Conventional Invasive Coronary Angiography Research Articles

Coronary evaluation in patients with stroke: Recognizing the risk

large series of consecutive patients with a nonfatal cerebral infarction and no previously known coronary heart disease. Coronary plaques on angiography were present in 61.9% of patients and diameter stenosis more than 50% was found in 25.7% of stroke patients [5]. This study included patients largely irrespective of the cause of stroke. A French study based on systematic 64-section computed tomography coronary angiography shows that almost 20% of patients between 45 and 75 years of age with non-disabling, non-cardioembolic ischemic stroke or transitory ischemic accident (TIA) have asymptomatic coronary artery disease (CAD) defined as coronary diameter stenosis of 50% or more [6]. The results of the present study by Hur and colleagues [7] with a prevalence of obstructive CAD (coronary diameter stenosis of 50% or more) based on coronary computed tomography angiography assessment of 48% corroberate and extend previous findings.

CT Coronary Angiography Versus Conventional Invasive Coronary Angiography – The View of the Referring Physician

Assessment of experience gained by local referring physicians with the procedure of coronary computed tomographic angiography (CCTA) in the everyday clinical routine. A 25-item questionnaire was sent to 179 physicians, who together had referred a total of 1986 patients for CCTA. They were asked about their experience to date with CCTA, the indications for coronary imaging, and their practice in referring patients for noninvasive CCTA or invasive catheter angiography. 53 questionnaires (30 %) were assessable, corresponding to more than 72 % of the patients referred. Of the referring physicians who responded, 94 % saw a concrete advantage of CCTA in the treatment of patients, whereby 87 % were 'satisfied' or 'very satisfied' with the reporting. For excluding coronary heart disease (CHD) where there was a low pre-test probability of disease, the physicians considered CCTA to be superior to conventional coronary diagnosis (4.2 on a scale of 1 - 5) and vice versa for acute coronary syndrome (1.6 of 5). The main reasons for unsuitability of CCTA for CT diagnosis were claustrophobia and the absence of a sinus rhythm. The level of exposure to radiation in CCTA was estimated correctly by only 42 % of the referring physicians. 90 % of the physicians reported that their patients evaluated their coronary CT overall as 'positive' or 'neutral', while 87 % of the physicians whose patients had undergone both procedures reported that the patients had experienced CCTA as the less disagreeable of the two. CCTA is accepted by the referring physicians as an alternative imaging procedure for the exclusion of CHD and received a predominantly positive assessment from both the referring physicians and the patients.

Comparison of 128-Slice Dual Source CT Coronary Angiography with Invasive Coronary Angiography.

Coronary artery disease (CAD) is one of the leading cause of the morbidity and mortality in India as well as worldwide and last decade has seen a steep rise in incidence of CAD in India. Direct visualization of the coronary arteries by invasive catheterization still represents the cornerstone of the evaluation of CAD. Cardiac imaging is a challenge of 21 (st) century and is being answered by 128 slice dual source CT as it has good temporal resolution, high scanning speed as well as low radiation dose. To assess the diagnostic accuracy of 128-slice dual source CT Cardiac Angiography in comparison with Conventional Catheter Cardiac Angiography. Forty patients attending the cardiology OPD with complaint of chest pain and suspected of having CAD were evaluated by CT coronary angiography and conventional invasive Catheter coronary angiography and the results were compared. All patients were checked for serum creatinine and ECG before the angiography. Computed Tomography (CT) coronary angiography was done using SIEMENS 128-slice Dual Source Flash Definition CT Scanner under either Retrospective or Prospective mode depending on the heart rate of the patient. Oral/IV beta-blocker were used whenever required. Coronary arteries were assessed as per 17- segment AHA model. A total of 600/ 609 segments were evaluable in 40 suspected patients on CT coronary angiography, of which 21 were false positives and 8 were false negatives with specificity of 95.12% and sensitivity and positive predictive value of 95.26% & 88.46% respectively. Non-invasive assessment of CAD is now possible with high accuracy on 128-slice dual source CT scanner.

Acceptance of noninvasive computed tomography coronary angiography: for a patient-friendly medicine

This study was done to evaluate the psychological state and anxiety of patients undergoing computed tomography coronary angiography (CTCA), and assess their acceptance and satisfaction compared to invasive conventional coronary angiography (CCA). A total of 442 consecutive patients (282 male; mean age 57.7±9.5years) who underwent CTCA for suspected or known coronary artery disease were evaluated with the Endler Multimodality Anxiety Scales (EMAS) before and after the scan, and a questionnaire administered after the scan. Among the 442 patients, 181 had a history of CCA. Two radiologists assessed the image quality of CTCA. Anxiety was more intense prior to the scan (EMAS score 51.7 vs. 46.7, p<0.01) and in patients with a history of CCA (EMAS score 55.5 vs. 49.1, p<0.01). Women presented more intense anxiety (EMAS score 59.5 vs. 47.3, p<0.01), higher mean heart rate (63.5±7.6 vs. 60.7±7.3beats per minute, p<0.01) and a lower image quality than men (p<0.0001). CTCA proved to be more acceptable than CCA because of accurate preparation, lower concern prior to the examination, negligible pain, higher comfort, and greater overall satisfaction (p<0.0001). Computed tomography coronary angiography is a patient-friendly imaging method because of the minimal perceived discomfort. Anxiety may affect CTCA image quality in women.

Coronary computed tomography as an alternative to invasive coronary angiography in the evaluation of patients referred for valvular disease surgery

Background: Coronary angiography is routinely performed in most patients referred for valvular or thoracic aortic disease surgery. Coronary computed tomography (CT) angiography is currently the only alternative to invasive angiography in the evaluation of coronary anatomy. Aim: An assessment of the usefulness of dual-source CT for the evaluation of coronary anatomy in patients before planned cardiac valvular surgery. Methods: 98 consecutive patients with a haemodynamically significant valvular heart disease and guideline based indications for coronary angiography to exclude CAD before planned valvular surgery were included. Exclusion criteria were: cardiac arrhythmia (atrial fibrillation, frequent ventricular and supraventricular premature beats), estimated glomerular filtration rate 1000. In the remaining patients, complete CT evaluation was performed with the administration of a contrast agent. Conventional invasive coronary angiography was subsequently performed in patients with at least one > 50% stenosis, artifacts due to calcifications, or motion artifacts. Results: In 79 (80.6%) patients, CT angiography excluded the presence of a significant coronary artery stenosis without the need for invasive angiography. Conventional coronary angiography was required in 19 (19.4%) patients, including 13 (13.3%) patients with a > 50% stenosis in CT angiography, 2 (2%) patients with calcification artifacts, 1 (1%) patient with motion artifacts, 2 (2%) patients with CACS > 1000 in whom CT angiography was nor performed, and 1 (1%) patient with allergic symptoms during administration of a test dose of the contrast agent. Ultimately, significant CAD was diagnosed in 9 (9.2%) patients in whom coronary artery bypass surgery was also performed. In addition, cardiac CT angiography revealed vascular anomalies in 5 (5.1%) patients. In 14 patients, CT angiography was also used for previously planned evaluation of a coexisting aortic aneurysm. Conclusions: Coronary CT angiography may be useful to exclude significant CAD in patients referred for valvular disease surgery. It also allows concomitant evaluation of other cardiac structures, large vessels including the thoracic aorta, and calcifications within the aorta, aortic valve and mitral apparatus.

Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

BackgroundCoronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780).Methods/DesignThe analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest likelihood of coronary artery disease. A bivariate random-effects model will be used to calculate pooled mean negative and positive predictive values as well as sensitivity and specificity. The primary outcome of interest will be positive and negative predictive values of coronary computed tomography angiography for the presence of coronary artery disease as a function of pretest likelihood of coronary artery disease, analyzed by meta-regression. As a secondary endpoint, factors that may influence the diagnostic performance and clinical value of computed tomography, such as heart rate and body mass index of patients, number of detector rows, and administration of beta blockade and nitroglycerin, will be investigated by integrating them as further covariates into the bivariate random-effects model.DiscussionThis collaborative individual patient data meta-analysis should provide answers to the pivotal question of which patients benefit most from noninvasive coronary computed tomography angiography and thus help to adequately select the right patients for this test.

Spontaneous coronary artery dissection diagnosed by intravascular ultrasound and followed up by cardiac computed tomography

Spontaneous coronary artery dissection diagnosed by intravascular ultrasound and followed up by cardiac computed tomography

Pre-operative CT coronary angiography in patients with mitral valve prolapse referred for surgical repair: Comparison of accuracy, radiation dose and cost versus invasive coronary angiography

BackgroundThe aims of this study are to evaluate the accuracy of low dose multidetector computed tomography coronary angiography (MDCT) versus invasive coronary angiography (ICA) in ruling out CAD in patients with mitral valve prolapse and severe mitral regurgitation (MVP) before cardiac surgery and to compare the overall effective radiation dose (ED) and cost of a diagnostic approach in which conventional ICA should be performed only in patients with significant CAD as detected by MDCT. MethodsEighty patients with MVP and without history of CAD were randomized to MDCT (Group 1) or ICA (Group 2) to rule out CAD before surgery. However, ICA was also performed as gold standard reference in Group 1 to test the diagnostic accuracy of MDCT. A diagnostic work-up A in whom all patients underwent low-dose MDCT as initial diagnostic test and those with positive findings were referred for ICA was compared with work-up B in which all patients were referred for ICA according to the standard of care in terms of ED and cost. ResultsThe two groups were homogeneous in terms of gender, age and body mass index. The overall feasibility and accuracy in a patient-based model were 99% and 93%, respectively. The overall ED and costs were significantly lower in diagnostic work-up A compared to diagnostic work-up B. ConclusionsThe accuracy of low dose MDCT for ruling out the presence of significant CAD in patients undergoing elective valve surgery for mitral valve prolapse is excellent with a reduction of overall radiation dose exposure and costs.

Noninvasive imaging in cardiovascular therapy: the promise of coronary arterial 18F-sodium fluoride uptake as a marker of plaque biology

The majority of myocardial infarctions are caused by atherosclerotic plaque rupture. However, identifying lesions at risk of rupture, so-called vulnerable plaques, is challenging. Most are not flow-limiting [1,2] and will therefore not be detected by conventional stress testing or invasive coronary angiography. Other methods are therefore required to improve the prediction of adverse coronary events. The presence of calcium in the coronary arteries is pathognomic of atherosclerosis and can be quantified using computed tomography (CT) and the Agatston score. This provides a surrogate of the coronary atherosclerotic burden and offers powerful cardiovascular risk prediction [3], presumably because with an increasing number of plaques, more are likely to be vulnerable. Vulnerable plaques are known to have certain pathological characteristics, which include inflammation and spotty calcification. Activated macrophages infiltrate the thin fibrous cap, secreting matrix metalloproteinases, which predispose the plaque to rupture [4]. Spotty calcification represents the very earliest stage of the vascular calcific process and is frequently not resolved by CT. Unlike the confluent calcification observed later in the disease process, microcalcif ication increases wall stress, predisposing the plaque to microfractures and rupture [5–7]. We have recently investigated the feasibility of using PET to image these two processes in the coronary arteries [8]. In a cohort of 119 patients, we performed PET/ CT imaging using F-fluorodeoxyglucose (F-FDG) to detect plaque inflammation and F-sodium f luoride (F-NaF) to image calcification. Both tracers are easy to manufacture in modern cyclotrons and are commercially available. F-FDG has become well established as a measure of vascular inflammation [9,10], whereas F-NaF has been used to image new bone formation, primarily cancer metastases, for 50 years. Fluoride ions exchange with hydroxyl ions in exposed hydroxyapatite, a key structural crystal that is deposited in both bone matrix and in the initial stages of vascular calcium formation. Retrospective data derived from the use of F-NaF in cancer imaging have previously suggested that vascular uptake may identify novel or developing regions of arterial calcification [11–13]. In our study results for F-FDG were disappointing, being hampered by myocardial uptake from which it was difficult to isolate activity in the coronary Noninvasive imaging in cardiovascular therapy: the promise of coronary arterial 18F-sodium fluoride uptake as a marker of plaque biology

Escore de cálcio e angiotomografia coronariana na estratificação do risco cardiovascular

Cardiovascular disease is the leading mortality cause worldwide. The capacity to identify among the asymptomatic individuals the subgroup at greater risk for developing cardiovascular events is fundamental in any strategy aimed at reducing the rate of cardiovascular events. The first step in cardiovascular risk stratification is the use of global risk scores, the Framingham risk score being the most frequently used. However, previous studies have shown that, although very useful, clinical scores, when used alone, have a limited capacity for stratifying cardiovascular risk in a significant part of the population. In that context, coronary artery calcium score (CACS) and coronary computed tomographic angiography might play an important role as complementary tools for risk stratification of asymptomatic patients. The CACS provides important prognostic information that is incremental to clinical scores based on traditional risk factors and other diagnostic modalities, such as C-reactive protein measurement. In addition, CACS has the potential to change and help the patients' clinical management. On the other hand, coronary computed tomographic angiography provides a detailed assessment of the anatomy of the coronary arteries, allowing visualizing not only the lumen, but also the coronary arterial walls. Compared with conventional invasive coronary angiography, coronary computed tomographic angiography has excellent accuracy to identify and mainly exclude the presence of significant obstructive lesions. In addition, it proved to be able to provide incremental prognostic information to traditional risk factors and CACS.

The NICE guidelines on the assessment of chest pain

The National Institute for Health and Clinical Excellence (NICE) published guidelines on the investigation of patients with chest pain of recent onset. The most prominent change to current protocols is that calcium scoring is proposed as the first-line investigation in patients with an estimated likelihood of coronary artery disease (CAD) of 10–29%, proceeding to multidetector computed tomography coronary angiography (CTCA) if the calcium score is above zero.1 For patients with 30–60% likelihood of CAD, functional testing is recommended with stress echocardiography, single photon emission computed tomography (SPECT) or cardiac magnetic resonance (CMR). For patients with 61–90% likelihood of CAD or calcium score greater than 400, X-ray invasive coronary angiography is recommended. The rationale underpinning these recommendations is that cardiac CT is considered an accurate ‘rule out’ test in patients with low likelihood of CAD given the extensive data confirming excellent prognosis of a zero calcium score in asymptomatic populations, and the excellent negative predictive value of CTCA.2 Functional tests on the other hand have better diagnostic performance in patients with higher pretest likelihood of CAD than in patients with low likelihood (Bayes theorem). It is hoped that the guidelines will reduce the high rate of normal coronary arteries at X-ray invasive coronary angiography, which was 39% in a recent ACC National Cardiovascular Data Registry, and is likely to be similar in most NHS Trusts.3 As exercise tolerance testing is no longer recommended; the guidelines will lead to an increase in referrals for imaging functional tests. The choice of imaging modality has been deliberately left open in the guidelines. Although this choice will often be driven by local availability, there are some differences in the evidence base and diagnostic yield and with the increasing awareness of the risks of ionizing radiation from medical exposure, the cumulative radiation burden of patients in their diagnostic journey, warrants particular consideration. Until recently, the median radiation dose for CTCA has been as high as 22 mSv, which can equate to an estimated risk of future cancer of 1 in every 270 in 40-year-old women undergoing the test.4 However, it is now possible to significantly reduce the radiation dose from CTCA by reducing the scan length and the scanning field of view to cover just the heart, electrocardiographically controlled tube current modulation during the cardiac cycle and reduction of the output of computed tomography X-ray tube from 120 kVp to 100 kVp for non-obese patients. The most effective way to lower the radiation dose, suitable in patients with regular heart rates below 60 bpm, is prospective electrocardiogram-triggering, which limits the acquisition to 10% of the cardiac cycle reducing the dose to 2–4 mSv.5 This is lower than conventional X-ray invasive coronary angiography, but not the new dual axis rotational coronary angiography which reduces radiation dose and contrast load. Such low radiation doses will however not be achievable in many UK centres without some investment.

CT coronary angiography vs. invasive coronary angiography in CHD.

Scientific background Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT) coronary angiography are used in the diagnosis of coronary heart disease (CHD).

Noninvasive Evaluation of Coronary Artery Bypass Grafts with 16-Slice Multidetector Computed Tomography

The aim of this study was to investigate the diagnostic accuracy of 16-slice multislice, multidetector computed tomography (MDCT) angiography for the evaluation of grafts in patients with coronary artery bypass grafting (CABG). Fifty-eight consecutive patients with CABG who underwent both MDCT and conventional invasive coronary angiography were included. The median time interval between the 2 procedures was 10 days (range, 1-32 days). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDCT for the detection of occluded grafts were calculated. The accuracy of MDCT angiography for detecting significant stenoses in patent grafts and the evaluability of proximal and distal anastomoses were also investigated. Optimal diagnostic images could not be obtained for only 3 (2%) of 153 grafts. Evaluation of the remaining 150 grafts revealed values for sensitivity, specificity, PPV, NPV, and diagnostic accuracy of the MDCT angiography procedure for the diagnosis of occluded grafts of 87%, 97%, 94%, 93%, and 92%, respectively. All of the proximal anastomoses were optimally visualized. In 4 (8%) of 50 patent arterial grafts, however, the distal anastomotic region could not be evaluated because of motion and surgical-clip artifacts. The accuracy of MDCT angiography for the detection of significant stenotic lesions was relatively low (the sensitivity, specificity, PPV, and NPV were 67%, 98%, 50%, and 99%, respectively). The number of significant lesions was insufficient to reach a reliable conclusion, however. Our study showed that MDCT angiography with 16-slice systems has acceptable diagnostic performance for the evaluation of coronary artery bypass graft patency.

Coronary imaging techniques with emphasis on CT and MRI

Coronary artery imaging in children is challenging, with high demands both on temporal and spatial resolution due to high heart rates and smaller anatomy. Although invasive conventional coronary angiography remains the benchmark technique, over the past 10 years, CT and MRI have emerged in the field of coronary imaging. The choice of hardware is important. For CT, the minimum requirement is a 64-channel scanner. The temporal resolution of the scanner is most important for optimising image quality and minimising radiation dose. Manufacturers have developed several modes of electrocardiographic (ECG) triggering to facilitate dose reduction. Recent technical advances have opened new possibilities in MRI coronary imaging. As a non-ionising radiation technique, MRI is of great interest in paediatric imaging. It is currently recommended in centres with appropriate expertise for the screening of patients with suspected congenital coronary anomalies. However, MRI is still not feasible in infants. This review describes and discusses the technical requirements and the pros and cons of all three techniques.

Diagnostic Application of Multidetector-Row Computed Tomographic Coronary Angiography to Assess Coronary Abnormalities in Pediatric Patients: Comparison With Invasive Coronary Angiography

Multidetector-row computed tomographic (MDCT) coronary angiography has been validated for noninvasive assessment of coronary anatomy. However, we have less experience in diagnosing children with congenital or acquired coronary artery abnormalities by MDCT. We compared the results of MDCT with invasive coronary angiography (ICA) on identifying coronary abnormalities in infants, children, and adolescents with coronary artery abnormalities, including aneurysm, coronary fistula, or anomalous left coronary artery from pulmonary artery (ALCAPA). From January 2002 to December 2009, patients with congenital or acquired coronary abnormalities underwent either ICA, MDCT, or both studies for assessment of coronary anatomy. We reviewed all patients' clinical diagnosis, coronary abnormalities identified by MDCT or ICA, and analyzed the advantages and disadvantages between those two methods. Thirty-three patients (20 males and 13 females) with a mean age of 10.3 years (range: 18 days to 25 years) had coronary abnormalities, including coronary artery aneurysm in Kawasaki disease (n=15), coronary artery fistula (n=12), myocardial bridge (n=2), and ALCAPA (n=4). In 17 patients only referred for ICA, 5 coronary aneurysms (3 on left main coronary artery, 1 on left anterior descending artery segment proximal, 1 on right coronary artery segment proximal), 11 coronary artery fistulas, and 2 ALCAPAs were detected. Sixteen patients received MDCT study, and 14 coronary artery aneurysms (4 on right coronary artery, 5 on left main coronary artery, 4 on left anterior descending artery, 1 on left circumflex artery), 3 myocardial bridges, 1 coronary artery fistulas, and 2 ALCAPAs were assessed. Ten patients with Kawasaki disease-related coronary lesions received MDCT study, and totally 102 (78.5%) segments permitted visualization with accurate diagnostic image quality. In this study, there were 11 patients with indication for conventional ICA spared invasive angiography after precise assessment by MDCT. We conclude that MDCT is a good and useful modality for assessment of congenital or acquired coronary abnormalities in pediatric patients. However, MDCT cannot replace invasive cardiac catheterization and ICA because of lack of therapeutic role.

Dipyridamole Stress and Rest Myocardial Perfusion by 64-Detector Row Computed Tomography in Patients With Suspected Coronary Artery Disease

Recently, stress myocardial computed tomographic perfusion (CTP) was shown to detect myocardial ischemia. Our main objective was to evaluate the feasibility of dipyridamole stress CTP and compare it to single-photon emission computed tomography (SPECT) to detect significant coronary stenosis using invasive conventional coronary angiography (CCA; stenosis >70%) as the reference method. Thirty-six patients (62 +/- 8 years old, 20 men) with previous positive results with SPECT (<2 months) as the primary inclusion criterion and suspected coronary artery disease underwent a customized multidetector-row CT protocol with myocardial perfusion evaluation at rest and during stress and coronary CT angiography (CTA). Multidetector-row computed tomography was performed in a 64-slice scanner with dipyridamole stress perfusion acquisition before a second perfusion/CT angiographic acquisition at rest. Independent blinded observers performed analysis of images from CTP, CTA, and CCA. All 36 patients completed the CT protocol with no adverse events (mean radiation dose 14.7 +/- 3.0 mSv) and with interpretable scans. CTP results were positive in 27 of 36 patients (75%). From the 9 (25%) disagreements, 6 patients had normal coronary arteries and 2 had no significant stenosis (8 false-positive results with SPECT, 22%). The remaining patient had an occluded artery with collateral flow confirmed by conventional coronary angiogram. Good agreement was demonstrated between CTP and SPECT on a per-patient analysis (kappa 0.53). In 26 patients using CCA as reference, sensitivity, specificity, and positive and negative predictive values were 88.0%, 79.3%, 66.7%, and 93.3% for CTP and 68.8, 76.1%, 66.7%, and 77.8%, for SPECT, respectively (p = NS). In conclusion, dipyridamole CT myocardial perfusion at rest and during stress is feasible and results are similar to single-photon emission CT scintigraphy. The anatomical-perfusion information provided by this combined CT protocol may allow identification of false-positive results by SPECT.

Coronary calcification: Achilles’ heel in the assessment for coronary artery disease in patients with symptomatic angina?

Coronary calcium quantification has emerged as a reliable and independent predictor of adverse cardiovascular events. Advances in multidetector scanning and imaging protocols have resulted in decreased contrast volumes, shorter scan times, and decreased radiation exposure, as well as improved spatial resolution and enhanced image quality. In subsets of patients with high calcium scores (particularly C400), however, the artifactual effects and scatter associated with radiodense calcium deposits have limited the specificity of CT coronary angiography (CTCA) in delineating the extent of clinically significant coronary artery disease (CAD). In the present study in the International Journal of Cardiovascular Imaging, Meijs et al. [1] conduct a multicenter prospective analysis of the diagnostic performance of 64-CTCA to predict the incidence of CAD in 360 patients who had been referred for conventional invasive coronary angiography (ICA) on the basis of symptomatic angina (stable and unstable) regardless of coronary calcium score (CS) over a 2-year time interval. As expected, the incidence of significant CAD correlated with increased CS. In patients with a CS C 400, the prevalence of significant CAD was 87% as compared to 24% in those with a CS 10. The specificity of CTCA as well as the positive likelihood ratio for significant CAD decreased significantly, however, as the CS increased. In patients with a CS 10, the specificity was 89% (95%CI 76–96%) while in patients with CS [ 400, the specificity was only 20% (95%CI 5–49%) [1]. The findings of this study are not inconsistent with the current literature, though the dramatic decline in specificity with increasing CS demonstrates a significant degree of inter-study variability. Early studies comparing the diagnostic capabilities of CTCA with ICA often excluded patients with elevated baseline CS as a result of the negative impact of high CS on CTCA accuracy or the inability to assess the presence or absence of stenosis with increased calcification [2– 4]. Studies which did include arterial segments with high levels of calcification usually denoted a significant decline in the diagnostic capability of the test. For example, the multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial which enrolled 230 patients regardless of CS, demonstrated a decline of specificity of CTCA for the 50% threshold CAD level from 86.3% in patients with CS B 400 to 52.6% in patients with CS [ 400 (P 0.0003) [5]. Studies of the implications of reduced specificity of CTCA have suggested that patients with very high calcium scores should forego multidetector coronary CT angiography in favor of ICA given the decreased Editorial comment on the article of Meijs et al. (doi:10.1007/s10554-009-9485-7).

Diagnostic accuracy of MDCT coronary angiography in patients referred for heart valve surgery

The aim of our study was to evaluate the role of multidetector-row computed tomography (MDCT) in patients referred for heart valve surgery. We studied the diagnostic performance of CT coronary angiography (CTCA) compared with conventional coronary angiography (CCA) before valve surgery. During a 13-month period, 55 consecutive patients under evaluation for aortic (40/55) or mitral valve (15/55) disease before potential valve replacement underwent CTCA using a 64-detector-row scanner within 2 months of CCA for comparative purposes. All 17 major coronary artery segments were evaluated by one observer and compared with the reference standard. Patient-based, vessel-based and segment-based analyses of the data were performed. Prevalence of significant coronary artery disease, defined as having at least one stenosis >/=50% per patient, was 36%. On a patient-based analysis, sensitivity, specificity and positive and negative predictive values were 100%, 91%, 83% and 100%, respectively. The diagnostic accuracy of 64-row CTCA for ruling out the presence of significant coronary stenoses in patients undergoing valve surgery is excellent and allows CTCA to be used as a gatekeeper for invasive CCA in these patients. MDCT is a necessary preoperative examination that provides useful information for identifying potential operative complications of surgical procedures.

Diagnostic Accuracy of Angiographic View Image for the Detection of Coronary Artery Stenoses by 64-Detector Row CT A Pilot Study Comparison With Conventional Post-Processing Methods and Axial Images Alone

The angiographic view (AGV) image is a new post-processing method that is similar to conventional coronary angiography (CAG). The purpose of this study was to evaluate its accuracy for coronary stenosis detection by 64-detector row computed tomography (CT). CT evaluation results of 17 patients were compared with the results of invasive CAG on a coronary segment basis concerning the presence of stenoses>50% diameter reduction. All images of the 3 viewing methods (combination of conventional methods, AGV image alone, and axial images alone) were evaluated in consensus by 3 cardiovascular radiologists. Among 196 assessable segments, invasive CAG showed significant coronary artery stenoses in 44 segments. 43 of 44 lesions were detected with the AGV image, and absence of significant stenosis was correctly identified in 135 of 152 segments (sensitivity 98%; specificity 89%; accuracy 91%; positive predictive value 72%, negative predictive value 99%). The sensitivity of the AGV image was the same as that of conventional methods (98%). There was no significant difference in accuracy between the AGV image (91%) and conventional methods (94%). The accuracy of the AGV image was significantly higher than the axial images alone (78%). AGV image shows promise as a post-processing method for identifying coronary artery stenosis with high accuracy.

Noninvasive coronary angiography with 64-channel multidetector computed tomography in patients with acute coronary syndrome

Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of > or =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.