1. Cardiovascular Center, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon, Korea.
2. Cardiac and Vascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Division of Cardiology, College of Medicine, Kyung Hee University, Seoul, Korea.
4. Cardiovascular Center, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
5. Cardiac Catheterization Laboratory & Coronary Intervention, Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
6. Department of Cardiology, Ajou University Hospital, Suwon, Korea.