1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
2. Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, Korea
3. Cardiovascular Center, Seoul National University Hospital, Seoul, Korea
4. Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Gyeonggi, Korea
5. Department of Medical Statistics, College of Medicine, The Catholic University of Korea, Seoul, Korea