1. Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Federico II University, Naples, Italy.
2. Centro Cardiologico Monzino, IRCCS, Milan, Italy.
3. Cardiologia Riabilitativa, Fondazione S Maugeri, IRCCS, Milan, Italy.
4. Ospedali Riuniti di Trieste, Università degli Studi di Trieste, Trieste, Italy.
5. Heart Failure Unit, Cardiology Department, G da Saliceto Hospital, Piacenza, Italy.
6. Department of Cardiovascular Sciences, University of Milan, Milan, Italy.
7. Division of Respiratory Medicine and Critical Care, University of Washington, Seattle, WA, USA.