Prior aspirin use and outcomes in elderly patients hospitalized with acute myocardial infarction

OBJECTIVES We sought to assess the association between prior aspirin use and mortality, A-cause readmission, and condition-specific readmission at one month and six months in a national sample of Medicare beneficiaries hospitalized with a confirmed myocardial infarction (MI). BACKGROUND Prior aspirin use is considered a marker of higher risk in patients with MI, yet the prognostic significance of this factor has been debated. METHODS Medicare beneficiaries >= 65 years old hospitalized with MI were evaluated to determine whether there was an association between prior aspirin use and mortality (n = 118,992), all-cause readmission, and condition-specific readmission (n = 78,975) at one month and six months. RESULTS One-third of the patients (n = 39,531, 33.2%) were using aspirin before admission. Those with prior aspirin use had significantly lower mortality at one month (16.1% vs. 19.0%, p < 0.0001) and six months (24.7% vs. 27.5%, p < 0.0001). After multivariable adjustment, prior aspirin use was found to be associated with a lower risk of one-month (relative risk ratio 0.93, 95% confidence interval [CI] 0.90 to 0.96) and six-month mortality (hazard ratio 0.94, 95% CI 0.91 to 0.96). Prior aspirin use tended to reduce all-cause or coronary artery disease readmissions at one month or six months. CONCLUSIONS Prior aspirin use is not a marker of increased mortality in patients :65 years old hospitalized with MI.