The diagnostic accuracy of coronary computed tomography angiography in patients with and without previous coronary interventions

BackgroundInvasive coronary angiography (ICA) is the gold standard for imaging coronary arteries and the severity of coronary artery disease (CAD). Coronary computed tomography angiography (CCTA) has undergone remarkable progress in the diagnosis of CAD.ObjectivesTo evaluate the effect of prior vs no previous coronary interventions on the diagnostic accuracy of CCTA as an alternative to ICA to improve health outcomes for patients with suspected CAD.MethodsA prospective cohort study was carried out among patients suspected of CAD and for evaluation of grafts and stents to investigate recurrent ischemic symptoms. 120 patients imaged by CCTA were then referred to ICA, which is considered the gold standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CCTA were assessed relative to ICA.ResultsBased on a per-patient analysis, the comparison with ICA reveals variations in sensitivity, specificity, PPV, NPV and accuracy of CCTA. In patients without any previous coronary interventions, the sensitivity was 97.8%, and specificity was 95.6%. The PPV and NPV were 97.8% and 95.5%, respectively. Regarding patients with coronary artery bypass grafts (CABG), the sensitivity was 95% and specificity 100%. The PPV and NPV were 100% and 90.9%, respectively. Regarding patients with prior percutaneous coronary intervention (PCI), the results were a sensitivity of 84.6%, specificity of 77.8%, PPV of 84.6% and NPV of 77.8%.ConclusionCCTA is a powerful diagnostic tool, especially for the evaluation of the major coronary arteries and evaluation of patients with prior CABG. ICA is recommended for evaluation of patients with an intracoronary stent.     

Feasibility and diagnostic performance of fractional flow reserve measurement derived from coronary computed tomography angiography in real clinical practice

Non-invasive fractional flow reserve measured by coronary computed tomography angiography (FFR_CT) has demonstrated a high diagnostic accuracy for detecting coronary artery disease (CAD) in selected patients in prior clinical trials. However, feasibility of FFR_CT in unselected population have not been fully evaluated. Among 60 consecutive patients who had suspected significant CAD by coronary computed tomography angiography (CCTA) and were planned to undergo invasive coronary angiography, 48 patients were enrolled in this study comparing FFR_CT with invasive fractional flow reserve (FFR) without any exclusion criteria for the quality of CCTA image. FFR_CT was measured in a blinded fashion by an independent core laboratory. FFR_CT value was evaluable in 43 out of 48 (89.6?%) patients with high prevalence of severe calcification in CCTA images [calcium score (CS) >400: 40?%, and CS?>?1000: 19?%). Per-vessel FFR_CT value showed good correlation with invasive FFR value (Spearman’s rank correlation?=?0.69, P?<?0.001). The area under the receiver operator characteristics curve (AUC) of FFR_CT was 0.87. Per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 68.6, 92.9, 52.4, 56.5, and 91.7?%, respectively. Even in eight patients (13 vessels) with extremely severely calcified lesions (CS?>?1000), per-vessel FFR_CT value showed a diagnostic performance similar to that in patients with CS?≤?1000 (Spearman’s rank correlation?=?0.81, P?<?0.001). FFR_CT could be measured in the majority of consecutive patients who had suspected significant CAD by CCTA in real clinical practice and demonstrated good diagnostic performance for detecting hemodynamically significant CAD even in patients with extremely severe calcified vessels.     

Utility of 64 detector coronary computed tomographic angiography in patients with and without prior equivocal stress tests

This study sought to compare and the utility of cardiac computed tomographic angiography (CCTA) in patients with and without prior equivocal stress testing, and the subsequent need for invasive angiography and revascularization after CCTA. Evidence for the clinical utility of CCTA in the assessment of low to intermediate risk patients with equivocal stress testing is limited. Consecutive patients referred for outpatient CCTA for evaluation of suspected CAD with and without prior equivocal stress testing were included. CCTA studies were performed on a 64 detector scanner (Toshiba Aquilion). The diagnostic yield of CCTA for coronary stenoses and the subsequent need of the patients for invasive angiography and revascularization was evaluated. Of 228 patients evaluated, 43.9% were male, average age 59.3 ± 10.3. 66.2% (n = 151) had an equivocal stress test prior to CCTA. The prevelance of significant lesions (>50% stenosis) was high at 31% (n = 71), and was similar for those with and without a prior equivocal stress test (29.1 vs. 35.0%, P = NS). During a mean follow up of 1.4 ± 0.4 years, all patients with normal or stenosis by CCTA of <50% remained free from revascularization. Among those with a >50% stenosis by CCTA, the revascularization rate was 33.8%. The rates of angiography and revascularization were similar in those with or without prior stress tests (19 vs. 27%, P = 0.13 and 12 vs. 7.8%, P = 0.34 respectively). Regardless of whether or not patients had prior equivocal stress tests, CCTA detected a substantial number of obstructive CAD lesions and effectively identified the need for subsequent invasive angiography and revascularization. It appears to be a very promising triage test in this population.     

CT angiography with cardiac MRI: non-invasive functional and anatomical assessment for the etiology in newly diagnosed heart failure

Exclusion of ischemia is important in patients with newly diagnosed systolic heart failure (HF). We prospectively compared standard-of-care invasive catheter angiography (iCA) and echocardiography to a novel non-invasive strategy of both Coronary Computed Tomographic Angiography (CCTA) and Cardiovascular MRI (CMR) to determine the etiology of myocardial dysfunction Prospective data were collected from consecutive patients referred for iCA to investigate echocardiographically-confirmed new onset HF. CMR (1.5T GE) and dual source CCTA were performed within 2-7 days of iCA. Results were blinded and separately analyzed by expert readers. 426 coronary segments from 28 prospectively enrolled patients were analyzed by CCTA and quantitative iCA. The per-patient sensitivity and specificity of CCTA was 100% and 90%, respectively, negative predictive value (NPV) 100%, positive predictive value (PPV) 78%. Mean ejection fraction by CMR was 24%. Presence of ischemic-type LGE on CMR conferred a 67% sensitivity, 100% specificity, 90% NPV and 100% PPV. Combining CCTA with CMR conferred 100% specificity, 100% sensitivity, 100% PPV and 100% NPV for detection or exclusion of coronary disease. In patients with negative CCTA all invasive angiograms could have been avoided. In addition, two patients with no ischemic LGE by CMR had severe coronary disease on both CCTA and iCA, indicating global hibernation. This is a noteworthy finding in contrast to previous reports which suggested that absence of LGE rules out significant CAD. CCTA with CMR in newly-diagnosed HF enables non-invasive assessment of coronary artery disease, the severity and etiology of myocardial dysfunction and defines suitability for revascularization. Absence of ischemic-type LGE at CMR does not exclude CAD as a cause of LV dysfunction. A first-line strategy of functional and anatomic imaging with CMR and CCTA appears appropriate in newly diagnosed HF.     

Ultrasound Measurement of Carotid Intima–Media Thickness and Plaques in Predicting Coronary Artery Disease

Ultrasound measurement of carotid intima–media thickness (CIMT) and plaque thickness (PT) may be an additional tool for risk stratification of patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). The aim of this study was to evaluate the correlation of CIMT and PT with coronary artery disease (CAD) in risk stratification tests.This prospective observational study was conducted in an academic tertiary care ED. Carotid ultrasound measurements were obtained for emergency patients with suspected ACS. Carotid measurements included PT, mean CIMT and maximum CIMT. The correlations between carotid ultrasound and the results of coronary catheter angiography (CA), coronary computed tomography angiography (CCTA) and stress tests were identified. The convenience sample included 58 patients comprising 39 men and 19 women with a mean age of 60 ± 12 y. Twenty-two percent (13/58) of patients were positive for CAD, as indicated by results of the cardiac risk stratification tests. Presence of plaque correlated with CCTA findings, with a high specificity (92.8%) for a positive test. Max CIMT predicted abnormal CCTA (area under the curve [AUC] = 0.93, 95% confidence interval: 0.80–1). The correlations with stress test (0.78, 0.46–1) and CA (0.55, 0.28–0.82) were weaker. Presence of carotid plaque correlated significantly with findings of CAD on all risk stratification tests, but especially with CCTA. Carotid ultrasound could have a role in risk stratification in the ED, though more research is needed.     

64层螺旋CT冠状动脉成像在冠心病诊断中的初步应用

目的 评价64层螺旋CT冠状动脉成像（coronary 64-slice computed tomographic angiography,64S-CCTA）在诊断冠状动脉疾病（CAD）中的临床应用价值.方法 回顾性分析92例行64S-CCTA患者完整资料,并以近期（2周之内）实施的X线冠状动脉造影检查（coronary artery disease,CAG）结果为金标准进行对比.结果 所有可用于评估1,129段冠脉中,64S-CCTA显示轻度和明显狭窄病变各为122、231段,其中各有61、198段得到CAG证实;64S-CCTA判断冠状动脉明显狭窄的灵敏度、特异度、阳性预测值、阴性预测值、阳性似然比、阴性似然比分别为88.39%、96.35%、85.71%、97.10%及24.22、0.12;在CAG确诊狭窄节段中,64S-CCTA在轻度狭窄和明显狭窄中分别检测出非钙化性斑块、钙化斑块各为32、65 和154、53个.结论 64S-CCTA是一种简便、可靠的无创性检查方法,对病变血管管腔狭窄及不同性质粥样硬化斑块与狭窄关系的评价有一定价值,可作为临床拟诊冠心病患者筛查的有效手段.     

Comparison of angiographic and IVUS derived coronary geometric reconstructions for evaluation of the association of hemodynamics with coronary artery disease progression

Wall shear stress (WSS) has been investigated as a prognostic marker for the prospective identification of rapidly progressing coronary artery disease (CAD) and atherosclerotic lesions likely to gain high-risk (vulnerable) characteristics. The goal of this study was to compare biplane angiographic vs. intravascular ultrasound (IVUS) derived reconstructed coronary geometries to evaluate agreement in geometry, computed WSS, and association of WSS and CAD progression. Baseline and 6-month follow-up angiographic and IVUS imaging data were collected in patients with non-obstructive CAD (n?=?5). Three-dimensional (3D) reconstructions of the coronary arteries were generated with each technique, and patient-specific computational fluid dynamics models were constructed to compute baseline WSS values. Geometric comparisons were evaluated in arterial segments (n?=?9), and hemodynamic data were evaluated in circumferential sections (n?=?468). CAD progression was quantified from serial IVUS imaging data (n?=?277), and included virtual-histology IVUS (VH-IVUS) derived changes in plaque composition. There was no significant difference in reconstructed coronary segment lengths and cross-sectional areas (CSA), however, IVUS derived geometries exhibited a significantly larger left main CSA than the angiographic reconstructions. Computed absolute time-averaged WSS (TAWSS_ABS) values were significantly greater in the IVUS derived geometries, however, evaluations of relative TAWSS (TAWSS_REL) values revealed improved agreement and differences within defined zones of equivalence. Associations between VH-IVUS defined CAD progression and angiographic or IVUS derived WSS exhibited poor agreement when examining TAWSS_ABS data, but improved when evaluating the association with TAWSS_REL data. We present data from a small cohort of patients highlighting strong agreement between angiographic and IVUS derived coronary geometries, however, limited agreement is observed between computed WSS values and associations of WSS with CAD progression.     

Adenosine stress cardiac magnetic resonance imaging for the assessment of ischemic heart disease

Aims  This prospective study was designed to determine the diagnostic value of adenosine stress cardiac magnetic resonance imaging (CMRI) in patients referred to elective coronary angiography. Methods and results  Myocardial perfusion measurements at rest and adenosine stress were performed in 141 patients (105 men, 36 women, mean age 63.4 years) at 1.5 T with a Turbo Flash sequence. Stress-induced perfusion deficits were correlated to angiographic stenoses ≥75%. The overall sensitivity for CMRI depicting coronary artery disease (CAD) with relevant stenoses was 90.4%, the specificity was 77.4%, the positive predictive value was 85.9%, the negative predictive value was 84.2% and the accuracy 85.2%. Subgroup analysis was performed for 3-vessel disease (n = 44, sensitivity 92.3%, specificity 75.0%), 2-vessel disease (n = 43, sensitivity 92.6%, specificity 92.9%), 1-vessel disease (n = 27, sensitivity 93.1%, specificity 71.4%) and patients without CAD (n = 27, specificity 70.4%) as well as for patients with prior myocardial infarction (n = 44, sensitivity 92.9%, specificity 86.7%), prior coronary artery bypass surgery (n = 21, sensitivity 88.2%, specificity 66.7%), prior coronary interventions (n = 88, sensitivity 91.9%, specificity 75.0%), or diabetics (n = 27, sensitivity 90.5%, specificity 83.3%). Conclusion  Our study shows that stress perfusion CMRI can accurately predict relevant CAD and contributes to the identification of hemodynamic relevant stenoses in patients scheduled for coronary angiography. C. Doesch and A. Seeger have equally contributed to this publication.     

Incidence of subclinical coronary atherosclerosis in patients with suspected embolic stroke using cardiac computed tomography

The purpose of this study was to investigate the incidence of subclinical coronary artery disease (CAD) in patients with suspected acute embolic stroke or transient ischemic attack (TIA) using 64-row multi-slice computed tomography (MSCT) and to examine its association with conventional risk stratification. We consecutively enrolled 175 patients (66?±?13?years, 50% men) suspected to have had embolic stroke/TIA clinically or radiologically, and underwent 64-row MSCT to evaluate for a possible cardiac source of embolism. Both coronary artery calcium scoring (CACS) and coronary CT angiography (CCTA) were concurrently performed based on standard scanning protocols. Patients with a history of angina or documented CAD, and those with significant carotid stenosis were excluded. Atherosclerotic plaques were indentified in 105 (60%) individuals; 37 (21%) had occult CAD of ≥50% diameter stenosis on CCTA. Subjects with and without ≥50% occult CAD on CCTA had similar prevalence of cardiovascular risk factors. Thirty out of 175 (17%) individuals with ≥50% occult CAD would have missed further cardiac testing based on the American Heart association and the American Stroke Association guideline. However, these numbers would be reduced to 2% (4/175) using CACS. In logistic regression analysis, only CACS independently predicted the presence ≥50% occult CAD evidenced by CCTA. Subclinical CAD, including ≥50% stenotic disease, is highly prevalent in patients who had suffered a suspected embolic stroke. The current guideline for further cardiac testing may have limited value to identify patients with ≥50% CAD in this patient population, which can be improved by adopting CACS.     

经食管超声心动图探查胸主动脉粥样梗化对冠状动脉粥样硬化的预测价值

本文采用经食管超声心动图技术观察了６４例行冠脉造影患者的胸主动脉粥样硬化病变。结果表明４２例阳性患者中ＴＥＥ发现３６例有胸主动脉粥样斑块，而２２例阴性中仅２例存在斑块，二者相比有高度显著性差异（Ｐ＜０．００１）。以冠脉造影结果为金标准，斑块为预测冠心病的指标，其敏感性８５．７％，特异性９０．９％。冠脉造影阳性组的胸主动脉粥样硬化病变多为Ⅱ、Ⅲ级，而阴性组多为０、Ⅰ级，二组差异显著（Ｐ＜０．００５）。多支冠脉病变组胸主动脉粥样梗化程度较单支组严重（Ｐ＜０．０１），但正常组和狭窄＜５０％组之间无显著差异（Ｐ＞０．０５）。本研究认为胸主动脉粥样斑块能预报有临床意义的冠状动脉狭窄，胸主动脉可作为了解冠状动脉粥样硬化程度的窗口     

320排动态容积CT冠状动脉成像诊断冠心病:ROC曲线分析

目的应用ROC曲线分析方法评价320排动态容积CT冠状动脉成像(CCTA)诊断冠心病(CHD)的价值。方法回顾性分析临床疑似冠心病的37例患者的CCTA和冠状动脉造影(CAG)资料,以冠状动脉狭窄≥50%作为冠心病诊断标准,对结果采用配对t检验及ROC曲线分析。结果 CCTA诊断冠心病的敏感度为78.57%(55/70),特异度为95.13%(391/411),阳性预测值为73.33%(55/75),阴性预测值为96.31%(391/406),准确率为92.72%(446/481);CCTA和CAG结果呈高度相关性;CCTA的ROC曲线下面积为0.962。CCTA诊断的斑块数量较CAG多(68vs 45)。结论 320排动态容积CCTA诊断冠状动脉狭窄具有较高的准确性,能有效识别斑块及其危险程度。     

冠心病患者运动前后血浆内皮素水平变化的研究

目的：研究冠心病患者运动前后血浆内皮素水平的变化,以探讨其内在关系。方法：利用放射免疫测定技术检测了２０ 例已确诊冠心病的患者和１８ 个正常人在运动试验前、中、后的外周血内皮素（ＥＴ）水平。结果：冠心病患者与正常人在静息状态下血浆ＥＴ值比较无统计学意义（ Ｐ＞ ０．０５）; 运动后,冠心病者的血浆ＥＴ值呈逐渐上升趋势,在１ｈ 后最为显著（Ｐ＜０．００１）;而正常人在运动前后血浆ＥＴ值无明显变化（Ｐ＞ ０．０５）。并且经冠状动脉造影发现累及冠脉病变越严重（如多支病变）,则运动后血浆ＥＴ值升高越明显。结论：对有冠状动脉疾病者应减少负荷性运动,避免ＥＴ分泌、释放增加。     

Computer-aided simple triage (CAST) for coronary CT angiography (CCTA)

Purpose

Following a recent introduction of computer-aided simple triage (CAST) as a new subclass of computer-aided detection/diagnosis (CAD), we present a CAST software system for a fully automatic initial interpretation of coronary CT angiography (CCTA). We show how the system design and diagnostic performance make it CAST-compliant and suitable for chest pain patient triage in emergency room (ER).

Methods

The processing performed by the system consists of three major steps: segmentation of coronary artery tree, labeling of major coronary arteries, and detection of significant stenotic lesions (causing >?50% stenosis). In addition, the system performs an automatic image quality assessment to discards low-quality studies. For multiphase studies, the system automatically chooses the best phase for each coronary artery. Clinical evaluation results were collected in 14 independent trials that included more than 2000 CCTA studies. Automatic diagnosis results were compared with human interpretation of the CCTA and to cath lab results.

Results

The presented system performs a fully automatic initial interpretation of CCTA without any human interaction and detects studies with significant coronary artery disease. The system demonstrated higher than 90% per patient sensitivity and 40?C70% per patient specificity. For the chest pain, ER population, the specificity was 60?C70%, yielding higher than 98% NPV.

Conclusions

The diagnostic performance of the presented CCTA CAD system meets the CAST requirements, thus enabling efficient, 24/7 utilization of CCTA for chest pain patient triage in ER. This is the first fully operational, clinically validated, CAST-compliant CAD system for a fully automatic analysis of CCTA and detection of significant stenosis.     

Implication of coronary CT angiography combined with four-dimensional speckle tracking echocardiography for predicting major adverse cardiac events

Coronary computed tomography angiography (CCTA) can provide abundant information about the anatomy of the coronary artery. However, this modality is limited in evaluation of myocardial function. Four-dimensional speckle tracking echocardiography (4DSTE) is a novel and sensitive technique for quantitative evaluation of myocardial deformation. We estimated the value of these imaging modalities to predict the risk of MACE in 209 patients with suspected coronary artery disease(CAD) after a median follow-up of 727 days. Three models were established: (1) CCTA alone, (2) CCTA combined with 4DSTE, and (3) CCTA combined with 4DSTE and clinical risk factors. Forty-six (22.0%) patients developed MACE. The hazard ratio (HR) of CCTA classification to predict the risk of MACE was greater (HR?=?4.86) than for other parameters, including B-type natriuretic peptide (BNP) (HR?=?2.44) and left ventricular ejection fraction (LVEF) (HR?=?0.40). The area under the curve of models 2 and 3 to predict MACE was significantly greater than that of model 1 (0.92 and 0.93 vs. 0.84, respectively, p?<?0.001). We conclude that there is direct relationship between CCTA classification and MACE risk. CCTA combined with 4DSTE can improve the ability of CCTA to predict the risk of MACE. This approach provides cardiologists a noninvasive, objective, and efficient method to predict MACE.     

Relationship between airflow obstruction and coronary atherosclerosis in asymptomatic individuals: evaluation by coronary CT angiography

Airflow obstruction is associated with increased cardiovascular morbidity and mortality. However, the causal mechanisms linking airflow obstruction with higher incidence of cardiovascular events remain elusive. We evaluated the relationship between airflow obstruction, a key feature of chronic obstructive pulmonary disease (COPD), and prevalence, extent, and severity of coronary atherosclerosis in a large cohort of asymptomatic subjects. Participants were recruited from those undergoing spirometry and coronary computed tomography angiography (CCTA) as part of a general health evaluation from March 2009 to February 2011. Subjects were required to be over 40 years of age with no known CAD. Airflow obstruction was defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <?70%. Obstructive CAD, as measured by CCTA, was defined as maximum intra-luminal stenosis ≥?50%. Participants with airflow obstruction or normal lung function were compared in terms of obstructive CAD prevalence, the extent and severity of coronary atherosclerosis; including coronary artery calcium score (CACS), atheroma burden score (ABS), atheroma burden obstructive score (ABOS), segment involvement score (SIS), and segment stenosis score (SSS). A total of 1888 subjects were eligible for study inclusion. Compared with participants with normal lung function, those exhibiting airflow obstruction were more likely to have obstructive CAD (p?=?0.002). Airflow obstruction was associated with higher CACS (p?=?0.043), ABS (p?=?0.002), ABOS (p?=?0.017), SIS (p?=?0.003), and SSS (p?=?0.002). Multivariable analyses adjusted for conventional cardiovascular risk factors revealed that airflow obstruction was independently associated with presence of CAD (odds ratio 1.673, confidence intervals [CI] 1.002–2.789, p?=?0.048). In this asymptomatic population, the presence of airflow obstruction was associated with a greater prevalence, extent, and severity of coronary atherosclerosis and was seen to be an independent predictor of the presence of CAD.     

Cardiac CT for acute chest pain in the emergency department: advantages of prospective triggering

Coronary CT angiography (CCTA) is emerging as a powerful tool for the diagnosis and characterization of coronary artery disease. In the emergency department (ED) setting, the high negative predictive value of CCTA has been shown to reduce the length of stay and the cost of care in the evaluation of patients at low and intermediate risk for an acute coronary syndrome (ACS). In addition, CCTA and triple-rule-out protocol CT examinations which simultaneously evaluate the coronary arteries, aorta and pulmonary arteries, have the potential to diagnose not only significant atherosclerotic coronary artery disease (CAD) and coronary artery anomalies, but noncoronary etiologies of chest pain, including pulmonary embolism, aortic dissection, infection, pleural and pericardial disease. Caution has been raised about the widespread use of CCTA in this setting, particularly given the prevalence of repeat ED visits for chest pain, due to the radiation exposure associated with retrospectively-gated CCTA. However, the recent development of prospectively-triggered coronary artery CTA makes the ED evaluation possible with a substantially lower radiation exposure to the patient. Although most studies of CCTA to date are performed with retrospective ECG gating, early reports on prospectively triggered CCTA demonstrate equivalent image quality and accuracy when compared to studies acquired with retrospective ECG gating.     

Subtraction coronary CT angiography using second-generation 320-detector row CT

The purpose of this study was to explore the feasibility of subtraction coronary computed tomography angiography (CCTA) by second-generation 320-detector row CT in patients with severe coronary artery calcification using invasive coronary angiography (ICA) as the gold standard. This study was approved by the institutional board, and all subjects provided written consent. Twenty patients with calcium scores of >400 underwent conventional CCTA and subtraction CCTA followed by ICA. A total of 82 segments were evaluated for image quality using a 4-point scale and the presence of significant (>50 %) luminal stenosis by two independent readers. The average image quality was 2.3 ± 0.8 with conventional CCTA and 3.2 ± 0.6 with subtraction CCTA (P < 0.001). The percentage of segments with non-diagnostic image quality was 43.9 % on conventional CCTA versus 8.5 % on subtraction CCTA (P = 0.004). The segment-based diagnostic accuracy for detecting significant stenosis according to ICA revealed an area under the receiver operating characteristics curve of 0.824 (95 % confidence interval [CI], 0.750–0.899) for conventional CCTA and 0.936 (95 % CI 0.889–0.936) for subtraction CCTA (P = 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value for conventional CCTA were 88.2, 62.5, 62.5, and 88.2 %, respectively, and for subtraction CCTA they were 94.1, 85.4, 82.1, and 95.3 %, respectively. As compared to conventional, subtraction CCTA using a second-generation 320-detector row CT showed improvement in diagnostic accuracy at segment base analysis in patients with severe calcifications.     

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.     

Value of additional myocardial perfusion imaging during dobutamine stress magnetic resonance for the assessment of intermediate coronary artery disease

This study was performed to assess the role of additional myocardial perfusion imaging during high dose dobutamine/atropine stress magnetic resonance (DSMR-wall motion) for the evaluation of patients with intermediate (50?C70%) coronary artery stenosis. Routine DSMR-wall motion was combined with perfusion imaging (DSMR-perfusion) in 174 consecutive patients with chest pain syndromes who were scheduled for a clinically indicated coronary angiography. When defining CAD as the presence of a????50% stenosis, the addition of perfusion imaging improved sensitivity (90 vs. 79%, P?<?0.001) with a non-significant reduction in specificity (85 vs. 90%, P?=?0.13) and an improvement in overall diagnostic accuracy (88 vs. 84%, P?=?0.008). Adding perfusion imaging improved sensitivity in patients with intermediate stenosis (87 vs. 72%, P?=?0.03), but not in patients with severe (??70%) stenosis (93 vs. 84%, P?=?0.06). In patients with severe stenosis specificity of DSMR-perfusion versus DSMR-wall motion decreased (61 vs 70%, P?=?0.001) resulting in a lower overall accuracy (71 vs 74%, P?=?0.03). Using a cutoff of ??50% for the definition of CAD, sensitivity of DSMR-perfusion compared to DSMR-wall motion was significantly higher in patients with single vessel (88 vs. 77%, P?=?0.03) and multi vessel disease (93 vs. 79%, P?=?0.03), whereas no significant differences were found using a cutoff of ??70% stenosis for the definition of CAD. The addition of perfusion imaging during DSMR-wall motion improved the sensitivity in patients with intermediate coronary artery stenosis. Overall diagnostic accuracy increased only when defining CAD as ??50% stenosis. In patients with ??70% stenosis DSMR-wall motion alone had higher accuracy due to more false-positive cases with DSMR-perfusion.     

Meta-analysis of the diagnostic performance of stress perfusion cardiovascular magnetic resonance for detection of coronary artery disease

Aim

Evaluation of the diagnostic accuracy of stress perfusion cardiovascular magnetic resonance for the diagnosis of significant obstructive coronary artery disease (CAD) through meta-analysis of the available data.

Methodology

Original articles in any language published before July 2009 were selected from available databases (MEDLINE, Cochrane Library and BioMedCentral) using the combined search terms of magnetic resonance, perfusion, and coronary angiography; with the exploded term coronary artery disease. Statistical analysis was only performed on studies that: (1) used a [greater than or equal to] 1.5 Tesla MR scanner; (2) employed invasive coronary angiography as the reference standard for diagnosing significant obstructive CAD, defined as a [greater than or equal to] 50% diameter stenosis; and (3) provided sufficient data to permit analysis.

Results

From the 263 citations identified, 55 relevant original articles were selected. Only 35 fulfilled all of the inclusion criteria, and of these 26 presented data on patient-based analysis. The overall patient-based analysis demonstrated a sensitivity of 89% (95% CI: 88-91%), and a specificity of 80% (95% CI: 78-83%). Adenosine stress perfusion CMR had better sensitivity than with dipyridamole (90% (88-92%) versus 86% (80-90%), P = 0.022), and a tendency to a better specificity (81% (78-84%) versus 77% (71-82%), P = 0.065).

Conclusion

Stress perfusion CMR is highly sensitive for detection of CAD but its specificity remains moderate.