[1] St Olavs Univ Hosp, Clin Heart Dis, N-7006 Trondheim, Norway
[2] Univ Tromso, Dept Community Med, Tromso, Norway
[3] Univ Tromso, Dept Clin Med, Tromso, Norway
[4] Univ Hosp North Norway, Dept Cardiol, Tromso, Norway
[5] Norwegian Univ Sci & Technol, Dept Publ Hlth & Gen Med, Trondheim, Norway
[6] Norwegian Univ Sci & Technol, Dept Circulat & Med Imaging, Trondheim, Norway
[7] Oslo Univ Hosp, Dept Cardiol, Oslo, Norway
[8] Oslo Univ Hosp, Dept Radiol, Oslo, Norway
[9] Oslo Univ Hosp, Dept Heart Dis, Oslo, Norway
[10] Univ Oslo, Fac Med, Oslo, Norway
[11] Feiring Heart Clin, Dept Cardiol, Feiring, Norway
[12] Haukeland Hosp, Dept Heart Dis, Bergen, Norway
[13] Univ Bergen, Dept Clin Sci, Bergen, Norway
[14] Stavanger Univ Hosp, Dept Cardiol, Stavanger, Norway
[15] Sorlandet Hosp, Dept Med, Arendal, Norway