1. Cardiovascular Center, Seoul National University Hospital, Seoul, Republic of Korea (Y.-J.K., J.K., H.-M.Y., K.W.P., H.-J.K., B.-K.K., J.-K.H., H.-S.K.).
2. Department of Internal Medicine, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea (M.-C.C.).
3. Division of Cardiology, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea (C.-J.K.).
4. Department of Cardiology, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Republic of Korea (Y.A., M.H.J.).