2. An intermediate-term study in which the patients from the phase 1 study will be ambulatory. During this phase of the study the effect of continuous maintenance and optimization will be monitored. Patients will come to the hospital for their pumping session at which time the protocol tests will be performed. Patients that were assigned to the conventional/conservative arm in phase 1 will be examined as per protocol at 1, 2 and 3 weeks after admission but BNP levels will be repeated only after the 3rd week.