Follow-up. Each patient will undergo a clinical visit or a telephone assessment of his/her clinical conditions at 1 and 3 months after discharge and every 6 months thereafter until the end of the study. Unplanned ambulatory visits will be allowed based on the clinical conditions and needs of the patient. An echocardiographic exam and the assessment of the 6 minutes walk distance will be repeated 6 months after the initial hospitalization. Standard laboratory exams will be repeated at 1, 3 and 6 months after discharge