1. Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea.
2. Department of Cardiology, Chonnam National University Hospital, Gwangju, Korea.
3. Division of Cardiology, Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
4. Department of Internal Medicine, Gyeongsang National University School of Medicine and Cardiovascular Center, Gyeongsang National University Changwon Hospital, Changwon, Korea.
5. Heart Vascular and Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Division of Cardiology, Department of Internal Medicine and Cardiovascular Centre, Seoul National University Hospital, Seoul, Korea.
7. Division of Cardiovascular, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Korea.
8. Department of Internal Medicine, College of Medicine, Chungbuk National University, Cheongju, Korea.
9. Cardiology Division, Cardiovascular Research Institute, Yonsei University College of Medicine, Seoul, Korea.
10. Cardiovascular Center, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
11. Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Korea.
12. School of Medicine, Kyungpook National University, Daegu, Korea.