Myocardial perfusion cardiac magnetic resonance for the diagnosis of coronary artery disease: do we need rest images?

Adenosine stress cardiovascular magnetic resonance (CMR) has been reported to be useful for the diagnosis of coronary artery disease (CAD). Most studies use rest and stress perfusion images. The objectives of this study were to determine (Barkhausen et al. in J Magn Reson Imaging 19(6):750–757, 1) the accuracy of visual assessment and myocardial perfusion reserve index (MPRI) in the diagnosis of CAD and (Rieber et al. in Fur Heart J 27(12):1465–1471, 2) the accuracy of analysis based on rest–stress and stress images. We enrolled patients with suspected CAD and referred them for coronary angiography (CAG). All the patients underwent adenosine stress CMR before CAG. Rest and stress perfusion images were analyzed by calculation of MPRI and visual assessment separately. Visual assessment was performed separately by using rest and stress images and by using only stress images. CAG was considered the gold standard. Sensitivity, specificity, and accuracy of both methods were calculated and compared. A total of 66 patients (mean age, 61.3 ± 11.7 years) were studied. Thirty-eight patients (57.6%) were diagnosed with CAD. The sensitivity and specificity for the diagnosis of CAD (≥50% stenosis) were 89.5 and 78.6% for MPRI, 76.3 and 75% for stress–rest visual method, and 86.8 and 75% for stress visual method, respectively. CMR perfusion had a relatively lower accuracy in patients with left ventricular systolic dysfunction, high left ventricular mass, or presence of late gadolinium enhancement than in patients without those CMR findings. Visual assessment of stress image of CMR perfusion is accurate and comparable to MPRI for the detection of CAD.     

Multislice computed tomography coronary angiography in patients admitted with a suspected acute coronary syndrome

Objectives The aim of this prospective clinical study was to assess the accuracy and clinical relevance of multislice computed tomography coronary angiography (MSCTCA) in patients presenting with acute chest pain. Background Multislice computed tomography coronary angiography has shown ability to detect accurately coronary artery disease (CAD) in selected elective patient groups. Methods One hundred and twenty patients presenting with acute chest pain (<24 h) underwent MSCTCA (Siemens Sensation 16) before a scheduled inpatient conventional coronary angiogram (CCA). Exclusion criteria included patients with STEMI, non-sinus rhythm, contraindication to β blockers and renal impairment. Blinded visual assessment of MSCTCA to detect CAD was performed on an 11-segment model. The accuracy of MSCTCA was compared to CCA to detect significant stenoses (≥50%). Results One hundred and thirteen patients underwent both investigations. The prevalence of significant CAD was 74%. 1,243 native segments were assessed by MSCTCA. The overall ability of MSCTCA to detect the presence of ≥1 significant stenosis in all native segments had a sensitivity of 92% (95%CI 83–97%), specificity of 55% (95%CI 35–74%), positive predictive value of 86% (95%CI 76–93%) and negative predictive value of 70% (95%CI 47–87%). 22% of all segments (mostly distal) were non-analyzable. Coronary calcification was a major cause of false positivity. Conclusion In a prospective study of unselected patients presenting with acute chest pain, the diagnostic accuracy of 16-slice CT coronary angiography was moderate and less than reported from studies in elective patients. The clinical relevance of this technology to screen patients with acute chest pain is limited.

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Condensed Abstract Multislice CT coronary angiography (MSCTCA) and conventional coronary angiography (CCA) were used to assess 120 patients presenting with acute chest pain. MSCTCA was compared to CCA to detect significant stenoses (≥50%). In 113 directly comparable patients MSCTCA had a sensitivity of 92% (95%CI 83–97%) and specificity of 55% (95%CI 35–74%) to detect the presence of ≥1 significant stenosis in all native segments. In this patient cohort with a high prevalence of coronary disease and coronary calcification, the accuracy and clinical relevance of 16 slice MSCTCA to screen and risk stratify patients with acute chest pain is limited.

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Diagnostic performance of exercise bicycle testing and single-photon emission computed tomography: comparison with 64-slice computed tomography coronary angiography

To conduct a comparison of the diagnostic performance of exercise bicycle testing and single-photon emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376 symptomatic patients (254 men, 122 women, mean age 60.4 ± 10.0 years) referred for noninvasive stress testing (exercise bicycle test and/or SPECT) and invasive coronary angiography were included. All patients underwent additional 64-slice CTCA. The diagnostic performance of exercise bicycle testing (ST segment depression), SPECT (reversible perfusion defect) and CTCA (≥50% lumen diameter reduction) was presented as sensitivity, specificity, positive and negative predictive value (PPV and NPV) to detect or rule out obstructive CAD with quantitative coronary angiography as reference standard. Comparisons of exercise bicycle testing versus CTCA (n = 334), and SPECT versus CTCA (n = 61) were performed. The diagnostic performance of exercise bicycle testing was significantly (P value < 0.001) lower compared to CTCA: sensitivity of 76% (95% CI, 71–82) vs. 100% (95% CI, 97–100); specificity of 47% (95% CI, 36–58) vs. 74% (95% CI, 63–82). We observed a PPV of 70% (95% CI, 65–75) vs. 91% (95% CI, 87-94); and NPV of 30% (95%, 25–35) vs. 99% (95%, 90–100). There was a statistically significant difference in sensitivity (P value < 0.05) between SPECT and CTCA: 89% (95% CI, 75–96) vs. 98% (95% CI, 87–100); but not in specificity (P value > 0.05): 77% (95% CI, 50–92) vs. 82% (95% CI, 56–95). We observed a PPV of 91% (95% CI, 77–97) vs. 93% (95% CI, 81–98); and NPV of 72% (95%, 46–89) vs. 93% (95%, 66–100). SPECT and CTCA yielded higher diagnostic performance compared to traditional exercise bicycle testing for the detection and rule out of obstructive CAD in patients with stable angina.     

Left ventricular cavity-to-myocardium count ratio in exercise and resting technetium-99m-tetrofosmin SPECT: correlation with left ventricular function

The aim of this study was to assess the value of the cavity-to-myocardium count ratio (C/M ratio) calculated in exercise and resting technetium-99m (Tc-99m) tetrofosmin single photon emission computed tomography (SPECT) images to identify patients with depressed exercise and resting left ventricular ejection fraction (LVEF). We studied 60 patients with recent coronary artery diseases (CAD) undergoing first-pass ventriculography to calculate LVEF and myocardial perfusion SPECT imaging to calculate left ventricular C/M ratios. The group A of 30 CAD patients with higher LVEF (40%) had significant higher C/M ratios than the group B of 30 CAD patients with abnormal LVEF (<40%) during exercise and rest. However, C/M ratios between exercise and rest did not differ significantly in the both groups A and B. There is significant correlation between exercise/rest LVEF and exercise/rest C/M ratios. Tc-99m tetrofosmin C/M ratios calculated SPECT perfusion images are useful parameters in identifying patients with depressed LVEF in CAD patients.     

The absence of coronary artery calcification does not rule out the presence of significant coronary artery disease in Asian patients with acute chest pain

The absence of coronary artery calcification (CAC) has been used to as an indication to rule out significant coronary artery disease (CAD). However, diagnostic usefulness of ‘zero calcium score criteria’ as a decision-making strategy to rule out significant CAD as the etiology of acute chest pain has not been studied in depth, especially in Asian ethnicity. We prospectively enrolled 136 Korean patients (58% men, 56 ± 13 years) who presented to the emergency department (ED) with acute chest pain and non-diagnostic ECG. All patients underwent 64-slice CT for calcium scoring and coronary CT angiography (cCTA). We investigated the association of CAC with the presence of ≥50% CAD on cCTA and with a final diagnosis of an acute coronary syndrome (ACS). Ninety-two patients out of 136 (68%) did not show detectable CAC, and 14 out of these 92 without CAC (15%) had ≥50% CAD on cCTA. Sensitivity, specificity, positive predictive value and negative predictive value of zero calcium score criteria for the detection of ≥50% CAD were 0.66 (95% confidence interval, 0.50–0.80), 0.83 (0.74–0.90), 0.64 (0.48–0.77), 0.85 (0.75–0.91), respectively. Patients who had ≥50% CAD without detectable CAC were younger (P = 0.001), and had a higher prevalence of smoking (P = 0.048) as compared to patients with a degree of CAC. Most of the patients with ≥50% CAD of non-calcified plaque were younger than 60 years of age (79%, 11/14), however, 3 of them were older than 60 years of age. Forty-five patients (33%) were subsequently diagnosed as having ACS, and 38% (17/45) of them had no CAC. Zero calcium score did not necessarily guarantee the absence of significant CAD, even in patients older than 60 years, in Asian ethnicity presenting to the ED with chest pain.     

Tc-99m tetrofosmin myocardial SPECT perfusion imaging: comparison of rest-stress and stress-rest protocols

Aim. The purpose of this study was to evaluate the diagnostic value of Tc-99m tetrofosmin SPECT myocardial perfusion scintigraphy rest/stress and stress/rest protocols for the assessment of coronary artery disease (CAD). Methods. 65 patients underwent both rest and stress SPECT imaging in a one-day protocol and coronary angiography within 2 months before or after scintigraphy. Scintigraphic data was obtained according to two different protocols; 1) rest-stress (n=18) and 2) stress-rest (n=47). Results. Scintigraphic evidence for myocardial ischaemia was found in 36 patients (55%). The overall sensitivity to detect CAD (>50% luminal stenosis) was 94% (34/36), specificity 66% (19/24), positive predictive value 77%, negative predictive value 90%. The sensitivity to detect CAD for protocols 1 and 2 were 100% and 93%, specificity 56% and 70%, positive predictive value 69% and 81% and negative predictive value 100% and 88%, respectively. The left anterior descending coronary artery showed a sensitivity (overall, protocol 1 & 2) of 78%, 75% (3/4) and 79% (15/19) and a specificity of 71%, 64% (9/14) and 75% (21/28). The right coronary artery showed a sensitivity (overall, protocol 1 & 2) of 91%, 100% (6/6) and 88% (14/16) and a specificity of 70%, 92% (11/12) and 61% (19/31). The left circumflex coronary artery showed a sensitivity (overall, protocol 1 & 2) of 50%, 67% (2/3) and 46% (6/13) and a specificity of 94%, 100% (15/15) and 91% (31/34). Conclusion. Tc-99m tetrofosmin appears to be a valuable tool in predicting significant CAD. The sensitivity and the positive predictive value are high, making this test highly appropriate for the diagnosis of CAD. The diagnostic value of the individual coronary arteries is high to moderate. No significant differences were found between both protocols.     

Utility of nonspecific resting electrocardiographic features for detection of coronary artery stenosis by Computed Tomography in acute chest pain patients: from the ROMICAT trial

Twelve-lead surface electrocardiography (ECG) and computed tomography (CT) are used to evaluate for myocardial ischemia and coronary artery disease (CAD), respectively. We aimed to determine features on resting ECG that predict coronary artery stenosis by cardiac CT. In 309 acute chest pain patients, we compared the initial triage resting ECG to contrast-enhanced 64-slice cardiac CT angiography. We assessed for 6 quantitative (QT interval, QTc interval, QTc > 440 ms, gender-specific QTc, QT dispersion and QRS duration) and 4 qualitative ECG parameters (ST depression >0.05 to ≤0.1 mV, T wave inversion ≥0.1 mV, T wave flattening, and any T wave abnormalities) and for the presence of coronary stenosis by CT (>50% luminal narrowing). Specificities of these ECG parameters were excellent (83.6–97.0%) while sensitivities were poor (12.2–29.3%). For coronary stenosis detection, the ECG features with the greatest performance were the presence of ST depression (positive likelihood ratio [LR+] 4.09) and T wave inversion (LR+ 4.58). In multivariable analyses, the risk for coronary stenosis increased by 33–41% for every 20 ms prolongation of the QTc interval after adjusting for age, gender, and cardiac risk factors or adjustment for Framingham risk score. Similarly, there was an increase of fourfold with the presence of ST depression >0.05 to ≤0.1 mV or T wave inversion ≥0.1 mV. In acute chest pain patients, resting ECG features of QTc interval prolongation, mild ST depression, and T wave inversion are independently associated with the presence of CT coronary stenosis and their presence suggests an increase risk of CAD.     

Noninvasive diagnosis of coronary artery disease in patients with diabetes by dobutamine stress real-time myocardial contrast perfusion imaging

OBJECTIVE: The aim of this study was to assess the accuracy of real-time myocardial contrast perfusion imaging (MCPI) during dobutamine stress in the diagnosis and localization of coronary artery disease (CAD) in patients with diabetes. Myocardial contrast echocardiography is a new technique that allows evaluation of myocardial perfusion. Its utility in diabetic patients has not been defined. RESEARCH DESIGN AND METHODS: Dobutamine-atropine stress test was performed in conjunction with MCPI using Optison or Definity at rest and at peak stress in 128 patients with diabetes and suspected CAD who underwent coronary angiography within 1 month. CAD was defined as > or =50% stenosis in one or more coronary artery. MCPI was considered diagnostic of CAD in the presence of reversible perfusion abnormalities. The normalcy rate of MCPI was additionally determined in 18 asymptomatic nondiabetic patients with low probability. RESULTS: CAD was detected in 101 (79%) patients by angiography. Reversible perfusion abnormalities were detected in 90 patients with and 13 patients without CAD. The overall sensitivity of MCPI was 89% (95% CI 83-95), specificity 52% (33-71), and accuracy 81% (75-88). Reversible abnormalities were detected in two or more vascular distributions in 44 of 56 patients with multivessel CAD and in 8 of 63 patients without (sensitivity 68%, specificity 87%, positive predictive value 84%, and accuracy 79%). Regional sensitivity was 75% (65-85) for left anterior descending CAD, 71% (60-83) for left circumflex, and 67% (55-78) for right CAD. MCPI was normal in 16 of the 18 patients with low clinical probability of CAD (normalcy rate 89%). CONCLUSIONS: MCPI is a useful noninvasive technique for the diagnosis and localization of CAD in diabetic patients. The extent of perfusion abnormalities can identify patients with multivessel CAD with a moderate sensitivity and high specificity.     

Using clinical cardiovascular risk scores to predict coronary artery plaque severity and stenosis detected by CT coronary angiography in asymptomatic Chinese subjects

We aimed to determine whether the Framingham risk score (FRS), systematic coronary risk evaluation (SCORE), and Chinese multi-provincial cohort study (CMCS) could predict anatomic severity of coronary plaques. From January 2007 to October 2010, we performed a contrast-enhanced 64-slice or 256-slice multidetector computed tomography coronary angiography as part of a health check-up protocol in 806 asymptomatic subjects (70.5% male, 56 ± 9 year-old). Risk scores significantly correlated with calcium volume score, plaque stenosis score and plaque distribution score (P < 0.001). Of the 3 risk scores, the SCORE system showed the best correlation. Overall, 180 (22%) and 37 (5%) subjects were found to have stenosis of 50-69% and more than 70% in at-least one coronary artery segment, respectively. In the prediction of the presence of obstructive CAD (≥50% diameter stenosis), all risk scores had similar discrimination. In the prediction of severe CAD (≥70% diameter stenosis), FRS and CMCS had similar area under curves but SCORE discriminated better than FRS (P < 0.05). The optimal cutoff point to predict obstructive CAD was 9.54% for FRS, 1.05% for CMCS, and 0.95% for SCORE, whereas to predict severe CAD was 9.63, 1.05, 1.15% for FRS, CMCS, SCORE, respectively, with a sensitivity of 0.61–0.70 and a specificity of 0.55–0.66. Cardiovascular risk scores are associated with the severity and extent of coronary artery plaque. The stronger association might translate into a better discrimination using SCORE. These findings will aid in the appropriate selection or recalibration of the risk assessment system for cardiovascular disease screening.     

Diagnostic accuracy of first generation dual-source computed tomography in the assessment of coronary artery disease: a meta-analysis from 24 studies

The objective of this study is to evaluate the diagnostic accuracy of the first generation dual-source computed tomography (DSCT) in the diagnosis of coronary artery disease (CAD). We selected articles from four databases (Pubmed, Embase, the Cochrane central register of controlled trials (CENTRAL) and Chinese biomedical literature database. The strict study selection was made, and two reviewers independently extracted data back-to-back from included studies. Meta-Disc version 1.4 was used to obtain the pooled results. 24 studies were included in meta-analysis. A cut off point of ≥50% stenosis was used in all the studies to define significant coronary artery stenosis. In patient-based analysis (n = 801), pooled sensitivity was 0.980 [95% confidence interval (CI):0.970–0.990], specificity 0.870 (95% CI: 0.830–0.900), median positive predictive value (PPV) across studies 0.876 (range from 0.741 to 0.943) and negative predictive value (NPV) 0.964 (range from 0.900 to 1.000). In vessel-based analysis (n = 3,620) DSCT pooled sensitivity was 0.957 (95% CI: 0.943–0.969), specificity 0.930 (95% CI: 0.910–0.940), median PPV across studies 0.838 (range from 0.534 to 0.964) and NPV 0.973 (range from 0.885 to 0.996). In segment-based analysis (n = 6,177) DSCT pooled sensitivity was 0.915 (95% CI: 0.901–0.928), specificity 0.959 (95% CI: 0.956–0.963), median PPV 0.782 (range from 0.320 to 0.927) and NPV 0.985 (range from 0.929 to 0.999). In subgroups analysis, pooled sensitivity and specificity in segment based analysis were 93.1 and 92.3% when heart rate (HR) is beyond 70 bpm; when HR was below 70 bpm, the sensitivity was similar (93%), but specificity increased a little from 92.3 to 94%. When analysed based on segment with a cut-off calcium score of 400, the sensitivity was slightly higher in the subgroup with a score over 400 than in the subgroup with a score below 400 (94 vs. 91%), while the specificity was much lower in the subgroup with the high calcium score than the subgroup with the low calcium score (85 vs. 96%). For subgroups with heart rate beyond and below 65 bpm in patient-based analysis, sensitivities were 0.95 (95% CI: 0.86–0.99) and 0.98 (95% CI 0.91–1.00), respectively, while the specificities were 0.88 (95% CI 0.81–0.94) and 0.85 (95% CI 0.77–0.91), respectively. The area under the receiver operating characteristic curve (AUC) in the two subgroups were 0.9608 and 0.9786, respectively. DSCT is highly sensitive for patient-based analysis of CAD and has high specificity and NPV for segment-based analysis of CAD. First generation DSCT may have a role in the evaluation of patients with chest pain as a simple non-invasive examination because of its ability to diagnose or exclude significant CAD.     

Eight-Row Multidetector Computed Tomography Coronary Angiography Evaluation of Significant Coronary Artery Disease in Patients with Severe Aortic Valve Stenosis

Background The aim of this study was to evaluate whether 8-row multidetector computed tomography coronary angiography (MDCT-CA) could replace invasive conventional coronary angiography (CCA) in patients with acquired severe aortic valve stenosis (AS). Coronary artery disease (CAD) diagnosis should be obtained with a noninvasive method in patients with AS undergoing valvular replacement. We evaluated the diagnostic accuracy of MDCT-CA in detecting high-grade (≥50%) stenoses in the main coronary arteries in patients with AS.Methods Twenty-three patients with acquired severe AS underwent both CCA and MDCT-CA. We calculated the total and volumetric calcium scores and evaluated the image quality of each coronary segment as assessable or nonassessable for stenosis. The images of the arteries were evaluated for the occurrence of artifacts and the presence of high-grade stenoses (≥50%) by visual estimation and comparison with that of CCA.Results Of the 322 segments screened 224 were assessable for stenosis. Heavy calcium load rendered 37 (38%) of the 98 coronary segments nonassessable.Compared to CCA, MDCT-CA had a sensitivity of 63%, a specificity of 96%, a positive predictive value of 52%, and a negative predictive value of 98% for ≥50% stenoses in the main coronary arteries.Conclusions Eight-row MDCT-CA revealed a low sensitivity in detecting significant coronary artery disease in patients with acquired severe AS. High calcium burden decreased visualization of the lumen and complicated most often a correct assessment. In this patient group, CCA should still remain the primary pre-surgical test to rule out coronary lesions requiring revascularization.     

心肌灌注显像在女性冠心病诊断中价值

目的评价心肌灌注显像对女性冠心病患者的诊断价值。方法 344例有胸痛、胸闷症状女性患者,行静息+药物负荷心肌灌注显像检测,并与冠状动脉造影结果进行对比分析。结果冠状动脉狭窄178例患者中心肌灌注显示异常者130例;冠状动脉造影无异常或不规则166例中心肌灌注显像异常50例,无异常116例;以冠状动脉造影结果为标准,心肌灌注显像对女性冠心病诊断的敏感度、特异度、阳性预测值、阴性预测值分别为73.0%,69.9%,72.2%,70.7%。结论心肌灌注显像对女性冠心病患者的诊断及是否进一步行冠状动脉造影的筛选有一定价值。     

Adenosine stress first pass perfusion for the detection of coronary artery disease in patients with aortic stenosis: a feasibility study

Purpose: Detection of coronary artery disease (CAD) with magnetic resonance imaging (MRI) using adenosine stress first pass perfusion in patients with aortic stenosis in comparison with invasive angiography. Twenty-three consecutive patients (15 male, mean age 68 ± 12 years) with relevant aortic stenosis (aortic valve area 0.90 ± 0.41 cm2) were examined by MRI (1.5 T, Philips Intera CV™). Contrast-enhanced first pass perfusion was performed with adenosine stress (140 μg/kg/min) and under rest conditions. The results were compared with invasive coronary angiography with regard to the presence of a relevant coronary artery stenosis (>70%). Three of 23 patients (13%) had contraindications for adenosine administration (one patient with atrioventricular block, two patients with mild claustrophobia). In the remaining 20 patients, adenosine stress perfusion could be performed without any complications. CAD was correctly detected in eight patients and correctly ruled out in 10 of 12 patients. False-positive results were seen in two patients with severe myocardial hypertrophy. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 80%, 83%, and 100%, respectively. Adenosine stress perfusion can be performed without complications even in patients with high grade aortic stenosis. MRI is helpful to detect and rule out significant CAD in these patients. Severe myocardial hypertrophy may lead to false-positive results. Our initial results indicate that due to a high negative predictive value pre-operative invasive coronary angiography might probably be waived in patients without perfusion defects in stress MRI.     

Multislice computed tomography for determination of coronary artery disease in a symptomatic patient population

Background Multislice computed tomography (MSCT) has started to replace Electron beam CT for quantitation of coronary artery calcium. However no study has evaluated the diagnostic accuracy of MSCT for prediction of coronary artery disease (CAD) in a symptomatic patient population using the volume score. Methods and Results 1347 symptomatic subjects (male = 803, mean age = 62 years) with suspected CAD underwent MSCT studies 1 ± 2 days before the coronary angiogram. The Agatston (ACS) and Volumetric calcium score (VCS) were calculated using a proprietary workstation. Statistical analyses included the Pearson’s correlation coefficient and the nonparametric Mann–Whitney U-test to compare the calcium score in different age groups and between men and women. Sensitivity, specificity and predictive accuracy were calculated for different calcium thresholds for prediction of CAD. ROC curve analyses were used to establish relations between the coronary calcium score and presence or absence of CAD. In 720 (53%) subjects (male = 419) angiography revealed a minimal lumen diameter stenosis greater than 50%. Patients with significant CAD had significantly higher total calcium score values than patients without CAD (P = 0.001). ACS and VCS demonstrate a close correlation for the whole study group, r = 0.99. The overall sensitivity of any calcium to predict stenosis was 99%, specificity = 32%. Exclusion of calcium was highly accurate for exclusion of CAD in subjects older than 50 years (predictive accuracy = 98%). An absolute cutoff >100 and an age and sex specific threshold (score over 75th percentile) were identified as the cutoff levels with the highest sensitivities (86–89%) and lowest false positive rates (20–22%). ROC analyses revealed MSCT calcium scanning as a good clinical test which can be performed with similar accuracy in all age groups with an area under the curve of 0.84. Conclusion Determination of coronary calcium with MSCT is an accurate imaging modality for prediction of significant CAD in a patient population with intermediate likelihood of CAD. Exclusion of any calcium provided strong evidence that patients older than 50 years did not have obstructive CAD. ACS and VCS show an equivalent diagnostic accuracy.     

Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography A systematic review and meta-analysis

To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta-analyses was conducted on 10 studies examining stable, symptomatic and intermediate risk patients by 64-slice CTA. Patients were followed up for a mean of 21 month. Patient groups with CT-angiographic non-obstructive (stenosis <50% of luminal narrowing) or obstructive (stenosis ≥50% of luminal narrowing) CAD were compared to those having normal angiography without CAD. MACE (cardiac death, non-fatal myocardial infarction and revascularization) numbers were used to calculate odds ratios (OR) with 95% confidence interval (CI) in each group. Ten studies including 5,675 patients were eligible for meta-analysis. The cumulative MACE rate over 21 months were 0.5% in patients with normal CTA, 3.5% in non-obstructive CAD and 16% in obstructive CAD. Compared to normal CTA, non-obstructive CAD was associated with significant increased risk of MACE with OR = 6.68 (3.01–14.82 CI 95%), P = 0.0001. Obstructive CAD was associated with further significant increased risk of MACE with OR = 41.19 (22.56–75.18, CI 95%), P = 0.0001. The studies were homogenous, P-value >0.05 for heterogeneity. 64-slice CTA is able to differentiate low-risk from high-risk patients with suspected or known CAD. Absence of CAD predicts excellent prognosis, while obstructive CAD is associated with markedly increased risk of MACE.     

The accuracy of 1-day dual-isotope myocardial SPECT in a population with high prevalence of coronary artery disease

Background: In order to evaluate the diagnostic efficacy of the 1-day separate acquisition dual-isotope single-photon emission computed tomography (SPECT) protocol, using ²⁰¹Tl for the rest and ^99mTc-tetrofosmin for the stress images, a consecutive series of patients with suspected or known coronary artery disease (CAD) was studied that also underwent coronary angiography. Methods: The results of myocardial SPECT, using a semi-quantitative visual analysis, were acquired in 123 patients and compared with the results of coronary angiography. Sensitivity and specificity were calculated, using thresholds of 50 and 70% stenosis. As an alternative for specificity, the normalcy rate was determined in a separate group of 87 patients with a <5% pre-test likelihood of CAD. Results: The prevalence of CAD using 50 and 70% stenosis was 88 and 78%, respectively. The sensitivity for detection of patients with 50 and 70% stenosis was 94 and 97%, respectively while specificity was 62 and 59%, respectively. The high rate of false positive perfusion defects resulting in a low specificity could be explained by specific clinical issues. However, the routine assessment with additional clinical and electrocardiographic data resulted in a correct interpretation of most of the false positive perfusion defects. The positive predictive value was 92 and 85% and the negative predictive value 46 and 77%, using thresholds of 50 and 70% stenosis, respectively. The normalcy rate was 91%. Conclusion: The one-day separate acquisition rest ²⁰¹Tl/stress ^99mTc-tetrofosmin SPECT protocol is an efficient procedure for myocardial perfusion scintigraphy with high sensitivity for detection of CAD. Specific clinical issues caused a low value for specificity. Therefore, clinical information and knowledge of the electrocardiogram is essential for a correct interpretation of SPECT images.     

A comparative evaluation of Tl-201 and Tc-99m sestamibi myocardial perfusion spect imaging in diabetic patients

Aim Myocardial perfusion scintigraphy (MPS) is an effective tool for early diagnosis of coronary artery disease (CAD) in type II diabetes mellitus (DM). The purpose of this study was to review the comparative findings of Tc-99m MIBI and Tl-201 MPS in defining normal and abnormal myocardial segments, type and extent of the perfusion defects with reference to coronary angiography findings in diabetic patients. Methods Thirty patients with type II DM who had abnormal Tc-99m MIBI MPS findings and underwent coronary angiography were included this study (20 male, 10 female; mean age was 64 ± 11 years). Those patients were also investigated with Tl-201 MPS thereafter. All scintigraphic images were evaluated semiquantitatively using a 20-segments myocardial model. The perfusion of myocardial segments, reversibility and severity of defects based on defect score were compared using the MIBI and Tl-201 images in relation to coronary angiography. Diffuse slow-washout of Tl-201 was also noted. Results A total of 600 myocardial segments were comparatively analyzed. Diagnostic concordance between both tracers in defining normal and abnormal perfusion on a segmental basis was 88% (κ = 0.71). The percentage of normal, reversible and non-reversible segments in the Tc-99m MIBI and Tl-201 study were 67–61%, 11–20% and 22–19% respectively. While the number of irreversible defects were similar for both tracers, more number of reversible defects were identified by Tl-201 MPS than Tc-99m MIBI (65 vs. 123, p = 0.001). No significant difference between the defect scores of both tracers was found. Conclusion MPS using both tracers offered agreement in defining or excluding perfusion abnormalities in a major part of the data. However, Tl-201 MPS yielded better detection rate of myocardial ischemia than Tc-99m MIBI MPS in diabetic patients.     

Tolerance and safety of adenosine stress perfusion cardiovascular magnetic resonance imaging in patients with severe coronary artery disease

We sought to assess the tolerance and safety of adenosine-stress cardiovascular magnetic resonance (CMR) perfusion imaging in patients with coronary artery disease (CAD). We retrospectively examined all adenosine CMR perfusion scans performed in our centre in patients with known or suspected (CAD) and normal volunteers at either 1.5 or 3 T. All subjects were initially screened for contraindications to adenosine. The dose of adenosine infused was 140 μg/kg/min. Significant CAD was defined angiographically as the presence of at least one stenosis of >50% diameter. Data were collected from 351 consecutive subjects (mean age 62 ± 11 years, range 25–85 years-245 men). Of the 351 subjects, 305 had a coronary angiogram, the remaining 46 subjects were normal volunteers studied for research protocols. In total, 233 subjects (76%) were found to have significant CAD of whom 128 had multi-vessel disease. There were no deaths, myocardial infarctions, or episodes of bronchospasm during the CMR study. Transient 2nd (Mobitz II) or 3rd-degree atrioventricular (AV) block occurred in 27 patients (8%). There were no sustained episodes of advanced AV block. Transient chest pain was the most common side effect (199 subjects—57%). The use of intravenous adenosine in CMR perfusion imaging is safe and well-tolerated, even in patients with severe CAD. Where a careful screening policy for contraindications to adenosine is followed, serious adverse events in the CMR scanner are relatively rare and symptoms resolve following termination of the infusion, without the need for aminophylline.     

The prognostic value of multidetector coronary CT angiography for the prediction of major adverse cardiovascular events: a multicenter observational cohort study

To assess the prognostic value of coronary artery stenosis identification by coronary computed tomographic angiography (CCTA) for the prediction of major adverse cardiac events (MACE) in a multicenter prospective cohort study. We performed a prospective multicenter observational cohort study of symptomatic patients with suspected or known coronary artery disease (CAD) (n = 172; 57% male) undergoing CCTA in accordance to ACC/AHA Appropriateness Criteria from 4 sites in and around Paris, France, and followed for a mean duration of 22.0 ± 4.5 months (interquartile range 18–26 months). Coronary arteries by CCTA were interpreted by physicians blinded to the patient characteristics for the presence or absence obstructive (≥70% luminal diameter stenosis), as well as for plaque composition categorized as non-calcified, calcified or “mixed.” MACE was defined as death, non-fatal myocardial infarction, unstable angina or target vessel revascularization. MACE event rates were compared between patients with or without obstructive plaque and with differing plaque compositions. MACE event rates were significantly higher in patients with obstructive coronary artery stenosis by CCTA compared to those without (61.1% vs. 3.9%, P < 0.01). In patients with obstructive stenosis, mixed (83.3% vs. 25.3%, P < 0.01) and calcified (94.4% vs. 50.7%, P < 0.01) plaque presence was significantly higher than in patients without obstructive stenosis, with no differences in prevalence of non-calcified plaque (27.8% vs. 20.8%, P = NS). For MACE, the negative predictive value of no observed coronary artery plaque was 100% in the follow-up period. In this prospective multicenter study of symptomatic patients with suspected or known CAD undergoing CCTAs interpreted by imagers blinded to patient characteristics, CCTA presence of plaque severity and composition successfully identifies patients at risk for incident MACE events. Importantly, a negative CCTA portends an extremely low risk for incidence MACE.     

Imaging of Coronary Stents by Coronary CT-Angiography: Current Status

Coronary CT-angiography evolved as a valuable tool in the diagnostic work-up of patients after coronary revascularization therapy. With 64-slice or newer generation CT scanners it has a negative predictive value in the range of 98 %. Therefore, it is increasingly used to rule out in-stent restenosis. However, about 10 % to 15 % of stents are not accessible mostly due to motion or metal artifacts. Best results are achieved in stents ≥3 mm having thin stent struts. While the diagnosis of in-stent restenosis is currently based on the direct morphologic assessment of the stent lumen, functional information on the hemodynamic significance of in-stent restenosis will become available with the most recent generation of CT-scanners by means of myocardial perfusion imaging. This review describes technical considerations and summarizes the current evidence for stent imaging by means of coronary CT-angiography.