Left atrial strain predicts risk and prognosis in patients with acute coronary syndrome: A retrospective study with external validation oleh Yi-Tong Li, Wen-Qian Shen, Xin Duan, Yang Li, Yan-Xia Wang, Xing-Xing Ren, Qi-Qi Liu, Jia-Wei Tian, Guo-Qing Du