- Patients must have symptomatic congestive heart failure, NYHA Class II to IV symptoms and an ejection fraction < 40% by nuclear ventriculography within the previous 6 months. Patients must be stable with no change in dosage on conventional therapy (including digoxin, diuretics, ACE inhibitors, hydralazine, nitrates, angiotensin II receptor blockers and/or beta blocker) for at least 4 weeks