Abstract: Objective To explore the diagnostic value of myeloperoxidase (MPO) combined with high-sensitivity troponin T(hs-TNT)in the elderly patients with acute myocardial infarction (AMI). Methods A total of 122 elderly patients with suspected AMI admitted to Nanjing First Hospital from August 2023 to January 2024 were retrospectively enrolled. According to the time from onset to admission, they were divided into <2 h group, 2－6 h group and >6 h group. The serum levels of MPO, hs-TNT, creatine kinase (CK) and creatine kinase-MB (CK-MB) were detected in all patients and compared between AMI group and non-AMI group. Receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of serum MPO level in elderly patients with AMI. Results Among the elderly patients admitted within 2 h and 2－6 h, the MPO level in AMI group was significantly higher than that in non-AMI group (P<0.05), while there were no significant differences in the levels of hs-TNT, CK and CK-MB between the two groups (all P>0.05). Among the elderly patients admitted after 6 h, there were significant differences in the levels of serum MPO, hs-TNT, CK and CK-MB between AMI group and non-AMI group (all P<0.05). The results of ROC curve analysis showed that in the patients admitted within 2 h and 2－6 h, MPO had a significantly high diagnostic efficacy for AMI, with AUC of 0.85 and 0.83 respectively (both P<0.001). In the elderly patients admitted after 6 h, MPO combined with hs-TNT had a significantly high diagnostic efficacy for AMI (AUC=0.88, P<0.001). Conclusions Serum MPO is a reliable indicator for the diagnosis of AMI in the elderly patients. For those elderly AMI patients with a long time from onset to admission, MPO needs to be combined with hs-TNT for diagnosis.

Key words: myeloperoxidase, high-sensitivity troponin T, acute myocardial infarction, diagnosis, aged