Background: There are few data characterizing temporal changes in hospitalization for recurrent acute myocardial infarction (AMI) after AMI.
Methods and results: Using a national sample of 2 305 441 Medicare beneficiaries hospitalized for AMI from 1999 to 2010, we evaluated changes in the incidence of 1-year recurrent AMI hospitalization and mortality using Cox proportional hazards models. The observed recurrent AMI hospitalization rate declined from 12.1% (95% CI 11.9 to 12.2) in 1999 to 8.9% (95% CI 8.8 to 9.1) in 2010, a relative decline of 26.4%. The observed recurrent AMI hospitalization rate declined by a relative 27.7% in whites, from 11.9% (95% CI 11.8 to 12.1) to 8.6% (95% CI 8.5 to 8.8) versus a relative decline in blacks of 13.6% from 13.2% (95% CI 12.6 to 13.8) to 11.4% (95% CI 10.9 to 12.0). The risk-adjusted rate of annual decline in recurrent AMI hospitalizations was 4.1% (HR 0.959; 95% CI 0.958 to 0.961), and whites experienced a higher rate of decline (HR 0.957, 95% CI 0.956 to 0.959) than blacks (HR 0.974, 95% CI 0.970 to 0.979).The overall, observed 1-year mortality rate after hospitalization for recurrent AMI declined from 32.4% in 1999 to 29.7% in 2010, a relative decline of 8.3% (P<0.05). In adjusted analyses, 1-year mortality after recurrent AMI hospitalization declined 1.8% per year (HR, 0.982; 95% CI 0.980 to 0.985).
Conclusions: In a national sample of Medicare beneficiaries hospitalized for AMI from 1999 to 2010, hospitalization for recurrent AMI decreased, as did subsequent mortality, albeit to a lesser extent. The risk of recurrent AMI hospitalization declined less in black patients than in whites, increasing observed racial disparities by the end of the study period.
Keywords: epidemiology; mortality; myocardial infarction.
© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.