1. Department of Cardiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
2. Department of Cardiology, St Marianna University School of Medicine, Kawasaki, Japan
3. Department of Cardiology, Tokushima Red Cross Hospital, Komatsushima, Japan
4. Department of Cardiology, Nagoya Daini Red Cross Hospital, Nagoya, Japan
5. Department of Cardiology, Ibaraki Prefectural Central Hospital, Kasama, Japan
6. Department of Cardiology, Hiroshima University, Hiroshima, Japan
7. Department of Cardiology, National Hospital Organization Kagoshima Medical Center, Kagoshima, Japan
8. Department of Cardiology, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan
9. Department of Cardiology, Tokyo Medical and Dental University, Tokyo, Japan
10. Division of Biostatistics and Clinical Epidemiology, University of Toyama, Toyama, Japan