Trends in mortality and recurrent coronary heart disease events after an acute myocardial infarction among Medicare beneficiaries, 2001-2009

Abstract

Few contemporary studies examine trends in recurrent coronary heart disease (CHD) events and mortality after acute myocardial infarction (AMI) and whether these trends vary by race or sex. We used data from the national 5% random sample of Medicare fee-for-service beneficiaries for 1999 to 2010. We included beneficiaries who experienced an AMI (International Classification of Disease [ICD] 9 410.xx, except 410.x2) between January 1, 2001, and December 31, 2009. Each beneficiary's first AMI was included as their index event. Outcomes included all-cause mortality, recurrent AMI, and recurrent CHD events during the 365days after discharge for the index AMI. To examine secular trends, we pooled calendar years into 3 periods (2001-2003, 2004-2006, and 2007-2009). Among 48,688 beneficiaries with index AMIs from 2001 to 2009, we observed decreases in the age-adjusted rates for mortality (-3.8% for each 3-year period, 95% CI -6.1% to -1.6%, P trend = .001), recurrent AMI (-15.0%, 95% CI -18.6% to -11.2%, P trend < .001), and recurrent CHD events (-11.1%, 95% CI -14.0% to -8.0%, P trend < .001) in the 365days after the index AMI. In 2007 to 2009, blacks had excess risk relative to whites for mortality and recurrent AMI (black/white incidence rate ratio of 1.38 for mortality [95% CI 1.21-1.57] and 1.38 for recurrent AMI [95% CI 1.07-1.79]). Despite overall favorable trends in lower mortality and recurrent events after AMI, efforts are needed to reduce racial disparities.