[1] FuWai Hosp, Dept Cardiol, Beijing 100037, Peoples R China
[2] Chinese Peoples Liberat Army, Dept Geriatr Cardiol, Gen Hosp, Beijing, Peoples R China
[3] Chinese Acad Med Sci, Cardiovasc Inst, Beijing 100730, Peoples R China
[4] Peking Union Med Coll, Beijing 100021, Peoples R China