1. Centro Cardiologico Monzino, IRCCS, Institute of Cardiology, University of Milan
2. Division of Respiratory and Critical Care Medicine, Department of Medicine, University of Washington, Seattle, Washington, USA
3. Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Milan and Department of Cardiology, S. Luca Hospital, Istituto Auxologico Italiano, Milan
4. Department of Cardiovascular, Respiratory and Morphologic Sciences, University “La Sapienza”, Rome
5. Division of Internal Medicine, S. Giuseppe Hospital, Istituto Auxologico Italiano, Piancavallo, Verbania, Italy