National Trends in Recurrent AMI Hospitalizations 1 Year After Acute Myocardial Infarction in Medicare Beneficiaries: 1999–2010

Abstract

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.