2. Symptomatic CHF (NYHA class II-IV) at some time during the 6 months before randomization, despite therapy with an ACE inhibitor (however, patients who do not tolerate an ACE inhibitor are eligible). Asymptomatic patients (NYHA class I) with either a prior hospitalization for CHF during the 6 months before randomization or with a left ventricular ejection fraction of </=25% are also eligible.