International, Multicenter, Open-Label and Randomized Withdrawal Study of Oral Lixivaptan in Heart Failure Patients With Chronic Hyponatremia

Capsules containing 25, or 50 mg doses of oral lixivaptan to be administered BID or QD Lixivaptan will be administered for 12 weeks in the Open-Label Period which will be followed by a 4 week Randomized, Placebo-Controlled period.