The relationship between coronary artery calcification detected by non-gated multi-detector CT in patients with suspected ischemic heart disease and myocardial ischemia detected by thallium exercise stress testing

OBJECTIVE: To examine whether we could predict myocardial ischemia when coronary artery calcification is detected by non-gated multidetector CT in patients with suspected ischemic heart disease. METHODS: Eighty-three patients suspected of having ischemic heart disease (55 men, 28 women; age range 36-83 years; mean age 68 years) underwent multidetector CT and T1-201 single photon emission computed tomography. Prediction of myocardial ischemia by coronary arterial calcification detected on CT was evaluated by comparing the coronary artery territories that showed calcification with the area of myocardial ischemia determined by SPECT. The sensitivity, specificity, positive predictive value, and negative predictive value of multidetector CT for predicting myocardial ischemia were calculated. Coronary angiography was also examined and compared with multidetector CT. Risk factors, including hypertension, smoking, hyperlipidemia, diabetes, and family history, were compared for evidence of coronary artery calcification detected by multidetector CT and myocardial ischemia detected by thallium nuclear scans. RESULTS: For analysis by patients, the sensitivity, specificity, positive predictive value, and negative predictive value of coronary artery calcification for myocardial ischemia detection were 65, 63, 56, and 71%, respectively. Similarly, for analysis by coronary arterial territories, those values were 56, 77, 41 and 86%, respectively. Coronary stenosis on CAG was also related to the ischemia determined by SPECT and calcification on multidetector CT. Ischemia was better influenced by risk factors than was coronary arterial calcification. CONCLUSIONS: For analysis by coronary arterial territories, the specificity and negative predictive value of coronary arterial calcification seen by multidetector CT are relatively high.     

Correlation and predictive value of aortic root calcification markers with coronary artery calcification and obstructive coronary artery disease

Objective

To evaluate the correlation between aortic root calcification (ARC) markers and coronary artery calcification (CAC) derived from coronary artery calcium scoring (CACS) and their ability to predict obstructive coronary artery disease (CAD).

Methods

We retrospectively analyzed 189 patients (47% male, age 60.3 ± 11.1 years) with an intermediate probability of CAD who underwent clinically indicated CACS and coronary CT angiography (CCTA). ARC markers [aortic root calcium score (ARCS) and volume (ARCV)] were calculated and compared to CAC markers: coronary artery calcium score (CACS), volume (CACV), and mass (CACM). CCTA datasets were visually evaluated for significant CAD (stenosis ≥ 50%) and the ability of ARC markers to predict obstructive CAD was assessed.

Results

ARCS (mean 67.7 ± 189.5) and ARCV (mean 67.3 ± 184.7) showed significant differences between patients with and without CAC (109.4 ± 238.6 vs 9.42 ± 31.4, p < 0.0001; 108.5 ± 232.4 vs 9.9 ± 30.5, p < 0.0001). A strong correlation was found for ARCS and ARCV with CACS, CACM, and CACV (all p < 0.0001). In a multivariate analysis, ARCS (OR 1.09, p = 0.033) and ARCV (OR 1.12, p = 0.046) were independent markers for CAC. Using a receiver-operating characteristics analysis, the AUC to detect severe CAC was 0.71 (p < 0.0001) and 0.71 (p < 0.0001) for ARCS and ARCV, respectively. ARCS (0.67, p < 0.0001) and ARCV (0.68, p < 0.0001) showed discriminatory power for predicting obstructive CAD, yielding sensitivities 61 and 78% and specificities of 62 and 80%, respectively.

Conclusion

ARC markers are associated with and independently predict the presence of CAC and obstructive CAD. Further testing is required in patients with severe ARC and significant CAD in order to reliably obtain these markers from thoracic-CT or X-ray for proper risk classification.

     

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.     

Calcium begets calcium: progression of coronary artery calcification in asymptomatic subjects

PURPOSE: To test the hypothesis that the rate of coronary artery calcium progression is sex specific, namely, that it is greater in men than in women, and that it is age related, particularly in women. MATERIALS AND METHODS: This was a retrospective study of the progression of coronary artery calcium in 217 consecutive asymptomatic subjects who underwent at least two electron-beam computed tomographic studies of the heart. Calcium in the distribution of the epicardial arteries was quantified by using both the conventional coronary artery calcium score (CCS) and the calcium volume score (CVS). Linear regression models were used to judge the joint influence of various risk factors, including sex and age, on rates of coronary artery calcium progression. RESULTS: This study included 103 women and 114 men. The mean interval between the subjects' first and last studies was 25 months +/- 11 (SD). Regression analyses clearly demonstrated that the amount of coronary artery calcium present at the initial study was the most important determinant of calcium progression. This was true when coronary artery calcium was quantified by using the conventional CCS (P <.001) or CVS (P <.001). Neither sex nor age was a significant predictor of coronary artery calcium progression. Among traditional risk factors, only hypertension (P =.02) and diabetes (P =.01) were significant independent factors for calcium progression. CONCLUSION: In asymptomatic subjects, the initial CCS and CVS were the most important factors that affected rate of coronary artery calcium progression. Neither age nor sex was as important as these factors in determination of coronary artery calcium progression.     

Relation of coronary vasoreactivity and coronary calcification in asymptomatic subjects with a family history of premature coronary artery disease

Electron-beam computed tomography (EBCT) allows non-invasive imaging of coronary calcification and has been promoted as a screening tool for coronary artery disease (CAD) in asymptomatic high-risk subjects. This study assessed the relation of coronary calcifications to alterations in coronary vascular reactivity by means of positron emission tomography (PET) in asymptomatic subjects with a familial history of premature CAD. Twenty-one subjects (mean age 51±10 years) underwent EBCT imaging for coronary calcifications expressed as the coronary calcium score (CCS according to Agatston) and rest/adenosine-stress nitrogen-13 ammonia PET with quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR). The mean CCS was 237±256 (median 146, range 0–915). The CCS was <100 in eight subjects and >100 units in 13. As defined by age-related thresholds, 15 subjects had an increased CCS (>75th percentile). Overall mean resting and stress MBF and CFR were 71±16 ml 100 g^–1 min^–1, 218±54 ml 100 g^–1 min^–1 and 3.20±0.77, respectively. Three subjects with CCS ranging from 114 to 451 units had an abnormal CFR (<2.5). There was no relation between CCS and resting or stress MBF or CFR (r=0.17, 0.18 and 0.10, respectively). In asymptomatic subjects a pathological CCS was five times more prevalent than an abnormal CFR. The absence of any close relationship between CCS and CFR reflects the fact that quantitative myocardial perfusion imaging with PET characterises the dynamic process of vascular reactivity while EBCT is a measure of more stable calcified lesions in the arterial wall whose presence is closely related to age.     

Relationship between the arterial calcification detected in mammography and coronary artery disease

OBJECTIVE: Arterial calcification is frequently encountered in mammography. The frequency of breast arterial calcification (BAC) increases with increasing age. Studies have shown that BAC is seen more frequently among the people who are under the risk of coronary artery diseases (CAD) such as diabetes and hypertension. The objective of this study is to investigate the relationship between the arterial calcification detected in mammography and the CAD. MATERIAL AND METHODS: Screening mammography was performed in 123 women above the age of 40 years who had been examined with coronary angiography for the evaluation of CAD. The presence of BAC, number of affected vessels, and the distribution of calcification in the vessel wall were evaluated in the mammography. Subjects were questioned in terms of the cardiovasculary risk factors. The severity of CAD was evaluated according to the Gensini scoring. In addition, the number of blood vessels with stenosis of more than 50% was used as the vascular score. The correlation between Gensini and the vascular scores, and BAC was statistically evaluated using Mann-Whitney U and Kruskal-Wallis tests. RESULTS: Eighty (65%) of 123 patients had CAD. BAC was detected in the mammography of 49 (39.8%) subjects. The ages and duration of menopause of the cases with BAC were significantly higher than those without BAC (p<0.001). There was an almost significant correlation between the BAC and Gensini scores (p=0.059). There was a significant increase in the frequency of BAC among subjects with more than two vessels with stenosis (p=0.033). CONCLUSION: Frequency of BAC increases with increasing age. BAC is also frequently seen in subjects having severe coronary artery disease. Although increasing age may be a factor increasing the frequency of BAC, BAC may also be an indicator of CAD. Therefore, the mentioning of arterial calcification in mammography reports may be important in warning the clinician in terms of CAD.     

Increased intrathoracic and hepatic visceral adipose tissue independently correlates with coronary artery calcification in asymptomatic patients

Background

Visceral adipose tissue (VAT) is associated with cardiac events, but it is not clear which, if any of the various measures of VAT independently correlate with coronary artery disease (CAD).

Methods

We studied 400 patients undergoing computed tomography to determine coronary artery calcium (CAC) score. VAT was measured in the form of epicardial adipose tissue (EAT) volume and thickness, intrathoracic adipose tissue volume (ITAV), and hepatic steatosis.

Results

Of the 400 subjects, the average CAC score was 112.2 ± 389.3. When each measure of VAT (EAT volume and thickness, ITAV, hepatic steatosis) was added to the traditional model (they were independently associated with greater risk of CAC score ≥100 AU as measured by IDI/NRI (P < .05). On univariable logistic regression analysis, each of the 4 measures of VAT showed association with greater risk of a CAC score of ≥100 AU (OR > 1).

Conclusions

Each measure of VAT is a strong correlate of CAC score ≥100 AU in asymptomatic subjects—these VAT assessments correlate more significantly than do traditional CAD risk factors. This incremental power in the predictive models is likely the result of measurement of a fundamental expression of the metabolic syndrome and consequent proatherogenic derangements.     

Nuclear exercise testing and the management of coronary artery disease

Three hundred seventy-eight patients referred for nuclear exercise testing were classified using demographics and symptoms into low, intermediate, and high coronary disease likelihood categories. These likelihood groups constituted 15%, 41%, and 15% of referrals, respectively. Patients with prior infarction or disease at angiography (proven disease) made up the remaining 29% of patients. Only 2% of low likelihood patients had typical angina, but physicians diagnosed coronary disease in 64%, prescribed antianginal therapy in 50%, and were considering catheterization in 28% of these patients, all as frequently as for patients with intermediate or high likelihoods for disease. Patients with proven disease were treated differently in that 79% were receiving antianginal therapy and 56% were considered for catheterization (p less than 0.001). Nuclear exercise test results reduced the perceived need for catheterization in all groups, on average by 49%. Nuclear exercise tests are a standard by which patients are managed, sometimes substituting for the traditional role of the history in physician decision making.     

Beta-blockers, exercise, and the immune system in men with coronary artery disease

PURPOSE: The purpose of the present study was to examine the effect of aerobic exercise training on the immune system in coronary artery disease patients treated with beta-blockers. METHODS: Twenty-five patients (46.1 +/- 2 yr) treated with atenolol, a beta-blocker agent, for 3 months before exercising were divided randomly into two groups: 15 underwent an aerobic exercise training program for 12 wk at 65-70% of their work capacity, whereas the other 10 patients served as controls. RESULTS: After training, levels of CD4 and CD8 cells were significantly (P < 0.05) higher and concomitantly the CD4/CD8 ratio decreased significantly (P < 0.05) in the exercising group compared with the control group. CONCLUSIONS: Data suggest that coronary artery disease patients exercising aerobically at 65-70% of their work capacity gain a statistically significant higher lymphocyte T cell function as compared with their untrained counterparts.     

国人冠状动脉钙化的电子束CT检测结果及其临床意义

目的了解电子束ＣＴ（ＥＢＣＴ）检测冠状动脉钙化（ＣＡＣ）在国人中的状况；探讨其在临床冠心病诊断和预测中的价值和限度。材料与方法对经ＩｍａｔｒｏｎＣ－１５０型ＥＢＣＴ机检测ＣＡＣ的７１８例受检者进行研究。分析ＣＡＣ率和积分与年龄、性别及临床冠心病发病的关系，评价其对临床冠心病的诊断和预测价值。结果本研究中男性组的ＣＡＣ率为６５．３％，显著高于女性组（４５．５％，Ｐ＜０．００１）；男、女组ＣＡＣ率和积分均随年龄增加而显著增高（Ｐ＜０．００１）；冠心病组ＣＡＣ率与国外报道相仿，而ＣＡＣ积分却明显低于西方人；非冠心病组的ＣＡＣ率、积分均明显低于文献报道（３０～３９岁年龄段除外）；各年龄段冠心病组的ＣＡＣ率和积分均显著高于非冠心病组（Ｐ＜０．０５）。结论ＥＢＣＴ测定的国人ＣＡＣ与文献报道的西方人有一定差别；无ＣＡＣ或其积分较高对冠心病发病危险性预测的价值较大，有ＣＡＣ，但其积分较低时，对冠心病的诊断和预测应结合临床确定。     

Relationships between coronary calcification detected at electron beam computed tomography and percutaneous transluminal coronary angioplasty results in coronary artery disease patients

Our objective was to assess the relationship between coronary artery calcification and outcomes of percutaneous transluminal coronary angioplasty (PTCA). Electron beam computed tomography (EBCT) was performed in 80 patients with coronary artery disease (CAD) who underwent PTCA. The calcium score in each coronary artery vessel was estimated (in Agatston units) and compared with the occurrence of complications and restenosis. Angioplasty had been performed in 96 coronary artery segments with stenosis in 80 patients. The average calcium score in the unsuccessful PTCA segments was significantly higher than in ones with successful results. For complications these values were 65.0±79.9 and 27.0±44.7, respectively (p=0.02), and for restenosis 63.9±87.9 and 27.3±41.3, respectively (p=0.03). Applying receiver operating characteristics analysis we determined sensitivity and specificity of EBCT for forecasting complications and restenosis. The best cut-off value of calcium score in segment of PTCA for prediction of restenosis was 27 (sensitivity 73%, specificity 67%), and for prediction of complications 29 (sensitivity 80%, specificity 74%). Coronary segments with extensive calcification were not optimal target lesions for PTCA. Analysis of coronary calcium score should be taken into consideration during planning of endovascular coronary interventions. Electronic Publication     

Technetium 99m-labeled tetrofosmin myocardial tomography in patients with coronary artery disease: Comparison between adenosine and dynamic exercise stress testing

Background

Pharmacologic coronary vasodilation with adenosine, combined with myocardial scintigraphy, is a useful test for the diagnosis of coronary artery disease (CAD) in patients unable to exercise. It has been demonstrated recently that exercise ^99mTc-labeled tetrofosmin cardiac imaging can be used for the detection of CAD. However, no data are available comparing ^99mTc-labeled tetrofosmin adenosine and exercise tests in the same patients.

Methods and Results

The results of adenosine and exercise ^99mTc-labeled tetrofosmin myocardial tomography were compared in 41 patients (37 men and four women; mean age 53±8 years) with suspected or known CAD who underwent coronary angiography. All patients were submitted, on separate days, to three injections of ^99mTc-labeled tetrofosmin (740 MBq intravenously): one at rest, one during bicycle exercise, and one during adenosine infusion (140 μg/kg/min for 6 minutes with injection of ^99mTc-labeled tetrofosmin at 4 minutes). A total of 902 myocardial segments were analyzed quantitatively. One patient had normal coronary vessels, 19 patients had single-vessel CAD, 12 patients had two-vessel CAD, and nine patients had three-vessel CAD (>50% coronary stenosis) on coronary angiography. Adenosine induced a significant increase in heart rate (88±16 beats/min at peak vs 72±11 beats/min at rest; p<0.01). Systolic and diastolic blood pressure was not significantly different after adenosine infusion compared with rest. Double product was 22931 ± 7039 at peak exercise and 11229±3413 after adenosine (p<0.01). Agreement on the presence of abnormal single-photon emission computed tomography by adenosine and exercise was 100% by quantitative analysis. In all segments a significant relationship between exercise and adenosine ^99mTc-99m-labeled tetrofosmin uptake was observed (r=0.90; p<0.001). Segmental agreement for regional ^99mTc-labeled tetrofosmin uptake score between exercise and adenosine was observed in 737 (82%) of the 902 segments (kappa value of 0.66). Concordance between the two studies for identification of perfusion status was observed in 809 (90%) of the segments (kappa value of 0.80). Sensitivity and specificity for detection of stenosed vessels were not different for dynamic exercise stress testing and adenosine ^99mTc-labeled tetrofosmin cardiac tomography.

Conclusions

Despite different hemodynamic effects, adenosine and dynamic exercise ^99mTc-labeled tetrofosmin single-photon emission computed tomographic imaging provides similar information in the diagnosis and localization of CAD.     

Effect of exercise position during stress testing on cardiac and pulmonary thallium kinetics and accuracy in evaluating coronary artery disease

We compared the effects of symptom-limited upright and supine exercise on 201Tl distribution and kinetics in the heart and lungs of 100 consecutive patients. Our analysis was based on data obtained with a digital gamma camera in the 45 degrees left anterior oblique position at 5, 40, 240, and 275 min postadministration of [201Tl]chloride. We found significant differences in the results at the 5- and 40-min intervals; viz, higher cardiac and lower pulmonary thallium activity after upright exercise in 94 subjects at both intervals, and greater variability in total and regional cardiac thallium kinetics after supine exercise. With supine exercise, the relatively low initial cardiac activity, relatively high lung activity, and the greater variability in thallium kinetics combined to make interpretation of quantitative data and cardiac images difficult and less accurate with respect to detection of coronary artery disease. These observations have important implications for the interpreting physician when thallium stress tests are performed in the supine position.     

Influence of coronary dominance on coronary artery calcification burden

ObjectiveTo evaluate the influence of coronary artery dominance on observed coronary artery calcification burden in outpatients presenting for coronary computed tomography angiography (CCTA).MethodsA 12-month retrospective review was performed of all CCTAs at a single institution. Coronary arterial dominance, Agatston score and presence or absence of cardiovascular risk factors including hypertension (HTN), hyperlipidemia (HLD), diabetes and smoking were recorded. Dominance groups were compared in terms of calcium score adjusted for covariates using analysis of covariance based on ranks. Only covariates observed to be significant independent predictors of the relevant outcome were included in each analysis. All statistical tests were conducted at the two-sided 5% significance level.Results1223 individuals, 618 women and 605 men were included, mean age 60 years (24–93 years). Right coronary dominance was observed in 91.7% (n = 1109), left dominance in 8% (n = 98), and codominance in 1.3% (n = 16). The distribution of patients among Agatston score severity categories significantly differed between codominant and left (p = 0.008), and codominant and right (p = 0.022) groups, with higher prevalence of either zero or severe CAC in the codominant patients. There was no significant difference in Agatston score between dominance groups. In the subset of individuals with coronary artery calcification, Agatston score was significantly higher in codominant versus left dominant patients (mean Agatston score 595 ± 520 vs. mean 289 ± 607, respectively; p = 0.049), with a trend towards higher scores in comparison to the right-dominant group (p = 0.093). Significance was not maintained upon adjustment for covariates.ConclusionsWhile the distribution of Agatston score severity categories differed in codominant versus right- or left-dominant patients, there was no significant difference in Agatston score based on coronary dominance pattern in our cohort. Reporting and inclusion of codominant subsets in larger investigations may elucidate whether codominant anatomy is associated with differing risk.     

CT-based abdominal aortic calcification score as a surrogate marker for predicting the presence of asymptomatic coronary artery disease

Objectives

To assess the value of a CT-based abdominal aortic calcification (AAC) score as a surrogate marker for the presence of asymptomatic coronary artery disease (CAD).

Methods

The AAC scores of 373 patients without cardiac symptoms who underwent both screening coronary CT angiography and abdominal CT within one year were calculated according to the Agatston method. Logistic regression was used to derive two multivariate models from traditional cardiovascular risk factors, with and without AAC scores, to predict the presence of CAD. The AAC score and the two multivariate models were compared by calculating the area under the receiver operating characteristic curve (AUC) and the net reclassification improvement (NRI).

Results

The AAC score alone showed a marginally higher AUC (0.823 vs. 0.767, P?=?0.061) and significantly better risk classification (NRI?=?0.158, P?=?0.048) than the multivariate model without AAC. The multivariate model using traditional factors and AAC did not show a significantly higher AUC (0.832 vs. 0.823, P?=?0.616) or NRI (0.073, P?=?0.13) than the AAC score alone. The optimal cutoff value of the AAC score for predicting CAD was 1025.8 (sensitivity, 79.5 %; specificity, 75.9 %).

Conclusions

AAC scores may serve as a surrogate marker for the presence or absence of asymptomatic CAD.

Key Points

? Severe vascular calcification indicates a high probability of coronary artery disease. ? Vascular calcification in the abdominal aorta can be quantified by computed tomography. ? Abdominal CT could lead to early detection of asymptomatic coronary artery disease.     

Increased prevalence of coronary artery calcification in patients with suspected pulmonary embolism

RATIONALE AND OBJECTIVES: The authors explored the possibility that patients with suspected pulmonary embolism are at high risk for coronary artery disease. To this purpose, they compared the presence of coronary artery calcification on computed tomography (CT) in patients suspected of pulmonary embolism with age- and gender-matched controls. MATERIALS AND METHODS: The CT scans of 214 patients were reviewed. Of those, 107 consecutive patients (50%) had pulmonary CT angiography for suspected pulmonary embolism (PE group). The remaining 107 age- and gender-matched patients were scanned for reasons other than pulmonary embolism (non-PE group). All CT scans were performed with the same 8-detector-row multislice scanner. Two radiologists reviewed scans of 5-mm slices using a five-grade modified coronary calcium scoring system: 1 = no calcification; 2 = minimal calcification; 3 = mild calcification; 4 = moderate calcification; and 5 = severe calcification. The Marginal Homogeneity test was used to compare the distribution and severity of calcification in the two groups. RESULTS: Of 107 patients in the PE group, seven (6.54%) had pulmonary embolism detected on CT. Coronary artery calcification was detected in 61 patients (57%) in the PE group compared with 42 patients (39%) in the non-PE group. The Marginal Homogeneity test showed that patients with pulmonary embolism symptoms were 2.9 times more likely to have calcification detected compared with those patients who had chest CT for some other reason (P = .0034). However, in patients in whom coronary artery calcification was detected, the distribution of severity of calcification was the same in both groups. CONCLUSION: Assuming coronary artery calcification indicated coronary atherosclerosis, patients undergoing CT for suspected pulmonary embolism may be at high risk for coronary artery disease.