1 Liverpool Centre for Cardiovascular Science at University of Liverpool, Liverpool John Moores University and Liverpool Heart & Chest Hospital, Liverpool, United Kingdom.
2 Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
3 Heart Center, Turku University Hospital and University of Turku, Turku, Finland.
4 Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.