1. First Critical Care Department, Evangelismos University Hospital, Medical School National and Kapodistrian University of Athens Athens Greece
2. Department of Cardiology and Cardiac Rehabilitation Asklepieio General Hospital Athens Greece
3. Second Department of Surgery, Aretaeion University Hospital, Medical School National and Kapodistrian University of Athens Athens Greece
4. Heart Failure Unit, Cardiac Department G. da Saliceto Hospital Piacenza Italy
5. Heart Failure Unit, Attikon University Hospital, Medical School National and Kapodistrian University of Athens Athens Greece