Does aspirin attenuate the effect of angiotensin-converting enzyme inhibitors on health outcomes of very old patients with heart failure?

Abstract

Concomitant ischemic heart disease (IHD) is common in older individuals with heart failure (HF). We estimated the effect of aspirin use on the rate of mortality, morbidity, and decline in physical functioning in nursing home residents with HF taking angiotensin-converting enzyme (ACE) inhibitors. We conducted a retrospective cohort study using a nursing home database linking resident information collected via the Minimum Data Set (MDS) with drug utilization data. Nursing homes in four states (1992-1995). Of 49,779 residents with HF admitted to these homes, 12,703 residents were taking an ACE inhibitor; 2,046 of these took aspirin. Medicare enrollment files provided the date of death, and we used the Part A Medicare files to identify hospital admissions. The activity of daily living scale from repeat MDS assessments allowed us to evaluate decline in physical function. Cox proportional hazards models provided adjusted estimates of the aspirin effect, with nonusers as the reference group. The overall mortality rate, hospitalization rate,and rate of decline in physical function of aspirin users were not different from those of nonusers (e.g., hospitalization rate ratio = 0.99, 95% confidence interval = 0.92-1.07). This effect did not vary by presence of concomitant IHD or by dose or type of ACE inhibitor. In a cohort of older HF residents receiving ACE inhibitors in nursing homes, we found that treatment with aspirin did not appear to affect outcomes negatively.