1. Division of Cardiology Yokohama City University Medical Centre Yokohama Japan
2. Department of Biostatistics and Epidemiology Yokohama City University Medical Centre Yokohama Japan
3. Division of Cardiovascular Diseases Mayo College of Medicine Rochester MN USA
4. Division of Cardiology Fujisawa City Hospital Fujisawa Japan
5. Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan