2nd Department of Cardiology, Attikon University Hospital, National and Kapodistrian University of Athens Medical School, Rimini 1, Chaidari, 12462, Athens, Greece. Cardiology Department, Patras University Hospital, Patras, Greece. Cardiology Department, Hellenic Red Cross General Hospital, Athens, Greece. Department of Cardiology, University Hospital of Ioannina, Ioannina, Greece. Department of Cardiology, Konstantopoulion Hospital, Athens, Greece. Cardiology Department, George Papanikolaou General Hospital, Thessaloniki, Greece. Department of Cardiology, Heraklion University Hospital, Heraklion, Greece. Department of Cardiology, Sismanoglio-Amalia Fleming General Hospital of Athens, Athens, Greece. Cardiology Department, Asklepeion Hospital, Athens, Greece. Department of Clinical Therapeutics, "Alexandra" University Hospital, Athens, Greece. Department of Cardiology, "Tzaneio" General Hospital of Piraeus, Piraeus, Greece. Department of Cardiology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece. 2nd Department of Cardiology, Attikon University Hospital, National and Kapodistrian University of Athens Medical School, Rimini 1, Chaidari, 12462, Athens, Greece. dalex@med.uoa.gr.