BACKGROUND: Although half of elderly patients with heart failure have preserved left ventricular ejection fraction (LVEF), little is known about predictors of mortality in this group. METHODS: We reviewed the charts of 400 patients hospitalized at an academic medical center in 1999 with a principal discharge diagnosis of heart failure. Patients were divided into 4 groups on the basis of age > or =75 or <75 years and the presence of preserved or reduced LVEF. Vital status was ascertained as of October 2001. RESULTS: A total of 373 patients (mean age 69.1 years, 56.0% female, 47.5% nonwhite) underwent echocardiography to assess LVEF. Of these, 216 patients were <75 years of age (81 with preserved LVEF [group 1, 21.7%] and 135 with reduced LVEF [group 2, 36.2%]), and 157 were > or =75 years of age (81 with preserved LVEF [group 3, 21.7%] and 76 with reduced LVEF [group 4, 19.6%]). After a mean follow-up of 25 months, independent predictors of mortality among the 4 groups differed substantially: group 1, male sex, prescription of a calcium-channel blocker, and diuretic dose at discharge; group 2, blood urea nitrogen (BUN), lower hemoglobin level, and not being prescribed a beta-blocker at discharge; group 3, BUN; and group 4, older age, history of myocardial infarction, severity of reduced LVEF, and diuretic dose. CONCLUSION: In patients with heart failure, predictors of mortality vary by age and by the presence of preserved or reduced LVEF. Traditional predictors of mortality in patients with reduced LVEF may not apply to elderly patients with preserved LVEF.