Dobutamine technetium-99m tetrofosmin SPECT imaging for the diagnosis of coronary artery disease in patients with limited exercise capacity

BACKGROUND: Technetium-99m tetrofosmin single photon emission computed tomography (SPECT) imaging is increasingly used in conjunction with exercise and vasodilator stress test as a means of evaluating coronary artery disease (CAD). Dobutamine stress test is an alternative in patients with limited exercise capacity. This study assessed the accuracy of dobutamine-atropine stress tetrofosmin SPECT as a means of diagnosing and localizing CAD. METHODS AND RESULTS: We studied 124 patients (mean age, 57+/-12 years; 88 men) with limited exercise capacity and suspected CAD with dobutamine (as much as 40 microg/kg/min)-atropine (as much as 1 mg) Tc-99m tetrofosmin SPECT. Resting images were acquired 24 hours after the stress test. Significant CAD was defined as 50% or greater luminal diameter stenosis in 1 or more major coronary arteries. Myocardial perfusion abnormalities (fixed and/or reversible defects) were detected in 70 of 88 patients with CAD and in 10 of the 36 patients without CAD (sensitivity = 80%, CI, 72 to 87; specificity = 72%, CI, 64 to 80; accuracy = 77%, CI, 70 to 85). Sensitivity and accuracy rates were higher by using the criterion of any defect than by using the criterion of reversible defects only (80% vs 51%, P<.0001; 77% vs 60%, P<.01, respectively). The sensitivity rate was higher in patients with multivessel CAD than in patients with single-vessel CAD (88% vs 63%, P<.05). Patients with multivessel CAD had a larger stress perfusion defect score (4.5+/-3.1 vs. 2.7+/-2.5, P<.01) than patients with single-vessel CAD. CONCLUSION: Dobutamine stress Tc-99m tetrofosmin SPECT is a useful method for the diagnosis and localization of CAD in patients with limited exercise capacity. Optimal accuracy of the technique is achieved by using both fixed and reversible perfusion abnormalities for the diagnosis of CAD in patients without an earlier myocardial infarction.     

Gated Tc-99m sestamibi SPECT versus stress-rest SPECT in detecting coronary artery disease: correlation with coronary angiography in patients without myocardial infarction

PURPOSE: It is possible to simultaneously evaluate wall thickening and perfusion abnormalities with radionuclide techniques that use tracers such as Tc-99m MIBI. We presumed that detection of wall thickening by gated MIBI SPECT imaging in the presence of a stress-induced perfusion defect correlates with reversibility of that defect on resting images. Therefore, the aim of our study was to analyze, in patients without myocardial infarction, resting wall thickening and stress perfusion imaging as an alternative to conventional stress-rest imaging. METHODS AND RESULTS: The patients (n = 44) underwent an exercise (n = 37) or pharmacologic (n = 7) stress protocol. All patients had previous coronary angiography within 3 months. Stress-rest MIBI SPECT and gated MIBI SPECT studies were analyzed by visual scoring. The sensitivity and specificity of segmental analysis of both stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies for the overall detection of coronary artery disease were, respectively, 71% and 96%. For patient evaluation for detection of coronary artery disease, stress-rest MIBI SPECT perfusion and gated MIBI SPECT studies showed a sensitivity rate of 96% for both and specificity rates of 84% and 79%, respectively. CONCLUSIONS: Our data revealed close agreement between reversible perfusion defects on stress-rest MIBI SPECT scans and significant wall thickening on gated MIBI SPECT stress images in patients without previous myocardial infarction (95%). Gated MIBI SPECT stress, without resting studies, which provide an assessment of wall motion and wall thickening, potentially allows stress defect reversibility to be evaluated in patients without previous myocardial infarction.     

Adenosine coronary vasodilation quantitative technetium 99m methoxy isobutyl isonitrile myocardial tomography in the identification and localization of coronary artery disease

Background

Exercise and dipyridamole ^99mTc-labeled methoxy isobutyl isonitrile (MIBI) myocardial scintigraphy have been widely used for the diagnosis of coronary artery disease (CAD). However, only limited data on adenosine ^99mTc-labeled MIBI cardiac imaging are currently available. This study was designed to assess the accuracy of quantitative adenosinerest ^99mTc-labeled MIBI tomography in the diagnosis and localization of CAD.

Methods and Results

Fifty-seven consecutive patients with suspected CAD who underwent coronary angiography and 22 normal volunteers were studied. All patients underwent ^99mTc-labeled MIBI tomography after administration of adenosine (140 μg/kg intravenously for 6 minutes) and at rest. A total of 171 vascular coronary territories were analyzed quantitatively. All patients with CAD (≥50% luminal stenosis) (n=55) had abnormal ^99mTc-labeled MIBI tomograms. The normalcy rate was 86% by quantitative analysis. Overall sensitivity, specificity, and diagnostic accuracy for detection of individual stenosed vessels were 84%, 87%, and 85%, respectively. In patients with one-vessel CAD (n=24), sensitivity and diagnostic accuracy in the detection of individual stenosed vessels were significantly (p<0.05) higher compared with patients with multivessel CAD (n=31). Moreover, 75% of patients with one-vessel disease showed a scintigraphic pattern characterized by the presence of perfusion defects in only one coronary artery territory, and 74% of patients with multivessel disease showed a scintigraphic pattern characterized by the presence of perfusion defects in two or more coronary artery territories. Sensitivity, specificity, and diagnostic accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=18) compared with those with previous myocardial infarction (n=39). In myocardial territories related to noninfarcted areas (n=124), sensitivity and specificity in the detection of stenosed vessels were 75% and 88%. In infarcted areas (n=47), sensitivity and specificity in the detection of stenosed vessels were 98% and 80% (differences not significant vs noninfarcted areas).

Conclusions

Adenosine-controlled coronary vasodilation combined with quantitative ^99mTc-labeled MIBI tomography is accurate for identifying patients with CAD and localizing individual stenosed coronary arteries.     

Accuracy of stress Tc-99m tetrofosmin myocardial perfusion tomography for the diagnosis and localization of coronary artery disease in women

Background  Earlier studies have suggested a modest accuracy of stress thallium 201 myocardial perfusion imaging (MPI) for the diagnosis of coronary artery disease (CAD) in women. The accuracy of stress MPI with technetium 99m tetrofosmin has not been studied in women. The aim of this study was to assess the accuracy of stress Tc-99m tetrofosmin MPI for the diagnosis and localization of CAD in women. Methods and Results  We studied 88 women who underwent exercise or dobutamine stress Tc-99m tetrofosmin tomography and coronary angiography within 3 months. Significant CAD was defined as a stenosis 50% or greater in diameter in at least 1 major epicardial coronary artery. Myocardial perfusion abnormalities were detected in 44 of 53 patients with significant CAD and in 7 of 35 patients without significant CAD (overall sensitivity, 83% [95% confidence interval (CI), 73%-93%]; specificity, 80% [95% CI, 67%-93%]; and accuracy, 82% [95% CI, 74%-90%]). The sensitivity was 72% (18/25) in patients with single-vessel CAD and 93% (26/28) in patients with multivessel CAD. Perfusion abnormalities were detected in 2 or more vascular distributions in 20 of 28 patients with multivessel CAD and in 4 of 60 patients without multivessel CAD (sensitivity for the identification of multivessel CAD, 71% [95% CI, 55%-88%]; specificity, 93% [95% CI, 86%-98%]; and accuracy, 86% [95% CI, 79%-93%]). The sensitivity, specificity, and accuracy were 82%, 84%, and 83%, respectively, for the diagnosis of CAD in the left anterior descending artery; 77%, 84%, and 81%, respectively, for CAD in the right coronary artery; and 74%, 80%, and 78%, respectively, for CAD in the left circumflex artery. Conclusion  Stress Tc-99m tetrofosmin MPI is an accurate noninvasive technique for the diagnosis and localization of CAD in women. Supported in part by a publication grant from GE Healthcare     

Comparison of dobutamine stress echocardiography and technetium-99m sestamibi single-photon emission tomography for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy

Stress echocardiography has been considered an accurate method for the diagnosis of coronary artery disease in hypertensive patients and in patients with left ventricular hypertrophy. In contrast, the specificity of myocardial perfusion scintigraphy in these patients has been questioned. The aim of this study was to compare the accuracy of these two imaging modalities in conjunction with dobutamine stress test for the diagnosis of coronary artery disease in hypertensive patients with and without left ventricular hypertrophy. Dobutamine (up to 40 μg kg^–1min^–1) stress echocardiography in conjunction with sestamibi (MIBI) single-photon emission tomography (SPET) was performed in 84 patients with the diagnosis of systemic hypertension who had been referred for evaluation of myocardial ischaemia. Ischaemia was defined as new or worsened wall motion abnormalities at echocardiography and reversible perfusion defects at SPET. Significant coronary artery disease (≥50% luminal diameter stenosis) was detected in 66 patients (79%). The sensitivity, specificity and accuracy of the ischaemic pattern at echocardiography for the diagnosis of coronary artery disease were 73% (CI 63%–82%), 83% (CI 75%–91%) and 75% (CI 66%–84%), those for MIBI were 67% (CI 57%–77%), 83% (CI 75%–91%) and 70% (CI 60%–80%) respectively (P = NS vs echocardiography). Significant stenosis was detected in 123 (49%) of the 252 analysed coronary arteries. The sensitivity, specificity and accuracy of echocardiography for the regional diagnosis of coronary artery disease were 63% (CI 56%–69%), 90% (CI 86%–94%) and 77% (CI 72%–82%). Those for MIBI were 58% (CI 51%–64%), 91% (CI 87%–94%) and 75% (CI 69%–80) respectively (P = NS vs echocardiography). Left ventricular hypertrophy was detected in 59 patients (70%) by echocardiography and did not influence the overall or regional specificity of echocardiography or MIBI SPET. It is concluded that in hypertensive patients, dobutamine stress echocardiography and MIBI SPET have a comparable accuracy for the overall and regional diagnosis of coronary artery disease. Hypertensive patients with or without left ventricular hypertrophy should not be considered unsuitable candidates for stress myocardial perfusion scintigraphy. Received 10 July and in revised form 19 September 1997     

Incremental value of assessment of regional wall motion for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible perfusion defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether worsening of left ventricular regional wall motion assessed by an automated algorithm in exercise (201)Tl electrocardiography-gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: Two hundred one patients underwent exercise (201)Tl gated SPECT. Software that automatically analyzes left ventricular function was used to assess exercise and rest regional wall motion. Regional wall motion on initial images was compared with that on rest images, that is, delayed images for patients without reinjection images and reinjection images for patients with reinjection images. The left ventricle was divided into 9 segments, with individual segments assigned to 3 coronary territories. Worsening of wall motion was defined as worsening in any segment on initial images compared with rest images. RESULTS: Of 73 patients with multivessel CAD, 20 (27.4%) had reversible perfusion defects in multiple coronary territories, 26 (35.6%) exhibited worsening of regional wall motion in multiple territories, and 37 (50.7%) had reversible perfusion defects or worsening of regional wall motion in multiple territories. The sensitivity of the combination of reversible perfusion defect and worsening of regional wall motion was significantly higher than that of reversible perfusion defect alone for detection of multivessel CAD (50.7% vs. 27.4%, P < 0.05). The specificity of the combination of reversible perfusion defect and worsening of regional wall motion for detecting multivessel CAD did not differ from that of reversible perfusion defect alone and that of worsening of regional wall motion alone (94.5% vs. 99.2% and 97.7%, respectively, P = not statistically significant). CONCLUSION: Combined assessment of worsening of left ventricular regional wall motion by exercise and perfusion data in exercise (201)Tl gated myocardial SPECT was more sensitive, with acceptable specificity, than was assessment with perfusion data alone for detection of multivessel CAD.     

高血压病心肌灌注及硝酸甘油介入显像与室性心律失常关系的研究

目的　探讨高血压病心肌显像异常的临床意义及与心律失常的关系。方法　对 88例高血压患者行99Tcm 甲氧基异丁基异腈心肌灌注断层显像 ,对其中 5 7例显像异常者再行硝酸甘油介入心肌显像。所有患者均行Holter检查 ,冠状动脉造影 31例。结果　运动和静息显像后仍有 6 4 8%患者灌注减低 ,6 0 2 %的灌注减低节段硝酸甘油介入显示有填充或不完全填充 ,提示合并冠心病。多因素逐步回归分析表明 ,室性心律失常与心肌灌注减低的程度及左室肥厚 (LVH)呈线性回归关系。结论　心肌灌注断层显像及硝酸甘油介入心肌显像能反映高血压患者是否合并冠心病 ,并与其他高血压性病理改变所致的灌注减低相区别。高血压合并冠心病及LVH是心律失常的重要病理基础。     

静注潘生丁,锝—甲氧异丁异睛心肌灌注SPECT诊断冠心病的评价

目的:全面评价静注潘生丁99m锝—MIBI心肌单光子发射计算机断层显像术(SPECT)诊断冠心病(CAD)的临床价值.材料和方法:在51名受试者中与冠状动脉造影比较得出SPECT的敏感性、特异性、准确度、阳性预测值、阴性预测值;并将SPECT与活动平板心电图(TECG)、Holter直接比较.结果:SPECT的敏感性为83%、特异性84%、准确度84%、阳性预测值89%、阴性预测值86%;在均接受SPECT、TECG的31例中,前者较后者为优(敏感性89%与68%、特异性77%与54%、准确度84%与62%).在42名受试者中SPECT也较Holter准确(敏感性80%与48%、特异性82%与47%、准确度81%与48%).结论:SPECT心肌灌注显像是准确性较高的诊断CAD的无创伤性方法.     

Dobutamine-atropine stress myocardial perfusion SPECT imaging in the diagnosis of graft stenosis after coronary artery bypass grafting

Objective  To assess the accuracy of dobutamine stress myocardial perfusion single photon emission computed tomographic imaging (SPECT) for the diagnosis of vascular stenosis after coronary artery bypass grafting (CABG). Background  Exercise thallium scintigraphy is a clinically useful method for the diagnosis of graft stenosis after CABG. Although dobutamine perfusion scintigraphy is an alternative method for the evaluation of patients with limited exercise capacity, its value in the diagnosis of vascular stenosis after CABG has not been studied. Methods  Dobutamine (up to 40 μg/kg/min)-atropine (up to 1 mg) stress test in conjunction with myocardial perfusion SPECT imaging (²⁰¹Tl or 99m technetium sestamibi [MIBI]) was performed in 71 patients (mean age 58±9 years, 57 men) with limited exercise capacity referred for evaluation of myocardial ischemia 3.7±3.5 years after CABG. Significant vascular stenosis was defined as ≥50% luminal diameter stenosis of a graft or a native nongrafted coronary artery and was predicted on the basis of reversible perfusion abnormalities. Results  Significant vascular stenosis was detected in 52 patients. Sensitivity, specificity, and accuracy of reversible perfusion defects at dobutamine SPECT for the overall diagnosis of vascular stenosis were 81%, confidence interval (CI) 72 to 90, 79%, CI 69 to 88, and 80%, CI 71 to 90, respectively. Significant vascular stenosis was detected in 73 arterial regions. Sensitivity, specificity, and accuracy of dobutamine SPECT for the diagnosis of regional vascular stenosis were 66%, CI 58 to 74, 83%, CI 76 to 89, and 74%, CI 67 to 81, respectively. Patients with multivessel stenosis had a higher number of ischemic segments (1.6±1.3 vs 1±1, P<.05) and ischemic perfusion score (3.2±2.7 vs 2.2±2.3, P<.05) than patients with single-vessel stenosis, respectively. Significant graft stenosis was detected in 67 graft regions. Sensitivity, specificity, and accuracy of dobutamine SPECT for the diagnosis of regional graft stenosis were 64%, CI 56 to 73, 85%, CI 78 to 91, and 74%, CI 66 to 82, respectively. Conclusion  Dobutamine stress myocardial perfusion SPECT imaging is a useful method for the diagnosis of significant vascular stenosis after CABG in patients with limited exercise capacity. Supported in part by the Department of Cardiology, Cairo University Hospital, Cairo, Egypt and by a grant from the NUFFIC, the Hague, the Netherlands.     

电子束CT检出冠状动脉钙化及其与心肌灌注显像的对比研究

目的比较电子束ＣＴ（ＥＢＣＴ）检查冠状动脉钙化（ＣＡＣ）及核素心肌灌注显像（ＭＰＩ）评价冠心病（ＣＨＤ）的价值。材料与方法本组５０例均为临床疑诊或确诊为ＣＨＤ患者。所有患者均行ＥＢＣＴ、ＭＰＩ及冠状动脉造影。结果４０例患者共８４支血管冠状动脉造影证实有明显的冠状动脉病变（ＣＡＤ）（狭窄＞５０％），其中１４例为单支病变，８例为双支病变，１８例为三支病变，另有１０例冠状动脉造影正常。ＥＢＣＴ预测ＣＡＤ的敏感性、特异性及准确性为８３％、８０％及８２％，ＭＰＩ预测ＣＡＤ的敏感性、特异性及准确性分别为８５％、８０％及８４％，ＥＢＣＴ与ＭＰＩ的结果间无显著性差异（Ｐ＞０．０５）。ＣＡＣ血管供血区出现心肌缺血者达６５％。结论ＣＡＣ是预测ＣＡＤ的有价值指标。在有症状的人群中ＥＢＣＴ检出ＣＡＣ预测ＣＡＤ的敏感性、特异性及准确性与ＭＰＩ相似。有症状人群中检出ＣＡＣ患者多有心肌缺血或梗死，因此为早期诊断冠心病，应对无症状人群进行筛选。     

Incremental value of left ventricular ejection fraction for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether the left ventricular ejection fraction (LVEF) in exercise (201)Tl gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: One hundred eighty-two patients underwent exercise (201)Tl gated SPECT. Automated LV function analysis software was used for calculation of the postexercise and the rest LVEF. The best threshold between 0- to 1-vessel CAD and 2- to 3-vessel CAD was determined as the cutoff that on receiver-operating-characteristic analysis resulted in the best sensitivity for detection of multivessel CAD with an associated specificity of >90%. RESULTS: Only 18 (26.9%) of 67 patients with multivessel CAD had reversible defects in multiple territories. Sensitivities of the postexercise and the rest LVEF and the worsening of the LVEF by exercise did not differ from those of perfusion data alone. Sensitivities of the combination of perfusion data and the postexercise and rest LVEF did not differ from those of perfusion data alone, whereas the sensitivity of the combination of perfusion data and worsening of the LVEF (i.e., reversible defects in multiple territories or worsening of the LVEF >5.6% [or both]) was significantly greater than that of perfusion data alone (43.3% vs. 26.9%; P < 0.05), with an acceptable level of specificity (90.4%). CONCLUSION: The worsening of the LVEF by exercise has the potential to detect patients with multivessel CAD among those without multivessel patterns of reversible defects.     

Sensitivity,specificity and accuracy of stress SPECT myocardial perfusion imaging for detection of coronary artery disease in the distribution of first-order branch vessels,using an anatomical matching of angiographic and perfusion data

We sought to investigate the utility of stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the identification of coronary artery disease (CAD) in the distribution of first-order branch vessels. We evaluated 135 consecutive patients with coronary angiography and stress SPECT MPI. We anatomically matched angiography and SPECT to assess the sensitivity, specificity and accuracy of SPECT MPI for the detection of CAD in the distribution of first-order branches. Subgroup analysis for stress test performance and previous coronary artery bypass grafting (CABG) was also performed. The sensitivity, specificity and accuracy of stress SPECT MPI for the detection of CAD in the distribution of first-order branch vessels were all 67%. For isolated branch vessel CAD, stress SPECT MPI had a sensitivity of 44%. In patients without CABG, the sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order branch vessels were 71%, 67% and 68%, compared with 60%, 67% and 64% for patients with CABG. The sensitivity for isolated branch vessel CAD was 50% for patients without CABG, but only 29% for patients with CABG. The sensitivity and specificity for CAD in the distribution of branch vessels were similar for all patients for all stress test modalities and heart rate response (sensitivity, 64-69%; specificity, 61-69%). Stress SPECT MPI offers intermediate sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order coronary artery branch vessels. However, for isolated branch vessel CAD, stress SPECT has a lower sensitivity, particularly in patients with previous CABG.     

Quantitative coronary arterial stenosis assessment by multidetector CT and invasive coronary angiography for identifying patients with myocardial perfusion abnormalities

Background

Semi-quantitative stenosis assessment by coronary CT angiography only modestly predicts stress-induced myocardial perfusion abnormalities. The performance of quantitative CT angiography (QCTA) for identifying patients with myocardial perfusion defects remains unclear.

Methods

CorE-64 is a multicenter, international study to assess the accuracy of 64-slice QCTA for detecting ??50% coronary arterial stenoses by quantitative coronary angiography (QCA). Patients referred for cardiac catheterization with suspected or known coronary artery disease were enrolled. Area under the receiver-operating-characteristic curve (AUC) was used to evaluate the diagnostic accuracy of the most severe coronary artery stenosis in a subset of 63 patients assessed by QCTA and QCA for detecting myocardial perfusion abnormalities on exercise or pharmacologic stress SPECT.

Results

Diagnostic accuracy of QCTA for identifying patients with myocardial perfusion abnormalities by SPECT revealed an AUC of 0.71, compared to 0.72 by QCA (P?=?.75). AUC did not improve after excluding studies with fixed myocardial perfusion abnormalities and total coronary arterial occlusions. Optimal stenosis threshold for QCTA was 43% yielding a sensitivity of 0.81 and specificity of 0.50, respectively, compared to 0.75 and 0.69 by QCA at a threshold of 59%. Sensitivity and specificity of QCTA to identify patients with both obstructive lesions and myocardial perfusion defects were 0.94 and 0.77, respectively.

Conclusions

Coronary artery stenosis assessment by QCTA or QCA only modestly predicts the presence and the absence of myocardial perfusion abnormalities by SPECT. Confounding variables affecting the relationship between coronary anatomy and myocardial perfusion likely account for some of the observed discrepancies between coronary angiography and SPECT results.     

Dobutamine stress thallium-201 single-photon emission tomography versus echocardiography for evaluation of the extent and location of coronary artery disease late after myocardial infarction.

Dobutamine stress echocardiography and thallium-201 myocardial perfusion scintigraphy are clinically useful methods for the evaluation of coronary artery disease (CAD). However, the relative merits of these imaging modalities in the evaluation of the extent of CAD after myocardial infarction have not been well studied. The aim of this study was to compare the accuracy of dobutamine stress echocardiography and simultaneous 201Tl single-photon emission tomography (SPET) imaging for the diagnosis and localization of CAD late after acute myocardial infarction. Dobutamine (up to 40 micrograms kg-1 min-1)-atropine (up to 1 mg) stress echocardiography in conjunction with stress-reinjection 201Tl SPET was performed for the evaluation of myocardial ischaemia in 90 patients with previous myocardial infarction who underwent coronary angiography. Significant CAD was predicted on bases of myocardial ischemia (new or worsening wall motion abnormalities on echocardiography and reversible perfusion defects on 201Tl SPET). Significant CAD (> or = 50% luminal diameter stenosis) was detected in 73 (81%) patients. The sensitivity, specificity and accuracy of echocardiography in detecting remote ischaemia for the diagnosis of remote CAD (present in 53 patients) were, respectively, 79% (CI 70%-88%), 85% (CI 77%-93%) and 81% (CI 73%-90%), while the corresponding figures for 201Tl SPET were 75% (CI 66%-85%), 78% (CI 69%-87%) and 76% (CI 67%-86%) respectively (P = NS vs echocardiography). The sensitivity, specificity and accuracy of echocardiography in detecting peri-infarction ischaemia for the diagnosis of infarct-related artery stenosis (present in 70 patients) were, respectively, 77% (CI 68%-86%), 85% (CI 78%-92%) and 79% (CI 70%-87%) while the corresponding figures for 201Tl SPET were 73% (CI 64%-82%), 85% (CI 78%-92%) and 76% (CI 67%-84%) respectively (P = NS vs echocardiography). The agreement between the two methods for the diagnosis of peri-infarction and remote ischaemia was 70% (kappa = 0.37) and 80% (kappa = 0.59) respectively. It is concluded that dobutamine stress echocardiography and 201Tl SPET have comparable accuracy for the diagnosis of infarct related and remote CAD in patients with previous myocardial infarction. The agreement between the methods is higher for the diagnosis of remote CAD than for that of peri-infarction ischaemia.     

Added value of coronary artery calcium score as an adjunct to gated SPECT for the evaluation of coronary artery disease in an intermediate-risk population.

The coronary artery calcium (CAC) score is a readily and widely available tool for the noninvasive diagnosis of atherosclerotic coronary artery disease (CAD). The aim of this study was to investigate the added value of the CAC score as an adjunct to gated SPECT for the assessment of CAD in an intermediate-risk population. METHODS: Seventy-seven prospectively recruited patients with intermediate risk (as determined by the Framingham Heart Study 10-y CAD risk score) and referred for coronary angiography because of suspected CAD underwent stress (99m)Tc-tetrofosmin SPECT myocardial perfusion imaging (MPI) and CT CAC scoring within 2 wk before coronary angiography. The sensitivity and specificity of SPECT alone and of the combination of the 2 methods (SPECT plus CAC score) in demonstrating significant CAD (>/=50% stenosis on coronary angiography) were compared. RESULTS: Forty-two (55%) of the 77 patients had CAD on coronary angiography, and 35 (45%) had abnormal SPECT results. The CAC score was significantly higher in subjects with perfusion abnormalities than in those who had normal SPECT results (889 +/- 836 [mean +/- SD] vs. 286 +/- 335; P < 0.0001). Similarly, with rising CAC scores, a larger percentage of patients had CAD. Receiver-operating-characteristic analysis showed that a CAC score of greater than or equal to 709 was the optimal cutoff for detecting CAD missed by SPECT. SPECT alone had a sensitivity and a specificity for the detection of significant CAD of 76% and 91%, respectively. Combining SPECT with the CAC score (at a cutoff of 709) improved the sensitivity of SPECT (from 76% to 86%) for the detection of CAD, in association with a nonsignificant decrease in specificity (from 91% to 86%). CONCLUSION: The CAC score may offer incremental diagnostic information over SPECT data for identifying patients with significant CAD and negative MPI results.     

Stress myocardial perfusion imaging versus echocardiography for the diagnosis and risk stratification of patients with known or suspected coronary artery disease

Stress perfusion imaging and stress echocardiography (ECHO) are both very useful for assessment of diagnosis and risk stratification of patients with coronary artery disease (CAD). Both techniques have been well validated during exercise and inotropic stress, but coronary vasodilation stress is better used in combination with perfusion imaging. The overall sensitivity for detection of CAD is slightly higher by single photon emission computed tomography (SPECT) than by two-dimensional (2D) ECHO during all stress modalities, whereas the specificity is slightly higher by ECHO, although the differences in general are not statistically significant. SPECT, however, appears to be superior to ECHO in the diagnosis of isolated circumflex stenosis, as well as for the correct identification of multivessel CAD. A substantially greater amount of information is available regarding risk stratification with SPECT than with 2D ECHO. Although the data suggest that both techniques are very useful for risk stratification of patients with stable CAD, after myocardial infarction, and for preoperative risk stratification, the risk for cardiac events is lower in the presence of a normal stress SPECT study than of a normal stress ECHO.     

99Tcm-MIBI静息心肌断层显像对年轻心肌梗死患者心肌损伤的评价

目的　用99Tcm 甲氧基异丁基异腈 (MIBI)静息SPECT显像评价年轻心肌梗死患者的心肌损伤。方法　总结分析了 42例年龄 <40岁的心肌梗死患者99Tcm MIBI静息心肌灌注断层显像 ,并与冠状动脉造影和ECG进行比较。结果　 42例年轻心肌梗死患者 ,90 % (38例 )心肌灌注显像异常 ,10 % (4例 )未见明显异常 ,诊断灵敏度为 90 %。与ECG相比 ,心肌灌注显像对梗死灶定位更准确 ,特别是心尖和后壁梗死。结论　心肌灌注显像显示年轻心肌梗死患者心肌受损较严重。     

The value of Tc-99m MIBI SPECT during isosorbide dinitrate infusion in assessment of viable myocardium in patients with myocardial infarction

Tc-99m MIBI myocardial SPECT has shown promise for evaluation of coronary artery disease. But its role in predicting myocardial viability is still under investigation. The purpose of this study was to evaluate the value of Tc-99m MIBI myocardial SPECT during isosorbide dinitrate (ISDN) infusion in the assessment of myocardial viability. Thirty-seven patients with previous myocardial infarction (the infarct age ranged from ≤ 30 days to 900 days) were studied, of them 13 patients had Tc-99m MIBI studies before and after coronary artery bypass grafting (CABG). The results showed that out of 134 segments with hypoperfusion at resting SPECT, 56 segments (41.8%) had an increase in Tc-99m MIBI uptake during ISDN infusion. Among them, 17 segments (30.4%) were normalized, 6 segments (10.7%) were significantly improved and 33 segments (58.9%) were improved. The degree of improvement in perfusion was related to the age of the myocardial infarction. In 13 patients with CABG, of 31 segments with improvement in perfusion post CABG, 25 segments (80.6%) showed perfusion improvement during ISDN infusion, and of 28 segments with improved wall motion post CABG, 23 segments (82.1 %) showed improvement in perfusion during ISDN infusion. Tc-99m MIBI SPECT during ISDN infusion may therefore be a useful approach for assessing myocardial viability.     

Clinical implication of reverse redistribution on99mTc-sestamibi images for evaluating ischemic heart disease

OBJECTIVE: The purpose of this study was to clarify the usefulness of 99mTc-sestamibi (MIBI) delayed imaging in the assessment of the severity of myocardial ischemia in patients with coronary artery stenosis. METHODS: Forty-three angina pectoris with coronary stenosis of greater than 75% were enrolled in this study. Myocardial perfusion SPECT images were obtained 1 and 6 hours after an intravenous injection of MIBI at rest. Stress myocardial perfusion SPECT images were also acquired after the injection of MIBI. And myocardial fatty acid metabolism images were obtained 30 minutes after the injection of BMIPP at rest. Myocardial perfusion SPECT images were divided into 20 segments which were semiquantitatively assessed according to a 4-level defect score scale: score 0 (normal) to score 3 (severely); then the extent score (ES) and severity score (SS) were calculated. RESULTS: The sensitivity for myocardial ischemia showed the highest rate at 88.3% with MIBI delayed SPECT. According to the coronary angiography findings, MIBI stress SPECT and MIBI delayed SPECT detected the severity and extent of ischemia with more sensitivity than MIBI early SPECT in 12 patients (group A) with stenosis of more than 75% but less than 90% (p < 0.01). Even though MIBI stress SPECT detected the severity and extent of ischemia in 31 patients (group B) with stenosis of more than 90% but less than 100%, there was no significant difference between MIBI stress SPECT and MIBI delayed SPECT. BMIPP SPECT revealed significant differences between group A and group B regarding the severity of myocardial ischemia. MIBI reverse redistribution was observed in 33 patients and no significant difference existed between groups A and B. CONCLUSIONS: Myocardial washout of MIBI was frequently observed in patients with angina pectoris and the detection accuracy for ischemia was high. MIBI imaging is considered useful for assessment not only of myocardial perfusion but also mitochondrial function. The imagings with BMIPP and delayed MIBI could serve to determine the severity of myocardial ischemia more accurately.     

Clinical evaluation of the 99mTc-CPI myocardial perfusion imaging

99mTc-CPI myocardial perfusion scintigraphy including planar images in 35 patients and SPECT images in 16 patients has been studied. Scintigraphic data revealed that high quality 99mTc-CPI myocardial perfusion images were obtained. The sensitivity and specificity of 99mTc-CPI planar images in detecting CAD was 92% and 80% respectively. There was no significant difference in sensitivity for detecting CAD between planar and SPECT. However, the specificity of SPECT was much better than that of planar imaging.