1. Department of Cardiology, Copenhagen University Hospital , Blegdamsvej 9, 2100 Copenhagen , Denmark
2. Department of Cardiology, Nordsjællands Hospital , Dyrehavevej 29, 3400 Hillerød , Denmark
3. Department of Cardiology, Aalborg University Hospital , Hobrovej 18-22, 9000 Aalborg , Denmark
4. Department of Public Health, University of Copenhagen , Øster Farimagsgade 5, 1353 Copenhagen , Denmark