Lee K S1, Choo M S2, Paick J S 3, Lee J G 4, Seo J T 5, Lee J Z 6, Yoon H 7, Park C H 8, Na Y 9, Jeong Y B 10, Lee J B 11, Park W H 12 1. Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, 2. Asan Medical Center, Univeristy of Ulsan College of Medicine, Seoul, 3. Seoul National University College of Medicine, Seoul, 4. Korea University Anam Hospital, Seoul, 5. Sungkyunkwan University School of Medicine, Seoul, 6. Pusan National University Hospital, Pusan, 7. Ewha Womans University School of Medicine, Seoul , 8. Keimyung University School of Medicine, Daegu, 9. College of Medicine Chungnam National University, Daejeon, 10. Chonbuk National University Medical School, Jeonju, 11. Gachon Medical University, Incheon, 12. College of Medicine Inha University, Incheon