Feilong Hei is dean and professor of Extracorporeal Circulation Center, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, P.R. China.Yulong Guan is professor of Extracorporeal Circulation Center, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, P.R. China.Kun Yu is professor of Extracorporeal Circulation Center, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, P.R. China.