Interdisciplinary Rendez-Vous Approach in Endovascular Stroke Treatment: A New Concept to Accelerate Mechanical Thrombectomy in Primary Stroke Centers.

PURPOSE: Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC). To address this problem, we present a concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional neuroradiologists and cardiologists: the Rendez-Vous approach. METHODS: Thirty-five patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes. RESULTS: Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p = 0.57). The time from diagnosis of LVO to groin puncture was reduced by mean 74.3 min with the Rendez-Vous concept (p < 0.01). Regarding the clinical outcome, a functionally independent status was achieved in 45.5% in the Rendez-Vous group and in 22.6% in the control group (p = 0.029). CONCLUSION: Thanks to interdisciplinary teamwork between cardiology and interventional neuroradiology in local PSCs, times to successful reperfusion can be reduced. This has a potentially positive impact on the clinical outcome of stroke patients.

Cardiovascular events during World Cup soccer.

BACKGROUND: The Fédération Internationale de Football Association (FIFA) World Cup, held in Germany from June 9 to July 9, 2006, provided an opportunity to examine the relation between emotional stress and the incidence of cardiovascular events. METHODS: Cardiovascular events occurring in patients in the greater Munich area were prospectively assessed by emergency physicians during the World Cup. We compared those events with events that occurred during the control period: May 1 to June 8 and July 10 to July 31, 2006, and May 1 to July 31 in 2003 and 2005. RESULTS: Acute cardiovascular events were assessed in 4279 patients. On days of matches involving the German team, the incidence of cardiac emergencies was 2.66 times that during the control period (95% confidence interval [CI], 2.33 to 3.04; P<0.001); for men, the incidence was 3.26 times that during the control period (95% CI, 2.78 to 3.84; P<0.001), and for women, it was 1.82 times that during the control period (95% CI, 1.44 to 2.31; P<0.001). Among patients with coronary events on days when the German team played, the proportion with known coronary heart disease was 47.0%, as compared with 29.1% of patients with events during the control period. On those days, the highest average incidence of events was observed during the first 2 hours after the beginning of each match. A subanalysis of serious events during that period, as compared with the control period, showed an increase in the incidence of myocardial infarction with ST-segment elevation by a factor of 2.49 (95% CI, 1.47 to 4.23), of myocardial infarction without ST-segment elevation or unstable angina by a factor of 2.61 (95% CI, 2.22 to 3.08), and of cardiac arrhythmia causing major symptoms by a factor of 3.07 (95% CI, 2.32 to 4.06) (P<0.001 for all comparisons). CONCLUSIONS: Viewing a stressful soccer match more than doubles the risk of an acute cardiovascular event. In view of this excess risk, particularly in men with known coronary heart disease, preventive measures are urgently needed.

Safety, efficacy, and indications of beta-adrenergic receptor blockade to reduce heart rate prior to coronary CT angiography.

For selected indications, coronary computed tomographic (CT) angiography is an established clinical technology for evaluation in patients suspected of having or known to have coronary artery disease. In coronary CT angiography, image quality is highly dependent on heart rate, with heart rate reduction to less than 60 beats per minute being important for both image quality and radiation dose reduction, especially when single-source CT scanners are used. ß-Blockers are the first-line option for short-term reduction of heart rate prior to coronary CT angiography. In recent years, multiple ß-blocker administration protocols with oral and/or intravenous application have been proposed. This review article provides an overview of the indications, efficacy, and safety of ß-blockade protocols prior to coronary CT angiography with respect to different scanner techniques. Moreover, implications for radiation exposure and left ventricular function analysis are discussed.

Pericardial adipose tissue determined by dual source CT is a risk factor for coronary atherosclerosis.

OBJECTIVES: Pericardial fat as a visceral fat depot may be involved in the pathogenesis of coronary atherosclerosis. To gain evidence for that concept we sought to investigate the relation of pericardial fat volumes to risk factors, serum adiponectin levels, inflammatory biomarkers, and the quantity and morphology of coronary atherosclerosis. METHODS AND RESULTS: Using Dual source CT angiography pericardial fat volume and coronary atherosclerosis were assessed simultaneously. Plaques were classified as calcified, mixed, and noncalcified, and the number of affected segments served as quantitative score. Patients with atherosclerotic lesions had significant larger PAT volumes (226 cm3+/-92 cm3) than patients without atherosclerosis (134 cm3+/-56 cm3; P>0.001). No association was found between BMI and coronary atherosclerosis. PAT volumes >300 cm3 were the strongest independent risk factor for coronary atherosclerosis (odds ratio 4.1; CI 3.63 to 4.33) also significantly stronger compared to the Framingham score. We furthermore demonstrated that elevated PAT volumes are significantly associated with low adiponectin levels, low HDL levels, elevated TNF-alpha levels, and hsCRP. CONCLUSION: In the present study we demonstrated that elevated PAT volumes are associated with coronary atherosclerosis, hypoadiponectinemia, and inflammation and represent the strongest risk factor for the presence of atherosclerosis and may be important for risk stratification and monitoring.

Predictive value of coronary calcifications for future cardiac events in asymptomatic individuals.

BACKGROUND: Reliable risk stratification is crucial for efficient prevention of coronary artery disease. The following prospective study determined the predictive value of coronary calcifications for future cardiovascular events. METHODS: We included 1726 asymptomatic individuals (1018 men, 708 women, age 57.7 +/- 13.3 years) referred for a cardiological examination. Coronary calcifications were determined with the Imatron C 150 XP electron beam computed tomography scanner. For quantification of coronary calcifications, we calculated the Agatston score. Over a mean observation period of 40.3 +/- 7.3 months we registered the event rate for cardiac death (CD) and myocardial infarction (MI). RESULTS: The Agatston score in patients who died of CD (n = 65) or had an MI (n = 114) was significantly higher compared with those without cardiac events (458 +/- 228 vs 206 +/- 201, P < .01). An Agatston score above the 75th percentile was associated with a significantly higher annualized event rate for MI (3.6% vs 1.6%, P < .05) and for CD (2.2% vs 0.9%) compared with patients with scores below the 75th percentile. No cardiac events were observed in patients where coronary calcifications could be excluded. CONCLUSIONS: By determination of coronary calcifications, patients at risk for future MI and CD could be identified within an asymptomatic population independent of concomitant risk factors. At the same time, future cardiovascular events could be excluded in patients without coronary calcifications.

Predictive value of coronary calcifications for future cardiac events in asymptomatic patients with diabetes mellitus: a prospective study in 716 patients over 8 years.

BACKGROUND: To establish an efficient prophylaxis of coronary artery disease reliable risk stratification is crucial, especially in the high risk population of patients suffering from diabetes mellitus. This prospective study determined the predictive value of coronary calcifications for future cardiovascular events in asymptomatic patients with diabetes mellitus. METHODS: We included 716 patients suffering from diabetes mellitus (430 men, 286 women, age 55.2+/-15.2 years) in this study. On study entry all patients were asymptomatic and had no history of coronary artery disease. In addition, all patients showed no signs of coronary artery disease in ECG, stress ECG or echocardiography. Coronary calcifications were determined with the Imatron C 150 XP electron beam computed tomograph. For quantification of coronary calcifications we calculated the Agatston score. After a mean observation period of 8.1+/-1.1 years patients were contacted and the event rate of cardiac death (CD) and myocardial infarction (MI) was determined. RESULTS: During the observation period 40 patients suffered from MI, 36 patients died from acute CD. The initial Agatston score in patients that suffered from MI or died from CD (475+/-208) was significantly higher compared to those without cardiac events (236+/-199, p<0.01). An Agatston score above 400 was associated with a significantly higher annualised event rate for cardiovascular events (5.6% versus 0.7%, p<0.01). No cardiac events were observed in patients with exclusion of coronary calcifications. Compared to the Framingham risk score and the UKPDS score the Agatston score showed a significantly higher diagnostic accuracy in the prediction of MI with an area under the ROC curve of 0.77 versus 0.68, and 0.71, respectively, p<0.01. CONCLUSION: By determination of coronary calcifications patients at risk for future MI and CD could be identified within an asymptomatic high risk group of patients suffering from diabetes mellitus. On the other hand future events could be excluded in patients without coronary calcifications.

Comparison of progression of coronary calcium in postmenopausal women on versus not on estrogen/progestin therapy.

The prophylactic effect of postmenopausal hormone replacement therapy on coronary atherosclerosis remains controversial. We, therefore, examined the influence of combined estrogen/progestin therapy on the progression of coronary calcium as a marker of coronary atherosclerosis. We determined the extent of coronary calcium in 277 women (age 57 +/- 6 years, time after menopause 3.9 +/- 2.4 years, group I) at the beginning of hormone replacement therapy using multislice computed tomography. For quantification, we calculated the volume score. After an observation period of 3 years, we determined the progression of coronary calcium in a second scan. The results were compared with those from an age- and risk factor-adjusted group of postmenopausal women without hormone substitution (group II). No significant difference was found in the volume score (59 +/- 95 vs 58 +/- 88) or risk factor distribution between the 2 groups on study entry. In 56 women of group I and 52 women of group II, coronary calcium could be excluded on the initial scan (p = NS). After a mean observation time of 38.5 +/- 4.9 months, we observed no significant difference between the 2 groups regarding an increase in volume score (17 +/- 24 vs 19 +/- 27, p = NS) or the fraction of women with an increase in volume score (82.2% vs 84.2%). In conclusion, a reduced progression of coronary calcium in postmenopausal women on combined estrogen/progestin therapy could not be observed compared with a matched group of women without hormone substitution.

Diagnostic accuracy of dual-source computed tomography in the diagnosis of coronary artery disease.

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of dual-source computed tomography (DSCT) with reference to invasive coronary angiography in the diagnosis of coronary artery disease (CAD) on a per-patient as well as on a per-segment basis. MATERIALS AND METHODS: Thirty-five patients with known or suspected CAD underwent both DSCT (Somatom Definition, Siemens Medical Solutions) and quantitative x-ray coronary angiography (QCA). Parameters of CT acquisition were gantry rotation time 0.330 seconds (ie, temporal resolution 83 milliseconds), tube voltage 120 kV, tube current 560 mA with ECG-triggered tube current modulation and full current at 70% of the cardiac cycle for heart rates below 70 beats per minute or full current between 30% and 80% for higher and arrhythmic heart rates. The pitch was also adapted to the heart rate, ranging from 0.2 to 0.43. Volume and flow rate of contrast material (Ultravist 370, Schering AG) were adapted to the patient's body weight. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT in the detection or exclusion of significant CAD (ie, stenoses >50%) were evaluated on a per-patient and per-segment basis. RESULTS: All 35 CT angiograms were of diagnostic image quality. QCA demonstrated significant CAD in 48% (n = 17) and nonsignificant disease or normal coronary angiograms in 52% (n = 18) of the patients. Sensitivity, specificity, PPV, and NPV of DSCT on a per-patient basis were 100%, 89%, 89%, and 100%, respectively. On a per-segment basis, 473 of 481 coronary artery segments were assessable (98%). QCA demonstrated stenoses >50% in 32 segments (7%), and no disease or nonsignificant disease in 433 segments (93%). For the detection of stenoses >50% on a per-segment basis, DSCT showed a sensitivity, specificity, PPV, and NPV of 88%, 98%, 78%, and 99%, respectively. CONCLUSIONS: The comparison of coronary DSCT with QCA shows a very robust image quality and a high diagnostic accuracy in a patient-based as well as a per-segment analysis. Maximal sensitivity and NPV in the per-patient analysis show the strength of the technique in ruling out significant CAD.

ECG-gated 64-MDCT angiography in the differential diagnosis of acute chest pain.

OBJECTIVE: The most important differential diagnoses of acute chest pain include myocardial infarction, aortic dissection, and pulmonary embolism. The purpose of this study was to evaluate the diagnostic value of an ECG-gated 64-MDCT angiography protocol for simultaneous assessment of the pulmonary arteries, coronary arteries, and aorta within a single breath-hold. SUBJECTS AND METHODS: In 55 patients with acute chest pain, ECG-gated CT angiography was performed with a CT system in which 64 slices per gantry rotation were acquired. Density measurement and visual assessment of motion artifacts were performed to evaluate image quality. CT findings were correlated with results of laboratory tests and clinical follow-up. For 20 patients, two independent blinded reviewers compared findings on CT angiography with those on X-ray coronary angiography. RESULTS: Adequate contrast enhancement of the pulmonary vessels, coronary arteries, and aorta was achieved in all cases. Regarding image quality of the coronary arteries, there was minor blurring in seven patients, and in one examination the images did not provide enough information for diagnosis. The average image quality rating was 1.2 on a scale in which 1 indicated no artifacts; 2, minor motion artifacts; and 3, image insufficient for diagnosis. The cause of chest pain was correctly identified with MDCT in 37 patients. The diagnoses included pulmonary embolism (n = 10), coronary stenosis (n = 9), and aortic dissection (n = 1). In four patients, additional diagnoses were found with other examinations. CONCLUSION: With current techniques, ECG-gated CT angiography of the entire chest has very good image quality. The protocol proved helpful in the differential diagnosis of acute chest pain.

Combined functional and morphological imaging consisting of gated myocardial perfusion SPECT and 16-detector multislice spiral CT angiography in the noninvasive evaluation of coronary artery disease: first experiences.

INTRODUCTION: Appropriate diagnosis and therapy of coronary artery disease (CAD) frequently require information about both the functional and morphological status of the coronary artery tree. We hypothesized that the combination of multislice spiral CT (MDCT) angiography and myocardial perfusion SPECT (MPI) provides accurate allocation of perfusion defects (PD) to their determining coronary lesion. METHODS: Twenty patients (14 male, mean age 64+/-9.2 years) with known CAD were retrospectively studied. Gated MPI, CT angiography using a 16-detector CT scanner, and conventional coronary angiography (CCA) were performed in each patient. Reversible and fixed PD were subsequently allocated to their determining lesion separately by different observers for MDCT angiography and CCA. RESULTS: All patients showed significant CAD in CCA; six patients with one-, six with two-, six with three-, and two with four-vessel disease; three patients had bypass grafts; and five patients had prior myocardial infarction. Correct diagnosis of CAD was stated in 14 of 20 patients by MDCT angiography. Five reversible and five fixed PD were detected in 9 of 20 patients; one patient showed both reversible and fixed PD. Five of five reversible PD could be allocated to appropriate coronary artery stenoses in CCA. In MDCT angiography, five of five reversible PD were allocated to the same lesions; all lesions were rated as >/=50%. CONCLUSIONS: The preliminary results of the present study show high accuracy for multislice spiral CT angiography to allocate reversible perfusion defects in myocardial scintigraphy to their determining coronary artery lesions in a small patient collective with known coronary artery disease.

Hemodynamic and vascular effects of ventricular sourcing by stent-based ventricle to coronary artery bypass in patients with multivessel disease undergoing coronary artery bypass surgery.

BACKGROUND: The hemodynamic and vascular effects of ventricular sourcing by a stent-based (VSTENT, Percardia) left ventricle-to-coronary artery bypass were studied in a patient subgroup of the European multicenter ADVANTAGE study (ADjunctive treatment with the VCAB/VSTENT myocardial implANT system in coronary Artery bypass Graft patiEnts). METHODS AND RESULTS: Twelve patients who underwent VSTENT implantation in addition to coronary artery bypass surgery were studied up to 12 months after the procedure. The VSTENT was implanted distal to a hemodynamically relevant coronary artery stenosis. Coronary flow velocity was assessed at rest and during dobutamine stress. Intraoperative VSTENT implantation was successful in 11 of 12 patients. Early postoperative angiograms showed patent VSTENT in 8 of 11 patients, with predominantly systolic flow distal to the VSTENT. Coronary flow velocity reserve induced by dobutamine stress was 1.7+/-0.1 (P=0.006). VSTENT patency at 2- to 6-month follow-up was present in 5 of 11 patients, with concomitant VSTENT stenosis in 4 of those 5. In all patients, coronary flow velocity increased 3- to 4-fold proximal to the VSTENT, which was associated with a moderate degree of arterial remodeling. Except for target vessel reintervention (n=5), no other major adverse events were observed in 11 of 12 patients. One patient died on the second postoperative day, though the cause was probably not related to the VSTENT implantation. CONCLUSIONS: VSTENT implantation seems to be safe in the mid-term follow-up and leads to a predominantly systolic coronary flow pattern in the vessel supplied by the VSTENT, with a flow reserve similar or close to that seen with conventional bypass. VSTENT patency rate, however, was unacceptably low at 3- to 6-month follow-up and needs to be improved.

Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound.

OBJECTIVES: The aim of the present study was to determine the diagnostic accuracy of 64-slice computed tomography (CT) to identify and quantify atherosclerotic coronary lesions in comparison with catheter-based angiography and intravascular ultrasound (IVUS). BACKGROUND: Currently, the ability of multislice CT to quantify the degree of coronary artery stenosis and dimensions of coronary plaques has not been evaluated. METHODS: We included 59 patients scheduled for coronary angiography due to stable angina pectoris. A contrast-enhanced 64-slice CT (Senation 64, Siemens Medical Solutions, Forchheim, Germany) was performed before the invasive angiogram. In a subset of 18 patients, IVUS of 32 vessels was part of the catheterization procedure. RESULTS: In 55 of 59 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality (American Heart Association 15-segment model). The overall correlation between the degree of stenosis detected by quantitative coronary angiography compared with 64-slice CT was r = 0.54. Sensitivity for the detection of stenosis <50%, stenosis >50%, and stenosis >75% was 79%, 73%, and 80%, respectively, and specificity was 97%. In comparison with IVUS, 46 of 55 (84%) lesions were identified correctly. The mean plaque areas and the percentage of vessel obstruction measured by IVUS and 64-slice CT were 8.1 mm2 versus 7.3 mm2 (p < 0.03, r = 0.73) and 50.4% versus 41.1% (p < 0.001, r = 0.61), respectively. CONCLUSIONS: Contrast-enhanced 64-slice CT is a clinically robust modality that allows the identification of proximal coronary lesions with excellent accuracy. Measurements of plaque and lumen areas derived by CT correlated well with IVUS. A major limitation is the insufficient ability of CT to exactly quantify the degree of stenosis.

Image quality, motion artifacts, and reconstruction timing of 64-slice coronary computed tomography angiography with 0.33-second rotation speed.

OBJECTIVES: We sought to evaluate the impact of patients' heart rate (HR) on coronary CTA image quality (IQ) and motion artifacts using a 64-slice scanner with 0.33/360 degrees rotation. MATERIALS AND METHODS: Coronary CTA data sets of 32 patients (HR 65 bpm to 75 bpm, n = 7) examined on a 64-slice scanner (Sensation 64, Siemens Medical Solutions, Forchheim, Germany) with 0.33s/360 degrees gantry rotation speed were analyzed. All patients had suspicion of coronary artery disease. Data acquisition was performed using 64 x 0.6-mm collimation, and contrast enhancement was provided by injection of 80 mL of iopromide (5 mL/s + NaCl). Images were reconstructed throughout the RR interval using half-scan and dual-segment reconstruction. IQ was rated by 2 observers using a 3-point scale from excellent (1) to nondiagnostic (3) for coronary segments. Quality was correlated to the HR, time point of optimal IQ analyzed, and the benefit of dual-segment reconstruction evaluated. RESULTS: Overall mean IQ was 1.31 +/- 0.32 for all HR, with IQ being 1.08 +/- 0.12 for HR 65 bpm 75 bpm (P = 0.0003). Dual-segment reconstruction did not significantly improve IQ in any HR group (P = NS). Mean IQ was significantly better for LAD than for RCA (P < 0.0001) and LCX (P < 0.01). A total of 3.5% (11/318) of coronary artery segments were rated nondiagnostic by at least one reader based on motion artifacts. Although in HR < 65 bpm, the best IQ was predominately in diastole (93%), in HR > 75 bpm, the best IQ shifted to systole in most cases (86%). CONCLUSIONS: Temporal resolution at 0.33-second rotation allows for diagnostic IQ within a wide range of HR using half-scan reconstruction. With increasing HR the time point of best IQ shifts from mid-diastole to systole.

Contrast bolus optimization for cardiac 16-slice computed tomography: comparison of contrast medium formulations containing 300 and 400 milligrams of iodine per milliliter.

OBJECTIVES: The aims of our study were to compare contrast injection protocols with contrast media containing 300 and 400 mg iodine per milliliter for optimal contrast enhancement in cardiac multidector row computed tomography (CT) and to evaluate the correlation of test bolus curve parameters with the final contrast density of the main bolus. MATERIALS AND METHODS: Sixty patients with known or suspected coronary artery disease were included in a prospective double-blind study. Patients were randomized to 2 groups. Group 1 received 83 mL of a contrast medium (CM) containing 300 mg of iodine (Iomeron 300, Bracco Imaging SpA, Milan, Italy) at a flow rate of 3.3 mL/s, whereas group 2 received 63 mL of the same agent containing 400 mg of iodine (Iomeron 400) at a flow rate of 2.5 mL/s. The test bolus volumes were 20 mL and 15 mL, respectively. Imaging was performed using a 16-slice CT system (16DCT; Somatom Sensation 16, Siemens Medical Solutions, Forchheim, Germany). Contrast densities (Hounsfield Units [HU]) were determined in the cardiac chambers and in the main coronary arteries. The peak density and area under the curve of the test bolus were calculated for each patient. RESULTS: The mean contrast densities of the coronary arteries were 259.1 +/- 46.7 HU for group 1 and 251.6 +/- 51.0 HU, for group 2. No noteworthy differences between groups were noted for density measurements in the cardiac chambers or for the ratio of right-to-left ventricle density. Whereas a positive correlation was noted for both groups between the area under the curve of the test bolus and the mean density of the main bolus, a positive correlation between peak density of the test bolus and mean density of the main bolus was noted only for group 1. CONCLUSION: Equivalent homogenous enhancement of the ventricular cavities and coronary arteries to that obtained using a CM with standard iodine concentration (Iomeron 300) can be achieved with lower overall volumes of administered CM and reduced injection flow rates when a CM with high iodine concentration (Iomeron 400) is used.

Clinical value of MDCT in the diagnosis of coronary artery disease in patients with a low pretest likelihood of significant disease.

OBJECTIVE: The aim of this study was to evaluate the clinical value of MDCT in the diagnosis of coronary artery disease in a population having a low pretest likelihood of significant disease. SUBJECTS AND METHODS: Sixty-four patients with suspected coronary artery disease and a low pretest likelihood of significant disease according to the criteria of the American Heart Association underwent both MDCT of the heart and quantitative conventional coronary angiography (QCA). MDCT examinations were performed on a 16-MDCT scanner. CT data sets were evaluated on a per-patient basis and a per-segment basis and were classified as indicating no disease, nonsignificant disease (stenoses 50%). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of 16-MDCT in the detection or exclusion of significant and nonsignificant coronary artery disease were evaluated on both per-patient and per-segment bases. RESULTS: Regarding the success rate of 16-MDCT, 94% (60/64) of patients and 92% (388/420) of vessel segments were of sufficient quality for diagnosis. In the remaining 60 patients evaluated, QCA revealed significant coronary artery disease, nonsignificant disease, and no disease in 8.3% (5/60), 75.0% (45/60), and 16.7% (10/60) of cases, respectively, on a per-patient basis, and in 1.3% (5/388), 23.2% (90/388), and 75.5% (293/388) of cases, respectively, on a per-segment basis. The sensitivity, specificity, NPV, and PPV of 16-MDCT for the detection of significant coronary artery disease were 80.0%, 94.5%, 98.1%, and 57.1%, respectively, on a per-patient basis, and 80.0%, 99.2%, 99.7%, and 57.1% on a per-segment basis. CONCLUSION: In a population having a low pretest likelihood of significant coronary artery disease, 16-MDCT shows a moderate to high sensitivity and high NPV for the detection or exclusion of significant disease, but has a somewhat reduced PPV compared with QCA.

Accuracy of 64-MDCT in the diagnosis of ischemic heart disease.

OBJECTIVE: The aim of this study was to evaluate the potential clinical value of a new generation of 64-MDCT systems with that of invasive coronary angiography in the diagnosis of coronary artery disease (CAD). SUBJECTS AND METHODS: Seventy-two consecutive patients with known or suspected CAD underwent both 64-MDCT and quantitative coronary angiography (QCA). A CT system with acquisition of 64 slices per gantry rotation was used with a spatial resolution of 0.4 x 0.4 x 0.4 mm and a gantry rotation time of 330 milliseconds. Sensitivity, specificity, and diagnostic accuracy of 64-MDCT in the detection or exclusion of CAD were evaluated on both a per patient and a per segment basis. RESULTS: Sixty-eight of 72 coronary CT angiograms (CTAs) (94%) were of diagnostic image quality. QCA showed significant CAD (i.e., one or more stenoses in > 50%) in 57% (39/68) and nonsignificant disease or healthy CTAs in 43% (29/68) of the patients. Sensitivity, specificity, and the negative predictive value (NPV) of 64-MDCT per patient were 97%, 79%, and 96%, respectively. Per segment, 923 of 1,020 coronary artery segments were assessable (90%). For the detection of stenoses of more than 50% and more than 75% per segment, 64-MDCT showed a sensitivity of 82% and 86%, respectively. Per segment, specificity and NPV were as high as 95% and 97%, respectively. CONCLUSION: In clinical routine, coronary CTA will primarily be used for risk stratification on a per patient basis. In the present study, coronary 64-MDCT showed a high diagnostic accuracy on both per patient and per segment analyses.

Assessment of coronary artery stent patency and restenosis using 64-slice computed tomography.

RATIONALE AND OBJECTIVES: Restenosis remains a major limitation of coronary catheter-based stent placement. Therefore, a reliable noninvasive diagnostic method for the evaluation of stented coronary arteries would be highly desirable. Our aim was to evaluate the diagnostic accuracy of high-resolution 64-slice computed tomography (64SCT) in a pilot study for the assessment of the lumen of coronary artery stents. MATERIALS AND METHODS: Twenty-five patients underwent 64SCT of the coronary arteries and quantitative x-ray coronary angiography (QCA) after coronary artery stent placement. 64SCT coronary angiography was performed with the following parameters: spatial resolution = 0.4 x 0.4 x 0.4 mm; temporal resolution = 83-165 milliseconds; contrast agent = 80 mL at a flow rate of 5 mL/second; retrospective electrocardiogram gating. The 64SCT scans were evaluated for image quality and for the presence of significant in-stent and peri-stent (proximal and distal) stenoses. Determinations were made of the sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values (PPV and NPV) of 64SCT for the detection or exclusion of stenoses. RESULTS: A total of 46 stents were evaluated, of which 45 (98%) were of diagnostic image quality. Significant in-stent restenosis or occlusion was detected on QCA in 8/45 cases (>/=50% stenosis = 6; occlusion = 2). The sensitivity, specificity, accuracy, PPV, and NPV of 64SCT for the detection of significant in-stent disease was 75%, 92%, 89%, 67%, and 94%, respectively. Both occluded coronary artery stents were correctly identified. The sensitivity, specificity, and accuracy values of 64SCT for the detection of significant proximal peri-stent stenoses were 75%, 95%, and 93%, respectively, whereas the values for detection of significant distal peri-stent stenoses were 67%, 85%, and 84%, respectively. CONCLUSION: The high spatial and temporal resolution of 64SCT may permit improved assessment of stent occlusion and peri-stent disease, although detection of in-stent stenosis remains difficult.

Influence of lipid-lowering therapy on the progression of coronary artery calcification: a prospective evaluation.

BACKGROUND: Coronary calcification measured by fast computed tomography techniques is a surrogate marker of coronary atherosclerotic plaque burden. In a cohort study, we prospectively investigated whether lipid-lowering therapy with a cholesterol synthesis enzyme inhibitor reduces the progression of coronary calcification. METHODS AND RESULTS: In 66 patients with coronary calcifications in electron beam tomography (EBT), LDL cholesterol >130 mg/dL, and no lipid-lowering treatment, the EBT scan was repeated after a mean interval of 14 months and treatment with cerivastatin was initiated (0.3 mg/d). After 12 months of treatment, a third EBT scan was performed. Coronary calcifications were quantified using a volumetric score. Cerivastatin therapy lowered the mean LDL cholesterol level from 164+/-30 to 107+/-21 mg/dL. The median calcified volume was 155 mm3 (range, 15 to 1849) at baseline, 201 mm3 (19 to 2486) after 14 months without treatment, and 203 mm3 (15 to 2569) after 12 months of cerivastatin treatment. The median annualized absolute increase in coronary calcium was 25 mm3 during the untreated versus 11 mm3 during the treatment period (P=0.01). The median annual relative increase in coronary calcium was 25% during the untreated versus 8.8% during the treatment period (P<0.0001). In 32 patients with an LDL cholesterol level <100 mg/dL under treatment, the median relative change was 27% during the untreated versus -3.4% during the treatment period (P=0.0001). CONCLUSIONS: Treatment with the cholesterol synthesis enzyme inhibitor cerivastatin significantly reduces coronary calcium progression in patients with LDL cholesterol >130 mg/dL.

Accuracy of multidetector spiral computed tomography in identifying and differentiating the composition of coronary atherosclerotic plaques: a comparative study with intracoronary ultrasound.

OBJECTIVES: We evaluated the accuracy of contrast-enhanced multidetector spiral computed tomography (MDCT) for the noninvasive detection and classification of coronary plaques and compared it with intracoronary ultrasound (ICUS). BACKGROUND: Noninvasive determination of plaque composition and plaque burden may be important to improve risk stratification and to monitor progression of coronary atherosclerosis. METHODS: We included 46 consecutive patients with a distinctive risk profile, who were investigated by ICUS (Goldvision, 20 MHz, Jomed Inc., Rancho Cordova, California). Due to the inability to slow the heart rate below 65 beats/min (n = 7) and due to renal insufficiency (n = 2), nine of 46 consecutive patients could not be studied by MDCT (Sensation 16, Siemens, Forchheim, Germany). RESULTS: In the remaining 37 patients, 68 vessels were investigated by ICUS, and 58 of these vessels were visualized by MDCT with image quality sufficient for analysis. In these vessels that were divided in 3-mm sections, MDCT correctly classified 62 of 80 (78%) sections containing hypoechoic plaque areas, 87 of 112 (78%) sections containing hyperechoic plaque areas, and 150 of 158 (95%) sections containing calcified plaque tissue. In 484 of 525 (92%) sections, atherosclerotic lesions were correctly excluded. The MDCT-derived density measurements within coronary lesions revealed significantly different values for hypoechoic (49 HU [Hounsfield Units] +/- 22), hyperechoic (91 HU +/- 22), and calcified plaques (391 HU +/- 156, p < 0.02). CONCLUSIONS: This study demonstrates that, in the case of diagnostic image quality, contrast-enhanced MDCT permits an accurate identification of coronary plaques and that computed tomography density values measured within plaques reflect echogenity and plaque composition.

Comparison of spiral multidetector CT angiography and myocardial perfusion imaging in the noninvasive detection of functionally relevant coronary artery lesions: first clinical experiences.

UNLABELLED: Compared with conventional coronary angiography, spiral multidetector CT (MDCT) angiography has delivered promising accuracy in the detection and validation of coronary lesions. Myocardial perfusion imaging (MPI) using SPECT is an established method for noninvasively assessing the functional significance of coronary stenoses and delivers valuable information for risk stratification. This retrospective analysis compared the accuracies of MDCT angiography and MPI in the detection of hemodynamically relevant lesions of the coronary arteries. METHODS: Twenty-five patients with suspected or known coronary artery disease were studied. Electrocardiographically gated MPI and 16-MDCT angiography were performed. Myocardial perfusion images were analyzed by 2 experienced observers, and reversible and fixed perfusion defects were detected and allocated to their corresponding coronary vessels. For the evaluation of MDCT angiography, image quality was determined, and lesions > or = 50% and luminal narrowing < 50% were visually assessed and characterized by 2 independent observers unaware of the results of MPI. RESULTS: Ninety-nine coronary vessels were analyzed, and the quality of MDCT angiography images was assessed for 330 coronary segments. Coronary artery diameter was interpretable for 231 (70%) of 330 segments, whereas in 99 (30%) of 330 segments, vessel diameter could not be evaluated because of heavy calcifications, blurring, motion artifacts, or intracoronary stents. MDCT angiography detected stenoses > or = 50% in 15 of 100 coronary arteries. Eight (53%) of 15 stenoses > or = 50% showed reversible or fixed perfusion defects in the corresponding myocardial areas on MPI. Sensitivity, specificity, and negative and positive predictive values were 100%, 87%, 100%, and 29%, respectively, for the ability of MDCT angiography to detect reversible perfusion defects in the corresponding myocardial areas. CONCLUSION: MDCT angiography detected myocardial ischemia, as defined by reversible perfusion defects on MPI, with a positive predictive value of 29% in a nonselected study cohort. Compared with MPI alone, MDCT angiography added important morphologic information, but MPI remains mandatory for evaluating the functional relevance of coronary artery lesions.