To investigate the effects of delayed recanalization through percutaneous coronary intervention (PCI) on the left ventricular function after acute anterior wall myocardial infarction in diabetes (DM) and non-DM patients, a total of 125 consecutive subjects with acute anterior wall myocardial infarction were recruited and divided into DM group (n=43) and non-DM group (n=82) based on the presence of DM. All patients received successful PCI at about 2 weeks after symptom onset. Ischemic viable myocardium was detected with low-dose dobutamine stress echocardiogram test, and left ventricular function and wall motion were also assessed before PCI. Clinical manifestations and angiograms before and after PCI were analyzed. Levels of creatinine kinase-MB (CK-MB) and troponin T (TnT) before PCI, 6 and 24 h after PCI were determined. All patients received clinical and echocardiographic follow-up 6 months after PCI. Higher rate of TIMI flow grade 2 and lower rate of TIMI flow grade 3 were observed immediately after PCI, and the elevation of serum CK-MB and/or TnT levels were higher in DM group when compared with non-DM group (P<0.05). In addition, 63% of DM patients and 56% of non-DM patients had viable myocardium before PCI (P>0.05). There were no significant differences in the LVEF, LVEDVI, LVESVI or wall motion score (WMS) between two groups before PCI (P>0.05). But, 6 months after PCI, WMS and LVEF were decreased and increased, respectively, in non-DM group, and the WMS and LVEF in DM group were not changed and the LVEDVI increased, when compared with before PCI. The LVEDVI, LVESVI, LVEF, and WMS differed significantly between two groups 6 months after PCI. Compared with non-diabetics, delayed revascularization with PCI in diabetics with acute myocardial infarction has less benefit on the improvement of left ventricular function, and it may be the insufficient reperfusion or reperfusion injury to myocardium but not the viable myocardium contribute to the poor result.

Key words: Diabetes, myocardial infarction, left ventricular function, percutaneous coronary intervention, delayed recanalization.