BackgroundRecent studies have indicated that monocyte chemoattractant protein-1 (MCP-1) plays an important role in the initiation and progression of ischaemic heart disease. However, no previous research has investigated the correlation between serum MCP-1 levels and early changes in myocardial function in patients with ST-segmental elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI).MethodsA total of 87 STEMI patients who had undergone a successful primary PCI were consecutively recruited. All the patients included in this study were grouped into two subgroups according to the median value of MCP-1 upon admission. An early change in left ventricular ejection fraction (LVEF) was defined as (LVEF at 3months post-STEMI)-(LVEF at 2days post-STEMI).ResultsSerum MCP-1 levels increased gradually over time during the first 72h after the onset of STEMI. The concentration of hypersensitive cardiac troponin I (hs-cTnI) upon admission as well as at 24h and 72h after primary PCI, especially the peak hs-cTnI concentration, declined significantly in the low admission MCP-1 group. As continuous variable, admission MCP-1 also correlated positively with admission hs-cTnI, hs-cTnI at 24h after primary PCI, and peak hs-cTnI. Additionally, the absolute early change in LVEF improved markedly in the low admission MCP-1 group (3.77%6.05% vs -0.18%+/- 7.69%, p=0.009) compared to that in the high admission MCP-1 group. Most importantly, the global LVEF in the low admission MCP-1 group also improved significantly at 3months compared to baseline LVEF (55.79%+/- 7.05% vs 59.60%+/- 6.51%, p=0.011), while an improvement in global LVEF was not observed in the high admission MCP-1 group. Furthermore, as a continuous variable, the MCP-1 level up admission also correlated negatively with early changes in LVEF (r=-0.391, p=0.001). After assessment by multiple linear regression analysis, the MCP-1 level upon admission remained correlated with early changes in LVEF [beta=-0.089, 95% CI (-0.163 to -0.015), p=0.020].Conclusion p id=Par4 MCP-1 upon admission not only correlated positively with hs-cTnI at different time points and peak hs-cTnI, but also associated inversely with early improvements in myocardial function in patients with first STEMI. So we speculated that suppression the expression of MCP-1 via various ways may be a promising therapeutic target in myocardial I/R injury in the future.