Objective To discuss the relationship between copy number of mitochondrial DNA (mtDNA) in peripheral circulation and short-term prognosis in patients with acute myocardial infarction (AMI). Methods The patients with ST-segment elevation myocardial infarction (STEMI) were chosen from Department of Cardiology in the Seventh People’s Hospital of Zhengzhou City from Jan. 2018 to Dec. 2020. The venous blood sample (5 ml) was collected, and mtDNA copy number in peripheral circulation was detected by using quantitative polymerase chain reaction (qPCR). The patients were treated with percutaneous coronary intervention (PCI) and other related subsequent treatments. The occurrence of severe heart failure (HF), severe atrioventricular block (AVB), ventricular tachycardia/ventricular fibrillation (VT/VF) were recorded after patients were followed up for 30 d. The correlation between mtDNA copy number in peripheral circulation and major adverse cardiovascular events (MACE) were reviewed by using multi-factor COX regression analysis. Results There were totally 253 patients included in this study, and mtDNA was not detected in 27 patients who were divided into negative mtDNA group. The patients (n=226) with positive mtDNA were divided, according to the median of detecting results, into high-level mtDNA group and low-level mtDNA group. The results of multi-factor COX regression analysis showed that the incidence rates of severe HF (HR=1.984, 95%CI: 1.206~3.266, P=0.007), severe AVB (HR=1.936, 95%CI: 1.064~3.525, P=0.031) and VT/VF (HR=4.046, 95%CI: 1.343~12.192, P=0.013) were higher in high-level mtDNA group then those in low-level mtDNA group. Conclusion The copy number of mtDNA in peripheral circulation is correlated to shortterm occurrence of MACE in AMI patients, and higher mtDNA copy number is an important indicator for short-term poor prognosis in AMI patients.
