Clinical investigation on the alteration of 99Tcm-MIBI washout rate in ischemic myocardium / 中华核医学杂志

ABSTRACT

Objective To investigate the changes of early and delayed washout rates of 99Tcm-methoxyisobutylisonitrile (MIBI) in ischemic heart disease (IHD), and to explore the value of 99Tcm-MIBI SPECT in evaluating impairment of ischemic myocardial cells. Methods Patients diagnosed of IHD with three-vessel stenosis ( ≥50% ) without myocardial infarction based on angiography (CAG) underwent 99Tcm-MIBI static planar and gated SPECT imaging. The early (90 min after the intravenous injection) and delayed (4 h after the intravenous injection) washout rates of 99Tcm-MIBI and left ventricular ejection fraction (LVEF) of IHD patients and normal subjects were compared using t-test. Linear correlation analysis was performed between the early, delayed washout rates and LVEF measured by gated SPECT. Results Statistically significant lower early washout rate of 99Tcm-MIBI was observed in IHD group than control group (13.44 ± 2.87 )%vs ( 17.32 ± 4.92) %, t = 2.384, P ＜ 0.05, but higher delayed washout rate of 99Tcm-MIBI was observed in IHD group than control group (19.24 ±4.71)% vs (15.23 ±3.81)%, t= -2.246, P＜0.05. LVEF in IHD group was significantly lower than that in control group (55.71 ±7.97)% vs (67.75 ±5.43)%, t =-4.418, P ＜0.01. There were no correlations between the early/delayed washout rates and LVEF, respectively in IHD patients (r = -0.212, P ＞ 0.05; r =0.352, P ＞ 0.05, respectively). Conclusion 99Tcm-MIBI washout rate may reflect myocardial cell impairment due to IHD.