Abstract: Objective To investigate the significance of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP)for the future risk evaluation of major adverse cardiac events (MACE) in elderly patients with stable coronary artery disease (SCAD). Methods A total of 810 elderly patients with SCAD were classified into non-MACE group(468 cases) and MACE group [342 cases, including cardiogenic readmission group (200 cases), nonfatal acute myocardial infarction (AMI) group(61 cases) and death group(81 cases)] according to disease prognosis. The 342 cases of MACE group were classified into the short-term MACE group(180 cases)and the long-term MACE group(162 cases). The serum NT-proBNP levels of 40 healthy controls and 810 elderly patients with SCAD, which were followed up in the third month, in the sixth month and in the twelfth month, were determined by bi-directional lateral flow immunoassay. The results were analyzed statistically. The MACE were followed up and observed for an average of 24 months. Results The serum NT-proBNP levels at initial admission in the MACE group and non-MACE group were significantly higher than those in the control group(P<0.01),the serum NT-proBNP levels at initial admission in the MACE group were significantly higher than those in the non-MACE group (P<0.01), the serum NT-proBNP levels at initial admission in the short-term MACE group were significantly higher than those in the long-term MACE group (P<0.05), and the serum NT-proBNP level at initial admission in the death group and nonfatal AMI group were significantly higher than those in the cardiogenic readmission group (P<0.05). The serum NT-proBNP levels at initial admission were negatively correlated with the interval time of the patients with readmission and AMI [r=-0.359(P=0.000),r=-0.458(P=0.026)]. The serum NT-proBNP level was higher,and the incidence rates of MACE were higher. The incidence rates of MACE in different serum NT-proBNP level groups were significantly different (P<0.01), except the NT-proBNP>6 000 ng/L group. Before MACE, the top value of serum NT-proBNP in the MACE group was significantly higher than that in the non-MACE group, and the top value of serum NT-proBNP in the death group was significantly higher than that in the other groups (P<0.05, P<0.01). In the third, sixth and twelfth months of follow-up period, the serum NT-proBNP levels in the MACE group were significantly higher than those at initial admission(P<0.01). The serum NT-proBNP levels in the non-MACE group were significantly lower than those at initial admission(P<0.01), and were significantly lower than those in MACE group(P<0.01). Kaplan-Meier curve showed that the survival rate with different serum NT-proBNP levels had statistical significance (P<0.01). The death group with various diseases had no statistical significance for the serum NT-proBNP levels (P>0.05). Conclusions The incidence rate of MACE and the interval time of the MACE in elderly patients with SCAD are closely correlated with the serum NT-proBNP level at initial admission and with the changes of serum NT-proBNP levels and the top value of serum NT-proBNP in the follow-up period. The serum NT-proBNP determination for the MACE risk evaluation in elderly patients with SCAD has an important prognostic significance.

Key words: N-terminal pro-B-type natriuretic peptide, Elderly stable coronary artery disease, Major adverse cardiac event