1 Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China.
2 Department of Geratology, Internal Medicine, The Third Hospital of Changsha, Changsha, Hunan 410011, China.
3 Center for Pulmonary Vascular Disease, FuWai Hospital & Cardiovascular Institute Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
4 Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China. Electronic address: xudanyan02@csu.edu.cn.