
authors.lastname: Abreu
authors.affiliation: Departamento de Saúde Pública, Universidade Estadual do Ceará, Fortaleza, CE, Brazil.
authors.forename: José Wellington O
authors.initials: JW
authors.lastname: Lima
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Marcelo de Paula Martins
authors.initials: Mde P
authors.lastname: Monteiro
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Almino Cavalcante
authors.initials: AC
authors.lastname: Rocha Neto
authors.affiliation: Instituto do Coração, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Camilla Viana Arrais
authors.initials: CV
authors.lastname: Goés
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Ana Gardênia P
authors.initials: AG
authors.lastname: Farias
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Carlos Roberto Martins
authors.initials: CR
authors.lastname: Rodrigues Sobrinho
authors.affiliation: Hospital Universitário, Universidade Federal do Ceará, Ceará, CE, Brazil.
authors.forename: Ana Rosa Pinto
authors.initials: AR
authors.lastname: Quidute
authors.affiliation: Instituto do Coração, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Maurício Ibrahim
authors.initials: MI
authors.lastname: Scanavacca
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000401:mortality*; D058409:Cardiac Resynchronization Therapy Devices / Q000706:statistics & numerical data; D004452:Echocardiography; D004812:Epidemiologic Methods; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000628:therapy; D016027:Heart Transplantation / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000401:mortality / Q000628:therapy