Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8641, Japan. Department of Cardiology, Ishikawa Prefectural Central Hospital, Kanazawa, Japan. Department of Internal Medicine, Komatsu Municipal Hospital, Komatsu, Japan. Department of Cardiology, Fukui Cardiovascular Center, Fukui, Japan. Department of Internal Medicine, Yokohama Sakae Kyosai Hospital, Yokohama, Japan. Department of Cardiology, Kanazawa Cardiovascular Hospital, Kanazawa, Japan. Department of Cardiology, Toyama Red Cross Hospital, Toyama, Japan. Department of Cardiology, Koseiren Takaoka Hospital, Takaoka, Japan. Department of Internal Medicine, Takaoka Municipal Hospital, Takaoka, Japan. Division of Medical Sciences, Kanazawa University Graduate School of Medicine, Kanazawa, Japan. Cardiovascular Imaging Center, Toyohashi, Japan. Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8641, Japan. myamagi@med.kanazawa-u.ac.jp.