[1] AHEPA Univ Hosp, Cardiol Dept 1, Thessaloniki 54636, Greece
[2] Klinikum Darmstadt, Darmstadt, Germany
[3] Univ Catania, Osped Ferrarotto, Catania, Italy
[4] Univ Ioannina, Michailide Cardiac Ctr, GR-45110 Ioannina, Greece
[5] Hosp Clin San Carlos, Madrid, Spain
[6] Brighton & Sussex Univ Hosp Trust, Sussex Cardiac Ctr, Brighton, E Sussex, England
[7] Aarhus Univ Hosp, Skejby, Denmark
[8] Univ Hosp Leicester, Leicester, Leics, England
[9] Ist Sci San Raffaele, I-20132 Milan, Italy
[10] Royal Brompton Hosp, London SW3 6LY, England
[11] Univ London Imperial Coll Sci Technol & Med, London, England
[12] Main Taunus Kliniken, Bad Soden, Germany