Objective To investigate the value of microcirculation resistance index (IMR) in evaluating the short-term prognosis of acute myocardial infarction (AMI) patients complicated with hyperhomocysteinemia (HHcy).

Methods A total of 80 patients with elective percutaneous coronary intervention (PCI) for AMI were selected.According to the plasma homocysteine (Hcy) level before PCI, these 80 patients were divided into HHcy group with 32 cases (Hcy≥10 μmol/L) and control group with 48 cases (Hcy < 10 μmol/L).The characteristics of coronary angiography, IMR of infarction-related vessels, left ventricular end diastolic diameter (LVEDd) and left ventricular ejection fraction (LVEF) before and after implementation of PCI, and the incidence of major adverse cardiovascular events (MACE) were compared between the two groups.

Results The levels of plasma Hcy, high-sensitivity C-reactive protein (hs-CRP), IMR and LVEDd in the HHcy group were significantly higher than those in the control group, while LVEF was significantly lower than that in the control group (P < 0.01).The difference value of LVEDd from 1 day to 3 months after PCI in the HHcy group was significantly higher than that in the control group, while the LVEF difference value was significantly lower than that in the control group (P < 0.01).Three months after PCI, the incidence of MACE in the HHcy group was significantly higher than that in the control group (P < 0.05).Logistic regression analysis showed that Hcy, LVEF and age were the independent risk factors for incidence of MACE at 3 months after PCI (r=0.335, 0.396, 0.317, OR=3.756, 5.016, 2.702).Hcy level was positively correlated with IMR (r=0.524, P < 0.001) and LVEDd (r=0.430, P=0.003), and negatively correlated with LVEF (r=-0.544, P < 0.001).

Conclusion HHcy is positively correlated with the IMR and severity of cardiac insufficiency, and it is also an important factor for incidence of MACE after elective PCI in patients with AMI.