Toshimitsu Kato1, Noriaki Takama2, Tomonari Harada2, Tomonobu Abe3. 1. Department of Clinical Laboratory, Gunma University Hospital, Maebashi, Japan. 2. Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan. 3. Department of Cardiovascular Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan.