1. Third Department of Cardiology, “Sotiria” Chest Disease Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
2. Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
3. Emergency Care Department, Laiko General Hospital, Athens, Greece
4. First Department of Cardiology, Hippokration General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
5. Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
6. First Department of Respiratory Medicine, “Sotiria” Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
7. Cardiovascular Division, Harvard Medical School, Brigham and Women’s Hospital, Boston, MA, USA