From the Cardiac Institute (Y.K., D.P., J.L., W.K., J.A., H.G.S., J.O., J.S.P., S.K., S.L., C.W.L., S.-W.P., S.-J.P.) and Division of Biostatistics (S.Y.), University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea. (At 2011-05-31)