[1] Seoul Natl Univ Hosp, Dept Internal Med, 101 Daehak Ro, Seoul 03080, South Korea
[2] Seoul Natl Univ, Coll Med, Dept Internal Med, Seoul 03080, South Korea
[3] Univ Liverpool, Liverpool John Moores Univ, Liverpool Ctr Cardiovasc Sci, Liverpool, England
[4] Liverpool Chest & Heart Hosp, Liverpool, England
[5] Aalborg Univ, Dept Clin Med, Aalborg, Denmark