Secondary outcomes: Incidence of cardiac mortality alone; combined incidence of cardiac deaths, cardiovascular hospitalizations and unplanned ambulatory visits; number of days spent in hospital during the first hospitalization; number of days spent in the hospital during follow-up; changes in the left ventricular ejection fraction, volumes and filling patterns from the first hospitalization to after 6 months; changes in NYHA class and in 6 minutes walk distance; changes in renal function from baseline to discharge and from discharge to the reassessment at 1, 3 and 6 months.