[1] Univ Hosp S Giovanni Battista, Dept Cardiol, Hosp Molinette, Turin, Italy
[2] Univ Edinburgh, Ctr Cardiovasc Sci, Edinburgh, Midlothian, Scotland
[3] Denver VA Med Ctr, Denver, CO USA
[4] Univ Padua, Div Cardiol, Dept Cardiac Thorac & Vasc Sci, Padua, Italy
[5] Univ Roma La Sapienza, Dept Medicosurg Sci & Biotechnol, I-00185 Rome, Italy