Usefulness of the Killip classification for early risk stratification of patients with acute myocardial infarction in the 1990s compared with those treated in the 1980s

The classification introduced in 1967 by Killip et al has proved to be a useful method for early risk stratification of patients with acute myocardial infarction (AMI). Over the past 3 decades the overall mortality due to AMI has decreased significantly. The present study evaluates the usefulness of the Killip classification as a method for early risk stratification of patients with AMI in the 1990s. One thousand eight hundred seventy-three consecutive AMI patients were hospitalized in 25 coronary care units operating in Israel, and were followed for 1 year. Higher Killip class was found to be associated with increased in-hospital and I-year mortality, in thrombolysis- and nonthrombolysis-treated patients (30-day mortality for all patients was 5%, 21%, 35%, and 67% in Killip classes I to IV, respectively). The overall mortality among AMI patients in the 1990s was found to be lower for each Killip class compared with a comparable patient population with AMI, hospitalized in Israel in the 1980s. Thus, the Killip classification is a useful method for early risk stratification of AMI patients in the 1990s. (C) 1997 by Excerpta Medica, Inc.