1. Department of Pediatric and Congenital Heart Surgery, Onassis Cardiac Surgery Center, Athens, Greece
2. Clinical Research Office, Onassis Cardiac Surgery Center, Athens, Greece
3. Hellenic Center for Disease Control and Prevention, Athens, Greece
4. Pediatric Intensive Care Unit, “PaidonPentelis” Children’s Hospital, Athens, Greece
5. Department of Thoracic Surgery, Sismanoglio General Hospital of Athens, Athens, Greece