Trani Carlo, Giordano Alessandro, Lombardo Antonella, Lupi Alessandro, Reale Francesca, Patrizi Roberto, Patrizi Giampiero, Mazzari Mario A, Schiavoni Giovanni, Maseri Attilio
Institute of Cardiology, Universitá Cattolica del Sacro Cuore, Rome, Italy.
J Nucl Cardiol. 2003 Sep-Oct;10(5):473-81. doi: 10.1016/s1071-3581(03)00522-1.
The main limitation of myocardial single photon emission computed tomography (SPECT) in detecting hibernating myocardium is the poor delivery of radiotracers in hypoperfused areas supplied by severely stenotic coronary arteries. Increasing local availability of radiotracers by intracoronary injection might represent an attractive solution. The hypothesis that the intracoronary administration of sestamibi could improve myocardial SPECT accuracy in detecting hibernating myocardium was addressed in this pilot study.
Seven patients with prior myocardial infarction and severe stenosis of the infarct-related artery underwent myocardial SPECT after intracoronary injection of technetium 99m sestamibi immediately before percutaneous transluminal coronary angioplasty (PTCA). Wall motion and perfusion were evaluated, before and 1 month after PTCA, by 2-dimensional echocardiography and rest-redistribution thallium 201 SPECT. A "low-flow area" was identified on the pre-PTCA Tl-201 SPECT image as the area with less than 50% of maximum radiotracer uptake. Changes in wall motion and perfusion in the low-flow area were compared with results of intracoronary sestamibi imaging. On a pixel-by-pixel analysis, intracoronary sestamibi predicted perfusion recovery within the low-flow area with a 91% sensitivity, a 78% specificity, and an 82% overall accuracy. Only in the 5 patients with an extent of sestamibi uptake greater than one third of the low-flow area was an improved regional and global left ventricular wall motion observed after PTCA (wall motion score index decreased from 1.95 +/- 0.28 to 1.60 +/- 0.34, P =.007; left ventricular ejection fraction increased from 42% +/- 7% to 49% +/- 7%, P =.001; asynergic segments in the low-flow area decreased from 3.6 +/- 0.9 to 1.8 +/- 1.5, P =.021).
In patients with prior myocardial infarction and severe stenosis of the infarct-related artery, sestamibi uptake after intracoronary administration identified viable myocardium that was undetected after rest-redistribution thallium SPECT but capable of clinically significant contractile improvement after revascularization.
心肌单光子发射计算机断层扫描（SPECT）在检测冬眠心肌时的主要局限性在于，放射性示踪剂在严重狭窄冠状动脉所供血的灌注不足区域内递送不佳。通过冠状动脉内注射增加局部放射性示踪剂的可用性可能是一种有吸引力的解决方案。本初步研究探讨了冠状动脉内注射 sestamibi 可提高心肌 SPECT 检测冬眠心肌准确性的假设。
7 例既往有心肌梗死且梗死相关动脉严重狭窄的患者，在经皮冠状动脉腔内血管成形术（PTCA）前即刻冠状动脉内注射锝 99m sestamibi 后接受心肌 SPECT 检查。在 PTCA 前和术后 1 个月，通过二维超声心动图和静息-再分布铊 201 SPECT 评估室壁运动和灌注情况。在 PTCA 前的铊 201 SPECT 图像上，将放射性示踪剂摄取量低于最大摄取量 50%的区域确定为“低灌注区”。将低灌注区内室壁运动和灌注的变化与冠状动脉内 sestamibi 成像结果进行比较。在逐像素分析中，冠状动脉内 sestamibi 预测低灌注区内灌注恢复的敏感性为 91%，特异性为 78%，总体准确性为 82%。仅在 sestamibi 摄取范围大于低灌注区三分之一的 5 例患者中，PTCA 后观察到局部和整体左心室室壁运动有所改善（室壁运动评分指数从 1.95±0.28 降至 1.60±0.34，P = 0.007；左心室射血分数从 42%±7%增至 49%±7%，P = 0.001；低灌注区内运动不协调节段从 3.6±0.9 减少至 1.8±1.5，P = 0.021）。
在既往有心肌梗死且梗死相关动脉严重狭窄的患者中，冠状动脉内注射后 sestamibi 的摄取确定了静息-再分布铊 SPECT 检查后未被检测到但在血运重建后收缩功能有显著临床改善能力的存活心肌。
