1 1 Department of Experimental and Clinical Medicine, University of Catania, Catania, Italy ; 2 Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia ; 3 Internal Medicine Clinic II, Helios Vogtland Klinikum Plauen, Academic Teaching Hospital of Leipzig University, Leipzig, Germany ; 4 Department of Cardiology, University Hospital of Zurich, Zurich, Switzerland.