Furthermore, in the on-pump group, there was a significant difference in serum NSE levels of CHD patients between before and after surgery (SMD = 1.28, 95 % CI = 0.31 ~ 2.25, P = 0.010), particularly at 0 h after surgery (SMD = 2.90, 95 % CI = 0.39 ~ 5.42, P = 0.024), while it was not significant at other time points (6 h: SMD = 0.17, 95 % CI = −2.69 ~ 3.04, P = 0.906; 24 h: SMD = 1.34, 95 % CI = −0.28 ~ 2.95, P = 0.105; 48 h: SMD = 1.75, 95 % CI = −1.10 ~ 4.59, P = 0.229; 72 h: SMD = 0.52, 95 % CI = −0.05 ~ 1.10, P = 0.076) (Fig. 2b). Here, ENO2 is linked to coronary artery disorder.