1. Department of Cardiology & National Clinical Research Center for Geriatric Diseases, 2nd Medical Center, Chinese PLA General Hospital, Fuxing Road, Haidian District, Beijing 100853, P.R. China
2. Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Science and Peking Union Medical College , Beijing , P.R. China
3. Beijing Anzhen Hospital, Capital Medical University , Beijing , P.R. China