小剂量腺苷负荷低能量心肌声学造影定量评价冠心病心肌灌注的临床研究

目的探索小剂量腺苷负荷低能量心肌声学造影（MCE）的量化指标是否能够准确区分冠心病患者正常、缺血以及再灌注良好的心肌。方法在标准半量（70μg^-1·kg^-1·min^-1）的腺苷负荷条件下用声学造影剂SonoVue和对比脉冲顺序（CPS）成像技术对14例冠心病患者进行心肌声学造影检查，在心尖四腔、两腔切面采集负荷前、负荷后心肌造影图像。用量化分析软件测量拟合图像满意节段的灌注曲线，并计算峰值强度（A）、曲线斜率（β）和灌注量（A·β）。根据患者冠状动脉造影（CAG）或64排CT冠状动脉重建成像（CTA）结果将获得的心肌节段分为无明显狭窄组（第1组）、成功再血管化组（第2组）和严重狭窄组（第3组），比较各组负荷前后灌注指标A、β和A·β的差异，以及在腺苷作用下各组灌注指标的变化量以及变化率。结果49节段心肌中第1组20段（20／49），第2组12段（12／49），第3组17段（17／49）；各组负荷前后灌注指标比较，负荷条件下第1组和第2组灌注增强；第2组和第3组灌注指标的变化量和变化率均低于第1组，第2组A·β增加量高于第3组，第3组在静息状态下灌注无明显减低，但负荷后A、A·β变化量低于第1组和第2组（P〈0．05）；腺苷负荷后A·β〈1．74dB／s诊断冠状动脉狭窄和灌注缺损的敏感性和特异性均为71％；腺苷负荷后A·β增加率〈81％诊断病变血管灌注储备降低的敏感性和特异性分别为83％和79％，β增加率〈54％敏感性和特异性分别为86％和79％。结论小剂量腺苷负荷的量化低能量心肌声学造影能够增加冠心病的临床诊断准确率及经皮冠状动脉介入术（PCI）疗效评价的准确性。其中量化诊断的指标A-β稳定性最好，负荷条件下B、A·β增加率也有较好的诊断价值。

The quantitative evaluation of coronary artery stenosis and myocardial perfusion by low-dose adenosine stress real-time myocardial contrast echocardiography

Objective To assess differentiation of the quantitative low-dose adenosine stress real- time myocardial contrast echocardiography（RT-MCE） among the myoeardium of normal perfusion, perfusion defect and successful reperfusion. Methods The RT-MCE was performed in 14 Randomized CAD patients who took coronary angiography, under a low-dose adenosine stress （70 μg^-1 . kg^-1 . min^-1 ） , with continuously infused SonoVue （Braeco Co. ） （23 ml/h） and CPS imaging system. The myocardial segments were classified into 3 groups according to the angiography results： Group 1, without significant stenosis （〈60%）; Group 2： successfully reperfused segments （TIMI3 flow）; Group 3, significant stenosis （ 〉80% ）. Perfusion images of these segments were analysed to obtain the refilling curves. A, β and A · β of baseline and stress, and the improvement of each viable by adenosine stress were compared among groups. Results Among a total of 49 segments, 20 were in group 1 （20/49）, 12 were in group 2 （ 12/49 ）, 17 were in group 3（17/49）. Perfusion of group 3 did not decrease significantly at baseline, but was lower than group 1 and 2 （ P 〈 0.05 ） after adenosine stress ; perfusion of group 1 （ A, β, A· β ; A, β, P 〈 0.05 ; A · β, P 〈 0.01 ） and 2（ A · β, P 〈0.05 ） were improved during adenosine stress. The improvement of A· β and β were significantly lower in group 2 and 3 than group 1 （ P 〈 0.05 ）. In ROC curve analysis, A · β under adenosine stress 〈 1.74 dB/s had sensitivity and specificity of 71% for diagnosis of coronary stenosis and perfusion defect; and improved adenosine-improving percentage of A · β〈 81% had sensitivity and specificity of 83% and 79% respectively for the diagnosis of low-reserved perfusion, and improved percentage of β〈54%, 86% vs 79%. Conclusions The rest perfusion of severely stenosed arteries is normal, but adenosine stress can detect the impaired perfusion reserve. Low-dose adenosine stress （70 μg^-1 . kg^-1.min^-1） RT-MCE provides good accuracy for the evaluation of coronary perfusion reserve. For the diagnosis of coronary stenosis, A · β under adenosine stress and the adenosine-improving percentage of β and A · β can be used.