The Effect of Age on Functional and Mortality Outcomes After Acute Myocardial Infarction

OBJECTIVES: To determine the prevalence of post-myocardial infarction (MI) functional decline and to describe its association with chronological age in survivors of MI.
DESIGN: Prospective observational registry.
SETTING: Nineteen U.S. hospitals.
PARTICIPANTS: Two thousand four hundred eighty-one patients with acute MI.
MEASUREMENTS: Baseline and 1-year interviews identified subjects with functional decline, defined as a more than 5-point decline in Medical Outcomes Study 12-item Short Form Questionnaire (SF-12) Physical Component score or being "too ill" to provide a follow-up interview at 1 year. The relationship between age and functional decline was evaluated using logistic regression models adjusted for baseline SF-12 score, comorbidities, sociodemographics, and treatment characteristics. One-year mortality and a combined endpoint of death or decline were also compared across age.
RESULTS: Of 2,009 patients who survived to 1 year, 582 (29%) experienced a functional decline. In survivors, age was not associated with functional decline in unadjusted (odds ratio (OR)=0.95/decade, 95% confidence interval (CI)=0.88–1.03) or multivariable (OR=0.94, 95% CI=0.85–1.05) models. Although age was strongly associated with 1-year mortality (adjusted hazard ratio=1.42, 95% CI=1.21–1.66), there was no association between age and the combined endpoint of death or functional decline (adjusted OR=1.02, 95% CI=0.92–1.12).
CONCLUSION: More than one in four survivors of MI experiences a significant decline in physical function by 1 year. Although age is strongly associated with mortality, it had no association with functional decline. Because older patients have the same potential for favorable functional outcomes after an MI, age alone should not preclude aggressive treatment after an MI.