1. Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Cardiovascular Center, Korea University Guro Hospital, Seoul, Korea.
3. Division of Cardiology, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
4. Division of Cardiology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoungnam, Korea.
5. Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Division of Cardiology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, Chungbuk National University College of Medicine, Korea.
8. Department of Internal Medicine, Cardiovascular Center, Seoul National University Hospital, Seoul, Korea.
9. Cardiology Department, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
10. Division of Cardiology, Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Korea.