Extent of the decrease of 28-day case fatality of hospitalized patients with acute myocardial infarction over 22...

No data exist regarding time trends of 28-day case fatality (CF) of patients with presumed acute myocardial infarction (AMI) using epidemiological criteria, clinical criteria, and AMI classification after validation of presumed in-hospital AMI-related deaths (gold-standard criteria).

From 1985 to 2004, we prospectively examined all 9210 AMI patients consecutively hospitalized in a large teaching hospital by using a broad epidemiological AMI definition (WHO-MONICA). Twenty-eight-day CF decreased significantly from 32% in 1985-1986 to 18% in 2003-2004, mostly because of a reduction in early deaths (<24 hours). When applying the clinical AMI definition, most of the early deaths were not counted as AMI related. A retrospective validation process from a sample of all early deceased patients by the epidemiological AMI definition (388/2076) and a prospective validation of the complete cohort in 2005-2006 revealed that only about 50% of early deaths are reclassified as a real fatal AMI using newer criteria resulting in a 28-day CF of 23% in 1985-1986 and 11% in 2005-2006. The difference between the AMI 28-day CF by applying gold-standard criteria and the clinical AMI 28-day CF (18% in 1985-1986 and 7% in 2005-2006) has decreased during recent years.

The application of broad epidemiological criteria for AMI overestimates 28-day CF by almost 2-fold compared with gold-standard criteria (after validation of early deaths) and almost 3-fold compared to the clinical definition. The growing similarity in 28-day CF between the clinically based definition and the gold-standard criteria implies that recent clinical-based registries may represent a realistic picture of trends regarding in-hospital AMI mortality.