Department of Cardiology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. Electronic address: mitzabe20@yahoo.co.jp. Department of Cardiology, Fujita Health University (FHU) Hospital & FHU Okazaki MC, Toyoake, Japan. Division of Medical Statistics, Fujita Health University School of Medicine, Toyoake, Japan. Department of Cardiology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom. Innovation and Research Support Center, International University of Health and Welfare, Tokyo, Japan. Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan. Caress Sapporo Hokko Memorial Clinic, Sapporo, Japan. Department of Cardiovascular Medicine, Shiga University of Medical Science Hospital, Otsu, Japan. Division of Cardiology, Yokohama City University Medical Center, Yokohama, Japan. Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan. Department of Cardiovascular Medicine, Kumamoto University Hospital, Kumamoto, Japan. Kumamoto University, Kumamoto, Japan. Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. Chiba University, Chiba, Japan. St. Hill Hospital, Ube, Japan. Kyoto University Graduate School of Medicine, Kyoto, Japan. Jichi Medical University, Shimotsuke, Japan.