1. Clinical Ergospirometry, Exercise & Rehabilitation Laboratory, 1st Critical Care Medicine Department, Evangelismos Hospital, National and Kapodistrian University of Athens, 10676 Athens, Greece
2. Department of Cardiology, 417 Army Share Fund Hospital of Athens (NIMTS), 11521 Athens, Greece
3. Department of Clinical Therapeutics, Faculty of Medicine, Alexandra Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece
4. Division of Cardiovascular Medicine, Section of Heart Failure and Transplantation, University of Iowa Hospitals and Clinics, Iowa, IA 52242, USA
5. Second Cardiology Department, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
6. Immunology and Histocompatibility Department, Evangelismos Hospital, 10676 Athens, Greece
7. Clinical Biochemistry Department, Evangelismos Hospital, 10676 Athens, Greece
8. Department of Cardiology, University Hospital of Larissa, 41334 Larissa, Greece
9. Cardiac Surgery Intensive Care Unit, Onassis Cardiac Surgery Center, 17674 Athens, Greece