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Objectives Lipoprotein(a) [Lp(a)] is an independent risk factor for aortic valve stenosis and aortic valve calcification (AVC) in the general population. In this study, we determined the association between AVC and both plasma Lp(a) levels and apolipoprotein(a) [apo(a)] kringle IV repeat polymorphisms in asymptomatic statin-treated patients with heterozygous familial hypercholesterolaemia (FH). Methods A total of 129 asymptomatic heterozygous FH patients (age 40–69 years) were included in this study. AVC was detected using computed tomography scanning. Lp(a) concentration and apo(a) kringle IV repeat number were measured using immunoturbidimetry and immunoblotting, respectively. Univariate and multivariate logistic regression were used to assess the association between Lp(a) concentration and the presence of AVC. Results Aortic valve calcification was present in 38.2% of patients, including three with extensive AVC (>400 Agatston units). Lp(a) concentration was significantly correlated with gender, number of apo(a) kringle IV repeats and the presence and severity of AVC, but not with coronary artery calcification (CAC). AVC was significantly associated with plasma Lp(a) level, age, body mass index, blood pressure, duration of statin use, cholesterol-year score and CAC score. After adjustment for all significant covariables, plasma Lp(a) concentration remained a significant predictor of AVC, with an odds ratio per 10-mg dL−1 increase in Lp(a) concentration of 1.11 (95% confidence interval 1.01–1.20, P = 0.03). Conclusion In asymptomatic statin-treated FH patients, plasma Lp(a) concentration is an independent risk indicator for AVC.

Since the introduction of coronary CT angiography (CCTA) there has been an enormous growth in the quantity of evidence to support the role of CCTA in the diagnosis of patients with suspected coronary artery disease (CAD). But what is the level of diagnostic accuracy of CCTA today? Have we attained sufficient reliable evidence to fully appreciate the role of CCTA in cardiologic practice? The technical details and potential clinical applications of CCTA have been reported in two recent reviews in ‘Education in Heart ’.1 ,2 In this current state-of-the-art exposition of CCTA for patients with suspected CAD it appears useful to arrange the available evidence according to a hierarchical model of efficacy of diagnostic imaging first described by Fryback and Thornburg in 1991.3 Efficacy is defined as: “the probability of benefit to individuals in a defined population from medical technology (CCTA) applied for a given medical problem under ideal conditions”.3 The model consists of six levels of efficacy: level 1 —technical efficacy; level 2 —diagnostic accuracy efficacy; level 3 —diagnostic thinking accuracy; level 4 —therapeutic efficacy; level 5 —patient outcome efficacy; level 6 —societal efficacy. The goal of the model not only involves the traditional view of the assessment of diagnostic imaging to generate optimal quality images and hence optimal diagnosis, but rather is a comprehensive assessment of patient and societal benefits of CCTA.3 This review is an update of the current position of CCTA in the diagnosis of patients with suspected CAD. The spatial resolution of 64-slice (or more) CCTA in the laboratory setting is 0.3–0.4 mm³ (isotropic spatial resolution allowing undistorted reconstruction of images in any plane), but in the clinical setting this is 0.5–0.6 mm³. The spatial resolution of CCTA is still limited compared to the 0.1–0.2 mm of invasive coronary angiography (ICA). The temporal resolution …

Contrast-enhanced CT coronary angiography (CTCA) has evolved as a reliable alternative imaging modality technique and may be the preferred initial diagnostic test in patients with stable angina with intermediate pre-test probability of CAD. However, because CTCA is moderately predictive for indicating the functional significance of a lesion, the combination of anatomic and functional imaging will become increasingly important. The technology will continue to improve with better spatial and temporal resolution at low radiation exposure, and CTCA may eventually replace invasive coronary angiography. The establishment of the precise role of CTCA in the diagnosis and management of patients with stable angina requires high-quality randomised study designs with clinical outcomes as a primary outcome.

The authors investigated the prognostic value of computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACE) in patients with suspected or known coronary artery disease (CAD), with particular focus on left main (LM) disease and obstructive vs. nonobstructive disease.A total of 727 consecutive patients (485 men, age 62 ± 11 years) with suspected (514; 70.1%) or known (213; 29.9%) CAD underwent CTCA. Patients were followed up for the occurrence of MACE (i.e. cardiac death, nonfatal myocardial infarction, unstable angina, percutaneous/surgical revascularisation).A total of 117 MACE [five cardiac deaths, 11 acute myocardial infarctions (AMI), five unstable angina, 86 percutaneous coronary interventions, ten coronary artery bypass grafts] occurred during a mean follow-up of 20 months. Severity and extension of CAD was associated with a progressively worse prognosis. The event rate was 0% among patients with normal coronary arteries at CTCA. The presence of LM disease was not associated with a worse prognosis either in patients with no history of CAD or in those with a history of CAD. At multivariate analysis, presence of obstructive CAD and diabetes were the only independent predictors of MACE.Evaluation of atherosclerotic burden by CTCA provides an independent prognostic value for prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up.

Purpose. Our purpose in this study was to compare the impact of contrast material volume in delayed-enhancement computer tomography (CT) imaging for assessing acute reperfused myocardial infarction. Materials and methods. In five domestic pigs (20-30 kg) the circumflex coronary artery (CX) was balloon-occluded for 2 h followed by reperfusion. After 5 days, CT imaging was performed after intravenous administration of iodinated contrast material (Iomeprol 400mgI/ml; Bracco, Italy). A 64-slice multidetector CT (MDCT) (Sensation 64, Siemens) scanner was used for imaging, with standard angiography characteristics. Three scans were performed: first, coronary angiography at first pass with 1.25 gl/kg of contrast material (ART); and remaining delayedenhancement (DE1-DE2) 15 min after administration of 1.25 (DE1) and 15 min after additional administration of 2.50 gI/kg (=total 3.75 gI/kg - DE2). Mean heart rate decreased to 51 +/- 9 bpm after intravenous administration of Zatebradine (10 mg/kg). Data sets were reconstructed during the end-diastolic phase of the cardiac cycle. Areas of infarction-enhanced (DE), no-reflow (no-reflow) and remote myocardial [remote left ventricle (LV)] were manually contoured. CT attenuation values (Hounsfield units) were measured using five regions of interest: DE, no-reflow, remote LV, left ventricular cavity (lumen LV) and in air. Differences, correlations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results. We found significant differences between the attenuation of DE, no-reflow and remote LV (p

Objective: To evaluate the performance of dual source CT coronary angiography (DSCT-CA) in the detection of in-stent restenosis (>= 50% luminal narrowing) in symptomatic patients referred for conventional angiography (CA). Design/patients: 100 patients (78 males, age 62 (SD 10)) with chest pain were prospectively evaluated after coronary stenting. DSCT-CA was performed before CA. Setting: Many patients undergo coronary artery stenting; availability of a non-invasive modality to detect in-stent restenosis would be desirable. Results: Average heart rate (HR) was 67 (SD 12) (range 46-106) bpm. There were 178 stented lesions. The interval between stenting and inclusion in the study was 35 (SD 41) (range 3-140) months. 39/100 (39%) patients had angiographically proven restenosis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of DSCT-CA, calculated in all stents, were 94%, 92%, 77% and 98%, respectively. Diagnostic performance at HR,70 bpm (n = 69; mean 58 bpm) was similar to that at HR >= 70 bpm (n = 31; mean 78 bpm); diagnostic performance in single stents (n = 95) was similar to that in overlapping stents and bifurcations (n = 83). In stents >= 3.5 mm (n = 78), sensitivity, specificity, PPV, NPV were 100%; in 3 mm stents (n = 59), sensitivity and NPV were 100%, specificity 97%, PPV 91%; in stents (2.75 mm (n = 41), sensitivity was 84%, specificity 64%, PPV 52%, NPV 90%. Nine stents (2.75 mm were uninterpretable. Specificity of DSCT-CA in stents >= 3.5 mm was significantly higher than in stents (2.75 mm (OR = 6.14; 99%CI: 1.52 to 9.79). Conclusion: DSCT-CA performs well in the detection of in-stent restenosis. Although DSCT-CA leads to frequent false positive findings in smaller stents ((2.75 mm), it reliably rules out in-stent restenosis irrespective of stent size.

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. Copyright © 2007 Wiley Periodicals, Inc.

Summary MSCT coronary angiography may evolve to assess the extent and severity of coronary artery disease in patients with unstable angina or non-ST-segment elevation myocardial infarction. There appears to be no role for MCST-coronary angiography in patients with acute ST-segment elevation myocardial infarction.

Objective: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction. Design and patients: The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period. Setting: Academic tertiary referral centre. Results: At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p = 1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p = 0.04). This was driven by stent thrombosis (n = 4), especially in the bifurcation stenting (n = 2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p = 0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p = 0.16). Conclusions: No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Calcification of the coronary arteries plays a key role in the pathophysiology of atherosclerosis. Coronary calcification is an active process culminating in extracellular matrix deposition of calcium by osteoblast-like cells that has some resemblance to bone formation [1]. Subintimal coronary calcification is almost exclusively associated with the presence of coronary atherosclerosis and is considered the hallmark of coronary atherosclerosis. Coronary calcific lesions are considered advanced lesions and calcification following plaque rupture of a high-risk plaque is thought to be part of the healing process [2]. The presence of coronary calcification is a surrogate marker of the overall plaque burden. Not all plaques are calcified and histological studies have revealed that the total calcium area was approximately 20 % of the total atherosclerotic plaque burden area [3]. There is no generally accepted relationship between plaque calcification and plaque stability. Traditionally calcific plaques are considered to be stable but plaques with spotty calcification (small amount of calcification in a spotty distribution) have been associated with plaque instability and acceleration to progression of CAD [4, 5]. However, the extent of calcification is a marker of instability somewhere in the coronary tree rather than a marker of local plaque instability [4]. Coronary calcification can be easily detected by computed tomography (CT). The epicardial vessels can be readily identified on a non-contrast enhanced CT scan (calcium scan), because the density of the coronary wall and blood is higher than the surrounding peri-coronary fat. Coronary calcium deposits have a 2 to 10 fold higher density than surrounding tissues and coronary calcium is identified as a hyper-attenuating coronary lesion above a threshold of 130 Hounsfield units (HU). The amount of calcium is quantified using the Agatston score (calcium score) which is derived from the product of the area of calcification (mm2) and a factor determined by the maximal density (HU) within that area. The factor is 1,2,3,4 with a density of 130 to 199, 200 to 299, 300 to 399 or >400 HU respectively [6]. The calcium scan does not require contrast medium and can be acquired with a low radiation dose of less than 1.0 mSv [7]. This is associated with a lifetime attributable risk of cancer that for men and women at 50 years of age at 8 and 20 per 100,000 persons per year, respectively. The calcium score is a significant predictor of risk of adverse cardiovascular events that has independent incremental value of risk prediction beyond the traditional risk prediction scores such as the Framingham risk score or the Euro risk score. Increasingly higher calcium scores are associated with increasingly higher risk of adverse cardiovascular events and all-cause mortality. The calcium score can also be used to predict the presence of obstructive coronary artery disease (CAD).

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 +/- 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 +/- 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% +/- 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

To evaluate the impact of heart rate on the diagnostic accuracy of coronary angiography by multislice spiral computed tomography (MSCT).Prospective observational study.78 patients who underwent both conventional and MSCT coronary angiography for suspicion of de novo coronary artery disease (n=53) or recurrent coronary artery disease after percutaneous intervention (n=25).Tertiary referral centre.Intravenously contrast enhanced MSCT coronary angiography was done during a single breath hold, and ECG synchronised images were reconstructed retrospectively. All coronary segments ofor = 2.0 mm without stents were evaluated by two investigators and compared with quantitative coronary angiography. Patients were classified according to the average heart rate (mean (SD)) into three equally sized groups: group 1, 55.8 (4.1) beats/min; group 2, 66.6 (2.8) beats/min; group 3, 81.7 (8.8) beats/min.Image quality was sufficient for analysis in 78% of the coronary segments in patients in group 1, 73% in group 2, and 54% in group 3 (p0.01). The sensitivity and specificity for detecting significant stenoses (or = 50% lumen reduction) in these assessable segments were: 97% (95% confidence interval (CI) 84% to 100%) and 96% in group 1; 74% (52% to 89%) and 94% in group 2; and 67% (33% to 90%) and 94% in group 3 (p0.05). Accounting for all segments ofor = 2.0 mm, including lesions in non-assessable segments as false negatives, the sensitivity decreased to 82% (28/34 lesions, 95% CI 69% to 91%), 61% (14/23 lesions, 42% to 77%), and 32% (6/19 lesions, 15% to 50%), respectively (p0.01).MSCT allows reliable coronary angiography in patients with low heart rates.

AIMS: We sought to compare the effect of intracoronary beta-radiation on the vessel dimensions in de novo lesions using three-dimensional intravascular ultrasound quantification after balloon angioplasty and stenting. METHODS AND RESULTS: Forty patients (44 vessels; 28 balloon angioplasty and 16 stenting) treated with catheter-based beta-radiation and 18 non-irradiated control patients (18 vessels; 10 balloon angioplasty and 8 stenting) were investigated by means of three-dimensional volumetric intravascular ultrasound analysis post-procedure and at 6-8 months follow-up. Total vessel (EEM) volume enlarged after both balloon angioplasty and stenting (+37 mm(3) vs +42 mm(3), P=ns), but vessel wall volume (plaque plus media) also increased similarly (+33 mm(3) vs +49 mm(3), P=ns) in the irradiated patients. Lumen volume remained unchanged in both groups (+3 mm(3) vs -7 mm(3), P=ns). In the stent-covered segments, neointima at follow-up was significantly smaller in the irradiated group than the control group (8 mm(3) vs 27 mm(3), P=0.001, respectively), but the total amount of tissue growth was similar in both groups (33 mm(3) vs 29 mm(3), P=ns). CONCLUSIONS: Intracoronary beta-radiation induces vessel enlargement after balloon angioplasty and/or stenting, accommodating tissue growth. Additional stenting may not play an important role in the prevention of constrictive remodelling in the setting of catheter-based intracoronary beta-radiotherapy.

Background Studies have reported benefit of oral therapy with the phosphodiesterase inhibitor, trapidil, in reducing restenosis after coronary angioplasty. Coronary stenting is associated with improved late outcome compared with balloon angioplasty, but significant neointimal hyperplasia still occurs in a considerable proportion of patients. The aim of this study was to investigate the safety and efficacy of trapidil 200mg in preventing in-stent restenosis. Methods Patients with a single native coronary lesion requiring revascularization were randomized to placebo or trapidil at least 1h before, and continuing for 6 months after, successful implantation of a coronary Wallstent. The primary end-point was in-stent neointimal volume measured by three-dimensional reconstruction of intravascular ultrasound images recorded at the 6 month follow-up catheterization. Results Of 312 patients randomized at 21 centres in nine countries, 303 (148 trapidil, 155 placebo) underwent successful Wallstent implantation, and 139 patients (90%) in the placebo group and 130 (88%) in the trapidil group had repeat catheterization at 26±2 weeks. There was no significant difference between trapidil and placebo-treated patients regarding in-stent neointimal volume (108·6± 95·6mm3vs 93·3±79·1mm3; P =0·16) or % obstruction volume (38±18% vs 36±21%; P =0·32), in angiographic minimal luminal diameter at follow-up (1·63±0·61mm vs 1·74±0·69mm; P =0·17), restenosis rate (31% vs 24%; P =0·24), cumulative incidence of major adverse cardiac events at 7 months (22% vs 20%; P =0·71) or anginal complaints (30% vs 24%; P =0·29). Conclusion Oral trapidil 600mg daily for 6 months did not reduce in-stent hyperplasia or improve clinical outcome after successful Wallstent implantation and is not indicated for this purpose.

The aim of this study was to explore the clinical possibilities of a new strategy for magnetic resonance imaging of the coronary arteries. Thirteen patients were studied by volume coronary angiography using targeted scans (VCATS) to visualize the major coronary arteries in a series of breath-holds. The proximal coronary arteries were clearly seen in 92% and the mid segments in 50–70% of the patients. VCATS was able to visualize a total vessel length of the left main (LM) (mean: 9.4 ± 3.4 mm), of the left anterior descending (LAD) 69 ± 20 mm, of the right coronary artery (RCA) 90 ± 33 mm and of the left circumflex (LCX) 41 ± 18 mm. There was a reasonable correlation between the VCATS and conventional coronary angiography (CAG) for vessel diameter (r = 0.71), with a slight overestimation of 0.7 mm by VCATS. There were nine significant stenoses present of which six were correctly detected, three were missed and one false positive was present. VCATS is fast strategy for visualizing the major coronary artery branches and has the potential to detect significant stenoses in these branches.

Management of acute coronary syndromes : acute coronary syndromes without persistent ST segment elevation; recommendations of the Task Force of the European Society of Cardiology.

Coronary angiography (CA) is presently considered the gold standard for the assessment of the coronary arteries. However, the presence of ionizing radiation, its invasiveness and the small associated risk of morbidity prompted long ago the development of more patient-friendly imaging modalities. A promising technique, magnetic resonance imaging (MRI), has been regarded as the major modality in the coming decade. Although still in its infancy qualitatively, its flexibility and non-invasiveness opens the door for a comprehensive evaluation of the heart and the coronary arteries in one single sitting with high anatomical definition and excellent soft tissue contrast capabilities, double-oblique tomographic sections and the possibility to quantify an innumerable number of cardiovascular physiological parameters. Numerous ideas have been assessed, comprising breath-hold and free-breathing two-dimensional and three-dimensional measurements. New ongoing trials with intravascular contrast agents may provide for all these techniques the long-awaited essential boost for reliable magnetic resonance coronary angiography (MRCA). Introduction of parallel MRI acquisition techniques, such as simultaneous acquisition of spatial harmonics (SMASH) and sensitivity encoding (SENSE) may provide the speed enhancement required to shorten imaging time for all techniques explored to date.

CT coronary angiography (CTCA) allows accurate noninvasive imaging of the coronary arteries. As illustrated by this case report, the threedimensional information provided by this technique might be of value to resolve complex coronary pathology encountered in the cathlab. However, the limitations inherent to an anatomical test also apply for CTCA, and bring in the need for functional information to ensure adequate patient management. (Neth Heart J 2009;17:292-4.19789698)

OBJECTIVE: To describe the long term clinical outcome (up to 11 years) after coronary stenting. DESIGN: A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12-132 months). RESULTS: Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the "anticoagulant era" and the "ticlopidine era" revealed significantly improved event free survival with ticlopidine (27% v 13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4. 1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1. 9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1. 5). CONCLUSIONS: Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

Magnetic resonance imaging of coronary arteries will visualize, besides the arteries, the myocardium, blood in the cavities and cardiac veins. This will hamper the application of projectional visualization techniques such as those used in conventional coronary angiography. Volume rendering, a different visualization technique, can be used to create a three-dimensional impression of a magnetic resonance data set on a two-dimensional surface. In this article, we will review the volume-rendering technique and anatomy of the coronary arteries and veins in the obtained images. Also we will discuss the relation between arteries and veins and the possible sites of confusion.

AIMS: Angiographic studies on the natural course of both focal and diffuse coronary atherosclerosis have not been performed before, but can both be assessed by quantitative coronary angiography. The objective of this study was to describe the natural course of focal and diffuse coronary atherosclerosis over time. METHODS AND RESULTS: In 129 patients with mild coronary artery disease, but not on lipid-lowering medication, three coronary angiograms were made each 2 years apart. Nine hundred and sixty five angiographically diseased and non-diseased segments were analysed by quantitative coronary angiography. Mean lumen diameter and minimal lumen diameter were used as measures of diffuse and focal coronary atherosclerosis. Mean lumen diameter and minimum lumen diameter decreased by 0.02 and 0.03 mm per year. The rate of progression was similar in the angiographically non-diseased, as in the mildly and moderately diseased segments. Progression of diffuse coronary atherosclerosis was largest in severely stenosed lesions (percentage diameter stenosis > or = 50%) and in the right coronary artery with a loss of 0.19 mm and 0.16 mm in mean lumen diameter. Progression of focal disease was most prominent in new and mild lesions and the right coronary artery, with a decrease in minimum lumen diameter of 0.34 mm and 0.22 mm. In most subgroups, progression occurred gradually over time. On a per segment level, progression and the occurrence of new lesions occurred in 4.4% and 4.2%. Regression and disappearance of a lesions was found in 2.3% and 1.9%. On a per patient level, 36% were progressors, 12% had a mixed response, 36% were stable, and 16% were regressors. CONCLUSION: Diffuse and focal coronary atherosclerosis progressed at the same rate in the first and second 2 years in stenosed and non-stenosed segments. The rate of coronary atherosclerosis progression was small, but was higher for focal than for diffuse disease. A minority of lesions progressed and spontaneous regression was rare.

Summary Background Excimer laser coronary angioplasty is reported to give excellent procedural results for treatment of complex coronary lesions, but this method has not been compared with balloon angioplasty in a randomised trial. Methods Patients (n=308) with stable angina and coronary lesions longer than 10 mm on visual assessment were included. 151 patients (158 lesions) were assigned randomly to laser angioplasty and 157 (167 lesions) to balloon angioplasty. The primary clinical endpoints were death, myocardial infarction, coronary bypass surgery, or repeat coronary angioplasty of the randomised segment during 6 months of follow-up. The primary angiographic end-point was the minimal lumen diameter at follow-up in relation to the baseline value (net gain), as determined by quantitative coronary angiography. Findings Laser angioplasty was followed by balloon angioplasty in 98% of procedures. The angiographic success rate was 80% in patients treated with laser angioplasty compared with 79% in patients treated with balloon angioplasty. There were no deaths. Myocardial infarction, coronary bypass surgery, and repeat angioplasty occurred in 4·6%, 10·6%, and 21·2%, respectively, of the patients in the laser angioplasty group compared with 5·7%, 10·8%, and 18·5% of the balloon angioplasty group. Net mean (SD) gain in minimal lumen diameter was 0·40 (0·69) mm in patients treated with laser angioplasty and 0·48 (0·66) mm in those treated with balloon angioplasty (p=0·34). The restenosis rate (>50% diameter stenosis) was 51·6% in the laser angioplasty group versus 41·3% in the balloon angioplasty group (p=0·13). Interpretation Excimer laser angioplasty followed by balloon angioplasty provides no benefit additional to balloon angioplasty alone with respect to the initial and long-term clinical and angiographic outcome in the treatment of obstructive coronary artery disease.

X-ray angiographywith selective contrast injection through cardiac catheterization remains the reference standard for the evaluation of the coronary arteries, but noninvasive alternatives, such as magnetic resonance imaging or computed tomography (CT), have been developed, the latter of which seems

Balloon angioplasty is associated with an often unpredictable risk of abrupt coronary occlusion, which is the leading cause of in-hospital death and myocardial infarction. Clinical, angiographic and lesion variables predictive of risk of abrupt occlusion are reviewed and a low, medium and high risk profile stratification is developed. Current management of abrupt occlusion is discussed.

To study the in-hospital outcome of all coronary angioplasty procedures performed in a single centre over a 1 year period, with regard to angiographic success and the clinical complications of death, myocardial infarction, emergency coronary bypass surgery and abrupt coronary occlusion necessitating reintervention. Methods: One thousand one hundred and thirty-three lesions were treated in 970 procedures in 799 patients between October 1993 and October 1994. Clinical, procedural, angiographic and outcome data were entered into a dedicated computer database and variables tested with respect to outcome using the chi-square test and univariate and multivariate analysis techniques. Results: Angioplasty was performed for stable angina in 473 (49%) patients, unstable angina in 410 (42%) and 80 procedures were emergency—primary myocardial infarction in 44 (4·5%) shock in two, abrupt closure in 34 (3·5%) and other indications in seven patients. There were 10(1·0%) deaths and 71 (7·3%) patients were documented to have suffered a myocardial infarction as a result of angioplasty. Nineteen (2·0%) patients underwent emergency coronary artery bypass surgery. Age >60 and a type C lesion were found to be associated with angiographic failure The chance of a complication was increased if the patient was aged >60 years, suffered unstable angina, had an ejection fraction

Objectives : The purpose of this study was to assess the dual action of lumen enlargement and vessel wall damage following either balloon angioplasty or directional atherectomy, using intracoronary ultrasound, and angioscopy. Background : Differences in the mechanisms of action of balloon angioplasty and directional atherectomy may have a significant bearing on the immediate outcome and the restenosis rate at 6 months. Methods : A total of 36 patients were studied before and after either balloon angioplasty (n=18) or directional atherectomy (n=18). Ultrasound measurements included changes in lumen area, external elastic membrane area and plaque burden. In addition, the presence and extent of dissections were assessed to derive a damage score. Angioscopic assessment of the dilated or atherectomized stenotic lesions was translated into semi-quantitative dissection, thrombus and haemorrhage scores. Results : Atherectomy patients had a larger angiographic vessel size compared with the angioplasty group (3.55±0.46 mm vs 3.00±0.64 mm, P

With the increasing clinical application of new devices for percutaneous coronary revascularization, maximization of the acute angiographic result has become widely recognized as a key factor in maintained clinical and angiographic success. What is unclear, however, is whether the specific mode of action of different devices might exert an additional independent effect on late luminal renarrowing. The purpose of this study was to investigate such a difference in the degree of provocation of luminal renarrowing (or 'restenosis propensity') by different devices, among 3660 patients, who had 4342 lesions successfully treated by balloon angioplasty (n = 3797), directional coronary atherectomy (n = 200), Palmaz-Schatz stent implantation (n = 229) or excimer laser coronary angioplasty (n = 116) and who also underwent quantitative angiographic analysis pre- and post-intervention and at 6-month follow-up. To allow valid comparisons between the groups, because of significant differences in coronary vessel size (balloon angioplasty = 2.62 +/- 0.55 mm, directional coronary atherectomy = 3.28 +/- 0.62 mm, excimer laser coronary angioplasty = 2.51 +/- 0.47 mm, Palmaz-Schatz = 3.01 +/- 0.44 mm; P < 0.0001), the comparative measurements of interest selected were the 'relative loss' in luminal diameter (RLoss = loss/vessel size) to denote the restenosis process, and the 'relative lumen at follow-up' (RLfup = minimal luminal diameter at follow up/vessel size) to represent the angiographic outcome. For consistency, lesion severity pre-intervention was represented by the 'relative lumen pre' (RLpre = minimal luminal diameter pre/vessel size) and the luminal increase at intervention was measured as 'relative gain' (relative gain = gain/ vessel size). Differences in restenosis propensity between devices was evaluated by univariate and multivariate analysis. Multivariate models were constructed to determine relative loss and relative lumen at follow-up, taking account of relative lumen pre-intervention, lesion location, relative gain, vessel size and the device used. In addition, model-estimated relative loss and relative lumen at follow-up at given relative lumen pre-intervention relative gain and vessel size, were compared among the four groups. Significant differences were detected among the groups both with respect to these estimates, as well as in the degree of influence of progressively increasing relative gain, on the extent of renarrowing (relative loss) and angiographic outcome (relative lumen at follow-up), particularly at higher levels of luminal increase (relative gain). Specifically, lesions treated by balloon angioplasty or Palmaz-Schatz stent implantation (the predominantly 'dilating' interventions) were associated with more favourable angiographic profiles than directional atherectomy or excimer laser (the mainly 'debulking' interventions). Significant effects of lesion severity and location, as well as the well known influence of luminal increase on both luminal renarrowing and late angiographic outcome were also noted. These findings indicate that propensity to restenosis after apparently successful intervention is influenced not only by the degree of luminal enlargement achieved at intervention, but by the device used to achieve it. In view of the clinical implications of such findings, further evaluation in larger randomized patient populations is warranted.

In animals in which atherosclerosis was induced experimentally (by a high cholesterol diet) regression of the atherosclerotic lesion was demonstrated after serum cholesterol was reduced by cholesterol- lowering drugs or a low-fat diet. Whether regression of advanced coronary arterly lesions also takes place in humans after a similar intervention remains conjectural. However, several randomized studies, primarily employing lipid-lowering intervention or comprehensive changes in lifestyle, have demonstrated, using serial angiograms, that it is possible to achieve less progression, arrest or even (small) regression of atherosclerotic lesions. The lipid-lowering trials (NHBLI, CLAS, POSCH, FATS, SCOR and STARS) studied 1240 symptomatic patients, mostly men, with moderately elevated cholesterol levels and moderately severe angiographic-proven coronary artery disease. A variety of lipid-lowering drugs, in addition to a diet, were used over an intervention period ranging from 2 to 3 years. In all but one study (NHBLI), the progression of coronary atherosclerosis was less in the treated group, but regression was induced in only a few patients. The overall relative risk of progression of coronary atherosclerosis was 0 x 62 and 2 x 13, respectively. The induced angiographic differences were small and did not produce any significant haemodynamic benefit. The most important result was tht the disease process could be stabilized in the majority of patients. Three comprehensive lifestyle change trials (the Lifestyle Heart study, STARS and the Heidelberg Study) studied 183 patients, who were subjected to stress management, and/or intensive exercise, in addition to a low fat diet, over a period ranging from 1 to 3 years. All three trials demonstrated less progression, and more regression with overall relative risks of 0 x 40 and 2 x 35 respectively, in the intervention groups. Angiographic trials demonstrated that retardation or arrest of coronary atherosclerosis was possible after an intervention, but the ultimate goal, regression of the lesion, was only achieved in a small number of patients. However, the ability to stabilize coronary atherosclerosis is a considerable achievement for those patients with coronary atherosclerosis.

Although intracoronary ultrasonography allows detailed tomographic imaging of the arterial wall, it fails to provide data on the structural architecture and longitudinal extent of arterial disease. This information is essential for decision making during therapeutic interventions. Three-dimensional reconstruction techniques offer visualization of the complex longitudinal architecture of atherosclerotic plaques in composite display. Progress in computer hardware and software technology have shortened the reconstruction process and reduced operator interaction considerably, generating three-dimensional images with delineation of mural anatomy and pathology. The indications for intravascular ultrasonography will grow as the technique offers the unique capability of providing ultrasonic histology of the arterial wall, and the need for a three-dimensional display format for comprehensive analysis is increasingly recognized. Consequently, three-dimensional imaging is being rapidly implemented in the catheterization laboratories for guidance of intracoronary interventions and detailed assessment of their results. However exciting the prospects may be, three-dimensional reconstructions at present remain partially artificial because the true spatial position of the imaging catheter tip is not recorded, and shifts in its location and curves of the arterial lumen result in pseudoreconstructions rather than true reconstructions. In this report, we address the principles of three-dimensional reconstruction with a critical review of its limitations. Potential solutions for refinement of this exciting imaging modality are presented.

We report on the use of intravascular ultrasound, coronary angioscopy and on-line quantitative angiography in an unstable patient soon after myocardial infarction. Combined intracoronary imaging made it possible to solve the therapeutic problem posed by an unusual angiographic appearance secondary to intracoronary thrombolysis during coronary recanalization. The pathological validation of the observations performed with angioscopy and intravascular ultrasound was made possible with the concomitant use of directional atherectomy.

BACKGROUND Radiographic technology plays an integral role in interventional cardiology. The number of interventions continues to increase, and the associated radiation exposure to patients and personnel is of major concern. This study was undertaken to determine whether a newly developed x-ray tube deploying grid-switched pulsed fluoroscopy and extra beam filtering can achieve a reduction in radiation exposure while maintaining fluoroscopic images of high quality. METHODS AND RESULTS Three fluoroscopic techniques were compared: continuous fluoroscopy, pulsed fluoroscopy, and a newly developed high-output pulsed fluoroscopy with extra filtering. To ascertain differences in the quality of images and to determine differences in patient entrance and investigator radiation exposure, the radiated volume curve was measured to determine the required high voltage levels (kVpeak) for different object sizes for each fluoroscopic mode. The fluoroscopic data of 124 patient procedures were combined. The data were analyzed for radiographic projections, image intensifier field size, and x-ray tube kilovoltage levels (kVpeak). On the basis of this analysis, a reference procedure was constructed. The reference procedure was tested on a phantom or dummy patient by all three fluoroscopic modes. The phantom was so designed that the kilovoltage requirements for each projection were comparable to those needed for the average patient. Radiation exposure of the operator and patient was measured during each mode. The patient entrance dose was measured in air, and the operator dose was measured by 18 dosimeters on a dummy operator. Pulsed compared with continuous fluoroscopy could be performed with improved image quality at lower kilovoltages. The patient entrance dose was reduced by 21% and the operator dose by 54%. High-output pulsed fluoroscopy with extra beam filtering compared with continuous fluoroscopy improved the image quality, lowered the kilovoltage requirements, and reduced the patient entrance dose by 55% and the operator dose by 69%. CONCLUSIONS High-output pulsed fluoroscopy with a grid-switched tube and extra filtering improves the image quality and significantly reduces both the operator dose and patient dose.

E VEN THOUGH percutaneous transluminal coronary angioplasty (PTCA) was introduced 15 years ago, 1 data on the long-term follow-up of patients who have undergone the procedure remains incomplete. So far, only nonrandomized long-term studies have been published. In this review the available information on medium and long-term outcome is examined. We have analyzed the data on the intention to treat principle and, thus, have only included studies providing follow-up data of all patients who underwent balloon angioplasty, including those with unsuccessful as well as successful procedures. We sought to answer the following questions: (1) how many patients underwent successful PTCA and were symptomfree at last follow-up after attempted balloon angioplasty and (2) what was the price they had to pay in terms of major adverse cardiac events.

Long-term changes in vasocontractility were examined in 23 coronary segments from 20 patients with variant angina using computer-based quantitative coronary angiography and ergonovine provocation tests repeated at an interval of 42 +/- 14 months. Measurements of vasospasticity at the sites of fixed stenoses were compared with values predicted by an elementary geometric theory based on the assumption that the cross-sectional area of a vessel wall is constant regardless of its state of vasoconstriction. While all patients were symptomatic initially, only 11 remained symptomatic at follow-up. At the initial provocation test, the response was correctly predicted in four segments, was lower than expected in one, and was stronger in 18. At follow-up, only one of the four segments in which the response had been initially predicted correctly again showed the predicted response and the remaining three showed a response weaker than expected; the one segment which was initially hypocontractile remained hypocontractile at follow-up; and of the 18 segments which were initially hypercontractile, 12 exhibited hypercontractility again, four had the predicted value and the remaining two showed hypocontractility. In only one of 23 segments did the geometric theory predict the behaviour of vasospasticity at the site of fixed stenosis on both tests. Vasospastic responsiveness is a dynamic process demonstrating temporal variability and is not directly predicted by geometric theory.

Coronary imaging is the ultimate challenge. During the last decade there have been great advances in this imaging technique, partly as a result of improved scanner hardware, but more because of advances in microprocessor technology Coronary imaging is the ultimate challenge for any imaging technique. This is because the coronary arteries are small (2–4 mm in diameter) and have a tortuous, complex, three dimensional course and are continuously in motion, except for a short period during mid diastole. During the last decade we have witnessed great advances in cardiac imaging. This was partly as a result of improved scanner hardware, but more because of advances in microprocessor technology, which allow for rapid processing of extremely large quantities of data necessary for the acquisition, post-processing, and construction of hitherto unimaginable, non-invasively obtained images of the coronary lumen and plaque. This raises two important questions. Firstly, has progress in non-invasive coronary imaging techniques gone so far that conventional invasive diagnostic coronary angiography has become redundant? Secondly, are these new imaging techniques capable of detecting which coronary plaque is stable, unstable or vulnerable? Magnetic resonance coronary angiography (MR-CA), electron beam computed tomography (EBCT), and multi-slice computed tomography (MS-CT) have recently emerged as new non-invasive diagnostic techniques that possess the potential to replace conventional diagnostic angiography.1–4 The diagnostic accuracy to detect a significant coronary stenosis is presented in table 1. However, it should be noted that: firstly, the diagnostic value only concerns the detection of stenoses in the proximal and mid segment of the coronary tree, because the smaller distal segments cannot be adequately visualised; and secondly, only in 70–80 % of these proximal and mid segments is image quality sufficient to allow a semiquantitative assessment. View this table: Table 1 Approximate diagnostic value of non-invasive coronary imaging techniques to detect significant coronary stenosis (> 50 % …

An attempt was made to assess the mechanism of directional coronary atherectomy using different methods of analysis. Quantitative coronary angiography was used as the gold standard to assess the immediate results of atherectomy, and a comparative quantitative analysis of atherectomy and balloon angioplasty was made. To determine whether the post-atherectomy cross-sectional area is close to a circle, we compared the area measurements obtained by edge detection with those obtained by videodensitometry. Finally, the extent of a 'Dotter' effect was established by quantitative angiography following crossing the stenosis with the atherectomy device. For the purpose of this study, the results of the first 113 successful atherectomy procedures were reviewed. In matched lesions, directional atherectomy induced a greater increase in minimal luminal diameter than balloon angioplasty (1.6 mm vs 0.8 mm; P < 0.0001). However, this luminal improvement is due to a substantial 'Dotter' effect induced by the bulky atherectomy device. Following atherectomy, only a slight difference in cross-sectional area measurements between edge detection and videodensitometry (mean difference: 0.28 mm2) was found. Histologic examination of an atherectomized coronary artery showed a near-circular postatherectomy area geometry. In conclusion, directional atherectomy is a very effective device with a substantially better initial result than balloon angioplasty. However, insertion of this bulky device itself causes an important 'Dotter' effect.

Purpose. This study evaluated the impact of tube current (mAs) in delayed-enhancement computed tomography (CT) imaging for assessing acute reperfused myocardial infarction in a porcine model. Materials and methods. In five domestic pigs (mean weight 24 kg), the circumflex coronary artery was balloon-occluded for 2 h and then reperfused. After 5 days, CT imaging was performed following administration of iodinated contrast material. A 64-slice CT system was used to perform first-pass coronary angiography with a tube current of 15 mAs/kg [Arterial Phase (ART)] followed by two delayed-enhancement (DE) scans 15 min after contrast material administration, with a tube current of 15 mAs/kg and 37.5 mAs/kg, respectively (DE1 and DE2). The mean heart rate decreased to 51 +/- 9 beats/min after administration of zatebradine (10 mg/kg IV). The data set was reconstructed during the end-diastolic phase of the cardiac cycle. Areas with DE, no reflow and remote myocardium [remote left ventricular (LV)] were calculated. CT values expressed in Hounsfield units (HU) were measured using five regions of interest (ROI): DE, no reflow, remote LV, LV cavity (LV lumen) and in air, respectively. Differences, correlations, image quality [signal-to-noise ratio (SNR)] and contrast resolution [contrast-to-noise ratio (CNR)] were calculated. Results. Significant differences were found between attenuation of areas of DE, no reflow and remote LV (p0.05). The SNR and CNR were not significantly different in DE1 vs. DE2 (p>0.05). Conclusions. Tube current does not significantly affect infarction area, image quality or contrast resolution of DE imaging with CT.

Directional coronary atherectomy has been introduced as an alternative to conventional balloon angioplasty when treating coronary artery stenoses with complex lesion morphology. To determine the immediate efficacy of coronary atherectomy in patients with such lesions, the first 113 attempts at directional atherectomy in two centres using quantitative angiography were reviewed in 105 patients. The lesions were classified as complex stenosis since 95% had a symmetry index less than 1.0, a length of 6.83 +/- 2.55 mm on average and an area of plaque of 9.77 +/- 6.69 mm2. Procedural success defined as a residual stenosis less than or equal to 50% after tissue retrieval was obtained in 90 (85.7%) of 105 patients. The primary angioplastic success rate, combining atherectomy and balloon angioplasty in case of failed attempt of atherectomy was 95.2%. Coronary atherectomy was unsuccessful in five patients; three were referred for emergency coronary artery bypass grafting. Major complications (death, emergency surgery and transmural infarction) were encountered in 5.7% of the patients. Assessed by quantitative coronary analysis, a residual minimal luminal diameter of 2.42 +/- 0.52 mm and a diameter stenosis of 26 +/- 12% were obtained immediately after directional coronary atherectomy. We conclude that directional coronary atherectomy is particularly suitable for the treatment of stenosis with complex lesion morphology and is associated with acceptable complication rates. Randomized trials comparing atherectomy with balloon angioplasty are warranted to clarify the role of atherectomy in the treatment of lesions in the proximal part of the three major epicardial coronary arteries.

Of all coronary angioplasties performed nowadays, 40% of the patients have multivessel disease. Angioplasty in patients with multivessel disease can be performed with a high immediate clinical success rate and an acceptable major complication rate. However, complete anatomic revascularization with coronary angioplasty is achieved in only 32 to 59%. This raises concern about the immediate and long-term outcome of patients in whom incomplete revascularization is achieved. This report reviews the literature and provides evidence that incomplete revascularization with coronary angioplasty is a safe and effective treatment in selected patients with multivessel disease, provided that adequate (functional) revascularization can be achieved. Adequate revascularization includes dilation of all significant lesions supplying large areas of viable myocardium.

This study was designed (1) to assess the relationship between stress exercise echocardiography (echo) and 201-Tl single photon emission computed tomography (SPECT) applied simultaneously in 23 patients who were candidates to percutaneous transluminal coronary angioplasty (PTCA), (2) to assess the relationship between the development of exercise-induced wall motion abnormalities, transient perfusion defects and the severity of quantitatively assessed coronary stenoses and (3) to compare the functional improvement after PTCA by exercise echo and SPECT. Before PTCA there was an agreement of 78% between stress echo (new wall motion abnormalities) and SPECT (transient perfusion defects) results. All patients with a percentage diameter stenosis greater than 70% had a positive echo and SPECT, while they were both negative if the percentage diameter stenosis was less than 50%. In 19 patients re-studied 4 weeks after PTCA, an ischaemic response at stress echo was found in two of the 13 patients who had a positive stress echo test before PTCA, and SPECT was still positive in three of the 10 patients who had a positive SPECT study before PTCA. Echo and SPECT were concordant in 17/19 cases. It is concluded that exercise echo and 201-Tl SPECT are useful non-invasive tools for the functional assessment of patients before and after PTCA, and that they provide highly concordant results.

OBJECTIVE--To study the immediate and long term clinical success of percutaneous transluminal coronary balloon angioplasty in patients over 70 years old. DESIGN--Patients undergoing percutaneous transluminal angioplasty were prospectively entered in a specially designed database. The clinical and angiographic data of all patients over 70 were reviewed. Follow up data were collected by interview, during outpatient visits, by questionnaire, or through the referring physician. SETTING--A tertiary referral cardiac centre. PATIENTS--166 patients over 70 (median 73, range 70-84) underwent coronary angioplasty because of unstable angina (81 patients), stable angina (76 patients), or acute myocardial infarction (nine patients). RESULTS--The initial clinical success rate was 86% (142 of 166 patients). A major procedural complication occurred in 10 patients (6%): four patients (2%) died, six patients (4%) underwent emergency bypass surgery, and five patients (3%) sustained an acute myocardial infarction. In 14 patients (8%) coronary angioplasty did not significantly reduce the diameter stenosis but there were no associated complications. A total of 226 lesions were attempted. The initial angiographic success rate was 192 out of 226 lesions (85%). The median follow up was 21 (range 0.5-66) months. Sixteen patients (10%) died during follow up, eight patients (5%) sustained a non-fatal myocardial infarction, 21 patients (13%) underwent a second or third balloon dilatation, and 17 patients (10%) underwent elective bypass surgery. Of the 146 survivors, 99 patients (68%) had sustained clinical improvement. The estimated survival at four years (Kaplan-Meier method) was 89 (SD 4)%. The event free survival at four years for the total study population was 61 (8)%. Multivariate logistic regression analysis showed that the extent of vessel disease was the only independent predictive factor for event free survival: the event free survival rate was 81 (10)% at four years for patients with single vessel disease, compared with 45 (12)% for patients with multivessel disease. CONCLUSIONS--Coronary angioplasty in patients over 70 was a safe and effective treatment for obstructive coronary artery disease. The extent of vessel disease, and not the completeness of revascularisation, was the only independent predictive factor for event free survival.

We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris. Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available a parts per thousand yen2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS). Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as a parts per thousand yen1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6 +/- 1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p < 0.05). MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.