1. Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands
2. Department of Cardiology, National University Heart Centre, National University Health System, 5 Lower Kent Ridge Rd, 119074 Singapore
3. Department of Cardiology, AHEPA University Hospital, St.Kiriakidis 1, PO Box 54636 Thessaloniki, Greece
4. Medical Statistics Department, Leiden University Medical Center, Albinusdreef 2, 2300RC Leiden, The Netherlands