1. Department of Cardiovascular Medicine, Saga University , 5-1-1 Nabeshima, Saga 849-8501 , Japan
2. Division of Cardiology, Saiseikai Futsukaichi Hospital , 3-13-1, Yumachi, Chikushino, Fukoka 818-8516 , Japan
3. Department of Cardiology and Clinical Examination, Faculty of Medicine , Oita University, 1-1, Idaigaoka, Hasama, Yufu, Oita 879-5593 , Japan
4. Education and Research Center for Community Medicine, Faculty of Medicine, Saga University , 5-1-1 Nabeshima, Saga 849-8501 , Japan
5. Department of Pathology and Microbiology, Saga University , Saga , Japan
6. Department of Cardiovascular Medicine, Nippon Medical School Tama Nagayama Hospital , Tama, Tokyo , Japan