[1] Copenhagen Univ Hosp, Dept Cardiol, Rigshosp, Copenhagen, Denmark
[2] North Zealand Hosp, Dept Cardiol, Hillerod, Denmark
[3] Aalborg Univ Hosp, Dept Cardiol, Aalborg, Denmark
[4] Herlev Gentofte Univ Hosp, Dept Cardiol, Herlev, Denmark
[5] Univ Copenhagen, Copenhagen Emergency Med Serv, Copenhagen, Denmark
[6] Univ Liverpool, Liverpool Ctr Cardiovasc Sci, Liverpool, Merseyside, England
[7] Liverpool Heart & Chest Hosp, Liverpool, Merseyside, England
[8] Aalborg Univ, Dept Clin Med, Aalborg, Denmark