1. Department of Cardiovascular Surgery, West China Hospital, Sichuan University , Guo Xue Alley 37, Chengdu, Sichuan 610041 , P.R. China
2. Department of Cardiovascular Surgery, Guang’an Hospital of West China Hospital of Sichuan University , No. 1, Section 4, Binhe Road, Guang’an, Sichuan 638001 , P.R. China