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Purpose: To perform a meta-analysis to evaluate the accuracy of 16- and 64-section spiral computed tomography (CT) to help assess coronary artery bypass grafts (CABGs)., Materials and Methods: The MEDLINE, Cochrane library, and BioMed Central databases were searched for relevant original articles published up to May 2007. Major criteria for article inclusion were that it (a) used multisection CT as a diagnostic test for the assessment of significant lesions (occlusion or >50% stenosis) of CABG, (b) used a 16- or 64-section scanner, and (c) used coronary angiography as the reference standard. After data extraction, the analysis was performed according to a random-effects model. Between-study statistical heterogeneity was also assessed by using the Cochran Q chi(2) test., Results: Of 158 screened articles, 15 fulfilled all inclusion criteria. Graft assessability (including distal anastomosis) ranged from 78%-100% among all included studies (mean, 92.4%; 90% with 16- and 96% with 64-section CT; P < .001). Statistical heterogeneity was observed for specificity and positive likelihood ratio (LR), justifying the use of the random-effects model. The analysis, pooled from 15 studies (723 patients, 2023 CABGs), provided the following results for the assessment of graft obstruction (occlusion and >50% stenosis): sensitivity, 97.6% (95% confidence interval [CI]: 96%, 98.6%); specificity, 96.7% (95% CI: 95.6%, 97.5%); positive predictive value, 92.7% (95% CI: 90.5%, 94.6%); negative predictive value, 98.9% (95% CI: 98.2%, 99.4%); positive LR, 23.42 (95% CI: 13.69, 40.07); negative LR, 0.045 (95% CI: 0.028, 0.071); and diagnostic odds ratio, 780.32 (95% CI: 379.12, 1606.1)., Conclusion: Multisection CT provided high accuracy for the evaluation of CABG obstruction in assessable conduits, and might be used as a noninvasive tool for the evaluation of suspected graft dysfunction in patients who are at high risk for complications from coronary angiography., ((c) RSNA, 2008.)

Aims: Although previous generations of multislice computed tomography (CT) have demonstrated accurate detection of obstructive bypass graft disease, progression of coronary disease is a more frequent cause for ischaemic symptoms late after bypass graft surgery. We explored the diagnostic performance of 64-slice CT in symptomatic patients after bypass surgery, for the assessment of both grafts and native coronary arteries., Methods and Results: The 64-slice CT angiography (Siemens Sensation 64, Germany) was performed in 52 symptomatic patients, 10 +/- 5 years after bypass surgery. Two independent, blinded observers assessed all grafts and coronary arteries for stenosis, using conventional quantitative angiography as a reference. A total of 109 grafts (182 graft segments), 123 distal coronary run-offs, and 116 non-bypassed coronary branches (288 segments) were analysed. Per-segment detection of graft disease yielded a sensitivity of 99% (71/72) and specificity of 96% (106/110). Sensitivity and specificity to detect run-off disease were 89% (8/9) and 93% (106/114), positive predictive value was 50% (8/16). In non-grafted coronary segments, CT detected significant stenosis with a sensitivity and specificity of 97% (62/64) and 86% (192/224). Overestimation occurred more frequently in calcified segments (P = 0.002)., Conclusion: The 64-slice CT allows angiographic evaluation of grafts and coronary arteries, although overestimation of coronary obstruction occurs, particularly in the presence of calcified disease.

Coronary artery disease remains the leading cause of death in the Western world. Non-invasive coronary artery imaging challenges any diagnostic modality because the coronary arteries are small and tortuous, whereas cardiac contraction and respiration cause motion artifacts. Therefore, non-invasive coronary imaging requires high spatial and temporal resolution. This review discusses the feasible applications in coronary imaging of magnetic resonance imaging and multi-slice computed tomography (MSCT), which are currently the only non-invasive diagnostic modalities for direct coronary atherosclerosis imaging. Particular attention and focus is devoted to the potential indications and clinical impact of MSCT due to its fast development and the robust results recently reported. MSCT of the coronary arteries is a promising imaging modality for the assessment of the coronary lumen and wall.

Objectives: This study was designed to define the current role of multislice spiral computed tomography (MSCT) for the diagnosis of coronary artery disease (CAD) using a meta-analytic process., Background: Multislice spiral computed tomography has recently been proposed as an alternative to conventional coronary angiography (CA) for the diagnosis of CAD., Methods: Using Medline, we identified 29 studies (2,024 patients) evaluating CAD by means of both MSCT (> or =16 slices) and conventional CA before July 2006. After data extraction the analysis was performed according to a random-effects model., Results: The per-segment analysis pooled the results from 27 studies corresponding to a cumulative number of 22,798 segments. Among unassessable segments, 4.2% were excluded from the analysis and 6.4% were classified at the discretion of the investigators, underscoring the shortcomings of MSCT. With this major limitation, the per-segment sensitivity and specificity were 81% (95% confidence interval [CI] 72% to 89%) and 93% (95% CI 90% to 97%), respectively, with positive and negative likelihood ratios of 21.5 (95% CI 13.1 to 35.5) and 0.11 (95% CI 0.06 to 0.21), respectively, and positive and negative predictive values of 67.8% (95% CI 57.6% to 78.0%) and 96.5% (95% CI 94.7% to 98.3%), respectively. As expected, the per-patient analysis has shown an increased sensitivity of 96% (95% CI 94% to 98%) but a decreased specificity of 74% (95% CI 65% to 84%)., Conclusions: Multislice spiral computed tomography has shortcomings difficult to overcome in daily practice and, at the more clinically relevant per-patient analysis, continues to have moderate specificity in patients with high prevalence of CAD. Studies evaluating the diagnostic performance of the newest generation of MSCT, including patients with low to moderate CAD prevalence, will be critical in establishing the clinical role of this emerging technology as an alternative to CA.

Aims: Relative plaque composition, more than its morphology alone, is thought to play a pivotal role in determining propensity to vulnerability. Thus, we investigated in vivo whether the distance from coronary ostium to plaque location independently affects plaque composition in humans. This may help explaining the recently reported non-uniform distribution of culprit lesions along the vessel in acute coronary syndromes., Methods and Results: In 51 consecutive patients (45 men), aged 38-76 years (mean age: 58+/-10), a non-culprit vessel was investigated through spectral analysis of IVUS radiofrequency data (IVUS-Virtual Histology). The study vessel was the left anterior descending artery in 23 (45%) patients; the circumflex artery in nine (18%), and right coronary artery in 19 (37%). The overall length of the region of interest, subsequently divided into 10 mm segments, was 41.5+/-13 mm long (range: 30.2-78.4). No significant change was observed in terms of relative plaque composition along the vessel with respect to fibrous, fibrolipidic, and calcified tissue, whereas the percentage of lipid core resulted to be increased in the first (median: 8.75%; IQR: 5.7-18) vs. the third (median: 6.1%; IQR: 3.2-12) (P=0.036) and fourth (median: 4.5%; IQR: 2.4-7.9) (P=0.006) segment. At multivariable regression analysis, distance from the ostium resulted to be an independent predictor of relative lipid content [beta=-0.28 (95%CI: -0.15, -0.41)], together with older age, unstable presentation, no use of statin, and presence of diabetes mellitus., Conclusion: Plaque distance from the coronary ostium, as an independent determinant of relative lipid content, is potentially associated to plaque vulnerability in humans.

Objectives: The purpose of this study was to investigate the long-term clinical and angiographic profile of sirolimus-eluting stent (SES) versus paclitaxel-eluting stent (PES) in patients undergoing percutaneous intervention for left main (LM) coronary disease., Background: The long-term clinical and angiographic impact of SES as opposed to PES implantation in this subset of patients is unknown., Methods: From April 2002 to March 2004, 110 patients underwent percutaneous intervention for LM stenosis at our institution; 55 patients were treated with SES and 55 with PES. The two groups were well balanced for all baseline characteristics., Results: At a median follow-up of 660 days (range 428 to 885), the cumulative incidence of major adverse cardiovascular events was similar (25% in the SES group vs. 29%, in the PES group; hazard ratio 0.88 [95% confidence interval 0.43 to 1.82]; p = 0.74), reflecting similarities in both the composite death/myocardial infarction (16% in the SES group and 18% in the PES group) and target vessel revascularization (9% in the SES group and 11% in the PES group). Angiographic in-stent late loss (mm), evaluated in 73% of the SES group and in 77% of the PES group, was 0.32 +/- 74 in the main and 0.36 +/- 0.59 in the side branch in the SES group vs. 0.46 +/- 0.57 (p = 0.36) and 0.52 +/- 0.42 (p = 0.41) in the PES group, respectively., Conclusions: In consecutive patients undergoing percutaneous LM intervention, PES may perform closely to SES both in terms of angiographic and long-term clinical outcome.

The introduction of multislice computed tomography (MSCT) has allowed non-invasive coronary angiography. Although widely applied, extensive information on technical details of the technique is lacking. This survey offers detailed information on patient preparation, data acquisition, reconstruction and interpretation. In addition, a summary of the available studies using MSCT for non-invasive angiography is provided. Based on pooled analysis of direct comparisons between MSCT and invasive angiography, the weighted mean sensitivity and specificity of current 16-slice MSCT for the detection of coronary artery disease are 88% and 96%, respectively. At present, the technique is particularly well suited for reliable exclusion of coronary artery disease. It is important to emphasise that MSCT only provides anatomical images, visualising the presence of atherosclerosis; information on the haemodynamic significance of these lesions (i.e. ischaemia) cannot be derived.

Multislice computed tomography is a rapidly emerging technique for the non-invasive visualization of coronary arteries. Over the past 5 years several scanner generation were introduced with a progressive improvement in the diagnostic accuracy in the detection of coronary artery stenosis in selected patients populations. The introduction of 64-slice technology has further improved the diagnostic performance. This technique is at the edge of clinical implementation and, even though large clinical trials are still missing, an increased demand for these type of studies is observed all over the world. We describe our experience of more than 1 year with 64-slice CT coronary angiography providing clues on reasonable clinical applications.

The past two decades have highlighted the pivotal role of the endothelium in preserving vascular homeostasis. Among others, nitric oxide (NO) is currently believed to be the main component responsible for endothelium dependent vasorelaxation and therefore for endothelial function integrity. Reduced NO bioavailability causes the so-called "endothelial dysfunction," which seems to be the common molecular disorder comprising stable atherosclerotic narrowing lesions or acute plaque rupture causing unstable angina or myocardial infarction. Compelling evidence is accumulating, stressing the role of oxidative stress in causing reduced NO bioavailability and subsequently endothelial dysfunction (ED). More recently, the role of endothelial cell (EC) apoptosis as a possible final stage of ED and plaque activation has been suggested. In vitro and in vivo evidence suggests a role of oxidative stress also as a putative mechanism finally leading to plaque denudation and activation through increased EC apoptosis. Thus, oxidative stress, irrespective of atherosclerotic disease stages, seems to represent a key phenomenon in vascular disease progression and possible prevention.