Thirty-year (1975 to 2005) trends in the incidence rates, clinical features, treatment practices, and short-term outcomes of patients <55 years of age hospitalized with an initial acute myocardial infarction.

Sparse data are available describing recent trends in the magnitude, clinical features, treatment practices, and outcomes of comparatively young adults hospitalized with acute myocardial infarction (AMI). The objectives of this population-based study were to describe 3 decade-long trends (1975 to 2005) in these end points in adults <55 years old who were hospitalized with an initial AMI. The study population consisted of 1,703 residents of the Worcester (Massachusetts) metropolitan area 25 to 54 years of age who were hospitalized with initial AMIs at all central Massachusetts medical centers during 15 annual periods from 1975 through 2005. Overall hospital incidence rate (per 100,000 residents) of initial AMI in our study population was 66 (95% confidence interval 63 to 69) and incidence rates of AMI decreased inconsistently over time. Patients hospitalized during the most recent study years were more likely to have important cardiovascular risk factors and co-morbidities present but were less likely to have developed heart failure during their index hospitalization. In-hospital and 30-day death rates decreased by approximately 50% (p = 0.04) during the years under study concomitant with increasing use of effective cardiac therapies. In conclusion, the results of this community-wide investigation provide insights into the magnitude, changing characteristics, and short-term outcomes of comparatively young patients hospitalized with a first AMI. Decreasing odds of developing or dying from an initial AMI during the 30 years under study likely reflect increased primary and secondary prevention and treatment efforts.