Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan. Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan. Department of Cardiovascular Medicine, Kitasato University School of Medicine, Kanagawa, Japan. Division of Cardiology, Department of Internal Medicine, Nippon Medical School Musashi-Kosugi Hospital, Kanagawa, Japan. Division of Cardiology, Department of Internal Medicine, Niigata Minami Hospital, Niigata, Japan.