[1] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Internal Med, Seoul, South Korea
[2] Inje Univ, Ilsan Paik Hosp, Dept Internal Med, Goyang, South Korea
[3] Chonnam Natl Univ, Chonnam Natl Univ Hosp, Med Sch, Dept Internal Med, Gwangju, South Korea
[4] Sungkyunkwan Univ, Sch Med, Kangbuk Samsung Hosp, Dept Internal Med, Seoul, South Korea
[5] Chungbuk Natl Univ, Coll Med, Chungbuk Natl Univ Hosp, Dept Internal Med, Cheongju, South Korea
[6] Chung Ang Univ, Gwangmyeong Hosp, Dept Internal Med, Coll Med, Gwangmyeong, South Korea
[7] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Div Cardiol,Dept Med,Heart Vasc Stroke Inst, 81 Irwon Ro, Seoul 06351, South Korea