Background: Anemia has been shown to be a predictor of mortality in patients with heart failure and impaired left ventricular systolic function (ISF). Although heart failure in the setting of preserved systolic function (PSF) is an important clinical problem, the relationship between anemia and outcomes in patients with PSF has not been carefully evaluated.
Methods: Patients undergoing diagnostic angiography from 1995 to 2003 with symptomatic heart failure (New York Heart Association class II or greater) were studied (N = 4951). Patients with primary valvular or congenital heart disease were excluded. Patients with ejection fraction < or = 0.40 (N = 1858) were considered the ISF group, and patients with ejection fraction > 0.40 (N = 3093) were classified as the PSF group. Anemia was defined by the World Health Organization criteria (hemoglobin < 13 g/dL for men and < 12 g/dL for women). Multivariable Cox proportional hazards models were used to adjust for baseline differences. The possibility of a differential effect of anemia by systolic function was tested using an interaction term in the multivariable model.
Results: Anemia was independently associated with adverse outcomes across the study cohort (adjusted hazard ratio = 1.53, P < .0001). There was no interaction between anemia and systolic function (ISF vs PSF) in the multivariable model (P = .31 for interaction). The hazard ratio for anemia was 1.61 for PSF patients and 1.45 for ISF patients.
Conclusions: Anemia is an independent predictor of mortality in heart failure, regardless of whether patients have preserved or impaired systolic function. This is the first report of an association between anemia and increased mortality in patients with heart failure and PSF. Future investigations of therapies for anemia in heart failure should consider including patients with PSF.