Detection Of Coronary Artery Calcification Research Articles

Increased prevalence of significant coronary artery calcification in patients with diabetes.

Coronary artery disease is the major cause of morbidity and mortality in patients with diabetes. Detection of coronary artery disease before the first myocardial infarction and before anginal symptoms will allow for strategies designed to reduce the cardiovascular event rate in this group of patients. Electron beam-computed tomography (EBCT) is a noninvasive technology for evaluating the extent of coronary artery atherosclerosis that relies on the detection of coronary artery calcium (CAC). We used EBCT to detect significant coronary artery atherosclerosis in diabetic patients without symptoms of heart disease. We used EBCT to evaluate calcium in the coronary arteries of 139 consecutive diabetic patients scanned over a 20-month period. The CAC scores in this group were compared with a randomly selected nondiabetic control group and a control group that was selected to match a number of established cardiovascular risk factors. Patients with diabetes had a significant increase in the prevalence of CAC scores > or =400 (25.9%) compared with the randomly selected (7.2%) and matched (14.4%) nondiabetic control groups. Scores in this range have been reported to be highly predictive for abnormal stress myocardial perfusion tomography and subsequent coronary events. Our results, therefore, indicate a substantial prevalence of significant coronary artery disease in an asymptomatic diabetic patient population compared with nondiabetic control subjects. They also suggest that EBCT may be a useful approach for selecting a group of diabetic subjects who would benefit most from additional evaluation for subclinical coronary artery disease.

Usefulness of spiral computed tomography (dual-slice mode) for the detection of coronary artery calcium in patients with chronic atypical chest pain, in typical angina pectoris, and in asymptomatic subjects with prominent atherosclerotic risk factors

The prevalence and extent of coronary calcium were retrospectively assessed by spiral computed tomography in 541 patients (mean age 62 +/- 9 years), of whom 101 had typical angina pectoris, 307 had atypical chest pain, and 133 were asymptomatic subjects with prominent atherosclerotic risk factors. The highest prevalence of coronary calcium was in men with angina pectoris (89%), whereas it was not detected in 48% of men and 56% of women with atypical chest pain.

Monitoring the effectiveness of preventive interventions using progression of coronary calcification with electron beam tomography.

Angiographic studies have demonstrated that progression of coronary artery disease can be slowed and in some cases regression obtained with appropriate medical therapies. However, coronary angiography is invasive and expensive. Detection of coronary artery calcification, a marker of atherosclerotic disease, with electron beam tomography imaging is achieved non-invasively and at a much lower cost. Therefore, this technology provides an opportunity to serially monitor the clinical effectiveness of medical therapy for coronary artery disease and could be useful for development of new therapies for atherosclerosis.

Effect of CT digital image compression on detection of coronary artery calcification.

To test the effect of digital compression of CT images on the detection of small linear or spotted high attenuation lesions such as coronary artery calcification (CAC). Fifty cases with and 50 without CAC were randomly selected from a population that had undergone spiral CT of the thorax for screening lung cancer. CT image data were compressed using JPEG (Joint Photographic Experts Group) or wavelet algorithms at ratios of 10:1, 20:1 or 40:1. Five radiologists reviewed the uncompressed and compressed images on a cathode-ray-tube. Observer performance was evaluated with receiver operating characteristic analysis. CT images compressed at a ratio as high as 20:1 were acceptable for primary diagnosis of CAC. There was no significant difference in the detection accuracy for CAC between JPEG and wavelet algorithms at the compression ratios up to 20:1. CT images were more vulnerable to image blurring on the wavelet compression at relatively lower ratios, and "blocking" artifacts occurred on the JPEG compression at relatively higher ratios. JPEG and wavelet algorithms allow compression of CT images without compromising their diagnostic value at ratios up to 20:1 in detecting small linear or spotted high attenuation lesions such as CAC, and there was no difference between the two algorithms in diagnostic accuracy.

Noninvasive coronary angiography by contrast-enhanced electron beam computed tomography.

Electron beam computed tomography (EBCT) is a cross-sectional imaging method with high temporal and spatial resolution. So far, it has mainly been applied for the detection of coronary artery calcifications which permit the very sensitive detection of coronary atherosclerosis even in the very early stages. However, after intravenous injection of a contrast agent, EBCT also permits the direct visualization of the coronary artery lumen. For these investigations, a volume data set is acquired that consists of 40 axial cross-sections of the heart (3 mm slice thickness). To evaluate the coronary arteries as to the presence of stenoses and occlusions, various forms of post-processing, including shaded surface display, maximum intensity projection, and multiplanar reconstruction, are applied. The sensitivities and specificities for the detection of coronary artery stenoses and occlusions are about 90%. Best results are obtained for coronary artery bypass grafts, the left main coronary artery, and the left anterior descending coronary artery, while reduced image quality impairs the results for the right coronary artery and the left circumflex coronary artery.

Detection of coronary artery calcium to differentiate patients with early coronary atherosclerosis from luminally normal arteries

In summary, fast CT can non-invasively differentiate patients with early coronary atherosclerosis from those with smooth, luminally normal arteries. The identified patients appear to comprise a higher risk subgroup that might benefit from more aggressive interventions targeted toward the primary prevention of cardiovascular disease.

Calcification of coronary arteries: detection and quantification with double-helix CT.

To evaluate the accuracy of double-helix computed tomography (CT) in coronary artery calcification detection and quantification. One hundred sixty patients with coronary disease (135 men, 25 women; age range, 45-62 years), of whom 138 had obstructive (stenosis of > 50% of diameter; n = 129) or mild (< 50% stenosis; n = 9) coronary artery disease (CAD) and 22 had normal coronary arteries (per angiographic findings), and 56 age-matched healthy control subjects underwent double-helix CT. Double-helix CT findings indicated that calcification was significantly more prevalent in patients with CAD (> 83%) than in patients with normal coronary arteries (27%) or in healthy control subjects (34%; P < .01). Sensitivity in detecting obstructive CAD was high (91%); however, specificity was low (52%) because of calcification in nonobstructive lesions. Comparison of double-helix CT and angiographic findings indicated that double-helix CT was 84% accurate with positive and negative predictive values of 89% and 59%, respectively. Double-helix CT is a useful noninvasive method for detection and quantification of coronary artery calcification.

Usefulness of cinefluoroscopic detection of coronary artery calcification in the diagnostic work-up of coronary artery disease

Aim: To determine in which patients (cine)fluoroscopic detection of coronary artery calcifications is recommended for the diagnosis of coronary artery disease and the consequence of this finding for referral for cinecoronary arteriography. Materials and methods: Data were retrospectively obtained from 778 patients who had been referred for cinecoronary arteriography. Excluded were patients with a previous myocardial infarction, a previous abnormal cinecoronary arteriogram and patients with unstable angina. The discriminating value was assessed with the help of the crude likelihood ratio (LR), as well as the LRs stratified for gender, age and symptomatology. The gold standard was the coronary arteriogram. Furthermore, the post-test probability was estimated using logistic regression to take dependence on age, sex and symptomatology into account. Results: The crude LR of a positive and negative test result, with 95% confidence intervals, was, respectively 5.8 (4.1–8.2) and 0.52 (0.47–0.58), but was dependent on the clinical variables. Estimated probabilities of having coronary artery disease (CAD) varied substantially for a negative as well as a positive test result with the categories of clinical variables. Conclusion: (Cine)fluoroscopy discriminates between patients with and without disease; the test proved to be especially useful in females with atypical angina and patients of both sexes with non-specific chest pain.

Age and Gender Differences in Coronary Calcium

Ultrafast computed tomography (CT) is a new technique highly sensitive for detection of coronary artery calcification, a marker of atherosclerosis. This study retrospectively examined the relation between ultrafast CT-detected coronary calcium and angiographic lumen narrowing at catheterization, and the influence of age and gender on this relationship. Ultrafast CT using an Imatron C-100 scanner and …

Detection of coronary artery calcium by ultrafast computed tomography and its relation to clinical evidence of coronary artery disease

Ultrafast computed tomography (CT) was used to evaluate the relation of coronary artery calcium, a marker of atherosclerosis, with a reported history of coronary artery disease (CAD) in 928 men and 290 women (mean age 53 ± 10 years; 11% with previous CAD). Total calcium score was calculated as the sum of each lesion-specific score, calculated as the product of pixel area and density >130 Hounsfeld units. Total score was 3 to 6 times greater (p < 0.01) and the probability of coronary artery calcium 30 to 40% greater (p < 0.01) in patients with a reported history of myocardial infarction, positive angiography, bypass surgery or angioplasty. From score cutoffs ranging from 1 to 500 for defining calcium, a negative test was accurate 93 to 98% of the time in ruling out CAD, whereas specificity increased from 43 to 93%; however, sensitivity decreased from 92 to 42%. A score cutoff of 50 showed modest sensitivity (78%) and specificity (71%); however, the predictive value for CAD from a positive test remained low (≤40%), regardless of score cutoff. From multiple logistic regression, total score was also an independent indicator of CAD after considering any effects due to age, sex and other CAD risk factors. Further study is needed to document the long-term prognostic use of coronary calcium screening, including criteria that best project future risk of CAD.

Computed Tomography of Normal and Calcified Coronary Arteries

The association between coronary artery calcification (CAC) and coronary artery disease is well established. The objectives of this article are to define the cross-sectional anatomy of the coronary arteries and to demonstrate the prevalence of CAC as seen on routine computed tomography (CT) of the thorax. A CT scan of a cadaver heart was performed in normal anatomic position. Additionally, a retrospective analysis of 103 consecutive thoracic scans was done by three experienced radiologists. The cross-sectional anatomy of the coronary arteries is described based on both these studies, and the prevalence of coronary calcification from the retrospective review was determined. The left anterior descending was the most commonly calcified artery (43% of all patients) followed in order by the left coronary (37%), circumflex (33%), and right coronary (20%). Seventy-nine percent of patients older than age 65 demonstrated coronary calcification on CT. This prevalence approaches that of reported autopsy series. Knowledge and understanding of the cross-sectional anatomy of coronary arteries is essential for detection of coronary artery calcification. We recommend that the presence of CAC should be reported on all thoracic CT scans because coronary calcification may signal unsuspected coronary artery disease.

Coronary artery calcification detected with ultrafast CT as an indication of coronary artery disease.

To assess the relationship of coronary artery calcification to angiographically detectable disease, the authors evaluated 100 patients less than 60 years of age who underwent clinically indicated coronary angiography and ultrafast computed tomography (CT). The ultrafast CT technique consisted of 3-mm-thick contiguous sections and a 100-msec acquisition time. All patients with clinically significant disease at angiography (defined as at least one stenosis with a diameter narrowing of at least 50%) had some coronary artery calcification present at ultrafast CT (100% sensitivity in this population). The absence of calcification at ultrafast CT had a 100% negative predictive value for clinically significant coronary artery disease. Specificity and positive predictive value were 47% and 62%, respectively. Sensitivity and specificity of ultrafast CT in the detection of patients with angiographically detectable disease were 94% and 72%, respectively. Ultrafast CT of the heart is an anatomically based, noninvasive test with high sensitivity for the detection of coronary artery calcification. Ultrafast CT may be beneficial in the screening of selected populations for the presence of atherosclerotic coronary disease.

Fluoroscopic coronary artery calcification and associated coronary disease in asymptomatic young men

Little is known about the diagnostic significance of coronary artery calcification detected fluoroscopically in apparently healthy young men. This study compared the presence of fluoroscopically detected coronary artery calcification with angiographic coronary artery disease in asymptomatic male military aircrew undergoing noninvasive cardiac screening tests and coronary arteriography for occupational indications. Of 1,466 men screened with coronary fluoroscopy, 613 underwent coronary arteriography because of one or more abnormal noninvasive test results. The mean age (±SD) of all subjects screened was 40.2 ± 5 years (range 26 to 65).Significant coronary artery disease (≥50% diameter stenosis) was found in 104 of the 613 subjects with arteriograms (16.9% disease prevalence). Overall sensitivity and specificity for coronary artery calcification detection of significant disease, based only on those subjects undergoing arteriography, were 66.3% and 77.6%, respectively. For measurable disease (mild plus significant), sensitivity was 60.6% and specificity 85.9%. Positive and negative predictive values were 37.7% and 91.9%, respectively, for significant disease. For measurable disease, positive and negative predictive values were 68.9% and 80.9%, respectively.In these asymptomatic young men, a fluoroscopic examination negative for coronary artery calcification indicated a low risk of significant coronary artery disease, whereas a positive test result (calcification present) substantially increased the likelihood of angiographically significant coronary artery disease.

Detection of calcific deposits in coronary arteries by ultrafast computed tomography and correlation with angiography

Calcium, when present in coronary arteries, is located in atherosclerotic plaque. 1–3 The presence of radiographically detectable calcium often correlates with the presence of angiographically significant coronary artery disease, particularly in younger populations. 3 The sensitivity and specificity of coronary artery calcium have been compared with coronary arteriography as the gold standard for definition of coronary artery stenosis. Fluoroscopic radiographic imaging methods have been previously used to detect coronary artery calcium. In addition, conventional computed tomography (CT) has been used to identify it, 4,5 and we have utilized ultrafast CT to detect its presence during routine clinical studies. 6 This study was performed to determine the potential clinical utility of ultrafast computed tomography detection of coronary artery calcium as a noninvasive screening tool for the prediction of angiographically significant coronary artery disease.

Association of coronary calcification with obstructive disease in coronary arteries in Indian patients.

A total of 1150 consecutive patients (1052 males and 98 females; age 51.2 +/- 10.1 years) with suspected coronary artery disease (Group I) were subjected to fluoroscopy for detection of coronary artery calcification (CAC) and coronary angiography. Another group (Group II) of 120 patients (95 males and 25 females; age 51.4 +/- 9.4 years) catheterized for cardiac diseases other than coronary artery disease (CAD) were subjected to the same protocol of fluoroscopy and coronary angiography to exclude incidental CAD in view of their age. CAC was present in 240 patients (20.0%) in Group I. Of these, 200 (83.4%) had triple-vessel disease (TVD); 20 (8.3%) had double-vessel disease (DVD); 19 (7.9%) had single-vessel disease (SVD); and 37 (15.4%) patients had left main coronary disease (LMCAD). Only one of these patients had insignificant CAD considered as "normal" coronary arteries (NC). Incidence of LMCAD, TVD, DVD, SVD, and NC in patients without CAC was 4.4%, 56.3%, 18.2%, 14.0%, and 11.5%, respectively. Incidence of CAC in patients with LMCAD, TVD, DVD, SVD, and NC was 48.1%, 28.1%, 10.8%, 13.0%, and 1.0% respectively. In Group II (n = 120), 24 patients (20%) had CAD, CAC was present in 5 patients with CAD (20.9%), and in two patients without CAD (2%). CAC is relatively uncommon in Indian CAD patients. Its presence, however, indicates severe multivessel disease.

Combined cardiac cinefluoroscopy, exercise testing and ambulatory ST-segment monitoring in the diagnosis of coronary artery disease; a report of 104 symptomatic patients

To enhance diagnostic accuracy in coronary artery disease, cardiac cinefluoroscopy for the detection of coronary artery calcification was combined with exercise test and ambulatory ST-segment monitoring in 104 symptomatic patients before they underwent coronary angiography. In 44 patients with typical angina the combination of the three noninvasive tests and the exercise test alone both detected 92% of subjects with clinically important coronary artery disease. In 60 patients with atypical angina, the combination of the three noninvasive tests screened 77% of the subjects with clinically important coronary artery disease versus 43% after exercise test only ( P < 0.001). The exercise electrocardiogram was false negative in a substantial number of patients with atypical angina due to the presence of a good coronary reserve or to a daily circadian variation in the tone of the coronary arteries. Under these circumstances, cardiac cinefluoroscopy gave additional anatomic information to the physiological assessment of ischemia provided by the exercise test and ambulatory ST-segment monitoring. Our study suggests that the combination of cardiac cinefluoroscopy with other noninvasive tests may be particularly useful in screening atypically symptomatic populations.

Chest Radiography and Cardiac Fluoroscopy in Coronary Artery Disease

Recent studies suggest a new and important role for the chest film and cardiac fluoroscopy in the assessment of coronary artery disease. The detection of coronary artery calcification and the radiographic appearance of myocardial infarction are just two of the topics thoroughly described in this article.

Analysis of multiple noninvasive test procedures for the diagnosis of coronary artery disease.

AbstractAll noninvasive tests used for the diagnosis of coronary artery disease are imperfect, both in sensitivity and in specificity. Accordingly, we evaluated the accuracy of four different diagnostic tests in various combinations in a population of 43 patients undergoing coronary angiography to determine if accuracy could be improved by multiple testing. These tests included stress electrocardiography for evaluation of exercise‐induced ST‐segment depression, stress cardio‐kymography (CKG) for detection of exercise‐induced precordial regional left ventricular dysfunction, stress 201thallium scintigraphy for assessment of exercise‐induced regional myocardial hypoperfusion, and cardiac fluoroscopy for detection of coronary artery calcification. A total of 46 (27%) of the 172 test responses observed were incorrect relative to angiography. These “false” responses were uniformly distributed over the four test procedures (12 ECG, 11 CKG, 10 201thallium, 13 fluoroscopy). Thus, a single test had a limited predictive accuracy for the detection or exclusion of coronary artery disease. The greater the number of abnormal responses observed in a given patient the greater the predictive accuracy for disease, especially multi‐vessel disease. Analysis of various combinations of these procedures revealed substantial differences both in cost of testing and net diagnostic yield. These data suggest that the four procedures employed are functionally independent and highly accurate relative to the diagnosis of coronary artery disease when used in combination. Cost‐effectiveness of diagnostic testing might be improved with the use of combinations of the less expensive and more accurate of these tests.

Application of conditional probability analysis to the clinical diagnosis of coronary artery disease.

Analysis of multiple noninvasive tests offers the promise of more accurate diagnosis of coronary artery disease, but discordant test responses can occur frequently and, when observed, result in diagnostic uncertainty. Accordingly, 43 patients undergoing diagnostic coronary angiography were evaluated by noninvasive testing and the results subjected to analysis using Bayes' theorem of conditional probability. The procedures used included electrocardiographic stress testing for detection of exercise-induced ST segment depression, cardiokymographic stress testing for detection of exercise-induced precordial dyskinesis, myocardial perfusion scintigraphy for detection of exercise-induced relative regional hypoperfusion, and cardiac fluoroscopy for detection of coronary artery calcification. The probability for coronary artery disease was estimated by Bayes' theorem from each patient's age, sex, and symptom classification, and from the observed test responses. This analysis revealed a significant linear correlation between the predicted probability for coronary artery disease and the observed prevalence of angiographic disease over the entire range of probability from 0 to 100% (P less than 0.001 by linear regression). The 12 patients without angiographic disease had a mean posttest likelihood of only 7.0 +/- 2.6% despite the fact that 13 of the 60 historical and test responses were falsely "positive." In contrast, the mean posttest likelihood was 94.1 +/- 2.8% in the 31 patients with angiographic coronary artery disease, although 45 of the 155 historical and test responses were falsely "negative." In 8 of the 12 normal patients, the final posttest likelihood was under 10% and in 26 of the 31 coronary artery disease patients, it was over 90%. These estimates also correlated well with the pooled clinical judgment of five experienced cardiologists (P less than 0.001 by linear regression). The observed change in probability for disease for each of the 15 different test combinations correlated with their information content predicted according to Shannon's theorem (P less than 0.001 by linear regression). These results support the use of probability analysis in the clinical diagnosis of coronary artery disease and provide a formal basis for comparing the relative diagnostic effectiveness and cost-effectiveness of different test combinations.

Noninvasive diagnosis of ischemic cardiomyopathy by fluoroscopic detection of coronary artery calcification

Twenty-four patients with severe congestive heart failure and cardiomegaly in whom the presence or absence of significant coronary disease could not be ascertained clinically underwent fluoroscopy for coronary artery calcification prior to cardiac catheterization. Ten of the patients were found to have significant coronary artery disease, and 14 had normal coronary arteriograms. Coronary artery calcification was found in all ten patients with significant coronary disease, and was absent in all of those patients with normal coronary arteriograms. We conclude that fluoroscopy for coronary artery calcification provides a reliable noninvasive method for differentiating ischemic from nonischemic cardiomyopathy.