1. Cardiovascular Center, Seoul National University Hospital, Republic of Korea (J.-K.H., S. Yang, D.H., S.-H. Park, J. Kang, H.-M. Yang, K.W. Park, H.-J. Kang, B.-K.K., H.-S. Kim).
2. Department of Internal Medicine, College of Medicine, Seoul National University, Republic of Korea (J.-K.H., H.-M. Yang, K.W. Park, H.-J. Kang, B.-K.K., H.-S. Kim).
3. Cardiovascular Center, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea (J.-M. Cho).
4. Department of Cardiology, Heart Center, Saint Carollo Hospital, Sun-cheon, Republic of Korea (J. Cho).
5. Division of Cardiology, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, Republic of Korea (D.W.B.).
6. Division of Cardiology, Department of Internal Medicine, Chungnam National University Sejong Hospital, Chungnam National University School of Medicine, Republic of Korea (J.-H. Lee).
7. Division of Cardiology, Department of Internal Medicine, Pusan National University Hospital, Busan, Republic of Korea (H.C. Lee).
8. Department of Internal Medicine, Ewha Womans University Medical Center, Ewha Womans University School of Medicine, Seoul, Republic of Korea (K.-J. Kim).
9. Department of Cardiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Republic of Korea (W.J.C.).
10. Departments of Internal Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea (W.-W.S.).
11. Division of Cardiology, Department of Internal Medicine, Hallym University Pyeongchon Sacred Heart Hospital, Anyang, Republic of Korea (W.-J. Park).
12. Division of Cardiology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Republic of Korea (S.M. Park).
13. Cardiovascular Center, Guro Hospital Korea University, Seoul, Republic of Korea (J.W. Kim).