1. 1st Cardiology Department, General Hospital of Athens “Hippokration”, University of Athens Medical School, 11528 Athens, Greece
2. Department of Cardiology, General Hospital of Athens “G. Gennimatas”, 11527 Athens, Greece
3. 3rd Cardiology Department, Sotiria Regional Hospital for Chest Diseases, University of Athens Medical School, 11527 Athens, Greece
4. Biomedical Research Foundation Academy of Athens, Heart Sector, Hygeia Hospitals Group, Attica, 15123 Athens, Greece