1. Department of Cardiovascular Surgery, General Hospital of Western Theater Command, Chengdu, Sichuan 610083, P.R. China
2. Medical Team, Unit 95437, People's Liberation Army, Nanchong, Sichuan 637100, P.R. China
3. National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing 400037, P.R. China