1. Ospedali Riuniti di Bergamo, Bergamo, Italy;
2. University of Cologne, Cologne, Germany;
3. University Hospital Ospedale di Circolo e Fondazione Macchi, Varese, Italy;
4. University of Pavia, Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy;
5. S. Bortolo Hospital, Vicenza, Italy;
6. University of Padua, Padua, Italy;
7. Medical University of Vienna, Vienna, Austria;
8. Policlinico Universitario A. Gemelli, Rome, Italy;
9. University of Florence, Florence, Italy; and
10. Mayo Clinic, Rochester, MN