[1] Korea Univ, Anam Hosp, Coll Med, Dept Cardiol,Cardiovasc Ctr, Seoul 02841, South Korea
[2] Korea Univ, Coll Med, Anam Hosp, Dept Pathol, Seoul 02841, South Korea
[3] Chung Ang Univ, Gwang Myeong Hosp, Heart & Brain Inst, Dept Cardiol,Coll Med, Gwangmyeong Si 14353, South Korea
[4] Univ Ulsan, Ulsan Univ Hosp, Dept Internal Med, Div Cardiol,Coll Med, Ulsan 44033, South Korea
[5] Pusan Natl Univ Hosp, Dept Internal Med, Div Cardiol, Busan 49241, South Korea
[6] Chonbuk Natl Univ, Med Sch, Dept Internal Med, Div Cardiol, Jeonju 54907, South Korea
[7] Chonnam Natl Univ, Chonnam Natl Univ Hosp, Dept Internal Med, Div Cardiol,Med Sch, Gwangju 61469, South Korea