1. Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA
2. University of Michigan, Ann Arbor, MI, USA
3. Massachusetts General Hospital, Boston, MA, USA
4. National Research Council, Lecce, Italy
5. Robert-Bosch Krankenhaus, Stuttgart, Germany
6. University of Massachusetts Hospital, Worcester, MA, USA
7. Tromsa University Hospital, Tromsa, Norway
8. University of Rostock, Rostock, Germany
9. Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA,