Marwick T, Willemart B, D'Hondt A M, Baudhuin T, Wijns W, Detry J M, Melin J
Division of Cardiology, Cliniques Universitaires St. Luc, University of Louvain, Brussels, Belgium.
Circulation. 1993 Feb;87(2):345-54. doi: 10.1161/01.cir.87.2.345.
The mechanisms of action of exercise-simulating and vasodilator stressors support their combination with imaging techniques that evaluate left ventricular function and perfusion, respectively. However, reported accuracies of either pharmacological stress together with two-dimensional echocardiography (2DE) or single photon emission computed tomography (SPECT) of myocardial perfusion are similar. The purpose of this study was to establish the optimal stress for each imaging technique by comparing the results of digitized 2DE and 99mTc-methoxyisobutyl isonitrile (MIBI) SPECT using both dobutamine and adenosine stresses in the same patients and conditions.
Ninety-seven consecutive patients without evidence of previous infarction undergoing coronary angiography for clinical indications were studied prospectively. Dobutamine was infused during clinical, ECG, and echocardiographic monitoring in dose increments from 5 to 40 micrograms.kg-1.min-1. Adenosine was infused under the same conditions in doses of 0.10, 0.14, and 0.18 mg.kg-1.min-1. For each protocol, the end points were achievement of peak dose, development of severe ischemia, or intolerable side effects. At peak stress, 20 mCi of MIBI was injected, and SPECT imaging was performed 2 hours later; abnormal poststress images were compared with resting SPECT: Digitized 2DE images were compared qualitatively before, during, and after stress in a cine-loop display. Significant coronary disease (n = 59 patients) was defined by the quantification of > 50% stenosis in a major epicardial vessel. The sensitivity of adenosine 2DE was 58%, less than those of adenosine MIBI (86%, p = 0.001), dobutamine 2DE (85%, p = 0.001), and dobutamine MIBI (80%, p = 0.01). Their respective specificities were 87%, 71%, 82%, and 74% (p = NS). The accuracy of adenosine 2DE was 69%, compared with 80% for adenosine MIBI (p < 0.001), 84% for dobutamine 2DE (p = 0.001), and 77% for dobutamine MIBI (p = 0.005); the latter three did not differ significantly in either sensitivity or accuracy.
This prospective, direct comparison of alternative pharmacological stresses in patients without myocardial infarction shows vasodilator stress scintigraphy and dobutamine stress echocardiography and scintigraphy to share equivalent levels of sensitivity. All three are significantly more sensitive than adenosine stress echocardiography. Dobutamine stress may be used for wall motion or perfusion imaging, but adenosine stress is best combined with perfusion scintigraphy.
运动模拟和血管扩张应激源的作用机制支持将它们与分别评估左心室功能和灌注的成像技术相结合。然而，已报道的药物负荷试验联合二维超声心动图（2DE）或心肌灌注单光子发射计算机断层扫描（SPECT）的准确性相似。本研究的目的是通过在相同患者和条件下比较使用多巴酚丁胺和腺苷负荷试验的数字化2DE和99mTc-甲氧基异丁基异腈（MIBI）SPECT的结果，确定每种成像技术的最佳负荷试验。
对97例因临床指征接受冠状动脉造影且无既往梗死证据的连续患者进行前瞻性研究。在临床、心电图和超声心动图监测下，以5至40微克·千克-1·分钟-1的剂量递增输注多巴酚丁胺。在相同条件下以0.10、0.14和0.18毫克·千克-1·分钟-1的剂量输注腺苷。对于每个方案，终点是达到峰值剂量、出现严重缺血或出现无法耐受的副作用。在负荷试验峰值时，注射20毫居里的MIBI，2小时后进行SPECT成像；将负荷试验后异常图像与静息SPECT进行比较：在电影环显示中对数字化2DE图像在负荷试验前、中、后进行定性比较。通过对主要心外膜血管狭窄>50%进行定量来定义显著冠状动脉疾病（n = 59例患者）。腺苷2DE的敏感性为58%，低于腺苷MIBI（86%，p = 0.001）、多巴酚丁胺2DE（85%，p = 0.001）和多巴酚丁胺MIBI（80%，p = 0.01）。它们各自的特异性分别为87%、71%、82%和74%（p =无显著性差异）。腺苷2DE的准确性为69%，相比之下，腺苷MIBI为80%（p < 0.001），多巴酚丁胺2DE为84%（p = 0.001），多巴酚丁胺MIBI为77%（p = 0.005）；后三者在敏感性或准确性方面无显著差异。
这项对无心肌梗死患者的替代药物负荷试验的前瞻性直接比较表明，血管扩张剂负荷试验闪烁显像、多巴酚丁胺负荷试验超声心动图和闪烁显像具有相当的敏感性水平。这三种方法均比腺苷负荷试验超声心动图敏感得多。多巴酚丁胺负荷试验可用于室壁运动或灌注成像，但腺苷负荷试验最好与灌注闪烁显像相结合。
