title: Validation of the Killip-Kimball classification and late mortality after acute myocardial infarction.
abstract: BACKGROUND
  The classification or index of heart failure severity in patients with acute myocardial infarction (AMI) was proposed by Killip and Kimball aiming at assessing the risk of in-hospital death and the potential benefit of specific management of care provided in Coronary Care Units (CCU) during the decade of 60.
  
  
  OBJECTIVE
  To validate the risk stratification of Killip classification in the long-term mortality and compare the prognostic value in patients with non-ST-segment elevation MI (NSTEMI) relative to patients with ST-segment elevation MI (STEMI), in the era of reperfusion and modern antithrombotic therapies.
  
  
  METHODS
  We evaluated 1906 patients with documented AMI and admitted to the CCU, from 1995 to 2011, with a mean follow-up of 05 years to assess total mortality. Kaplan-Meier (KM) curves were developed for comparison between survival distributions according to Killip class and NSTEMI versus STEMI. Cox proportional regression models were developed to determine the independent association between Killip class and mortality, with sensitivity analyses based on type of AMI.
  
  
  RESULTS
  The proportions of deaths and the KM survival distributions were significantly different across Killip class >1 (p <0.001) and with a similar pattern between patients with NSTEMI and STEMI. Cox models identified the Killip classification as a significant, sustained, consistent predictor and independent of relevant covariables (Wald χ2 16.5 [p = 0.001], NSTEMI) and (Wald χ2 11.9 [p = 0.008], STEMI).
  
  
  CONCLUSIONS
  The Killip and Kimball classification performs relevant prognostic role in mortality at mean follow-up of 05 years post-AMI, with a similar pattern between NSTEMI and STEMI patients.
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Bruno Henrique Gallindo de
authors.initials: BH
authors.lastname: Mello
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Gustavo Bernardes F
authors.initials: GB
authors.lastname: Oliveira
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Rui Fernando
authors.initials: RF
authors.lastname: Ramos
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Bernardo Baptista C
authors.initials: BB
authors.lastname: Lopes
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Cecília Bitarães S
authors.initials: CB
authors.lastname: Barros
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Erick de Oliveira
authors.initials: Ede O
authors.lastname: Carvalho
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Fabio Bellini P
authors.initials: FB
authors.lastname: Teixeira
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Guilherme D'Andréa S
authors.initials: GD
authors.lastname: Arruda
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Maria Sol Calero
authors.initials: MS
authors.lastname: Revelo
authors.affiliation: Instituto Dante Pazzanese de Cardiologia, São Paulo, SP, Brazil.
authors.forename: Leopoldo Soares
authors.initials: LS
authors.lastname: Piegas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis; D013997:Time Factors; D055815:Young Adult