1. State Key Laboratory of Cardiovascular Disease, Department of Cardiology, National Clinical Research Center of Cardiovascular Diseases, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, P.R. China
2. Department of Cardiology, National Center of Gerontology, Institute of Geriatric Medicine, Beijing Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, P.R. China