[1] Univ Ulsan, Coll Med, Asan Med Ctr, Div Cardiol, Seoul, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Div Biostat, Seoul, South Korea
[3] Keimyung Univ, Dongsan Hosp, Div Cardiol, Daegu, South Korea
[4] Korea Univ, Anam Hosp, Cardiovasc Ctr, Dept Cardiol, Seoul, South Korea
[5] Chung Ang Univ, Gwangmyeong Hosp, Coll Med, Div Cardiol, Seoul, South Korea
[6] Chung Ang Univ, Chung Ang Univ Hosp, Coll Med, Div Cardiol, Seoul, South Korea
[7] Pusan Natl Univ Hosp, Med Res Inst, Dept Internal Med, Div Cardiol, Busan, South Korea
[8] Chonnam Natl Univ, Chonnam Natl Univ Hosp, Med Sch, Dept Cardiol, Gwangju, South Korea
[9] Chungnam Natl Univ, Sejong Hosp, Div Cardiol, Gwangju, South Korea
[10] Yonsei Univ, Gangnam Severance Hosp, Heart Ctr, Div Cardiol,Coll Med, Seoul, South Korea
[11] Kyung Hee Univ, Coll Med, Dept Cardiol, Seoul, South Korea
[12] Konyang Univ Hosp, Dept Cardiol, Daejeon, South Korea
[13] Univ Ulsan, Coll Med, Asan Med Ctr, Div Cardiol, 88,Olymp Ro 43 Gil, Seoul 05505, South Korea