Impact of anemia on physical function and survival among patients with coronary artery disease

Abstract

Background: Anemia is a purported risk factor for adverse outcomes, particularly among patients with cardiac disease. Although anemia at the time of discharge has been associated with poor functional status and survival, its impact over time is not clear. Hypothesis: Among patients with significant coronary artery disease (CAD), anemia (hemoglobin <11 g/dL) is prevalent, and is associated with poor physical function (PF) and survival over time. Methods: Patients with significant CAD at the time of cardiac catheterization (n = 1,821) were enrolled into a single-center, observational, and prospective study. All patients were followed for up to 1 y for clinical events and self-reported PF. Prevalence of anemia at discharge and its' associations with outcomes over time were examined. Results: Anemia at the time of discharge was very common (40.4%), and was associated with increased odds of death at 12 mo (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.12-2.15), yet other clinical factors accompanying anemia accounted for this association (adjusted OR 1.13, 95% CI 0.79-1.62). Discharge anemia was also associated with significantly lower self-reported PF at 6 and 12 mo (p<0.05 for both); however, other clinical factors accompanying anemia also accounted for these associations. Conclusions: Although discharge anemia is highly prevalent, its association with adverse outcomes is largely explained by baseline patient characteristics. Further research is needed to clarify the relationship between anemia and outcomes in this population and to identify subpopulations that do not recover independently and for whom available therapies may be beneficial. © 2008 Wiley Periodicals, Inc.