Remote ischemic conditioning combined with transcutaneous vagus nerve stimulation reduces reperfusion injuries and improves cardiac function in acute ST-segment elevation myocardial infarctions

To investigate whether transcutaneous vagus nerve stimulation (TVNS) combined with left upper limb remote ischemic conditioning (RIC) before primary percutaneous coronary intervention (PCI) in patients with an acute ST-segment elevation myocardial infarction (STEMI) can reduce reperfusion injury and improve cardiac function. One hundred and thirty-two patients with STEMI were randomly assigned to three different groups—Control, TVNS, and Combined (RIC combined with TVNS) before PCI. The groups were compared by calculating and comparing the area under curve (AUC) of a CK-MB test within 72 h of incidence, the severity of ventricular arrhythmias (VAs) within 24 h after reperfusion, and left ventricular ejection fraction (LVEF) via echocardiography seven days after reperfusion. Compared with the control group, the combined group demonstrated significantly decreased areas under the curve (AUCs). Specifically, the incidence of VAs within 24 h after reperfusion and BNP levels seven days post-reperfusion were significantly reduced, while the LVEF values at seven days exhibited a significant improvement (P < 0.05).In contrast, when compared with the control group, the group receiving only TVNS showed a reduction in the incidence of VAs within 24 h after reperfusion. Although the AUC test presented a decreasing trend, the difference was not statistically significant. Additionally, BNP levels and LVEF values in this group did not show significant improvements (P > 0.05). When administered alone, TVNS treatment significantly reduced the incidence of ventricular arrhythmias (VAs) after reperfusion. However, in the acute phase post-reperfusion, there was no significant difference in myocardial infarct size or left ventricular systolic function, despite a tendency towards improvement. In contrast, the combination of TVNS and RIC treatment led to improvements in left ventricular systolic function, reductions in myocardial infarct size, and decreases in the incidence of VAs.