From the Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (H.-C.G., J.-Y.H., Y.B.S., J.-H.C., S.-H.C.); Cardiovascular Center, Seoul National University Main Hospital, Seoul (K.W.P., H.-J.K., B.-K.K., H.-S.K.); Seoul National University Bundang Hospital, Sungnam (I.-H.C.); Korea University Anam Hospital, Seoul (D.-S.L.); Kangdong Sacred Heart Hospital, Seoul (K.-R.H.); Gachon University Gil Medical Center, Incheon (T.A.);... (At 2012-01-24)