Exercise thallium-201 scintigraphy in the localization of myocardial ischaemia

Summary. We performed a retrospective study in order to study the ability of thallium-201 exercise scintigraphy to detect and to localize coronary artery perfusion defects (in comparison with a recent coronary angiogram). We studied 81 patients (67 males); their average age was 52.3 years (men 50.5 and women 54.1 years). They performed a pulse-conducted cycle exercise test, and 2 min before end of exercise 75 MBq of thallium-201 was infused intravenously, and tomographic images were reconstructed by using a Siemens-Rota SPECT gamma camera immediately and 4 h after exercise. The thallium-201 uptake defects were attributed to different coronary arteries, and the results were compared with a coronary angiogram made afterwards in 48 patients. The groups of one-, two- and three-vessel disease were 27, 21, and 21 patients, and only 12 patients did not have significant (over 50%) stenoses. The latter had the highest ejection fraction and working capacity. Sensitivity of thallium-201 exercise scintigraphy was 65%, whereas that of exercise ECG was 41% in patients with a low ejection fraction, while in the whole material the sensitivity of thallium-201 scintigraphy was 91% and that of exercise ECG was 54%. A stenosis in the right coronary artery was best localized by the thallium-201 scintigram (86% correctly); a stenosis in the left anterior descending artery was localized correctly in 75% of the cases, but a stenosis in left circumflex artery was localized correctly only in 44%. We conclude that exercise thallium-201 scintigraphy is a useful method not only in detecting but also in localizing coronary artery disease.     

Comparison of thallium-201 exercise SPECT and dobutamine stress echocardiography for diagnosis of coronary artery disease in patients with left bundle branch block

The present study assessed and compared the diagnostic accuracy of thallium-201 (Tl-201) exercise myocardial single photon emission computerised tomography (SPECT) and dobutamine stress echocardiography (DSE) for detection of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Study population consisted of 26 consecutive patients with permanent LBBB who were suffering from chest pain. Patients (8 women, 18 men mean age = 57 ± 8 years) were studied with DSE, Tl-201 SPECT and coronary angiography (CAG). Three different approaches for diagnosis of CAD were used to identify CAD in left arterial descending (LAD) coronary artery territories in scintigraphic studies: (1) Approach A (conventional approach): involvement of septal, and/or anterior, and/or apical wall. (2) Approach B: involvement of anterior and septal wall irrespective of apical wall. (3) Approach C: involvement of septum, anterior and apical wall. DSE gave a sensitivity of 91%, specificity of 92% and accuracy of 92% for diagnosis of CAD in the LAD coronary artery territory. Tl-201 SPECT (conventional approach) gave a sensitivity of 100%, specificity of 42% and diagnostic accuracy of 69% for diagnosis of CAD in the LAD coronary artery territory. Sensitivity, specificity and diagnostic accuracy of approach C were 33, 85 and 57% respectively. The specificity of Tl-201 SPECT significantly increased in approach C when compared with approach A and B (p < 0.02). However sensitivity of the Tl-201 SPECT with approach C showed significant decrease when compared with DSE and approach A and B (p < 0.005). Specificity of DSE for diagnosis of CAD in LAD were significantly higher than those of Tl-201 SPECT regarding the approach A and B (p < 0.01). In conclusion the use of DSE for diagnosis of CAD in patients with LBBB seems to be more suitable than Tl-201 SPECT.     

Changes in the left ventricular ejection fraction during exercise and in the thallium-201 perfusion after administration of dipyridamole in patients with coronary disease

46 patients with coronary artery disease (at least 70% stenoses) were studied with thallium-201 imaging following dipyridamole (0.50 mg/kg bodyweight intravenously) with 4-hour control and by radionuclide ventriculography at rest and during symptom-limited bicycle exercise in supine position. 38 patients (83%) had positive thallium-201 findings with persistent defects in 18 and transient defects in 20 cases. Mean left ventricular ejection fraction (EF) fell during exercise from 56.1% +/- 13.3 to 50.2% +/- 14.5 (p less than 0.001). 43 patients (93%) showed an abnormal EF response to exercise (rise of less than 10% of the control EF during exercise). In 8 patients with false negative thallium-findings the EF did not change from rest to exercise (64.1% +/- 10.0 vs. 64.6% +/- 8.5), however, in the 20 patients with transient Tl-201 defects a significant fall of the EF was noted (60.8% +/- 9.1 vs. 49.8% +/- 10.9, p less than 0.001), in the 18 patients with persistent defects only a slight decrease of the EF was induced with exercise (47.3% +/- 14.0 vs. 44.2% +/- 16.1, p less than 0.02). Thus transient Tl-201 defects usually predict functional impairment of the left ventricle with exercise, persistent defects suggest impaired rest function with only minor further dysfunction during exercise. Compared with rest and exercise ECG in these patients, both radionuclide techniques showed a significantly higher sensitivity.     

Exercise and redistribution thallium-201 myocardial scintigraphy: changes in distribution qualitatively unaffected by previous infarction

Summary. Eighteen patients with stable exertional angina pectoris were investigated by thallium-201 (²⁰¹T1) exercise and redistribution single photon emission computed tomography (SPECT) after coronary angiography. Eight of the patients had a previous myocardial infarct. Six patients had single-, eight double- and four triple-vessel disease. An exercise SPECT was acquired 10 min after the administration of isotope, injected 1–2 min before the termination of a symptom-limited exercise test. A redistribution SPECT was recorded 3 h later. ²⁰¹T1 activity per pixel was compared between the exercise and redistribution SPECT in relative and absolute terms. For each patient there was a good correlation between activity per pixel in the redistribution SPECT and the corresponding pixels in the exercise SPECT (mean correlation coefficient 0–86 ± 0–08), irrespective of the extent of coronary artery disease or presence of a previous infarction in the pixel region. Relative wash-out correlated to the degree of coronary artery stenosis (r= 0–48), but did not differ between infarcted and non-inf arcted myocardial regions. A similar relationship was documented for pixels with visual ‘refill’ in the redistribution SPECT. This implies that most of the information in the redistribution SPECT was present already in the exercise SPECT. Thus, qualitative information of a similar kind is obtained from images acquired immediately after exercise and after 3–4 h of redistribution.     

Diagnostic and prognostic value of exercise electrocardiography for coronary artery disease

A positive exercise ECG with greater than or equal to 1.0 mm ischemic ST-segment depression, limited exercise duration, persistence of ischemic ST-segment depression past 8 minutes in the recovery period, and exertional hypotension is associated with increasing severity and extent of CAD. The sensitivity and specificity of the exercise ECG are not dependent on the prevalence of CAD in the population tested. The positive and negative predictive values of the exercise ECG are both dependent on the prevalence of CAD in the population tested. Exercise-induced ST-segment elevation greater than or equal to 1.0 mm is associated with severe myocardial ischemia, left ventricular aneurysm, left ventricular wall motion abnormalities, and coronary artery spasm in patients with variant angina. Ischemic ST-segment depression greater than or equal to 1.0 mm, exercise duration, maximal exercise heart rate, and blood pressure response to exercise are correlated with new coronary events in patients with documented CAD. Low-level exercise tests within 3 weeks of uncomplicated MI can identify patients at high risk for new cardiac events. Early post-MI patients with exercise-induced ischemic ST-segment depression greater than or equal to 1.0 mm, exercise-induced angina, an inadequate blood pressure response to exercise, or limited exercise duration during a low-level exercise test should undergo coronary angiography and be considered for possible coronary artery surgery or angioplasty. Exercise testing will also help in the medical treatment of patients with exercise-induced angina or malignant ventricular arrhythmias. An exercise test performed 6 months after MI also provides prognostic information not available from clinical evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chest pain unit management of patients at low and not low-risk for coronary artery disease in the emergency department. A 5-year experience in the Florence area.

In this study, we screened a total of 6723 consecutive patients with chest pain and ECG non-diagnostic for acute myocardial infarction (AMI) on presentation to the emergency department (ED). The aim of the study was to avoid missed AMI, improve safe early discharge and reduce inappropriate coronary care unit (CCU) admission. Chest pain patients were triaged using a clinical chest pain score and managed in a chest pain unit (CPU). Patients with a low clinical chest pain score were considered at very 'low-risk' for cardiovascular events and discharged from the ED; patients with a high chest pain score were submitted to CPU management. Observation and titration of serum markers of myocardial injury were obtained up to 6 hours. Rest or stress myocardial scintigraphy (SPECT) was performed in patients > 40 years or with > or = 2 major coronary risk factors. Exercise Tolerance Test (ETT) or Stress-Echocardiogram (stress-Echo) were performed in younger patients or with < 2 coronary risk factor, or unable to exercise, respectively We discharged directly from the ED the majority of patients (4454; 66%): in this group there was only a 0.2% final diagnosis of coronary artery disease (CAD) at follow-up. The remaining 34% of patients, with non-diagnostic or normal ECG, were managed in the CPU. In this group, 1487 patients (representing 22% of the overall study group) were found positive for CAD, two-thirds because of delayed ECG or serum markers of myocardial injury, and one-third by Echo, SPECT or ETT. In conclusion, CPU based management allowed 22% early detection of myocardial ischaemia and 78% early discharge from the ED avoiding inappropriate CCU admission and optimizing the use of urgent angiography.     

Diagnostic accuracy of exercise stress testing for coronary artery disease: a systematic review and meta-analysis of prospective studies

Background: Exercise stress testing offers a non‐invasive, less expensive way of risk stratification prior to coronary angiography, and a negative stress test may actually avoid angiography. However, previous meta‐analyses have not included all exercise test modalities, or patients without known Coronary artery disease (CAD). Methods and Results: We systematically reviewed the literature to determine the diagnostic accuracy of exercise stress testing for CAD on angiography. MEDLINE (January 1966 to November 2009), MEDION (1966 to July 2009), CENTRAL (1966 to July 2009) and EMBASE (1980–2009) databases were searched for English language articles on diagnostic accuracy of exercise stress testing. We included prospective studies comparing exercise stress testing with a reference standard of coronary angiography in patients without known CAD. From 6,055 records, we included 34 studies with 3,352 participants. Overall, we found published studies regarding five different exercise testing modalities: treadmill ECG, treadmill echo, bicycle ECG, bicycle echo and myocardial perfusion imaging. The prevalence of CAD ranged from 12% to 83%. Positive and negative likelihood ratios of stress testing increased in low prevalence settings. Treadmill echo testing (LR+ = 7.94) performed better than treadmill ECG testing (LR+ = 3.57) for ruling in CAD and ruling out CAD (echo LR? = 0.19 vs. ECG LR? = 0.38). Bicycle echo testing (LR+ = 11.34) performed better than treadmill echo testing (LR+ = 7.94), which outperformed both treadmill ECG and bicycle ECG. A positive exercise test is more helpful in younger patients (LR+ = 4.74) than in older patients (LR+ = 2.8). Conclusions: The diagnostic accuracy of exercise testing varies, depending upon the age, gender and clinical characteristics of the patient, prevalence of CAD and modality of test used. Exercise testing, whether by echocardiography or ECG, is more useful at excluding CAD than confirming it. Clinicians have concentrated on individualising the treatment of CAD, but there is great scope for individualising the diagnosis of CAD using exercise testing.     

The higher likelihood of developing cardiomegaly during follow-up in patients with syndrome X and abnormal thallium-201 myocardial perfusion SPECT

`Syndrome X' describes patients with exertional chest pain and a normal coronary arteriogram. In some patients, acute myocardial ischemia can be demonstrated by regional myocardial perfusion defects on thallium-201 exercise test. However, some patients with typical angina have normal perfusion on thallium-201 heart scintigraphy. It is not clear whether there are different prognoses for patients with normal and abnormal thallium studies. In this study, the clinical features, long term follow-up and clinical results of syndrome X patients with normal and abnormal thallium studies were evaluated to determine the differences between these two groups. Fifty-nine patients (52 males, seven females, mean age 62 ± 6 years) with syndrome X were enrolled and divided into two groups on the basis of results of thallium-201 heart scintigraphy. Group I was comprised of 22 patients with normal thallium-201 perfusion scan and group II was comprised of 37 patients with abnormal thallium-201 heart scan. All subjects received coronary arteriography, exercise test, thallium-201 myocardial SPECT, ejection fraction of left ventricle, echocardiography, blood analysis and long term follow-up with questionnaire for 10 years. Lower maximal rate–pressure product and higher angina scores were found in group II. More patients developed cardiomegaly (nine of 33 patients) in group II than in group I (one of 21 patients). Both groups, however, were at low risk for cardiac events (cardiac death or myocardial infarction).     

运动压力测试中缺血修饰清蛋白的作用

目的 评估冠状动脉疾病患者进行运动压力测试后血液中缺血修饰清蛋白(IMA)的水平.方法 选取该院49例1周内出现胸痛的患者,进行冠状动脉造影与单车运动压力测试,采集开始运动测试时的血液样本测试IMA作为基线水平,5 min后再次采样测试IMA水平.结果 49例患者中,有25例(冠状动脉疾病组)有冠状动脉狭窄,另外24例(非冠状动脉疾病组)无冠状动脉狭窄.而IMA水平在基线水平与运动水平差异无统计学意义,冠状动脉疾病组与非冠状动脉疾病组基线水平分别为(70.7±7.2)U/mL、(72.5±6.4)U/mL,而运动后水平分别为(74.1±5.1)U/mL、(75.8±6.8)U/mL,冠状动脉疾病组与非冠状动脉疾病组对比结果 差异无统计学意义(P＞0.05).在运动后IMA水平变化值两组分别为(5.4±3.5)U/mL、(4.7±7.6)U/mL,差异无统计学意义(P＞0.05);在心电图阳性组(16例)与心电图阴性组(33例)IMA水平变化差异无统计学意义(P＞0.05).结论 IMA在运动测试中对于急性冠状动脉综合征的诊断并不适用.     

Comparison of thallium-201 SPECT redistribution patterns and rubidium-82 PET rest-stress myocardial blood flow imaging

To compare regional thallium-201 SPECT redistribution patterns with rubidium-82 PET, we studied 81 patients with both imaging modalities. Sixty patients had significant coronary artery disease. All patients underwent PET imaging after dipyridamole infusion, while SPECT imaging was performed after exercise stress (38 patients) and dipyridamole (43 patients). Sixty-eight percent of patients with prior infarct had fixed defects on SPECT, compared to 39% with PET. Sixty-one percent of patients with prior infarct had PET perfusion defects which exhibited ‘reflow’ or normal rubidium-82 tracer uptake (p < 0.05 vs. SPECT). Similar results were seen in patients without prior infarct (26% fixed defects on SPECT vs. 12% for PET, p < 0.05). Regional analysis showed that 57% of fixed SPECT defects corresponded to PET defects with reflow or normal rubidium-82 uptake, while 78% of ‘fixed’ PET defects corresponded to fixed SPECT defects. PET reflow and normal rubidium-82 uptake in sites of fixed thallium-201 SPECT perfusion defects suggest that imaging modalities employing separate tracer injections at rest and after stress, such as rubidium-82 PET, may be more specific in the assessment of myocardial viability, especially in patients with prior myocardial infarction.     

The relation of amino-terminal propeptide of type III procollagen and severity of coronary artery disease in patients without myocardial infarction or hibernation

OBJECTIVES: The association of cardiac fibrosis and coronary artery disease (CAD) in patients without infarction or hibernation is unclear. We investigated the relationship between serum concentrations of procollagen propeptides and severity of CAD in such patients. DESIGN AND METHODS: Forty-six patients (32 men; mean age 64 years) with chest pain were enrolled. All patients received stress thallium-201 single photon emission computed tomography (SPECT) and analysis of the serum levels of the amino-terminal propeptide of type I and III procollagen (PINP and PIIINP). RESULTS: In patients with thallium-201 perfusion defects, the number of diseased vessels was associated significantly with PIIINP (p=0.024) rather than PINP (p=0.613). Follow-up serum PINP and PIIINP levels after coronary intervention (mean 84 days) revealed no significant decrease. CONCLUSIONS: Serum PIIINP level is significantly associated with the severity of CAD in patients without myocardial infarction or hibernation.     

The Effect of Rate Responsive Pacing in Patients with Angina Pectoris on the Extent of Ischemia on 201-Thallium Exercise Scintigraphy

VAN CAMPEN, L.C.M.C., et al. : The Effect of Rate Responsive Pacing in Patients with Angina Pectoris on the Extent of Ischemia on 201-Thallium Exercise Scintigraphy. In patients with coronary artery disease (CAD), rate responsive pacing is considered to be contraindicated because an increase in heart rate may increase oxygen demand. Although previous studies have shown no subjective increase in ischemia during rate responsive pacing, data from objective assessment have not been documented. The goal of this study was to determine if there was an increase in ischemia on 201-Thallium (²⁰¹TI) exercise scintigraphy in this mode of pacing in patients with CAD and angina. Eighteen consecutive patients with chronic atrial fibrillation and symptomatic bradyarrhythmias with a pacemaker for more than 6 months participated in the study. In VVI and VVIR modes a symptom-limited exercise ²⁰¹TI scintigram was performed in a single blind randomized crossover fashion. Exercise duration, anginal attacks, use of nitroglycerine (NTG) tablets, blood pressure, and analysis of the scintigrams were assessed during each pacing mode. Fifteen men and three women were included (  age 65.9 ± 4.9 years, LVEF 0.44 ± 0.07  ). Four were in Class III angina pectoris, and 14 in class II. The mean exercise duration increased 28% in the VVIR group without an increase in anginal attacks per week or the use of NTG tablets. On scintigrams, no differences were seen between the two groups. One patient was withdrawn from the study because of an increase in angina pectoris (AP) attacks during VVIR pacing. Rate responsive pacing is safe and effective in patients with CAD without an increase in subjective and objective signs of ischemia.     

静息99mTc-MIBI心肌灌注断层显像诊断男性冠心病价值评估

目的：研究静息^99mTc-MIBI心肌灌注单光子发射计算机断层显像（SPECT）对男性冠心病的诊断价值。方法：以选择性冠状动脉造影术（CAG）为对照，将57例男性患者分为冠心病组（33例）及非冠心病组（24例），计算SPECT的各项评价指标，继而结合临床诊断将冠心病组分为心肌梗塞组（18例）及心绞痛组（15例），比较两组SPECT阳性率差异。结果：静息SPECT诊断男性冠心病灵敏度为87．88％，特异度为70．83％，准确度为80．70％，阴性预测值为80．95％，提示SPECT对男性冠心病检出率，符合率较高，而阴性对排除冠心病有较高的价值，心肌梗塞组阳性率为100％（18／18），心绞痛组为73．33％（11／15），提示静息SPECT检出男性心肌梗塞的阳性率高于心绞痛。结论：结合实验结果及SPECT具有无创，价廉，可重复等特点，SPECT可作为诊断男性冠心病的初筛检查。     

Additional value of thallium-201 SPECT to a conventional exercise test for the identification of severe coronary lesions after an episode of unstable coronary artery disease

The additional value of thallium-201 SPECT to a conventional exercise test for the identification of patients with severe coronary lesions was evaluated in 170 men, one month after an episode of unstable coronary artery disease. Severe coronary lesions at coronary angiography — defined as three vessel disease, left main stenosis or proximal left anterior descending artery stenosis as part of two vessel disease — were observed in 45.9%. In the SPECT image, the left ventricular myocardium was divided into nine segments and each segment was classified as either normal (=0), reduced uptake (=1) or uptake defect (=2). The sum of gradings in all segments post-exercise was denoted “SPECT score”. The patients were divided into nine different groups regarding ST-depression during exercise (no ST-depression, ST-depression in 1–2 leads or ≥ 3 leads) and “SPECT score” (no SPECT score, 1–3 scores or ≥ 4 scores). Severe coronary lesions were, in 68% identified by SPECT score ≥ 4 and in 65% by ST-depression in ≥ 1 lead at exercise test. The specificity for identification of severe coronary lesions was, for both tests, 65%. SPECT score ≥ 4 and/or ST-depression in ≥ 3 leads identified 82% of the patients with severe coronary lesions with a specificity of 63%. Furthermore, SPECT score ≥ 3 identified more patients with isolated proximal left anterior descending artery stenosis than ST-depression alone at exercise test.     

Stress echocardiography in the ED: diagnostic performance in high-risk subgroups

Purpose

To assess stress-echo (SE) diagnostic performance in patients presenting to the emergency department (ED) with spontaneous chest pain, especially in subgroups in which exercise ECG diagnostic performance has been questioned (women, elderly, history of coronary artery disease).

Methods

Between June 2008 and May 2011, 474 patients with an episode of spontaneous chest pain, non-diagnostic electrocardiogram and negative cardiac necrosis markers underwent SE. Patients with inducible ischemia (Isch) were asked to undergo coronary angiography. Patients with negative SE were discharged and contacted by telephone at least 6 months after discharge, to ascertain the occurrence of new cardiac events.

Main findings

Exercise stress-echo (ESE) was employed in 270 patients and dobutamine (DSE) in 218 (including 14 with inconclusive ESE); a diagnosis of coronary artery disease (CAD) was confirmed or excluded in 434 (92%) patients. SE was negative for Isch in 318 patients (206 ESE and 112 DSE) and positive in 132. During follow-up, patients with negative SE had 4 cardiac events. SE showed: sensitivity 90%, specificity 92%, positive predictive value 78% and negative predictive value 97%. Sensitivity was comparable between patients aged < or ≥ 70 years (84 vs 94%) and between gender (89 vs 96%), but lower in patients with known CAD (88 vs 94%, P < .05); specificity was comparable regardless of age (94 vs 99%) and presence of CAD (97 vs 91%), but was lower among women (87 vs 96%, P < .05).

Conclusions

SE had a very good diagnostic performance in ED patients with suspected Isch, both overall and in selected high-risk groups.     

The significance of transient left ventricular dilation during SPECT dipyridamole thallium-201 scintigraphy

We assessed the significance of transient left ventricular dilation (TLVD) during single photon emission computed tomography (SPECT) dipyridamole thallium-201 scintigraphy (DTS) in 49 patients who underwent both DTS and diagnostic coronary arteriography. Quantitative analysis of DTS images and independent review by 3 experienced observers determined that 17 patients had TLVD and 32 patients had no TLVD. Patients with TLVD were similar to patients without TLVD with respect to age, history of myocardial infarction, coronary risk factors and occurrence of chest pain or electrocardiographic changes during DTS. The frequency of three-vessel coronary artery disease (3VD) was greater in patients with TLVD than in patients without TLVD (94% vs. 16%, p<0.01). The sensitivity of TLVD was 76% and the specificity 96% for the detection of 3VD. Of the 16 patients with 3 VD who manifested TLVD, standard SPECT DTS analysis demonstrated defect or perfusion abnormalities in 14 patients and no abnormalities in 2 patients. In conclusion, the finding of TLVD during SPECT DTS is a specific marker for severe coronary disease and can provide additive information to standard SPECT thallium-201 analysis.     

Comparison of planar imaging and single-photon emission computed tomography for the detection and localization of coronary artery disease

Although single photon emission computed tomography (SPECT) has become widely utilized, the superiority of this technique compared to planar conventional imaging remains controversial. In order to compare these two techniques, we retrospectively analysed the results obtained in 70 patients who performed a thallium-201 exercise scintigraphy with a double acquisition during the same test, and who also underwent coronary and ventricular angiography. Overall, SPECT imaging yielded a higher sensitivity (93% vs 82% for SPECT and planar imaging respectively, p<0.05), especially in the inferior and anterior regions. SPECT was also more sensitive for the detection of a single-vessel disease (90% vs 74% for SPECT and planar imaging respectively, p<0.01). The specificity was assessed for both techniques with the help of circumferential computerized analysis, avoiding known causes of false positive scintigrams. We found a high specificity for both SPECT and planar imaging, without any significant difference between the two methods (87% vs 91% for the overall specificity of SPECT and planar imaging respectively, p=NS). Therefore, SPECT imaging analysed with discrimination shows an enhanced reliability over planar imaging for the detection and the localization of coronary artery disease, without increasing the risk of false positive tests.     

Increased myocardial wall thickening as index of viability assessment: a preliminary report on delayed contrast MRI

Purpose : Regional wall thickening measurement by delayed contrast MRI may assess myocardial viability and functional recovery of ischemic cardiomyopathy. Materials and methods : Delayed contrast MRI data was used in 40 patients with significant coronary artery disease and severe left ventricular dysfunction. Regional wall thickening on follow‐up MRI served as an index of functional recovery in patients receiving revascularization. For comparison, myocardial viability was assessed by MRI and ²⁰¹Tl SPECT in 10 patients using a 17‐segment method. Results : On 480 segments, MRI hyperintensities showed positive correlation with ²⁰¹Tl reduction (r = 0.71, p < 0.0001) in the inferior wall and apex. Delayed MRI detected myocardial viability better than ²⁰¹Tl SPECT. Delayed contrast‐enhanced MRI showed diagnostic accuracy 65%, sensitivity 95%, specificity 25%, positive predictive value 65% and negative predictive value 75%, whereas ²⁰¹Tl SPECT showed diagnostic accuracy 54%, sensitivity 72%, specificity 25%, positive predictive value 52% and negative predictive value 54%. Areas under the ROC curves by MRI and ²⁰¹Tl SPECT were 0.59 ± 0.04, 0.52 ± 0.05, respectively (p = 0.07). The viability concordance was 80% between ²⁰¹Tl SPECT and MRI. Conclusion : Delayed contrast‐enhanced MRI may detect the inferior wall thickening and apex as an index of viable myocardium better than ²⁰¹Tl SPECT. Myocardial viability may predict functional recovery after revascularization in ischemic cardiomyopathy. Copyright © 2009 John Wiley & Sons, Ltd.     

Multislice cardiac computed tomography in symptomatic middle-aged women

OBJECTIVE: To assess the accuracy of multislice cardiac computed tomography (MSCT) for detection of significant coronary artery disease (CAD) in middle-aged symptomatic women. METHODS: We included 70 women (51+/-8 years) with complaints of chest pain or dyspnea, and an abnormal maximum exercise electrocardiogram (ECG) (8.6+/-1.4 metabolic equivalents). All had a MSCT using a 16 detector rows scanner, and coronary arteriography (CA). Blinded results of the two modalities were compared using a segment, vessel, and patient-based analysis. RESULTS: On MSCT 36% had normal coronaries, 24% had significant CAD requiring revascularization, and the remainder had mild CAD. MSCT had reasonably high diagnostic accuracy at segment level (negative predictive value of 95%, positive predictive value 81%, specificity 99%, and sensitivity 50%), regarding single or multivessel CAD when both nonassessable and assessable segments were included in the analysis. The agreement between the segments comparing MSCT and CA for significant CAD was excellent at 98% (kappa value 0.89). CONCLUSIONS: In this cohort of middle-aged symptomatic women with an abnormal stress test, 24% had significant CAD requiring intervention. MSCT was highly accurate in diagnosing significant CAD with an excellent negative predictive value.     

Adenosine echocardiography — an alternative to dynamic stress echocardiography

Dynamic exercise echocardiography is sensitive and specific in detection and evaluation of coronary artery disease. Frequently, however, patients cannot achieve maximum exercise because of various factors. The aims of this study were to compare usefulness of adenosine infusion and dynamic exercise to induce myocardial ischemia detected with 2-D echocardiography and standard electrocardiography; to determine the sensitivity of the adenosine echo test; and to evaluate the safety and tolerability of adenosine infusion. In 31 men with clinical diagnosis of stable angina pectoris, myocardial ischemia was induced by: a) symptom-limited exercise test on a bicycle, and b) intravenous adenosine infusion. The two tests were performed with an average interval of 24 hours. Coronary angiography was performed in 29 of 31 patients and significant coronary artery disease (diameter narrowing >50%) was documented in 26 of these (12 single, 6 two- and 8 three-vessel disease). The criterion for echo positivity was a transient impairment of contraction as compared to the baseline examination in any of 10 segments, with an increase of left ventricular score index of 0.3 or more. ECG positivity was considered as ST₆₀ segment depression of 0.1 mV or more from the reference level in any lead. Adenosine echo test was positive in 22 out of 26 patients and exercise echo in 19 (sensitivity 85% and 73%, respectively, p=NS). Adenosine ECG test was positive in 14 of 26 patients and exercise ECG test in 21 (sensitivity 54% and 81% respectively, p= NS). In three patients with normal coronary arteriography adenosine echo was negative in all three, exercise echo, adenosine ECG and exercise ECG in two. Side effects due to adenosine infusion were always minor, well tolerated by the patients and disappeared within seconds after termination of infusion. The present study suggests that adenosine test is at least as useful as exercise echo test in the provocation of myocardial ischemia in patients with coronary artery disease and stable angina pectoris.