1. Department of Medical Sciences, Cardiology and Uppsala Clinical Research Center, Uppsala University, Sweden (S.B., G.S., B.L., D.L., S.J.).
2. Department of Cardiology, Örebro University Hospital, Sweden (O.F.).
3. Landspitali University Hospital, Reykjavik, Iceland (T.G.).
4. Department of Cardiology and Cardiovascular Research Center, University of Iceland, Reykjavik (T.G.).
5. Department of Cardiology, Aarhus University Hospital, Denmark (M.M.).
6. Department of Cardiology, Clinical Sciences, Lund University Hospital, Sweden (G.O.).