[Mechanical circulatory support systems : When and how much protection does a PCI need?] / Mechanische Kreislaufunterstützungssysteme : Wie viel Schutz braucht eine PCI wann?

The interventional treatment of high-risk patients remains challenging and has a high potential for improvement despite all technical innovations. Mechanical circulatory support (MCS) systems can be meaningful depending on the clinical situation, although a clear study situation for this is so far lacking. Multivessel coronary disease and a high SYNTAX score combined with impaired ventricular function is a possible predictor combination for the use of MCS that justifies the higher risk of complications.

[Imaging in structural heart disease : Impact on interventional therapy]. / Bildgebung bei struktureller Herzerkrankung : Bedeutung für die interventionelle Therapie.

For the treatment of structural heart disease, current options in the catheterization laboratory include MitraClip® implantation for treating severe mitral regurgitation, transcatheter aortic valve implantation (TAVI), closure of a patent foramen ovale (PFO) and occlusion of the left atrial appendage (LAA). These treatment options are based on a precise diagnosis provided by modern cardiac imaging, which is indispensable for treatment recommendations. Its importance for supporting the invasive procedures in the catheterization laboratory is less well known. Due to enhanced soft tissue characterization, it complements fluoroscopy and invasive angiography and thus enormously improves the safety of the procedures. In addition, it allows individualized follow-up care. The current article gives an overview of the clinically most frequently used procedures.

Association of impaired fasting glucose and coronary artery calcification as a marker of subclinical atherosclerosis in a population-based cohort--results of the Heinz Nixdorf Recall Study.

AIMS/HYPOTHESIS: Atherosclerosis and cardiovascular diseases are often present at the time of diagnosis of type 2 diabetes mellitus. Whether subclinical atherosclerosis can be detected in the pre-diabetic (borderline fasting hyperglycemia) state is not clear. This study investigated the association of impaired fasting glucose (IFG) and coronary artery calcification (CAC), a marker of subclinical atherosclerosis, among participants without a history of coronary heart disease or manifest diabetes mellitus. METHODS: Study participants (aged 45-75 years) of the population-based Heinz Nixdorf Recall Study were categorised into those with normal fasting glucose (glucose <6.1 mmol/l) and those with IFG (glucose >or=6.1 to <7.0 mmol/l), excluding participants with a history of CHD or diabetes mellitus. CAC was assessed by electron-beam computed tomography, and risk factors were assessed by extended interviews, anthropometric measurements and laboratory tests. Various CAC cut-off points were used in multiple logistic and ordinal logistic regression models to estimate ORs and 95% CIs. RESULTS: Of the 2,184 participants, more men had IFG than did women (37% vs 22%). Participants with IFG showed a higher prevalence of CAC > 0 (men OR 1.90, 95% CI 1.33-2.70; women 1.63, 1.23-2.15). Risk factor adjustment weakened this association in both sexes (men 1.63, 1.12-1.36; women 1.26, 0.93-1.70). When the age- and sex-specific 75th percentile was used as the cut-off point for CAC, the association further decreased in men (1.10, 0.81-1.50), but became stronger in women (1.41, 1.02-1.94). CONCLUSIONS/INTERPRETATION: These data support the hypothesis that CAC is already present in the pre-diabetic state and that IFG has a modest and independent impact on the atherosclerotic process. Biological sex appears to modify the association between IFG and CAC.

Coronary CT angiography (CCTA) using third-generation dual-source CT for ruling out in-stent restenosis.

AIMS: Late in-stent restenosis (ISR) has become increasingly important, in particular due to neo-atherosclerosis. CCTA is a highly sensitive method for detecting coronary plaques. Its diagnostic accuracy regarding ISR is controversial. Stent artifacts can impede image quality, but recent developments in CT-technology may help to overcome some of these problems and allow for improved diagnostic accuracy. METHODS: Consecutive patients after previous coronary revascularization who had stable symptoms or signs of possible disease progression were examined using a third-generation dual-source CT scanner. After the scan, patients were followed for clinical events (MACE) over a mean of 399 days. Patients with high-grade stenoses were referred for invasive coronary angiography (ICA), unclear findings were further evaluated either by ICA or functional testing. RESULTS: Overall, 226 patients were included. A total of 457 stents were evaluated (2.0 ± 1.4 per patient). Mean stent diameter was 2.9 ± 0.45 mm. In 61%, a high-pitch protocol was employed. Mean dose-length product (DLP) of CCTA was 159.2 mGy cm, corresponding to 2.2 mSv using a conversion factor of k = 0.014. Mean amount of contrast agent was 58.3 ± 12.5 ml. In 145 patients (64%), CCTA was negative. In this group, one MACE occurred (acute coronary syndrome) during follow-up in a patient who had also undergone unremarkable ICA. In 23 patients (10%), CCTA detected 28 ISR which were confirmed and treated by ICA (true positive). In 27 patients (12%), ISR was suspected by CCTA but excluded by ICA (false positive), 30 patients (13%) had unclear findings and normal non-invasive tests. No MACE occurred during follow-up in these patients. One patient was misclassified in CCTA as having intermediate and not high-grade ISR who underwent revascularization within 3 months. Eleven patients (5%) were lost to follow-up. During follow-up, eight patients had myocardial infarctions due to five ISRs and three de novo lesions. No patient died. In cases with unclear or false-positive findings, the amount of stents was significantly higher, stents were smaller and patients had a higher BMI. CONCLUSION: In almost two-thirds of symptomatic patients with previous coronary stent implantation, ISR could be ruled out by CCTA. 10% of patients had definite ISR. The rate of false-negative findings was low (< 1%), whereas the rate of false positive or inconclusive findings was 25%, leading to invasive rule-out of ISR by ICA in 12%. CCTA appears valuable as a tool for safely excluding ISR. It might help to avoid invasive diagnostic procedures. Further analyses are warranted, in particular regarding the influence of stent dimensions and the total amount of stents in a patient.

Residential exposure to traffic is associated with coronary atherosclerosis.

BACKGROUND: Long-term exposure to fine-particulate-matter (PM2.5) air pollution may accelerate the development and progression of atherosclerosis. We investigated the associations of long-term residential exposure to traffic and fine particulate matter with the degree of coronary atherosclerosis. METHODS AND RESULTS: We used baseline data on 4494 participants (age 45 to 74 years) from the German Heinz Nixdorf Recall Study, a population-based, prospective cohort study that started in 2000. To assess exposure differences, distances between residences and major roads were calculated, and annual fine particulate matter concentrations, derived from a small-scale dispersion model, were assigned to each address. The main outcome was coronary artery calcification (CAC) assessed by electron-beam computed tomography. We evaluated the association between air pollution and CAC with logistic and linear regression analyses, controlling for individual level risk factors of coronary atherosclerosis. Compared with participants living >200 m away from a major road, participants living within 50, 51 to 100, and 101 to 200 m had odds ratios of 1.63 (95% CI, 1.14 to 2.33), 1.34 (95% CI, 1.00 to 1.79), and 1.08 (95% CI, 0.85 to 1.39), respectively, for a high CAC (CAC above the age- and gender-specific 75th percentile). A reduction in the distance between the residence and a major road by half was associated with a 7.0% (95% CI, 0.1 to 14.4) higher CAC. Fine particulate matter exposure was associated with CAC only in subjects who had not been working full-time for at least 5 years. CONCLUSIONS: Long-term residential exposure to high traffic is associated with the degree of coronary atherosclerosis.

In-vitro evaluation of coronary stents and 64-detector-row computed tomography using a newly developed model of coronary artery stenosis.

BACKGROUND: Stent implantation is the predominant therapy for non-surgical myocardial revascularization in patients with coronary artery disease. However, despite substantial advances in multidetector computed tomography (MDCT) coronary imaging, a reliable detection of coronary in-stent restenosis is currently not possible. PURPOSE: To examine the ability of 64-detector-row CT to detect and to grade in-stent stenosis in coronary stents using a newly developed ex-vivo vessel phantom with a realistic CT density pattern, artificial stenosis, and a thorax phantom. MATERIAL AND METHODS: Four different stents (Liberté and Lunar ROX, Boston Scientific; Driver, Medtronic; Multi-Link Vision, Guidant) were examined. The stents were placed on a polymer tube with a diameter of 2.5, 3.0, 3.5, or 4.0 mm. Different degrees of stenosis (0%, 30%, 50%, 70-80%) were created inside the tube. For quantitative analysis, attenuation values were measured in the non-stenotic vessel outside the stent, in the non-stenotic vessel inside the stent, and in the stenotic area inside the stent. The grade of stenosis was visually assessed by two observers. RESULTS: All stents led to artificial reduction of attenuation, the least degree of which was found in the Liberté stent (11.3+/-10.2 HU) and the Multi-Link Vision stent (17.6+/-17.9 HU; P = 0.25). Overall, the non-stenotic vessel was correctly diagnosed in 55.5%, the low-grade stenosis in 58.3%, the intermediate stenosis in 63.8%, and the high-grade stenosis in 80.5%. In the 3.0-, 3.5-, and 4.0-mm vessels, in none of the cases was a non-stenotic or low-grade stenotic vessel misdiagnosed as intermediate or high-grade stenosis. The average deviation from the real grade of stenosis was 0.40 for the Liberté stent, 0.46 for the Lunar ROX stent, 0.45 for the Driver stent, and 0.58 for the Multi-Link Vision stent. CONCLUSION: Our ex-vivo data show that non-stenotic stents and low-grade in-stent stenosis can be reliably differentiated from intermediate and high-grade in-stent stenosis in vessels with a diameter of 3 to 4 mm. With regard to artifacts and the grading of stenoses, the Liberté stent was best suited for CT coronary angiography.

[Current studies on the progression of coronary calcification]. / Aktuelle Studien zur Progression koronarer Kalzifikationen.

UNLABELLED: The quantification of coronary calcification facilitates improved prediction of cardiovascular diseases, in particular in persons with intermediate risk. The importance of serial measurement of coronary calcium in one to two-year intervals for evaluating the course of the disease and therapeutic monitoring after risk modification is unclear. The precise quantification of the progression of arteriosclerosis could contribute to the non-invasive detection of the chronic, often subclinical development of coronary heart disease at an asymptomatic stage of the disease, long before an irreversible clinical event in the pathogenetic cascade, such as sudden cardiac death or myocardial infarction, occurs. An important prerequisite for evaluating changes in the coronary calcium load is detailed knowledge of reproducibility or variability. In addition to a rapid image acquisition time and the use of calibration phantoms, low heart rate and breathing variability, image acquisition in the late systole, overlapping layers (at the expense of radiation dose) and optimized analysis algorithms also contribute to improvement in reproducibility. The limits of variability however are, above all, dependent upon the calcium load itself. Reproducibility is on the average about 10% and thus lies below the highest expected progression, which is about 10-50% per year, depending upon the initial value and pre-existing conditions Only a few studies have identified calcium score progression as an independent predictor for later events. In several studies, calcium score progression was related to the rate of events, but was not independent of other variables. The most important determinant appears to be the calcium score itself. Other relevant determinants are age, gender, diabetes, obesity and renal failure. Whether lipid values significantly influence the progression has not been clarified. CONCLUSION: Further studies on the natural course of coronary heart disease, particularly in the early disease stages, the determinants of progression and the extent to which the calcification progress can be modified are necessary to assess the benefit of serial score measurement for risk stratification. Until then, the repeated radiation exposure cannot be recommended outside of clinical studies.

Gadolinium as an alternative contrast agent during cardiac catheterization in patient with iodine-induced hyperthyroidism.

We report the first case of a male patient with iodine-induced hyperthyroidism and unstable angina pectoris in whom a diagnostic cardiac catheterization with gadolinium as contrast agent was chosen. The patient was hospitalized with an iodine-induced hyperthyroidism after angioplasty using an iodinated contrast agent. He presented with a continuous arrhythmia and unstable angina pectoris. A repeated cardiac catheterization using iodinated contrast agent was contraindicated. This case report shows that gadolinium is a useful alternative contrast agent for cardiac intervention in patients with iodine-induced hyperthyroidism.

Post-interventional homocysteine levels: failure as a predictive biomarker of in-stent restenosis.

OBJECTIVES: Purpose of our study was to determine if homocysteine plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions. BACKGROUND: The putative role of homocysteine as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine levels in the development of in-stent restenosis, however, is controversially discussed. METHODS: A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. Laboratory determination comprised blood sample evaluation for homocysteine and other conventional risk factors before baseline coronary intervention and prior to six months control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine levels as well as major adverse cardiac events. RESULTS: There was a significant correlation between the length of the implanted stent (p<0.006), the percentage of stenosis (p<0.003) and the pre-interventional luminal diameter (p<0.0001) with late loss index. Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine levels on angiographic restenosis, late lumen loss, or late loss index. CONCLUSIONS: In contrast to homocysteine levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of restenosis. Taking our data into consideration, we hypothesise that homocysteine may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting.

Intraoperative coronary graft flow determination--does it have a prognostic value for midterm graft patency?

OBJECTIVE: To characterise the prognostic value of intraoperative ultrasonic graft flow determination during CABG for mid-term patency. METHODS: From 01/2000 to 08/2003 3146 CABG procedures were performed at our institution. Graft flow was determined in all patients. Lumen diameter was given in mm and a sclerosis score was applied for the target vessel. 100 of these patients (3.2%) underwent postoperative coronary angiography at a mean time interval of 8.0 +/- 0.5 months. RESULTS: In 100 patients, 114 LITA and 204 venous anastomoses were performed. At re-angiography 112 LITA (98%) and 174 venous (85%) anastomoses were patent. The amount of occluded LITA grafts was to low to perform statistical analyses. Mean graft flow of patent vein grafts was 48 +/- 2 ml/min vs. 32 +/- 4 ml/min in occluded vein grafts (p = 0.001). After multiple logistic regression analysis, only intraoperative vein graft flow was found to be a predictor for patency at mid-term (p = 0.005, odds ratio 0.97, 95% confidence interval (CI) from 0.95-0.99). No differences were found concerning sclerosis scores or vessel lumen between patent and occluded grafts. CONCLUSIONS: Significant differences concerning intraoperative graft flow were found between vein grafts patent or occluded at re-angiography. The predictive power of intraoperative vein graft flow for mid-term patency was confirmed by multiple logistic regression analysis.

The coronary calcium score is a more accurate predictor of significant coronary stenosis than conventional risk factors in symptomatic patients: Euro-CCAD study.

AIMS: In this retrospective study we assessed the predictive value of the coronary calcium score for significant (>50%) stenosis relative to conventional risk factors. METHODS AND RESULTS: We investigated 5515 symptomatic patients from Denmark, France, Germany, Italy, Spain and the USA. All had risk factor assessment, computed tomographic coronary angiogram (CTCA) or conventional angiography and a CT scan for coronary artery calcium (CAC) scoring. 1539 (27.9%) patients had significant stenosis, 5.5% of whom had zero CAC. In 5074 patients, multiple binary regression showed the most important predictor of significant stenosis to be male gender (B=1.07) followed by diabetes mellitus (B=0.70) smoking, hypercholesterolaemia, hypertension, family history of CAD and age but not obesity. When the log transformed CAC score was included, it became the most powerful predictor (B=1.25), followed by male gender (B=0.48), diabetes, smoking, family history and age but hypercholesterolaemia and hypertension lost significance. The CAC score is a more accurate predictor of >50% stenosis than risk factors regardless of the means of assessment of stenosis. The sensitivity of risk factors, CAC score and the combination for prediction of >50% stenosis when measured by conventional angiogram was considerably higher than when assessed by CTCA but the specificity was considerably higher when assessed by CTCA. The accuracy of CTCA for predicting >50% stenosis using the CAC score alone was higher (AUC=0.85) than using a combination of the CAC score and risk factors with conventional angiography (AUC=0.81). CONCLUSION: In symptomatic patients, the CAC score is a more accurate predictor of significant coronary stenosis than conventional risk factors.

Gender and age effects on risk factor-based prediction of coronary artery calcium in symptomatic patients: A Euro-CCAD study.

BACKGROUND AND AIMS: The influence of gender and age on risk factor prediction of coronary artery calcification (CAC) in symptomatic patients is unclear. METHODS: From the European Calcific Coronary Artery Disease (EURO-CCAD) cohort, we retrospectively investigated 6309 symptomatic patients, 62% male, from Denmark, France, Germany, Italy, Spain and USA. All of them underwent risk factor assessment and CT scanning for CAC scoring. RESULTS: The prevalence of CAC among females was lower than among males in all age groups. Using multivariate logistic regression, age, dyslipidaemia, hypertension, diabetes and smoking were independently predictive of CAC presence in both genders. In addition to a progressive increase in CAC with age, the most important predictors of CAC presence were dyslipidaemia and diabetes (ß = 0.64 and 0.63, respectively) in males and diabetes (ß = 1.08) followed by smoking (ß = 0.68) in females; these same risk factors were also important in predicting increasing CAC scores. There was no difference in the predictive ability of diabetes, hypertension and dyslipidaemia in either gender for CAC presence in patients aged <50 and 50-70 years. However, in patients aged >70, only dyslipidaemia predicted CAC presence in males and only smoking and diabetes were predictive in females. CONCLUSIONS: In symptomatic patients, there are significant differences in the ability of conventional risk factors to predict CAC presence between genders and between patients aged <70 and ≥70, indicating the important role of age in predicting CAC presence.

Unstable coronary plaque and its relation to coronary calcium.

Coronary calcium is intimately associated with coronary atherosclerotic plaque development. The use of electron-beam computed tomography (EBCT) for accurate quantitative measurements has led to an increased interest in understanding the clinical importance of coronary calcium, particularly in terms of the ability to identify unstable coronary plaques that underlie the clinical acute coronary syndromes. Histopathologic studies have demonstrated that calcium is a frequent feature of ruptured plaques, but the presence or absence of calcium does not allow for reliable distinction between unstable versus stable plaques. This issue is complicated by the lack of a prospective definition for "unstable." Plaque rupture is sometimes found in apparently healthy subjects and in patients with clinically stable disease. Coronary atherosclerosis is a coronary systemic disease process. Imaging of coronary calcium, although unable to identify a localized unstable plaque, potentially can identify the more clinically pertinent "unstable patient." Almost all patients with a recent acute coronary syndrome have measurable coronary calcium because moderate-to-advanced coronary plaque disease is already present, although obstructive disease frequently is not. Prospective studies have demonstrated that extensive coronary calcium detected by EBCT is associated with a significantly increased incidence of subsequent myocardial infarction, need for revascularization, and coronary death. The incremental prognostic value of coronary calcium compared with that of risk factor assessment remains to be fully defined. The occurrence of an acute coronary syndrome is determined by many factors apart from the extent of atherosclerotic plaque disease. Large prospective trials in the general population are needed to define the subgroups that will benefit most from quantitative assessment of coronary calcium.

Abnormal coronary flow velocity reserve after coronary intervention is associated with cardiac marker elevation.

BACKGROUND: Residual reduction of relative coronary flow velocity reserve (rCVR) after successful coronary intervention has been related to microvascular impairment. However, the incidence of cardiac enzyme elevation as a surrogate marker of an underlying embolic myocardial injury in these cases has not been studied. METHODS AND RESULTS: A series of 55 consecutive patients with successful coronary stenting, periprocedural intracoronary Doppler analysis, and determination of creatine kinase (CK; upper limit of normal [ULN] for women 70 IU/L, for men 80 IU/L) and cardiac troponin T (cTnT; bedside test, threshold 0.1 ng/mL) before and 6, 12, and 24 hours after intervention were studied. Postprocedural rCVR was the only intracoronary Doppler parameter that independently correlated with cTnT (r=-0.498, P<0.001) and CK outcome (r=-0.406, P=0.002). Receiver operating characteristic analysis identified a postprocedural rCVR of 0.78 as the best discriminating value, with a sensitivity of 83.3% and 69.2% and a specificity of 79.1% and 76.2% for detection of cTnT and CK elevation, respectively. Stratified according to this cutoff value, the incidence of cTnT elevation was 52.6% in patients with (n=19) and 5.6% in patients without (n=36) a postprocedural rCVR <0.78 (P<0.001), associated with a CK elevation >1 times the ULN in 36.8% and 5.6% (P=0.005) of patients, respectively. CONCLUSIONS: Cardiac marker elevation can frequently be found after coronary procedures that are associated with a persistent reduction of rCVR, indicating procedural embolization of atherothrombotic debris with microvascular impairment and myocardial injury as a potential underlying mechanism.

Changes in QRS voltage in cardiac tamponade and pericardial effusion: reversibility after pericardiocentesis and after anti-inflammatory drug treatment.

OBJECTIVES: The goal of this study was to define the association between low QRS voltage and cardiac tamponade or pericardial effusion and to assess the reversibility of low QRS voltage after therapeutic procedures. BACKGROUND: It is unclear whether low QRS voltage is a sign of cardiac tamponade or whether it is a sign of pericardial effusion per se. METHODS: In a prospective study design, we recorded consecutive 12-lead electrocardiograms and echocardiograms in 43 patients who were referred to our institution for evaluation and therapy of a significant pericardial effusion. Cardiac tamponade was present in 23 patients (53%). Low QRS voltage (defined as maximum QRS amplitude <0.5 mV in the limb leads) was found in 14 of these 23 subjects (61%). Nine of these 14 patients were treated by pericardiocentesis (group A). Five patients received anti-inflammatory medication (group B). Group C consisted of nine patients with pericarditis and significant pericardial effusion who had no clinical evidence of tamponade. RESULTS: In group A, low QRS voltage remained largely unchanged immediately after successful pericardiocentesis (0.36 +/- 0.17 mV before vs. 0.42 +/- 0.21 mV after, p = NS), but QRS amplitude recovered within a week (0.78 +/- 0.33 mV, p < 0.001). In group B, the maximum QRS amplitude increased from 0.40 +/- 0.20 mV to 0.80 +/- 0.36 mV (p < 0.001) within six days. In group C, all patients had a normal QRS amplitude initially (1.09 +/- 0.55 mV) and during a seven-day follow-up (1.10 +/- 0.56 mV, p = NS). CONCLUSIONS: Low QRS voltage is a feature of cardiac tamponade but not of pericardial effusion per se. Our findings indicate that the presence and severity of cardiac tamponade, in addition to inflammatory mechanisms, may contribute to the development of low QRS voltage in patients with large pericardial effusions.

Intravenous electron-beam computed tomographic coronary angiography for segmental analysis of coronary artery stenoses.

OBJECTIVES: We sought to identify and localize significant coronary stenoses on a segmental basis by electron-beam computed tomography (EBCT) and intravenous administration of a contrast agent. BACKGROUND: The clinical applicability and limitations of intravenous EBCT coronary angiography have not been defined. METHODS: EBCT was performed within 24 h of selective coronary angiography (SCA) in 28 patients (19 men and 9 women, mean [+/-SD] age 60 +/- 10 years). After examination for coronary calcium, EBCT coronary angiography was performed using overlapping slices (in-plane resolution 0.34 to 0.41 mm) with a nominal slice thickness of 1 mm. Based on quantitative analysis of SCA, lumen diameter narrowing > or = 50% (i.e., significant stenoses) was evaluated in 8 (major) or 12 (including side branches) coronary artery segments, using both two-dimensional (tomographic) and three-dimensional (volume) data sets. RESULTS: Of the 330 segments assessable by SCA, 237 (72%) were visualized by EBCT. The sensitivity (+/-SE) for detection of significant stenoses was 82 +/- 6%; specificity was 88 +/- 2%; positive and negative predictive values were 57 +/- 7% and 96 +/- 2%, respectively; and overall accuracy was 87 +/- 2%. If only eight (major) coronary artery segments were considered, 194 (88%) of 221 segments were visualized, and the overall accuracy was 90 +/- 2%. Seven (18%) of 38 significantly stenotic segments were classified as having < 50% stenoses by EBCT. Six of these segments (86%), but only 9 (29%) of the 31 correctly classified stenotic segments, were severely calcified (area > 20 mm2, p = 0.02). In 23 (12%) of 199 nonstenotic segments falsely classified as having > or = 50% stenosis by EBCT, the lumen diameter was significantly smaller than that of the segments correctly classified as negative (mean [+/-SD] 1.5 +/- 0.8 vs. 2.9 +/- 1.1 mm, p < 0.001). CONCLUSIONS: Intravenous EBCT coronary angiography allows for accurate segmental evaluation of significant disease in the major coronary arteries and may be of value for ruling out significant disease. The main determinant of false negative results is substantial segmental calcification, whereas the main determinant of false positive results is small vessel size.

An algorithm for noninvasive identification of angiographic three-vessel and/or left main coronary artery disease in symptomatic patients on the basis of cardiac risk and electron-beam computed tomographic calcium scores.

OBJECTIVES: We sought to model an algorithm for noninvasive identification of angiographically obstructive three-vessel and/or left main disease based on conventional cardiac risk assessment and site and extent of coronary calcium determined by electron-beam computed tomography (EBCT). BACKGROUND: Such an algorithm would greatly facilitate clinical triage in symptomatic patients with no previous diagnosis of coronary artery disease (CAD). METHODS: We examined 291 patients with suspected, but not previously diagnosed, CAD who underwent coronary angiography for clinical indications. Cardiac risk factors were determined as defined by the National Cholesterol Education Program. An EBCT scan was performed in all patients, and a coronary calcium score (Agatston method) was computed. Total per-patient calcium scores and separate scores for the major coronary arteries were generated. These scores were also analyzed for localization of coronary calcium in the more distal versus proximal tomographic sections. These parameters and the risk factors were considered for the model described in the following section. RESULTS: Sixty-eight patients (23%) had angiographic three-vessel and/or left main CAD. Multiple logistic regression analysis determined male sex, presence of diabetes and left anterior descending (LAD) and circumflex (LCx) coronary calcium scores, independent from more distal calcium localization, as independent predictors for identification of three-vessel and/or left main CAD. Based on this four variable model, a simple noninvasive index (NI) was constructed as the following: loge(LAD score) + log(e)(LCx score) + 2[if diabetic] + 3[if male]. Receiver operating characteristic curve analysis for this NI yielded an area under the curve of 0.88+/-0.03 (p < 0.0001) for separating patients with, versus without, angiographic three-vessel and/or left main CAD. Various NI cutpoints demonstrated sensitivities from 87-97% and specificities from 46-74%. The NI values >14 increased the probability of angiographic three-vessel and/or left main CAD from 23% (pretest) to 65-100% (posttest), and NI values <10 increased the probability of no three-vessel and/or left main CAD from 77% (pretest) to 95-100% (posttest). CONCLUSIONS: On the basis of a simple algorithm ("noninvasive index"), EBCT calcium scanning in conjunction with risk factor analysis can rule in or rule out angiographically severe disease, i.e., three-vessel and/or left main CAD, in symptomatic patients.

Comparison of electron beam computed tomography with intracoronary ultrasound and coronary angiography for detection of coronary atherosclerosis.

OBJECTIVES: This analysis compared the results of electron beam computed tomography (EBCT) with those of coronary angiography and intracoronary ultrasound (ICUS) for the in vivo detection of coronary atherosclerotic plaques. BACKGROUND: EBCT is a new imaging modality for identification of coronary calcifications. Coronary angiography depicts advanced changes in coronary morphology, whereas ICUS is an established diagnostic tool that detects the early stages of coronary artery disease. METHODS: In 57 patients (54 +/- 9 years old), 267 coronary segments were analyzed with EBCT (3-mm slices, acquisition time 100 ms, threshold definition of coronary calcification at 130 Hounsfield units in an area > or = 1 mm2, Agatston calcium score), coronary angiography and ICUS. The analysis was based on the number and extent of coronary calcifications on EBCT, coronary lumen reduction on coronary angiography and plaque formation with and without ultrasound signs of calcifications on ICUS. RESULTS: Compared with coronary angiography, EBCT yielded a sensitivity of 66%, a specificity of 78%, a positive predictive value of 39% and a negative predictive value of 91%. Compared with ICUS, EBCT yielded an overall sensitivity of 66%, a specificity of 88% and an overall accuracy of 81%. For plaques with and without ultrasound signs of calcifications, the sensitivity of EBCT was 97% and 47%, specificity 80% and 75% and overall accuracy 82% and 69%, respectively. CONCLUSIONS: This in vivo correlation between ICUS and EBCT demonstrates that EBCT is a noninvasive method that helps to visualize the atherosclerotic process by localization and quantification of coronary artery calcifications. EBCT detects calcified plaques with high accuracy. Plaques without ultrasound signs of calcifications can be detected by EBCT but with lower sensitivity but equivalent specificity.

Independent and incremental value of coronary artery calcium for predicting the extent of angiographic coronary artery disease: comparison with cardiac risk factors and radionuclide perfusion imaging.

OBJECTIVES: The study was done to test the ability to predict the extent of angiographically determined coronary artery disease (CAD) by quantification of coronary calcium using electron-beam computed tomography (EBCT) and to compare it with more conventional parameters for delineating the angiographic extent of CAD, that is, cardiovascular risk factors and radionuclide single-photon emission computed tomography (SPECT). BACKGROUND: The angiographic extent of CAD is a powerful predictor of subsequent events. Use of EBCT may be able to define it by virtue of its ability to determine plaque burden. METHODS: We examined 308 patients presenting with suspected but not previously known CAD who underwent selective coronary angiography. As measures of the angiographic extent of CAD, coronary artery greater even 20 (CAGE > or =20) and CAGE > or =50 scores represented the total number of coronary segments with > or =20% or > or =50% stenoses, respectively. The EBCT-derived total calcium scores were obtained in 291 patients, risk factors as defined by the National Cholesterol Education Program in 239 patients, and SPECT scans in 136 patients. RESULTS: Using multiple linear regression analysis, total calcium scores were better independent predictors of both CAGE > or =20 and CAGE > or =50 scores than either a SPECT-derived radionuclide perfusion score or the risk factors age, male gender and ratio of total/high-density lipoprotein (HDL) cholesterol. The association between EBCT and angiographic scores remained highly significant after excluding the influence of all interrelated risk factors and SPECT variables (r = 0.65; p < 0.001 for CAGE > or =20 scores, r = 0.50; p < 0.001 for CAGE > or =50 scores). CONCLUSIONS: Coronary calcium predicts the angiographic extent of CAD in symptomatic patients and provides independent and incremental information to the more conventional clinical parameters derived from SPECT or risk assessment.