1. Regional Cardiovascular Center, Division of Cardiology, Department of Internal Medicine, Chungbuk National University School of Medicine, Cheongju, Korea.
2. Department of Pathology, Chungbuk National University School of Medicine, Cheongju, Korea.
3. Department of Pathology, College of Medicine, Seoul National University, Seoul, Korea.
4. Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University, Seoul, Korea.