1 Department of Internal Medicine, Subdivision of Vascular Medicine, Zuyderland Medical Centre, PO Box 5500, 6130 MB, Sittard/Heerlen, The Netherlands. d.vantwist@zuyderland.nl.
2 Department of Internal Medicine, Subdivision of Vascular Medicine, Zuyderland Medical Centre, PO Box 5500, 6130 MB, Sittard/Heerlen, The Netherlands.
3 Department of Geriatric Medicine, Zuyderland Medical Centre, Sittard/Heerlen, The Netherlands.