Comparison of thallium myocardial scintigraphy after exercise and transoesophageal atrial pacing in the diagnosis of coronary artery disease.

Forty-nine patients admitted for assessment of chest pain underwent coronary angiography, planar Thallium 201 myocardial scintigraphy after submaximal exercise (TE) and transoesophageal atrial pacing (TAP). Early hypofixation with redistribution after 4 h indicated ischaemia. The criterion for a myocardial infarction (MI) was a fixed perfusion defect. Coronary angiography was carried out in all patients. Sixteen patients (group 1) had no MI and over 50% narrowing of at least one main coronary vessel. Ischaemia was noted in 10 of the 16 patients during exercise, and in 14 of the 16 patients during atrial pacing. The sensitivity for the prediction of coronary stenosis was 62% for TE and 87% for TAP. Nineteen patients (group 2) had had a previous MI. Reversible ischaemia was noted in 10 of the 19 patients during exercise, and in 11 of the 19 patients during TAP. Four of 14 patients with normal coronary arteries (group 3) had a reversible ischaemia with TE, and three of these same patients developed a positive scan with TAP. The respective specificities were 71% and 78%. Comparison of segmental hypoperfusion after TE and TAP gave identical results in 72 of the 80 segments studied in group I (90%), and in 88 of the 95 segments studied in group 2 (92%). The localizing value of TAP was good in left anterior descending (12 out of 18) and right coronary disease (16 out of 19), but poor in left circumflex stenosis (3 out of 9) misclassified as right coronary disease in four patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic accuracy of peak exercise echocardiography in coronary artery disease: comparison with thallium-201 myocardial scintigraphy

To evaluate the accuracy of exercise two-dimensional echocardiography for the recognition of coronary artery disease, 53 patients (46 men and 7 women, age range 35 to 69 years) without either previous myocardial infarction or resting wall motion abnormalities, were studied. According to coronary angiography 26 had normal coronary arteries, 14 had one-vessel, seven had two-vessel, and six had three-vessel disease. After withdrawal of any therapy, all patients underwent a single exercise stress test with a stress table during which cine-loop digitized echocardiography was acquired and 74 MBq of thallium-201 (TI-201) were injected. Echocardiographic images were evaluated at rest and at peak exercise. Three-view planar scintigraphic images were collected immediately after exercise and 4 hours later. For the overall recognition of coronary artery disease, exercise electrocardiography had 77.8% sensitivity and 65.4% specificity; myocardial scintigraphy had 100% sensitivity and 92.3% specificity; and exercise echocardiography had 92.6% sensitivity and 96.2% specificity (both NS versus myocardial scintigraphy). Global accuracy was 71.7% for exercise electrocardiography, 94.3% for stress echocardiography, and 96.2% for myocardial scintigraphy. For the classification of the individual involved coronary arteries, the sensitivity of myocardial scintigraphy was 84.8% and that of exercise echocardiography was 63% (p less than 0.01); the related specificities were 98% and 98.2% respectively (NS). It may be concluded that exercise echocardiography is highly accurate for the recognition of coronary artery disease, whereas it appears less sensitive in the identification of the involved vessels, particularly in patients with multivessel disease.     

CT冠状动脉造影结合腺苷负荷核素心肌灌注显像诊断冠心病的应用价值

目的 探讨CT冠状动脉造影(CTCA)结合腺苷负荷核素心肌灌注显像(MPS)、解剖学成像结合功能学成像,无创全面诊断冠心病的可行性与准确性.方法 105例怀疑或诊断为冠心病的患者,在有创性冠状动脉造影(CAG)检查前4周内完成CTCA与腺苷负荷MPS检查.以CAG结果为参照,分别评价CTCA、负荷/静息MPS及CTCA结合MPS诊断冠心病的可行性、准确性及特点.结果 CTCA诊断冠状动脉阻塞性病变的敏感性为97.1%,特异性为75.0%,阳性预测值为8 8.2%,阴性预测值为93.1%,准确性为89.5%;负荷/静息MPS诊断冠状动脉阻塞性病变的敏感性为79.7%,特异性为63.9%,阳性预测值为80.9%,阴性预测值为62.2%,准确性为74.3%;CTCA结合MPS诊断阻塞性冠状动脉病变的敏感性为97.2%,特异性为98.5%,阳性预测值为98.5%,阴性预测值为89.7%,准确性为95.2%.结论 CTCA结合腺苷负荷MPS可以明显提高CTCA诊断冠心病的特异性及阳性预测值,且解剖学结合功能学成像可全面提供冠心病的诊断信息.

Abstract：

Objective To assess the accuracy and feasibility of combination of CT coronary angiography (CTCA) and adenosine stress myocardial perfusion scintigraphy (MPS) for diagnosis of coronary artery disease (CAD). Methods CTCA, MPS were performed in 105 patients with suspected or diagnosed CAD within 4 weeks before coronary angiography (CAG) examination. Results The sensibility,specificity, positive predictive value ( PPV ), negative predictive value ( NPV ) and accuracy were 97. 1%,75.0%, 88.2%, 93.1% and 89. 5%, respectively, for CTCA; 79.7%,63.9%,80.9%,62.2% and 74. 3%, respectively, for MPS and 97. 2% ,98. 5% ,98. 5% ,89. 7% and 95.2%, respectively, for CTCA +MPS. Conclusion Combination of CTCA and adenosine stress MPS, which provided both anatomical and functional information of coronary vessels, could significantly increase the specificity and PPV of diagnosing CAD with CTCA.     

Intravenous myocardial contrast echocardiography for the diagnosis of coronary artery disease

PURPOSE OF REVIEW: Myocardial contrast echocardiography is a recently developed technique that permits the noninvasive assessment of myocardial perfusion. Myocardial contrast enhancement from microbubbles characteristically reflects the myocardial blood volume. The analysis of microbubble kinetics using quantitative myocardial contrast echocardiography permits the evaluation of myocardial blood flow both at rest and during pharmacological stress. RECENT FINDINGS: Myocardial contrast echocardiography has been shown to have good concordance with single photon emission computed tomography for the localization of perfusion abnormalities. As a result of its better spatial resolution and the fact that it tracks myocardial blood flow changes, it seems to have higher sensitivity for the detection of angiographically significant coronary artery disease, while maintaining similar specificity to single photon emission computed tomography. Low mechanical index imaging techniques (real-time myocardial contrast echocardiography) have the advantage of permitting simultaneous analysis of wall motion and perfusion, which is particularly important during dobutamine stress. Myocardial perfusion analysis using real-time myocardial contrast echocardiography has been shown to have higher sensitivity and diagnostic accuracy than wall motion analysis for the detection of coronary artery disease. Quantitative myocardial contrast echocardiography seems to overcome the expertise requirements for appropriate interpretation of myocardial perfusion images, and may have been demonstrated to be an accurate supplemental technique for estimating the severity of coronary artery disease. SUMMARY: Recent technological advances have positioned myocardial contrast echocardiography as a safe and feasible technique for the evaluation of myocardial perfusion. The analysis of myocardial perfusion using myocardial contrast echocardiography has higher diagnostic accuracy than wall motion analysis for detecting coronary artery disease.     

Role of exercise thallium-201 myocardial perfusion scintigraphy in predicting prognosis in suspected coronary artery disease

While exercise thallium imaging has improved sensitivity and specificity for detection of coronary artery disease (CAD), its predictive value for morbid cardiac events is unclear. Of 532 consecutive patients who underwent exercise thallium imaging, follow-up was complete in 515 (97%) after an average of 36 months (range 31 to 48). Two hundred six patients had an abnormal exercise thallium response and 309 had a normal response. Twenty morbid cardiac events occurred (13 deaths and 7 acute myocardial infarctions [AMI]). Of the 13 patients who died, 12 had abnormal thallium results. Overall, 5.8% of the patients with abnormal thallium results died, in contrast to 0.3% of patients with normal results. Of the 7 patients who had a nonfatal AMI, 3 had abnormal exercise thallium results. Moreover, similar proportions of patients (1.4% and 1.3%) with normal and abnormal exercise thallium results had nonfatal AMI. Presence or absence of pathologic Q waves and inclusion of exercise electrocardiographic results did not significantly alter the results. Thus, although a normal exercise thallium response significantly reduces the likelihood of cardiovascular death, its predictive value for nonfatal AMI is limited. Moreover, the relatively low event rate for patients with a positive exercise thallium response further limits its prognostic value.     

Comparison of the high-dose dipyridamole-echocardiography test and exercise two-dimensional echocardiography for diagnosis of coronary artery disease

Fifty-five patients with effort angina pectoris and technically satisfactory baseline echocardiograms performed a supine exercise-echocardiography test (EET) and a high-dose dipyridamole-echocardiography test (DET, up to 0.84 mg/kg of intravenous dipyridamole in 10 minutes). All underwent coronary arteriography, which showed that at least 1 major artery had more than 70% stenosis in 34 patients. For each patient, the same physician performed both tests, with the same echocardiographic equipment. Detection of new onset or worsening regional asynergy was the only criterion of positivity for both tests. DET yielded interpretable studies in all 55 patients (100%); EET yielded only 40 such studies (73%) (p less than 0.01). In the 40 patients in whom both tests were interpretable, DET showed, compared with EET, a similar sensitivity (72% vs 76%) and specificity (100% vs 87%) (difference not significant for both) for detecting angiographically assessed coronary artery disease. In the 16 patients in whom both DET and EET yielded positive responses for ischemia, the same myocardial region showed reversible asynergy. Thus, independent of all factors that can affect the performance of each test (operator, patient and instrumentation), DET was significantly more feasible than EET, with comparable sensitivity and specificity. Dipyridamole provokes asynergy in the same regions that show ischemia during exercise.     

Evaluation of changes in myocardial perfusion and function on exercise in patients with coronary artery disease by gated MIBI scintigraphy.

OBJECTIVE--To investigate the ability of gated methoxy-isobutylisonitrile (MIBI) scintigraphy to measure changes in myocardial function as well as perfusion with exercise. SETTING--Regional cardiothoracic centre. PATIENTS--43 presenting with chest pain, 28 with coronary artery disease on angiography, and 15 with normal coronary arteriograms. RESULTS--Gated perfusion images showed an improvement in detecting regions with stenosed arteries compared with non-gated images (38/55 v 31/55, p < or = 0.01)). Functional analysis showed an increase in fractional shortening of 4.11% in subjects with normal coronary arteries, whereas in those with coronary disease a fall of 0.57% was found (p < or = 0.01). Both perfusion and function imaging showed an improved sensitivity compared with standard exercise testing (p < or = 0.01). When both function and perfusion imaging were analysed all patients with coronary disease were detected. There was agreement in abnormal regions in 33/55 territories supplied by a stenosed artery. Combined perfusion and function detected 49/55 (89%) of abnormal regions, thus improving the overall sensitivity from 38/55 (69%) by perfusion imaging alone (p < or = 0.01). CONCLUSIONS--Gated methoxy-isobutylisonitrile scintigraphy can successfully evaluate perfusion and function on exercise, so improving the diagnostic usefulness of this agent.     

Combining myocardial perfusion imaging with computed tomography for diagnosis of coronary artery disease

PURPOSE OF REVIEW: To illustrate where the integration of computed tomography with myocardial perfusion single photon tomography may improve current diagnostic imaging paradigms and allow for enhanced risk stratification. RECENT FINDINGS: Computed tomography has the advantage of detecting coronary atherosclerosis at its earliest stages and also identifying patients at high risk for having underlying myocardial ischemia, allowing initiation of appropriate therapeutic measures well before development of obstructive coronary artery disease. Single photon computed tomography can, conversely, clarify the anatomic findings of computed tomography, based on a functional assessment of myocardial blood flow, thereby guiding antiischemic and interventional therapies. SUMMARY: Hybrid imaging with single photon tomography and computed tomography angiography may prove important from a diagnostic and therapeutic viewpoint in several clinical scenarios. It is likely that fusion imaging may more precisely tailor therapy, reduce healthcare costs and improve patient outcome over the next decade.     

Comparison of exercise stress testing with dobutamine stress echocardiography and radionuclide ventriculography for diagnosis of coronary artery disease

Dobutamine stress echocardiography, Tc-99m radionuclide ventriculography (RNVG), and exercise stress testing were performed prospectively in 63 patients with suspected coronary artery disease to compare the values of exercise testing, dobutamine stress echocardiography and RNVG in the non-invasive diagnosis of coronary artery disease. The sensitivities of dobutamine stress echocardiography and RNVG were found to be higher than that of exercise testing (93-62%, p < 0.001; 83-62%, p < 0.05). The sensitivities of dobutamine stress echocardiography and RNVG were similar (p > 0.05). There were no differences between the sensitivities of the three techniques in multiple vessel disease (p > 0.05). The specificities of dobutamine stress echocardiography and RNVG were higher than that of exercise testing (for both of the tests 86-62%, p < 0.05). The diagnostic accuracy of dobutamine stress echocardiography and RNVG were similar (p > 0.05). The results of dobutamine stress echocardiography RNVG were concordant with each other in 46 patients (76%, kappa = 65%) in sectional analysis. Dobutamine stress echocardiography and RNVG tests were comparable with each other in 85% of the 189 segments (kappa = 64%). The expected 5% decrease at peak doses of dobutamine was not detected in stress echocardiography in 25 patients and in RNVG in 26 of the patients. Dobutamine stress echocardiography and RNVG are superior to exercise testing in the diagnosis of single vessel disease and there is no significant difference between the two techniques. When the ejection fraction is considered in dobutamine stress echocardiography and RNVG, it does not make an additional contribution to the diagnosis of coronary artery disease.     

Comparison of exercise radionuclide angiocardiography and thallium-201 myocardial perfusion imaging in coronary artery disease

First pass radionuclide angiocardiography and thallium-201 myocardial perfusion imaging were performed at rest and during exercise in 48 patients with chest pain: 39 with angiographically documented coronary artery disease and 9 with normal coronary arteries. Maximal graded upright bicycle exercise was used for both studies to assure identical exercise conditions. All nine patients without coronary artery disease had normal exercise thallium images, normal exercise regional wall motion and at least a 5 percent absolute increase in left ventricular ejection fraction during exercise (normal exercise left ventricular reserve). Ischemic S-T segment depression was demonstrated in 17 (44 percent) of the 39 patients with coronary artery disease. Findings on the two exercise tests were concordant in all cases. New or augmented thallium perfusion defects were detected in 24 (62 percent) of the 39 patients, whereas abnormal exercise left ventricular reserve was present in 33 (85 percent) (p <0.05). There was a close concordance between exercise-induced perfusion defects and regional wall motion abnormalities. The magnitude of change in ejection fraction from rest to exercise was significantly greater in patients with an abnormal exercise thallium study than in those with a normal study (−8 ± 2 percent versus −1 ± 1 percent, p <0.05). Both radionuclide studies were abnormal In 21 (54 percent) of the 39 patients, whereas both were normal only in 3 patients, all of whom had single vessel disease. Abnormal exercise left ventricular reserve was present in 12 patients with normal exercise thallium studies.     

Dipyridamole-atropine stress echocardiography versus exercise SPECT scintigraphy for detection of coronary artery disease in hypertensives with positive exercise test

OBJECTIVES: Many different stress echocardiographic and radionuclide perfusion imaging tests have been proposed for detecting epicardial coronary artery disease (CAD) in hypertensive patients. Their relative diagnostic and prognostic value has not been exactly established. BACKGROUND: A positive exercise electrocardiography test has a low diagnostic specificity in hypertensive patients and warrants for a complementary imaging test to confirm the diagnosis of coronary artery disease. METHODS: Hypertensive patients (n = 53), (29 males, aged 58 +/- 10 years) with normal left ventricular function detected by echocardiography and previous positive exercise test ( > or = 0.15 mV of ST segment depression on 12 lead electrocardiogram) underwent dipyridamole-atropine stress echocardiography (DASE) and thallium-201 stress/ rest myocardial single-photon emission computed tomography (SPECT). All patients had coronary angiography within 15 days and independently of imaging test results. RESULTS: Coronary angiogram showed significant ( > or = 50% qualitatively assessed diameter reduction) epicardial coronary artery disease in 23 (43%) patients. Sensitivity for detection of coronary artery disease was significantly higher for scintigraphy (DASE = 78% versus SPECT = 100%, P < 0.05) while specificity was higher for echo (DASE = 100% versus SPECT = 47%, P < 0.00001). Diagnostic accuracy was also higher for echo (DASE = 91% versus SPECT = 70%, P < 0.01). CONCLUSION: In patients with exercise-nduced ST segment depression, dipyridamole stress echo and SPECT perfusion scintigraphy are both good diagnostic options, with DASE characterized by higher specificity, lower sensitivity, and at least comparable diagnostic accuracy than SPECT.     

Incremental prognostic power of clinical history, exercise electrocardiography and myocardial perfusion scintigraphy in suspected coronary artery disease

The incremental ability of a clinical history, exercise electrocardiography (ECG) and myocardial perfusion scintigraphy to identify coronary events in the year after testing was assessed in 1,659 patients with symptoms suggestive of coronary artery disease (CAD), 74 of whom suffered a coronary event in the year after testing. Prognostic power was quantified in terms of the area under receiver operating characteristic curves derived from logistic regression. In 1,451 patients with normal rest ECG findings, a clinical history alone provided the most prognostic power (area = 72%). This improved significantly (by 5%) only when both tests were analyzed. In contrast, clinical history had significantly less prognostic power in the 208 patients with abnormal rest ECG findings (area = 58%), but each test then provided a significant incremental improvement in these patients (by 14% for each). A strategic model was thereby developed for prognostic assessment that recognizes the incremental power of these tests in specific patient groups as well as their overall accuracy and monetary cost. This strategy stratified individual patient risk for subsequent coronary events over a full order of magnitude (from 2 to 22%) at a 64% reduction in the cost of testing compared to performing both stress tests in all patients.     

Impact of hypertension on the accuracy of exercise stress myocardial perfusion imaging for the diagnosis of coronary artery disease

AIM—To compare the accuracy of exercise stress myocardial perfusion single photon emission computed tomography (SPECT) imaging for the diagnosis of coronary artery disease in patients with and without hypertension.
METHODS—A symptom limited bicycle exercise stress test in conjunction with 99m technetium sestamibi or tetrofosmin SPECT imaging was performed in 332 patients (mean (SD) age, 57 (10) years; 257 men, 75 women) without previous myocardial infarction who underwent coronary angiography. Of these, 137 (41%) had hypertension. Rest SPECT images were acquired 24 hours after the stress test. An abnormal scan was defined as one with reversible or fixed perfusion defects.
RESULTS—In hypertensive patients, myocardial perfusion abnormalities were detected in 79 of 102 patients with significant coronary artery disease and in nine of 35 patients without. In normotensive patients, myocardial perfusion abnormalities were detected in 104 of 138 patients with significant coronary artery disease and in 16 of 57 patients without. There were no differences between normotensive and hypertensive patients in sensitivity (77% (95% confidence interval (CI) 69% to 86%) v 75% (95% CI 68% to 83%)), specificity (74% (95% CI 60% to 89%) v 72% (95% CI 60% to 84%)), and accuracy (77% (95% CI 70% to 84%) v 74% (95% CI 68% to 80%)) of exercise SPECT for diagnosing coronary artery disease. The accuracy of SPECT was greater than electrocardiography, both in hypertensive patients (p = 0.005) and in normotensive patients (p = 0.0001). For the detection of coronary artery disease in individual vessels, sensitivity was 58% (95% CI 51% to 65%) v 57% (95% CI 51% to 64%), specificity was 86% (95% CI 82% to 90%) v 85% (95% CI 81% to 89%), and accuracy was 74% (95% CI 70% to 78%) v 74% (95% CI 70% to 78%) in patients with and without hypertension (NS).
CONCLUSIONS—In the usual clinical setting, the value of exercise myocardial perfusion scintigraphy for diagnosing coronary artery disease is not degraded by the presence of hypertension.


Keywords: hypertension; coronary artery disease; exercise stress test; myocardial perfusion     

超声心肌声学造影评价冠状动脉狭窄程度对心肌灌注的影响

目的经冠状动脉超声心肌声学造影(MCE)检测基础状态下不同狭窄程度冠状动脉所供应心肌组织灌注状况。方法30例患者行选择性冠状动脉造影,按有无冠状动脉病变及病变血管狭窄程度,将所涉及的共93个心肌节段分为对照组(18个)和病变组(75个),其中病变组又分为轻度狭窄组(12个)、中度狭窄组(28个)、重度狭窄组(35个);超声声学造影剂由冠状动脉直接注入,完成MCE。对心肌灌注进行定性分析,并由心肌灌注时间强度曲线进行定量分析。结果112个心肌节段中有93个(83.0%)获得较满意图像,经视觉判断,病变组共75个心肌节段中,正常灌注的为58个(77.3%),低灌注为17个(22.7%),其中,轻度狭窄组均为正常心肌灌注。定量分析显示,重度狭窄组反映心肌灌注的3个参数值与对照组均存在明显差异(P<0.05);而轻、中度狭窄组各参数值与对照组无明显差异。结论基础状态下,狭窄程度>90%的冠状动脉病变,其心肌组织灌注水平较正常偏低;而当血管狭窄程度≤90%时,心肌灌注水平与正常相似。     

冠状动脉造影与运动负荷心肌灌注显像诊断冠心病的对比分析

目的 :比较冠状动脉造影 (CAG)和运动负荷心肌灌注显像对诊断冠心病 (CHD)的作用。方法 :2 35例患者在 1个月内进行了CAG和运动负荷99mTc MIBI心肌灌注单光子发射计算机断层显像 (SPECT)检查。CAG在主要血管及分支病变狭窄≥ 5 0 %为阳性 ;心肌灌注检查将左室分为 16个节段 ,运动态和静息态相比较 ,存在放射性缺损或填充为阳性。结果 :2 35例中CHD170例 ,其他心脏病 4 3例 ,无器质性心脏病 2 2例。 170例CHD中 ,16 8例CAG阳性 ,16 2例运动SPECT阳性。 4 3例其他心脏病中 13例运动SPECT阳性 (30 .2 % )。 2 2例无器质性心脏病病例中 3例运动SPECT阳性 (13.6 % )。在CHD的诊断中 ,CAG的敏感性为 98.8% ;运动SPECT敏感性为95 .3% ,特异性为 86 .4 %。结论 :在临床工作中 ,CAG和运动SPECT均为诊断CHD的有效手段。由于后者的无创性 ,易于重复 ,是临床随访的较好方法。但在其他心脏病患者 ,运动SPECT阳性率可达 30 .2 % ;在无明显心脏疾病者可达 13.6 %。因此 ,临床上有必要鉴别运动SPECT阳性的非CHD患者