[Trends in the proportion of patients younger than 75 years with acute myocardial infarction and Killip class III and IV. variables associated with occurence and case-fatality: 1978-1997].

INTRODUCTION Acute pulmonary edema (Killip III) or cardiogenic shock (Killip IV) is associated with a higher mortality in the acute phase of myocardial infarction (AMI). OBJECTIVES To analyze trends in the proportion of patients who developed Killip III and IV in AMI over a 20-year period in order to identify the variables associated with occurrence and case-fatality. METHODS Hospital registry of first AMI in patients under than 75 years, from 1978 to 1997. Sociodemographic variables, cardiovascular risk factors, clinical variables, treatments, procedures, and worst Killip class were recorded. RESULTS The registry included 2,590 patients. Mean age was 60 years and 17% were women. Thirteen percent (13.5%) of the patients developed Killip III and IV, and no changes in this proportion were observed over the time period studied. Age, diabetes, previous angina, and anterior location of AMI were associated with a higher risk of Killip III and IV. Case-fatality at 28 days in this subgroup was 51.7%, with a decreasing linear trend over the years. Variables associated with a higher case-fatality were age and malignant ventricular arrhythmias, whereas the periods 1990-93 and 1994-97 were associated with a lower case-fatality. This protective effect disappeared after adjusting for treatment variables (antiplatelet agents and thrombolysis). CONCLUSIONS The proportion of patients with AMI in which Killip class III and IV develops has remained stable in the last two decades. Although the 28-day case-fatality in these patients is high, a decrease has been observed in recent years in relation to the availability of new treatments (antiplatelet agents and thrombolysis).