Very early noninvasive detection of acute experimental nonreperfused myocardial infarction with 99mTc-labeled glucarate.
Very early noninvasive detection of acute experimental nonreperfused myocardial infarction with 99mTc-labeled glucarate.
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DOI：
10.1161/01.cir.95.6.1577
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发表时间：
1997-03
期刊：
影响因子：
37.8
通讯作者：
J. Narula;A. Petrov;K. Pak;B. C. Lister;B. Khaw
中科院分区：
文献类型：
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作者：
J. Narula;A. Petrov;K. Pak;B. C. Lister;B. Khaw
研究背景99mTc葡萄糖酸酯最近被报道为一种抗梗死剂。评价99mTcGd显像对非再灌注型和再灌注型心肌梗死早期诊断的可行性，并与同时应用111In抗肌球蛋白定位进行比较。方法和结果实验分为4组，每组6只。兔冠状动脉左前降支(LAD)持续结扎(n=6)或40min后再灌流(n=6)。经201Tl核素显像证实LAD闭塞后，静脉注射99mTc葡萄糖酸盐(15.7+/-1.6mCI)和111In抗肌球蛋白(0.53+/-0.03mCI)。另一组兔(n=6)结扎左前降支5分钟或15分钟，观察99mTcGd对缺血心肌的亲和力。其余6只兔为再灌注性心肌梗死动物，用于99mTc葡萄糖酸亚细胞定位研究。99mTc葡萄糖从循环中迅速清除(消除T1/2，36分钟)。静脉给药后，再灌注区的梗死灶在10分钟内可见，未再灌流区的梗死灶在30分钟内可见。111抗肌球蛋白抗体在1~3小时内显示再灌注性脑梗塞，但在持续闭塞的兔中未见摄取。再灌注组和非再灌注组的99mTc葡萄糖摄取分别是正常心肌的28倍和12倍(P=0.0001)。观察到葡萄糖酸盐和抗肌球蛋白定位之间存在直接相关性(r=0.60；r=0.76；P<；0.0001)。缺血心脏未见葡萄糖摄取。在亚细胞内，99mTc葡萄糖主要分布在梗死灶的胞核部分，线粒体和胞浆部分分布较少。结论对持续性闭塞或再灌注性心肌梗死，99mTcGd可在数分钟内进行无创性心肌梗死显像。早期检测的结果是由于葡萄糖酸盐对急性坏死性心肌组织的快速血液清除和高亲和力。
BACKGROUND 99mTc glucarate has recently been reported to be an infarct-avid agent. The feasibility of imaging with 99mTc glucarate was evaluated for the early diagnosis of nonreperfused and reperfused myocardial infarction and compared with localization of simultaneously administered 111In anti-myosin. METHODS AND RESULTS Four groups of six rabbits each were studied. The left anterior descending coronary artery (LAD) was kept persistently occluded (n = 6) or reperfused after 40 minutes (n = 6) in rabbits. After confirmation of LAD occlusion by 201Tl scintigraphy, a mixture of 99mTc glucarate (15.7 +/- 1.6 mCi) and 111In anti-myosin (0.53 +/- 0.03 mCi) was administered intravenously. Another group of rabbits (n = 6) with 5 or 15 minutes of LAD occlusion were used to assess the affinity of 99mTc glucarate for the ischemic myocardium. The remaining 6 rabbits with reperfused myocardial infarction were used for the assessment of subcellular localization of 99mTc glucarate. 99mTc glucarate cleared rapidly from circulation (elimination t1/2, 36 minutes). Infarcts were visualized within 10 minutes in reperfused and within 30 minutes in nonreperfused coronary territories after intravenous administration. 111In anti-myosin delineated reperfused infarcts within 1 to 3 hours, but no uptake was seen in persistently occluded rabbits. 99mTc glucarate uptake in reperfused and nonreperfused infarct centers was 28 and 12 times greater, respectively, than that in normal myocardium (P = .0001). A direct correlation between glucarate and anti-myosin localization (r = .60 for nonreperfused; 0.76 for reperfused; P < .0001) was observed. Ischemic hearts showed no glucarate uptake. Subcellularly, 99mTc glucarate localized predominantly in the nuclear fraction of the infarct, with lesser extents in the mitochondrial and cytoplasmic fractions. CONCLUSIONS Noninvasive imaging of myocardial infarcts with 99mTc glucarate is possible within minutes in persistently occluded or reperfused myocardial infarcts. Early detectability results from the rapid blood clearance and high avidity of glucarate for the acutely necrotic myocardial tissue.