1. Division of Cardiology (D.-Y.K., J.-M.A., H.K., Y.C., J.L., D.-W.P., S.-J.P.), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
2. Division of Biostatistics (S.-C.Y.), Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3. Division of Cardiology, Keimyung University Dongsan Hospital, Daegu, Korea (S.-H.H., Y.-K.C., C.H.L.).
4. Department of Cardiology, Cardiovascular Center, Korea University Anam Hospital, Seoul, Korea (S.J.H., S.L.).
5. Division of Cardiology, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, Korea (S.-W.K.).
6. Division of Cardiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea (H.W.).
7. Division of Cardiology, Department of Internal Medicine, Medical Research Institute, Pusan National University Hospital, Korea (J.-H.O., J.C.C.).
8. Department of Cardiology, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea (Y.J.H.).
9. Division of Cardiology, Chungnam National University Sejong Hospital, Korea (Y.-H.Y.).
10. Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea (Y.W.Y.).
11. Department of Cardiology, College of Medicine, Kyung Hee University, Seoul, Korea (S.-J.K.).
12. Department of Cardiology, Konyang University Hospital, Daejeon, Korea (J.-H.B.).