Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea. Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Korea. Division of Nephrology, Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea. Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Cardiovascular Division, Department of Internal Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea. Division of Cardiology, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea. Medical Affairs, Sanofi-Aventis Korea, Seoul, Korea. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.