Background: Case fatality rates after acute myocardial infarction (MI) have decreased markedly over the last 3 decades. Some subgroups may have benefited more than others, but this hypothesis has not been evaluated in a large nationally representative cohort. Accordingly, we sought to assess long-term temporal trends in mortality after hospitalization for MI and to assess whether these trends differ by sex, race, or age in a cohort of elderly patients.
Methods: We studied a cohort of 4.9 million Medicare beneficiaries >or=65 years hospitalized for MI between 1984 and 2003 and calculated the proportion that died inhospital, within 30 days, and within 1 year of hospitalization. We used multivariable risk models to estimate relative and absolute changes in case fatality rate according to race, sex, and age groups.
Results: After adjustment for age, sex, and race, between 1984 and 2003, there was a 54.3% (95% CI 53.7%-54.8%), 39.7% (95% CI 39.1%-40.3%), and 23.0% (95% CI 22.5%-23.5%) reduction in the risk of inhospital, 30-day, and 1-year mortality, respectively. Relative and absolute reductions were greater in whites than in blacks, with the biggest differences observed for 1-year mortality. Small and inconsistent differences were seen by sex after stratifying by race. Patients aged >or=90 years experienced the smallest relative reductions in case fatality rates, with the biggest differences observed for 1-year mortality.
Conclusions: Among US Medicare beneficiaries, short-term MI case fatality rates have decreased significantly in all groups, but more so among whites than blacks. Additional studies are needed to clarify the basis for these observations.