Search

Aim: To assess the attenuation of non-calcified atherosclerotic coronary artery plaques with computed tomography coronary angiography (CTCA)., Methods: Four hundred consecutive patients underwent CTCA (Group 1: 200 patients, Sensation 64 Cardiac, Siemens; Group 2: 200 patients, VCT GE Healthcare, with either Iomeprol 400 or Iodixanol 320, respectively) for suspected coronary artery disease (CAD). CTCA was performed using standard protocols. Image quality (score 0-3), plaque (within the accessible non-calcified component of each non-calcified/mixed plaque) and coronary lumen attenuation were measured. Data were compared on a per-segment/per-plaque basis. Plaques were classified as fibrous vs lipid rich based on different attenuation thresholds. A P < 0.05 was considered significant., Results: In 468 atherosclerotic plaques in Group 1 and 644 in Group 2, average image quality was 2.96 ± 0.19 in Group 1 and 2.93 ± 0.25 in Group 2 (P ≥ 0.05). Coronary lumen attenuation was 367 ± 85 Hounsfield units (HU) in Group 1 and 327 ± 73 HU in Group 2 (P < 0.05); non-calcified plaque attenuation was 48 ± 23 HU in Group 1 and 39 ± 21 HU in Group 2 (P < 0.05). Overall signal to noise ratio was 15.6 ± 4.7 in Group 1 and 21.2 ± 7.7 in Group 2 (P < 0.01)., Conclusion: Higher intra-vascular attenuation modifies significantly the attenuation of non-calcified coronary plaques. This results in a more difficult characterization between lipid rich vs fibrous type.

Objectives: To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations., Design: Retrospective pooled analysis of individual patient data., Setting: 18 hospitals in Europe and the United States., Participants: Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively)., Main Outcome Measures: Obstructive coronary artery disease (≥ 50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model factors and use of the CT based coronary calcium score). We assessed discrimination (c statistic), calibration, and continuous net reclassification improvement by cross validation for the four largest low prevalence datasets separately and the smaller remaining low prevalence datasets combined., Results: We included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended model was a major predictor (0.79 to 0.88, 102%). Calibration for low prevalence datasets was satisfactory., Conclusions: Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates.

State of the art cardiac computed tomography (CT) enables the acquisition of imaging data of the heart over the entire cardiac cycle at concurrent high spatial and temporal resolution. However, in clinical practice, acquisition is increasingly limited to 3-D images. Estimating the shape of the cardiac structures throughout the entire cardiac cycle from a 3-D image is therefore useful in applications such as the alignment of preoperative computed tomography angiography (CTA) to intra-operative X-ray images for improved guidance in coronary interventions. We hypothesize that the motion of the heart is partially explained by its shape and therefore investigate the use of three regression methods for motion estimation from single-phase shape information. Quantitative evaluation on 150 4-D CTA images showed a small, but statistically significant, increase in the accuracy of the predicted shape sequences when using any of the regression methods, compared to shape-independent motion prediction by application of the mean motion. The best results were achieved using principal component regression resulting in point-to-point errors of 2.3±0.5 mm, compared to values of 2.7±0.6 mm for shape-independent motion estimation. Finally, we showed that this significant difference withstands small variations in important parameter settings of the landmarking procedure.

Aims: The aim was to validate, update, and extend the Diamond-Forrester model for estimating the probability of obstructive coronary artery disease (CAD) in a contemporary cohort., Methods and Results: Prospectively collected data from 14 hospitals on patients with chest pain without a history of CAD and referred for conventional coronary angiography (CCA) were used. Primary outcome was obstructive CAD, defined as ≥ 50% stenosis in one or more vessels on CCA. The validity of the Diamond-Forrester model was assessed using calibration plots, calibration-in-the-large, and recalibration in logistic regression. The model was subsequently updated and extended by revising the predictive value of age, sex, and type of chest pain. Diagnostic performance was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) and reclassification was determined. We included 2260 patients, of whom 1319 had obstructive CAD on CCA. Validation demonstrated an overestimation of the CAD probability, especially in women. The updated and extended models demonstrated a c-statistic of 0.79 (95% CI 0.77-0.81) and 0.82 (95% CI 0.80-0.84), respectively. Sixteen per cent of men and 64% of women were correctly reclassified. The predicted probability of obstructive CAD ranged from 10% for 50-year-old females with non-specific chest pain to 91% for 80-year-old males with typical chest pain. Predictions varied across hospitals due to differences in disease prevalence., Conclusion: Our results suggest that the Diamond-Forrester model overestimates the probability of CAD especially in women. We updated the predictive effects of age, sex, type of chest pain, and hospital setting which improved model performance and we extended it to include patients of 70 years and older.

Objective: To assess the feasibility of single-breath-hold three-dimensional cine b-SSFP (balanced steady-state free precession gradient echo) sequence (3D-cine), accelerated with k-t BLAST (broad-use linear acquisition speed-up technique), compared with multiple-breath-hold 2D cine b-SSFP (2D-cine) sequence for assessment of left ventricular (LV) function., Methods: Imaging was performed using 1.5-T MRI (Achieva, Philips, The Netherlands) in 46 patients with different cardiac diseases. Global functional parameters, LV mass, imaging time and reporting time were evaluated and compared in each patient., Results: Functional parameters and mass were significantly different in the two sequences [3D end-diastolic volume (EDV) = 129 ± 44 ml vs 2D EDV = 134 ± 49 ml; 3D end-systolic volume (ESV) = 77 ± 44 ml vs 2D ESV = 73 ± 50 ml; 3D ejection fraction (EF) = 43 ± 15% vs 2D EF = 48 ± 15%; p < 0.05], although an excellent correlation was found for LV EF (r = 0.99). Bland-Altman analysis showed small confidence intervals with no interactions on volumes (EF limits of agreement = 2.7; 7.6; mean bias 5%). Imaging time was significantly lower for 3D-cine sequence (18 ± 1 s vs 95 ± 23 s; p < 0.05), although reporting time was significantly longer for the 3D-cine sequence (29 ± 7 min vs 8 ± 3 min; p < 0.05)., Conclusions: A 3D-cine sequence can be advocated as an alternative to 2D-cine sequence for LV EF assessment in patients for whom shorter imaging time is desirable.

Aim: To assess the prognostic relevance of 64-slice computed tomography coronary angiography (CT-CA) and symptoms in diabetics and non-diabetics referred for cardiac evaluation., Methods: We followed 210 patients with diabetes type 2 (DM) and 203 non-diabetic patients referred for CT-CA for ruling out coronary artery disease (CAD). Patients were without known history of CAD and were divided into four categories on the basis of symptoms at presentation (none, atypical angina, typical angina and dyspnoea). Clinical end points were major cardiac events (MACE): cardiac-related death, non-fatal myocardial infarction, unstable angina and cardiac revascularizations. Cox proportional hazard models, with and without adjustment for risk factors and multiplicative interaction term (obstructive CAD × DM), were developed to predict outcome., Results: DM patients with dyspnoea or who were asymptomatic showed a higher prevalence of obstructive CAD than non-diabetics (p ≤ 0.01). At mean follow-up of 20.4 months, DM patients had worse cardiac event-free survival in comparison with non-DM patients (90% vs. 81%, p = 0.02). In multivariate analysis, CT-CA evidence of obstructive CAD (in DM patients: HR: 6.4; 95% CI: 2.3-17.5; p < 0.001; in non-DM patients: HR: 7.4; 95% CI: 2.1-26.7; p = 0.002) and the presence of typical angina (in DM patients: HR: 2.9; 95% CI: 1.3-6.3; p = 0.007; in non-DM patients: HR: 2.7; 95% CI: 1.1-7.1; p = 0.03) were independent predictors of MACE in both groups. Furthermore, other independent outcome predictors included dyspnoea (HR: 3.8; 95% CI: 1.7-8.5; p = 0.001), the number of segments with any CAD (HR: 1.1; 95% CI: 1.001-1.2; p = 0.04) in DM patients and coronary calcium score >100 in non-DM patients (HR: 5.6; 95% CI: 1.4-21.5; p = 0.01). In Cox regression analysis of the overall population, interaction term obstructive CAD × DM resulted in non-significance., Conclusions: Among DM patients, dyspnoea carried a high event risk with a MACE rate four times higher. CT-CA findings were strongly predictive of outcome and proved valuable for further risk stratification.

The treatment of coronary artery stenosis has progressively shifted over the past decades, from surgical (CABG) to percutaneous (PCI and stenting). The recent introduction of drug-eluting stents further reduced the occurrence of in-stent re-stenosis (ISR). However, a non-negligible number of patients need imaging/functional tests when symptoms recur. Multi-Slice CT Coronary Angiography (CT-CA) is a clinical reality for the evaluation of coronary artery stenosis, but still under evaluation in the follow-up of coronary stents. Several factors may impair proper depiction of in-stent lumen even with the most recent CT equipments. In highly selected populations CT-CA may play a clinical role even though the performance requirements both from the technical standpoint (i.e., CT scanner) and from the training (i.e., operators' experience) are still very demanding. In the meantime CT technology should improve towards higher contrast, spatial and temporal resolution in order to achieve the results that may be proper for clinical implementation.

Objectives: We sought to evaluate the contribution of noninvasive dual-source computed tomography angiography (CTA) in the comprehensive assessment of symptomatic patients after coronary artery bypass grafting (CABG)., Background: Assessment of bypass grafts and distal runoffs by invasive coronary angiography is cumbersome and often requires extra procedure time, contrast load, and radiation exposure., Methods: Dual-source CTA was performed in 52 (41 men, mean age 66.6 +/- 13.2 years) symptomatic post-CABG patients scheduled for invasive coronary angiography. No oral or intravenous beta blockers or sedation were administered before the scan. Mean interval between CABG surgery and CTA was 9.6 +/- 7.2 (range 0 to 20) years. Mean heart rate during scanning was 64.5 +/- 13.2 (range 48 to 92) beats/min. Seventy-five percent of patients had both arterial and venous grafts. A total of 152 graft segments and 142 distal runoffs vessels were analyzed. Native coronary segments were divided into nongrafted (n = 118) and grafted segments (n = 289). A significant stenosis was defined as >or=50% lumen diameter reduction, and quantitative coronary angiography served as reference standard., Results: The diagnostic accuracy of CTA for the detection or exclusion of significant stenosis in arterial and venous grafts on a segment-by-segment analysis was 100%. Sensitivity, specificity, positive predictive value, and negative predictive value to detect significant stenosis were 95% (95% confidence interval [CI]: 73% to 100%), 100% (95% CI: 96% to 100%), 100% (95% CI: 79% to 100%), 99% (95% CI: 95% to 100%) in distal runoffs respectively; 100% (95% CI: 97% to 100%), 96% (95% CI: 90% to 98%), 97% (95% CI: 93% to 99%), 100% (95% CI: 95% to 100%) in grafted native coronary arteries respectively; and 97% (95% CI: 83% to 100%), 92% (95% CI: 83% to 96%), 83% (95% CI: 67% to 92%), 99% (95% CI: 92% to 100%) in nongrafted native coronary arteries, respectively., Conclusions: Noninvasive CTA is successful for evaluating bypass grafts in symptomatic post-CABG patients, whereas invasive coronary angiography is still required for the assessment of significant stenosis in distal runoffs and native coronary arteries.

Objectives: This study sought to determine the diagnostic accuracy of 64-slice computed tomographic coronary angiography (CTCA) to detect or rule out significant coronary artery disease (CAD)., Background: CTCA is emerging as a noninvasive technique to detect coronary atherosclerosis., Methods: We conducted a prospective, multicenter, multivendor study involving 360 symptomatic patients with acute and stable anginal syndromes who were between 50 and 70 years of age and were referred for diagnostic conventional coronary angiography (CCA) from September 2004 through June 2006. All patients underwent a nonenhanced calcium scan and a CTCA, which was compared with CCA. No patients or segments were excluded because of impaired image quality attributable to either coronary motion or calcifications. Patient-, vessel-, and segment-based sensitivities and specificities were calculated to detect or rule out significant CAD, defined as >or=50% lumen diameter reduction., Results: The prevalence among patients of having at least 1 significant stenosis was 68%. In a patient-based analysis, the sensitivity for detecting patients with significant CAD was 99% (95% confidence interval [CI]: 98% to 100%), specificity was 64% (95% CI: 55% to 73%), positive predictive value was 86% (95% CI: 82% to 90%), and negative predictive value was 97% (95% CI: 94% to 100%). In a segment-based analysis, the sensitivity was 88% (95% CI: 85% to 91%), specificity was 90% (95% CI: 89% to 92%), positive predictive value was 47% (95% CI: 44% to 51%), and negative predictive value was 99% (95% CI: 98% to 99%)., Conclusions: Among patients in whom a decision had already been made to obtain CCA, 64-slice CTCA was reliable for ruling out significant CAD in patients with stable and unstable anginal syndromes. A positive 64-slice CTCA scan often overestimates the severity of atherosclerotic obstructions and requires further testing to guide patient management.

Objectives: We sought to determine the diagnostic accuracy of noninvasive visual (computed tomography coronary angiography [CTCA]) and quantitative computed tomography coronary angiography (QCT) to predict the hemodynamic significance of a coronary stenosis, using intracoronary fractional flow reserve (FFR) as the reference standard., Background: It has been demonstrated that CTCA provides excellent diagnostic sensitivity for identifying coronary stenoses, but may lack accurate delineation of the hemodynamic significance., Methods: We investigated 79 patients with stable angina pectoris who underwent both 64-slice or dual-source CTCA and FFR measurement of discrete coronary stenoses. CTCA and conventional coronary angiography (CCA), and QCT and quantitative coronary angiography (QCA), were performed to determine the severity of a stenosis that was compared with FFR measurements. A significant anatomical or functional stenosis was defined as >/=50% diameter stenosis or an FFR <0.75. Stented segments and bypass grafts were not included in the analysis., Results: A total of 89 stenoses were evaluated of which 18% (16 of 89) had an FFR <0.75. The diagnostic accuracy of CTCA, QCT, CCA, and QCA to detect a hemodynamically significant coronary lesion was 49%, 71%, 61%, and 67%, respectively. Correlation between QCT and QCA with FFR measurement was weak (R values of -0.32 and -0.30, respectively). Correlation between QCT and QCA was significant, but only moderate (R = 0.53; p < 0.0001)., Conclusions: The anatomical assessment of the hemodynamic significance of coronary stenoses determined by visual CTCA, CCA, or QCT or QCA does not correlate well with the functional assessment of FFR. Determining the hemodynamic significance of an angiographically intermediate stenosis remains relevant before referral for revascularization treatment.

Background: A high diagnostic accuracy of 64-slice CT coronary angiography (CTCA) has been reported in selected patients with stable angina pectoris, but only scant information is available in patients with non-ST elevation acute coronary syndrome (ACS)., Objectives: To study the diagnostic performance of 64-slice CTCA in patients with non-ST elevation ACS., Patients and Methods: 64-slice CTCA was performed in 104 patients (mean (SD) age 59 (9) years) with non-ST elevation ACS. Two independent, blinded observers assessed all coronary arteries for stenosis, using conventional quantitative angiography as a reference. Coronary lesions with >or=50% luminal narrowing were classified as significant., Results: Conventional coronary angiography demonstrated the absence of significant disease in 15% (16/104) of patients, and the presence of single-vessel disease in 40% (42/104) and multivessel disease in 44% (46/104) of patients. Sensitivity for detecting significant coronary stenoses on a patient-by-patient analysis was 100% (88/88; 95% CI 95 to 100), specificity 75% (12/16; 95% CI 47 to 92), and positive and negative predictive values were 96% (88/92; 95% CI 89 to 99) and 100% (12/12; 95% CI 70 to 100), respectively., Conclusion: 64-slice CTCA has a high sensitivity to detect significant coronary stenoses, and is reliable to exclude the presence of significant coronary artery disease in patients who present with a non-ST elevation ACS.

Objectives: We assessed the usefulness of 64-slice computed tomography coronary angiography (CTCA) to detect or rule out coronary artery disease (CAD) in patients with various estimated pretest probabilities of CAD., Background: The pretest probability of the presence of CAD may impact the diagnostic performance of CTCA., Methods: Sixty-four-slice CTCA (Sensation 64, Siemens, Forchheim, Germany) was performed in 254 symptomatic patients. Patients with heart rates > or =65 beats/min received beta-blockers before CTCA. The pretest probability for significant CAD was estimated by type of chest discomfort, age, gender, and traditional risk factors and defined as high (> or =71%), intermediate (31% to 70%), and low (< or =30%). Significant CAD was defined as the presence of at least 1 > or =50% coronary stenosis on quantitative coronary angiography, which was the standard of reference. No coronary segments were excluded from analysis., Results: The estimated pretest probability of CAD in the high (n = 105), intermediate (n = 83), and low (n = 66) groups was 87%, 53%, and 13%, respectively. The diagnostic performance of the computed tomography (CT) scan was different in the 3 subgroups. The estimated post-test probability of the presence of significant CAD after a negative CT scan was 17%, 0%, and 0% and after a positive CT scan was 96%, 88%, and 68%, respectively., Conclusions: Computed tomography coronary angiography is useful in symptomatic patients with a low or intermediate estimated pretest probability of having significant CAD, and a negative CT scan reliably rules out the presence of significant CAD. Computed tomography coronary angiography does not provide additional relevant diagnostic information in symptomatic patients with a high estimated pretest probability of CAD.

Multislice computed tomography coronary angiography (MSCT-CA) has emerged as a powerful noninvasive diagnostic modality to visualize the coronary arteries and to detect significant coronary stenoses. The latest generation 64-slice computed tomography (CT) scanners is a robust technique which allows high-resolution, isotropic, nearly motion-free coronary imaging. Coronary stenoses are detected with high sensitivity and a normal scan accurately rules out the presence of a coronary stenosis. With the introduction of further novel concepts in CT-technology one may expect that MSCT-CA will become a clinically used diagnostic tool., ((c) 2007 Wiley Periodicals, Inc.)

Objectives: Our objective was to prospectively evaluate the diagnostic performance of the high-speed dual-source computed tomography scanner (DSCT), with an increased temporal resolution (83 ms), for the detection of significant coronary lesions (> or =50% lumen diameter reduction) in a clinically wide range of patients., Background: Cardiac motion artifacts may decrease coronary image quality with use of earlier computed tomography scanners that have a limited temporal resolution., Methods: We prospectively studied 100 symptomatic patients (79 men, 21 women, mean age 61 +/- 11 years) with atypical (18%) or typical (55%) angina pectoris, or unstable coronary artery disease (27%) scheduled for conventional coronary angiography. Mean scan time was 8.58 +/- 1.52 s. Mean heart rate was 68 +/- 11 beats/min. Quantitative coronary angiography was used as the standard of reference. Irrespective of image quality or vessel size, all segments were included for analysis., Results: Invasive coronary angiography demonstrated no significant disease in 23%, single-vessel disease in 31%, and multivessel disease in 46% of patients; 1,489 coronary segments, containing 220 significant (14.8%) stenoses, were available for analysis. Sensitivity, specificity, and positive and negative predictive values of DSCT coronary angiography for the detection of significant lesions on a segment-by-segment analysis were 95% (95% confidence interval [CI] 90 to 97), 95% (95% CI 93 to 96), 75% (95% CI 69 to 80), 99% (95% CI 98 to 99), respectively, and on a patient-based analysis 99% (95% CI 92 to 100), 87% (95% CI 65 to 97), 96% (95% CI 89 to 99), and 95% (95% CI 74 to 100), respectively., Conclusions: Noninvasive DSCT coronary angiography is highly sensitive to detect and to reliably rule out the presence of a significant coronary stenosis in patients presenting with atypical or typical angina pectoris, or unstable coronary artery disease.

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.

Aims: To compare the performance of 64-slice computed tomography coronary angiography (CTCA) and invasive coronary angiography (ICA) in the detection and classification (according to the Medina system) of bifurcation lesions (BLs)., Methods and Results: We studied 323 consecutive patients undergoing 64-slice CTCA prior to ICA. All coronary segments >or=2 mm in diameter were evaluated for the presence of a significant (>or=50% diameter reduction on quantitative coronary angiography) BL. Evaluation of BL by CTCA included the assessment of significant lumen obstruction in both main and side branch vessels. Forty-one out of 43 patients (46/48 lesions) with significant BL were identified by CTCA. Excluding coronary segments with non-diagnostic image quality (5%), the sensitivity, specificity, and positive and negative predictive values of CTCA for detecting significant BL were 96, 99, and 85 and 99%, respectively. In 39 of these 41 patients, CTCA assessment was concordant with the Medina lesion classification on ICA., Conclusion: Sixty-four-slice CTCA allows accurate assessment of complex BL.

Aims: To determine the adjunctive value of CT coronary angiography (CTCA) in the diagnostic work-up of patients with typical angina pectoris., Methods and Results: CTCA was performed in 62 consecutive patients (45 male, mean age 58.8 +/- 7.7 years) with typical angina undergoing diagnostic work-up including exercise-ECG and conventional coronary angiography. Only patients with sinus heart rhythm and ability to breath hold for 20 s were included. Patients with initial heart rates >/=70 beats/min received beta-blockers. We determined the post-test likelihood ratios, to detect or exclude patients with significant (>/=50% lumen diameter reduction) stenoses, of exercise-ECG and CTCA separately, and of CT performed after exercise-ECG testing. The prevalence of patients with significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios for exercise-ECG were 2.3 [95% confidence interval (CI): 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) and for CTCA 7.5 (95% CI: 2.1-27.1) and 0.0 (95% CI: 0.0-8), respectively. CTCA increased the post-test probability of significant CAD after a negative exercise-ECG from 58 to 91%, and after a positive exercise-ECG from 89 to 99%, while CT correctly identified patients without CAD (probability 0%)., Conclusion: Non-invasive CTCA is a potentially useful tool, in the diagnostic work-up of patients with typical angina pectoris, both to detect and to exclude significant CAD.

Objectives: This study sought to evaluate the diagnostic accuracy of 64-slice multislice computed tomography (MSCT) coronary angiography in the follow-up of patients with previous coronary stent implantation., Background: Recent investigations have shown increased image quality and diagnostic accuracy for noninvasive coronary angiography with 64-slice MSCT as compared with previous-generation MSCT scanners, but data on the evaluation of coronary stents are scarce., Methods: In 182 patients (152 [84%] male, ages 58 +/- 11 years) with previous stent (> or =2.5 mm diameter) implantation (n = 192), 64-slice MSCT angiography using either a Sensation 64 (Siemens, Forchheim, Germany) or Aquilion 64 (Toshiba, Otawara, Japan) was performed. At each center, coronary stents were evaluated by 2 experienced observers and evaluated for the presence of significant (> or =50%) in-stent restenosis. Quantitative coronary angiography served as the standard of reference., Results: A total of 14 (7.3%) stented segments were excluded because of poor image quality. In the interpretable stents, 20 of the 178 (11.2%) evaluated stents were significantly diseased, of which 19 were correctly detected by 64-slice MSCT. Accordingly, sensitivity, specificity, and positive and negative predictive value to identify in-stent restenosis in interpretable stents were 95.0% (95% confidence interval [CI] 85% to 100%), 93.0% (95% CI 90% to 97%), 63.3% (95% CI 46% to 81%), and 99.3% (95% CI 98% to 100%), respectively., Conclusions: In-stent restenosis can be evaluated with 64-slice MSCT with good diagnostic accuracy. In particular, a high negative predictive value of 99% was observed, indicating that 64-slice MSCT may be most valuable as a noninvasive method of excluding in-stent restenosis.

Unlabelled: Coronary stent imaging with computed tomography is challenging because of high-density artifacts. However, noninvasive coronary angiography with computed tomography is gaining acceptance as a valid alternative to cardiac catheterization in a broader array of clinical settings, and the work-up of patients after coronary stent implantation represents an application of pressing clinical utility. Only a minority of patients who develop recurrent chest pain after stent implantation have myocardial ischemia, thus a sensitive noninvasive study is desirable. With an awareness of the limitations of the technique, the systematic application of dedicated strategies of data post-processing and display techniques permits partial compensation of the technical limitations brought about by metallic struts., Advances in Knowledge: 1. The role of coronary computed tomography angiography in the diagnostic work-up of patients with symptoms after stent placement 2. Systematization of post-processing, display, and review techniques for optimal evaluation of coronary stents with coronary computed tomography angiography., Summary Statement: The follow-up of patients after coronary stenting is an appealing but challenging application of coronary computed tomography angiography. The presence of intrinsic limitations requires the use of dedicated post-processing and visualization techniques.

Objectives: We studied the diagnostic performance of 64-slice computed tomography coronary angiography (CTCA) to rule out or detect significant coronary stenosis in patients referred for valve surgery., Background: Invasive conventional coronary angiography (CCA) is recommended in most patients scheduled for valve surgery., Methods: During a 6-month period, 145 patients were prospectively identified from a consecutive patient population scheduled for valve surgery. Thirty-five patients were excluded because of CTCA criteria: irregular heart rhythm (n = 26), impaired renal function (n = 5), and known contrast allergy (n = 4). General exclusion criteria were: hospitalization in community hospital (n = 4), no need for CCA (n = 4), previous coronary artery bypass surgery (n = 1), or percutaneous coronary intervention (n = 4). Of the remaining 97 patients, 27 denied written informed consent. Thus, the study population comprised 70 patients (49 male, 21 female; mean age 63 +/- 11 years)., Results: Prevalence of significant coronary artery disease, defined as having at least 1 > or =50% stenosis per patient, was 25.7%. Beta-blockers were administered in 71%, and 64% received lorazepam. The mean heart rate dropped from 72.5 +/- 12.4 to 59.5 +/- 7.5 beats/min. The mean scan time was 12.8 +/- 1.3 s. On a per-patient analysis, the sensitivity, specificity, and positive and negative predictive values were: 100% (18 of 18; 95% confidence interval [CI] 78 to 100), 92% (48 of 52; 95% CI 81 to 98), 82% (18 of 22; 95% CI 59 to 94), and 100% (48 of 48; 95% CI 91 to 100), respectively., Conclusions: The diagnostic accuracy of 64-slice CTCA for ruling out the presence of significant coronary stenoses in patients undergoing valve surgery is excellent and allows CTCA implementation as a gatekeeper for invasive CCA in these patients.

Objectives: We evaluated the accuracy of in vivo delayed-enhancement multislice computed tomography (DE-MSCT) and delayed-enhancement magnetic resonance imaging (DE-MRI) for the assessment of myocardial infarct size using postmortem triphenyltetrazolium chloride (TTC) pathology as standard of reference., Background: The diagnostic value of DE-MSCT for the assessment of acute reperfused myocardial infarction is currently unclear., Methods: In 10 domestic pigs (25 to 30 kg), the circumflex coronary artery was balloon-occluded for 2 h followed by reperfusion. After 5 days (3 to 7 days), DE-MRI (1.5-T) was performed 15 min after administration of 0.2 mmol/kg gadolinium-DTPA using an inversion recovery gradient echo technique. On the same day, DE-MSCT (64-slice) was performed 15 min after administration of 1 gI/kg of iodinated contrast material. One day after imaging, hearts were excised, sectioned in 8 mm short-axis slices, and stained with TTC. Infarct size was defined as the hyperenhanced area on DE-MSCT and DE-MRI images and the TTC-negative area on TTC pathology slices. Infarct size was expressed as percentage of total slice area., Results: Infarct size determined by DE-MSCT and DE-MRI showed a good correlation with infarct size assessed with TTC pathology (R2 = 0.96 [p < 0.001] and R(2) = 0.93 [p < 0.001], respectively). The correlation between DE-MSCT and DE-MRI was also good (R2 = 0.96; p < 0.001). The relative difference in CT attenuation value of infarcted myocardium compared to remote myocardium was 191 +/- 18%. The relative MR signal intensity between infarcted myocardium and remote myocardium was 554 +/- 156%., Conclusions: We demonstrated that DE-MSCT can assess acute reperfused myocardial infarction in good agreement with in vivo DE-MRI and TTC pathology.

Objectives: We studied the effect of drug-eluting stent implantation for chronic total coronary occlusion (CTO) on left ventricular volumes and function and assessed the predictive value of magnetic resonance imaging (MRI) performed before revascularization., Background: The effect of recanalization of CTO on long-term left ventricular function and the value of myocardial viability assessment with MRI is incompletely understood., Methods: Twenty-seven patients underwent contrast-enhanced MRI before and five months after successful drug-eluting stent implantation for CTO. A CTO was defined as a complete occlusion of a major epicardial coronary artery existing for at least six weeks (mean, 7 +/- 5 months). Myocardial wall thickening and left ventricular volumes were quantified on cine-images, and the transmural extent of infarction (TEI) was scored on delayed-enhancement images., Results: A significant decrease in mean end-systolic volume index (34 +/- 13 ml/m2 to 31 +/- 13 ml/m2; p = 0.02) and mean end-diastolic volume index (84 +/- 15 ml/m2 to 79 +/- 15 ml/m2; p < 0.002) was observed, whereas the mean ejection fraction did not change significantly (61 +/- 9% to 62 +/- 11%; p = 0.54). The extent of the left ventricle that was dysfunctional but viable before revascularization was related to improvement in end-systolic volume index (R = 0.46; p = 0.01) and ejection fraction (R = 0.49; p = 0.01) but not to the end-diastolic volume index (R = 0.10; p = 0.53). Segmental wall thickening improved significantly in segments with <25% TEI (21 +/- 15% to 35 +/- 25%; p < 0.001), tended to improve in segments with 25% to 75% TEI (18 +/- 22% to 27 +/- 22%; p = 0.10), whereas segments with >75% TEI did not improve (4 +/- 14% to -9 +/- 14%; p = 0.54)., Conclusions: Drug-eluting stent implantation for a CTO has a beneficial effect on left ventricular volumes and function that can be predicted by performing MRI before revascularization.

Unlabelled: The effects of reperfusion on early and late infarct size and left ventricular wall characteristics were studied by performing cine-magnetic resonance imaging, first-pass perfusion, and delayed enhancement imaging in 22 patients at five days and five months after successful primary angioplasty for first acute myocardial infarction. Infarct size, end-diastolic wall thickness, and segmental wall thickening were quantified, and the extent of microvascular obstruction (MO) was evaluated qualitatively. Infarct size decreased by 31%. Segments without MO had early increased wall thickness and late partially normalized wall thickening. Segments with MO showed late wall thinning and no functional recovery at five months., Objectives: We aimed to study the effects of early successful primary angioplasty for ST-segment elevation acute myocardial infarction (AMI) on early and late infarct size and left ventricular (LV) wall characteristics., Background: Early reperfusion treatment for AMI preserves LV function, but the effects on early and late infarct size, end-diastolic wall thickness (EDWT), and segmental wall thickening (SWT) are not well known., Methods: In 22 patients with successful primary angioplasty for first AMI, cine-magnetic resonance imaging (MRI), first-pass perfusion, and delayed-enhancement imaging was performed at five days and five months. The extent of microvascular obstruction (MO) was evaluated on perfusion images. Infarct shrinkage was defined as the difference between the volume of delayed-enhancement at five days and five months. The EDWT and SWT were quantified on cine-MRI., Results: Infarct shrinkage occurred to the same extent in small and large infarctions [r = 0.92; p < 0.001], with a mean decrease of 31% (35 +/- 21 g to 24 +/- 17 g). Dysfunctional segments without MO had an increased EDWT at five days compared with remote myocardium (9.2 +/- 1.7 mm vs. 8.4 +/- 1.7 mm; p < 0.001). At five months, EDWT in these segments became comparable to the thickness of remote myocardium (7.8 +/- 1.6 mm vs. 7.6 +/- 1.4 mm; p = 0.60), and SWT improved (21 +/- 15% to 40 +/- 24%; p < 0.001) but remained impaired (40 +/- 24% vs. 71 +/- 29%; p < 0.001). Segments with MO demonstrated wall thinning at five months (6.4 +/- 1.3 mm vs. 7.6 +/- 1.4 mm; p = 0.006) and no significant recovery in SWT (12 +/- 14% to 17 +/- 20%; p = 0.15)., Conclusions: Infarct size decreased by 31%. Segments without MO had early increased wall thickness and late partial functional recovery. Segments with MO showed late wall thinning and no functional recovery at five months.

Aims: To study recovery of segmental wall thickening (SWT), ejection fraction (EF), and end-systolic volume (ESV) after acute myocardial infarction (AMI) in patients who underwent primary stenting with drug-eluting stents. Additionally, to evaluate the predictive value of magnetic resonance imaging (MRI)-based myocardial perfusion and delayed enhancement (DE) imaging., Methods and Results: Twenty-two patients underwent cine-MRI, first-pass perfusion, and DE imaging 5 days after successful placement of a drug-eluting stent in the infarct-related coronary artery. Regional myocardial perfusion and the transmural extent of DE were evaluated. A per patient perfusion score was calculated and consisted of a summation of all segmental scores. Myocardial infarct size was quantified by measuring the volume of DE. At 5 months after AMI, cine-MRI was performed and SWT, EF, and ESV were quantified. EF increased from 48+/-11 to 55+/-9% (P<0.01). SWT at 5 months was inversely related to baseline segmental DE scores (P<0.001) and segmental perfusion scores (P<0.001). EF and ESV at 5 months were related to acute infarct size (R(2)=0.65; P<0.001 and R(2)=0.78; P<0.001, respectively) and the calculated perfusion score (R(2)=0.23; P=0.02 and R(2)=0.14; P=0.09, respectively) at baseline., Conclusion: Marked recovery of left ventricular function was observed in patients receiving a drug-eluting stent for AMI. DE imaging appears to be a better prognosticator than perfusion imaging.

Objectives: We sought to compare the diagnostic value of multi-slice computed tomography (MSCT) coronary angiography (CA) to detect significant stenoses (> or =50% lumen diameter reduction) with that of invasive CA., Background: The latest 16-row MSCT scanner has a faster rotation time (375 ms) and permits scanning with a higher X-ray tube current (500 to 600 mA) during MSCT CA when compared with previous scanners., Methods: We studied 51 patients (37 men, mean age 58.9 +/- 10.0 years) with stable angina or atypical chest pain. Patients with pre-scan heart rates > or =70 beats/min received oral beta-blockade. The heart was scanned after intravenous injection of 100 ml contrast (iodine content, 400 mg/ml). Mean scan time was 18.9 +/- 1.0 s. The MSCT scans were analyzed by two observers unaware of the results of invasive angiography, and all available coronary branches > or =2 mm were included., Results: Invasive CA demonstrated normal arteries in 16% (8 of 51), non-significant disease in 21% (11 of 51), single-vessel disease in 37% (19 of 51), and multi-vessel disease in 26% (13 of 51) of patients. There were 64 significant lesions. Sensitivity, specificity, and positive and negative predictive values for detection of significant lesions on a segment-based analysis were 95% (61 of 64, 95% confidence interval [CI] 86 to 99), 98% (537 of 546, 95% CI 96 to 99), 87% (61 of 70, 95% CI 76 to 98), and 99% (537 of 540, 95% CI 98 to 99), respectively. All patients with angiographically normal coronary arteries or significant lesions were correctly identified. Three of 11 patients with <50% lesions were incorrectly classified as having single-vessel disease., Conclusions: The 16-row MSCT CA reliably detects significant coronary stenoses in patients with atypical chest pain or stable angina pectoris.

Objectives: This study was designed to prospectively evaluate the diagnostic performance of multislice spiral computed tomography (MSCT) coronary angiography for the detection of significant lesions in all segments of the coronary tree potentially suitable for revascularization., Background: Noninvasive MSCT coronary angiography is a promising coronary imaging technique., Methods: Sixteen-row MSCT coronary angiography was performed in 128 patients (89% men, mean age 58.9 +/- 11.7 years) in sinus rhythm with stable angina pectoris scheduled for conventional coronary angiography. Sixty percent (77 of 128) of patients received pre-scan oral beta-blockers, resulting in a mean heart rate of 57.7 +/- 7.7 beats/min. The diagnostic performance of MSCT for detection of significant lesions (> or =50% diameter reduction) was compared with that of quantitative coronary angiography (QCA)., Results: The sensitivity of MSCT for detection of significant lesions was 92% (216 of 234, 95% confidence interval [CI]: 88 to 95). Specificity was 95% (1,092 of 1,150, 95% CI: 93 to 96), positive predictive value 79% (216 of 274, 95% CI: 73 to 88), and negative predictive value 98% (1,092 of 1,110, 95% CI: 97 to 99). Two > or =50% lesions were missed because of motion artifacts and two because of severe coronary calcifications. The rest (78%, 14 of 18) were detected but incorrectly classified as <50% obstructions. All patients with and 86% (18 of 21) of patients without significant lesions on QCA were correctly classified by MSCT. All patients with significant left main disease or total occlusions were correctly identified on MSCT., Conclusions: Sixteen-row MSCT coronary angiography permits reliable detection of significant obstructive coronary artery disease in patients with stable angina in sinus rhythm.