[1] Seoul Natl Univ Hosp, Ctr Cardiovasc, Seoul 110744, South Korea
[2] Seoul Natl Univ, Bundang Hosp, Ctr Cardiovasc, Div Cardiol, Songnam 464707, Gyeonggi Do, South Korea
[3] Eulji Gen Hosp, Seoul, South Korea
[4] Kyungpook Natl Univ Hosp, Taegu, South Korea
[5] Dankook Univ Hosp, Cheonan, South Korea
[6] Keimyung Univ, Dongsan Hosp, Taegu, South Korea
[7] Chonbuk Natl Univ Hosp, Jeonju, South Korea
[8] Chungnam Natl Univ Hosp, Taejon, South Korea
[9] Wonju Christian Hosp, Wonju, South Korea
[10] Wonkwang Univ Hosp, Iksan, South Korea
[11] Busan Paik Hosp, Pusan, South Korea
[12] Inha Univ Hosp, Inchon, South Korea
[13] Korea Univ, Guro Hosp, Seoul, South Korea
[14] Yonsei Univ, Severance Hosp, Seoul 120749, South Korea
[15] Konyang Univ Hosp, Taejon, South Korea
[16] Busan Natl Univ Hosp, Pusan, South Korea
[17] Choong Buk Natl Univ, Cheongju, South Korea
[18] Young Nam Univ Hosp, Taegu, South Korea
[19] Chonnam Natl Univ Hosp, Kwangju, South Korea
[20] Seoul Natl Univ, Coll Med, Dept Prevent Med, Med Res Collaborating Ctr, Seoul, South Korea