1. Division of Cardiology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
2. Division of Cardiology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.
3. Division of Cardiology, Department of Internal Medicine, Kangdong Sacred Heart Hospital, Seoul, Korea.
4. Division of Cardiology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
5. Division of Cardiology, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea.
6. Division of Cardiology, Department of Internal Medicine, The Catholic University of Korea Seoul St. Mary’s Hospital, Seoul, Korea.