1. Division of Cardiology, Cardiovascular Center, Mediplex Sejong General Hospital, Incheon, Korea.
2. Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
4. Division of Cardiology, Dongsuwon General Hospital, Suwon, Korea.
5. Division of Cardiology, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea.
6. Division of Cardiology, Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.