1. From the Division of Cardiology (D.-H. Kang, S.-A.L., S.L., D.-H. Kim, J.-M.S., J.-K.S.) and the Departments of Cardiothoracic Surgery (C.-H.C., J.-W.L.) and Biostatistics (S.-C.Y.), Asan Medical Center, College of Medicine, University of Ulsan, the Division of Cardiology, Samsung Medical Center, Sungkyunkwan University School of Medicine (S.-J.P., S.-W.P.), the Division of Cardiology, Severance Hospital (G.-R.H.), and the Cardiovascular Center, Seoul National University Hospital (H.-K.K.) — all in Seoul...