To compare rest-injected thallium-201 (Tl) redistribution and resting technetium-99m methoxyisobutylisonitrile (
99mTc-MIBI) myocardial uptake in chronic coronary artery disease (CAD), 15 patients with angiographically proven CAD and left ventricular (LV) dysfunction (ejection fraction 34%±9%) were studied. All patients underwent rest-redistribution Tl and resting
99mTc-MIBI cardiac imaging. Gated
99mTc-MIBI images were also acquired to assess regional LV wall motion (WM). Myocardial segments (
n=225) were divided into three groups on the basis of the degree of coronary artery stenosis: group 1 (total occlusion,
n=82), group 2 (50%–99% of stenosis,
n=84) and group 3 (<50% of stenosis,
n=59). WM was significantly worse in groups 1 and 2 compared to group 3 (
P<0.001), but no difference was observed between groups 1 and 2. TI and
99mTc-MIBI uptake were significantly lower in groups 1 and 2 compared to group 3 (
P < 0.001), and in group 1 compared to group 2 (
P<0.001). When TI and
99mTc-MIBI uptake were directly compared, TI uptake was higher than
99mTc-MIBI uptake in group 1 (
P<0.001), while no significant difference was observed in groups 2 and 3. Thus, both rest-injected TI redistribution and resting
99mTc-MIBI uptake reflected the severity of coronary artery stenosis in CAD. However, in myocardial segments with total coronary occlusion T1 uptake was significantly higher than
99mTc-MIBI uptake. Our data suggest that rest-injected Tl redistribution cardiac imaging may identify, more accurately than resting
99mTc-MIBI imaging, the presence of viable myocardium in chronic CAD, particularly when the coronary blood flow is severely impaired.
相似文献