Aspirin use in older patients with heart failure and coronary artery disease - National prescription patterns and relationship with outcomes

OBJECTIVES We sought to determine patterns of aspirin use and the relationship between aspirin prescription and outcomes in patients with coronary artery disease (CAD) and heart failure (HF). BACKGROUND Because of the potential for exacerbating hypertension or renal insufficiency and possible interactions with angiotensin-converting enzyme (ACE) inhibitors, the use of aspirin for secondary prevention of coronary events is controversial in patients with HF. METHODS We studied a national sample of Medicare beneficiaries >= 65 years old after hospitalization for HF with CAD and without aspirin contraindications between April 1998 and June 2001. We assessed factors associated with aspirin prescription and the relationship between aspirin and outcomes in regression models accounting for differences in patient, physician, and hospital characteristics and for clustering of patients by hospital. RESULTS Of the 24,012 patients, 54% received aspirin. Treated patients had lower unadjusted rates of death (31% vs. 39% for those not receiving aspirin, p < 0.001). In multivariable analyses, aspirin remained associated with a lower risk of death (risk ratio [RR] 0.94; 95% confidence interval [CI] 0.90 to 0.99). This association was similar regardless of hypertension, renal insufficiency, or treatment with ACE inhibitors (p for all interactions > 0.2). Aspirin also was associated with lower risks of death or all-cause readmission (RR 0.98; 95% CI 0.97 to 0.99) and of death or readmission for HF (RR 0.98; 95% CI 0.96 to 0.99). CONCLUSIONS Almost one-half of patients with CAD hospitalized for HF in the U.S. are not treated with aspirin. This study found no evidence of harm from aspirin in this population and suggests a treatment benefit. Withholding aspirin based upon theoretical concerns about adverse effects appears to be unjustified.