Sanno Hospital, International University of Health and Welfare, Tokyo, Japan. Department of Cardiovascular Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. masafumi-tky@umin.net. Department of Cardiovascular Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Department of Cardiology, National Defense Medical College, Saitama, Japan. Division of Cardiology, National Center for Global Health and Medicine, Tokyo, Japan. Department of Cardiovascular Medicine, Saiseikai Kawaguchi General Hospital, Saitama, Japan.