1 Clinical Laboratory Division, National Hospital Organization Shibukawa Medical Center, Gunma, Japan.
2 Division of Cardiology, Department of Cardiology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan. hhayama@hosp.ncgm.go.jp.
3 Division of Cardiology, Department of Cardiology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan.