1. Department of Heart Failure and Transplantation, National Cerebral and Cardiovascular Center , 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565 , Japan
2. Department of Clinical Laboratory, The Sakakibara Heart Institute of Okayama , Okayama , Japan
3. Department of Clinical Laboratory, The National Hospital Organization Osaka National Hospital , Osaka , Japan
4. Department of Cardiology, The Sakakibara Heart Institute of Okayama , Okayama , Japan
5. Department of Cardiovascular Surgery, The Sakakibara Heart Institute of Okayama , Okayama , Japan
6. Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center , Suita , Japan
7. Division of Cardiovascular Physiology, Faculty of Medicine, University of Miyazaki , Miyazaki , Japan