1. Department of Cardiovascular Surgery, Kanazawa Medical University Himi Municipal Hospital, Kurakawa, Himi, Toyama, Japan
2. Department of Cardiovascular Surgery, Kanazawa Medical University, Uchinada, Kahoku-gun, Ishikawa, Japan
3. Department of Community Medicine, Kanazawa Medical University, Uchinada, Kahoku-gun, Ishikawa, Japan