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Cardiac

Coronary Artery Evaluation With Calcium Scoring

  • “ While mere numeric values might be different, commercially available software platforms produce comparable CAC scoring results, which suggests a vendor-independence of the method; however, none of the analyzed software platforms appears to provide a distinct advantage for risk stratification, as the variability of CAC scores depending on the reconstruction interval persists across platforms.”
    Interplatform Reproducibility of CT Coronary Calcium Scoring Software
    Weininger M et al.
    Radiology 2012;265:70-77
  • “ Vendor independent reproducibiity of coronary artery calcium scores is a prerequisite for reliable comparison of results and has direct impact on cardiovascular risk stratification, risk modification, and therapeutic monitoring.”
    Interplatform Reproducibility of CT Coronary Calcium Scoring Software
    Weininger M et al.
    Radiology 2012;265:70-77
  • “ Within our population, Spearman rank correlation between the workstations was highest at 60% of the R-R interval, which supports the clinical use of this time point during the cardiac cycle for image reconstruction at CT CAC scoring.”
    Interplatform Reproducibility of CT Coronary Calcium Scoring Software
    Weininger M et al.
    Radiology 2012;265:70-77
  • Workstation Platforms Used in Comparison
    - Syngo Calcium Scoring ( Siemens Healthcare)
    - Aquarius (TeraRecon Inc)
    - Vitrea (Vital Images)
  • “ Budoff et al, in the Multi-Ethnic study of Atherosclerosis (MESA), has shown that even minimal CAC (Agaston scores of 1-10) increased the risk of CHD 3-fold and a score >100 confers a 10-fold risk of future cardiovascular events.”
    Risk stratification of non-contrast CT beyond the coronary calcium scan
    Madaj P, Budoff MJ
    J Cardiovasc Comput Tomogr (2012) 6, 301-307
  • “ The investigators concluded that patients with frequent lesions in the left main or patients with a higher number of calcified lesions have a significantly higher risk of mortality. The clincal implications are simple,clinicians can also report lesion counts in addition to total Agaston score, noting that larger number of lesions imparts a higher clinical significance.”
    Risk stratification of non-contrast CT beyond the coronary calcium scan
    Madaj P, Budoff MJ
    J Cardiovasc Comput Tomogr (2012) 6, 301-307

  • “ Coronary artery calcium (CAC) is an independent predictor of coronary artery disease (CAD) events and improves the ability to predict risk in vulnerable groups, adding information beyond current global risk assessment methods.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ A zero coronary calcium score stands as perhaps the most powerful negative risk factor for development of a coronary event.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ Emerging data suggest there are individuals considered to be in the low risk group who may benefit from CAC screening, especially those with a family history of premature CAD and woman younger than 60 years: further studies are needed for both groups.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ CAC testing has value in triaging low and intermediate risk patients with chest pain, a role acknowledged by current guidelines as it is associated with a very low risk of future cardiac events and thus the potential to reduce downstream testing and costs.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ It is estimated that in the next 15 years, 25 million people will die of stroke or heart disease with 80% of this burden occurring in developing countries. In approximately one-half of the individuals, the initial presentation of CAD is either myocardial infarction or sudden death.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ Unfortunately conventional risk factor assessment can be used to predict 65-80% of future cardiovascular events, leaving many middle aged and older individuals to experience a major cardiovascular event despite being classified as low risk by means of traditional approaches.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ These data reinforce our assessment than when CAC is used as a gatekeeper for downstream advanced testing in symptomatic individuals, pretest likelihood of CAD should always be taken into account. Absence of CAC has great potential in reducing downstream cost if used in low to intermediate risk asymptomatic individuals.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ The National Institute for Health and Clinical Excellence clinical guidelines have also acknowledged the role of CAC in layered testing among patients presenting with chest pain.”
    Role of Nonenhanced Multidetector CT Coronary Artery Calcium Testing in Asymptomatic and Symptomatic Individuals
    Nasir K, Clouse M
    Radiology 2012; 264:637-649
  • “ The acquisition of a coronary calcium score in every symptomatic patient referred for coronary CT angiography requires a case by case approach.”
    Coronary Calcium Scan Acquisition Before Coronary CT Angiography: Limited Benefit or Useful Addition
    Torres FS et al.
    AJR 2013; 200:66-73
  • “ Coronary artery calcium (CAC) score may be used as a gatekeeper for coronary CT angiography (CTA) when CAC score is very high, although there is no established upper limit of the total CAC score that could be used as a threshold above which coronary CTA should not be performed.”
    CT Perfusion in Oncologic Imaging: A Useful Tool-
    Garcia-Figueiras R et al
    AJR 2013; 200:8-19
  • “ The absence of coronary calcification is associated with a low prevalance of obstructive coronary artery disease (CAD) and with a very good near term prognosis in symptomatic patients, with a low to intermediate pretest probability of CAD. In these patients additional information (symptoms, clinical risk factors, and results of prior tests) should be entertained when considering deferring the coronary CTA on the basis of a CAC score of zero.”
    CT Perfusion in Oncologic Imaging: A Useful Tool-
    Garcia-Figueiras R et al
    AJR 2013; 200:8-19
  • “ Radiation dose from a CAC score and coronary CTA may vary widely. Newer scanner technologies and the use of radiation dose reduction strategies have helped to significantly decrease the radiation dose in both tests. If CAC score is to be acquired, much attention should be put to minimize radiation exposure and to plan the scanning range of the coronary CTA on the basis of coronary calcium score images.”
    CT Perfusion in Oncologic Imaging: A Useful Tool-
    Garcia-Figueiras R et al
    AJR 2013; 200:8-19

  • "Absolute CAC is superior to percentile rank calculated based on the MESA database in the prediction of obstructive CAD. Therefore, while for risk stratification purposes percentile rank remains an important predictor, for the purposes of predicting obstructive CAD and for further diagnostic referral, the absolute CAC might be preferred."

    Absolute Coronary Artery Calcium Scores are superior to MESA percentile rank in predicting obstructive coronary artery disease
    Akram K, Voros S
    Int J Cardiovasc Imaging (2008) 24:743-749

  • " The coronary artery calcium (CAC) score above which it is recommended that coronary computerized tomographic angiography (CTA) not be performed has been steadily increasing. Currently, calcium scores > 1000 are thought to prohibit CTA accurate interpretation. However, a reasoned approach suggests that there is no absolute upper limit that applies to all patients and imaging centers."

    How much calcium is too much calcium for coronary computerized tomographic angiography?
    Hecht HS, Bhatti T
    J Cardiovasc Comput Tomogr (2008) 2, 183-187
  • " A CAC score of >1000 or a pattern of isolated large, dense calcifications with CAC < 1000 should alert personnel to potential interpretation problems and should not be followed by CTA if the interpreting physician does not have extensive experience in dealing with these issues.

    How much calcium is too much calcium for coronary computerized tomographic angiography?
    Hecht HS, Bhatti T
    J Cardiovasc Comput Tomogr (2008) 2, 183-187
  • " CCS (calcium coverage score) may enable better stratification of patients according to risk compared with the Agaston or mass score and thereby aid physicians in determining appropriate individual treatment strategies."

    Coronary Calcium Coverage Score: Determination, Correlates, and Predictive Accuracy in the Multiethnic Study of Atherosclerosis
    Brown ER et al.
    Radiology 2008; 247:669-678
  • " The calcium coverage score (CCS) was highly associated with coronary heart disease (CHD) events, and a twofold increase in CCS was associated with a 34% increase in the risk of any hard CHD event and a 52% increase in the risk of any CHD event."

    Coronary Calcium Coverage Score: Determination, Correlates, and Predictive Accuracy in the Multiethnic Study of Atherosclerosis
    Brown ER et al.
    Radiology 2008; 247:669-678
  • "Retten et al. have demonstrated that an important factor affecting measurement variability is the partial volume effect that operates when contiguous, rather than overlapping, scans are reconstructed. The practical implication of this error might be a false negative study or inaccurate categorization of the severity of patient risk."

    Science to Practice: What is the Value of measuring Coronary Artery Calcification?
    Wexler L
    Radiology 246:1, Jan 2008;1-2
  • "These large observational cohorts show that the absence of coronary artery calcification by Cardiac CT is associated with a low adverse risk and therefore could be used as a tool to counsel patients about the risk of such events."

    Prognostic Significance of Zero Coronary Calcium Scores on Cardiac Computed Tomography
    Shareghi S et al.
    J Cardiovasc Comput Tomogr (2007)1, 155-159
  • "Summary data show that in a total follow-up of 35,765 asymptomatic patients, 16,106 (45%) had scores of zero. Pooled sensitivity for CAC to detect a cardiovascular event was 98.1%, and negative predictive value was 99.9%."

    Prognostic Significance of Zero Coronary Calcium Scores on Cardiac Computed Tomography
    Shareghi S et al.
    J Cardiovasc Comput Tomogr (2007)1, 155-159
  • "In conclusion, asymptomatic persons without CAC (scores of zero) are shown to have a very low risk (0.27% per year) of future cardiovascular events during the subsequent 3-5 years and is a group unlikely to derive short term benefit from risk reducing pharmacotherapy."

    Prognostic Significance of Zero Coronary Calcium Scores on Cardiac Computed Tomography
    Shareghi S et al.
    J Cardiovasc Comput Tomogr (2007)1, 155-159
  • "Aortic calcification scores at CT colonography are significantly associated with established cardiac-related events. This screening information can be obtained without additional scanning or risk to the patient."

    Assessment of Cardiovascular Risk Status at CT Colonography
    Davila JA et al.
    Radiology 2006; 240:110-115.
  • " CT angiography was performed in 67 patients (50 male, 17 female; mean age 60.1 +/- 10.5 years) with suspected coronary artery disease and compared with invasive coronary angiography. All vessels >/=1.5 mm were considered for the assessment of significant coronary artery stenosis (diameter reduction >50%). Forty-seven patients were identified as having significant coronary stenoses on invasive angiography with 18% (176/1005) affected segments. None of the coronary segments needed to be excluded from analysis. CT correctly identified all 20 patients having no significant stenosis on invasive angiography. Overall sensitivity for classifying stenoses was 94%, specificity was 97%, positive predictive value was 87%, and negative predictive value was 99%."
  • Material and Methods: Overall sensitivity for classifying stenoses was 94%, specificity was 97%, positive predictive value was 87%, and negative predictive value was 99%."

    Conclusion: Sixty-four-slice CT provides a high diagnostic accuracy in assessing coronary artery stenoses.

    Accuracy of MSCT coronary angiography with 64-slice technology: first experience.
    Leschka S et al. Eur Heart J. 2005 Apr 19; [Epub ahead of print
  • " The currently best available spatial and temporal resolution for retrospectively ECG gated coronary multi-detector-row CT angiography is 0.4 mm and 165 ms, respectively. These acquisition parameters are already rather close to cardiac catheter. Studies so far compared non-invasive coronary CT and convention angiography for the detection of coronary artery stenoses. The most promising result reported by all authors was the high negative predictive value of the CTA."

    Coronary CT angiography in symptomatic patients
    Becker CR.
    Eur Radiol. 2005 Feb;15 Suppl 2:B33-41
  • "The most promising result reported by all authors was the high negative predictive value of the CTA."

    Coronary CT angiography in symptomatic patients
    Becker CR.
    Eur Radiol. 2005 Feb;15 Suppl 2:B33-41
  • " CT Angiography is more accurate than calcium scoring in demonstrating coronary artery stenosis. A patient calcium score of greater than or equal to 400, however, can be used to potentially identify patients with significant coronary stenoses not detected at CT angiography."

    Coronary Artery Stenosis: Detection with Calcium Scoring, CT Angiography, and Both Methods Combined
    Lau GT et al.
    Radiology 2005; 235:415-422
  • " Combining CT angiography with Calcium Scoring (over 400) improved the sensitivity of CT angiography (from 93 to s100%) in demonstrating significant coronary disease in patients."

    Coronary Artery Stenosis: Detection with Calcium Scoring, CT Angiography, and Both Methods Combined
    Lau GT et al.
    Radiology 2005; 235:415-422
  • "In a population having a low pretest likelihood of significant coronary artery disease, 16-MDCT shows a moderate to high sensitivity and a high NPV for the detection or exclusion of significant disease, but has a somewhat reduced PPV compared with conventional coronary angiography."

    Clinical Value of MDCT in the Diagnosis of Coronary Artery Disease in Patients with a Low Pretest Likelihood of Significant Disease
    Nikolaou K et al.
    AJR 2006;186:1659-1668.
  • "Although 16-MDCT appeared to overestimate diagnoses as compared with QCA, resulting in a relatively high number of false-positive diagnosis of significant coronary artery disease, this may have been a consequence either of the relatively small patient population or of false negative diagnosis on QCA."

    Clinical Value of MDCT in the Diagnosis of Coronary Artery Disease in Patients with a Low Pretest Likelihood of Significant Disease
    Nikolaou K et al.
    AJR 2006;186:1659-1668.
  • "CTA has the potential to perform cross-sectional imaging through the narrowed portion of the lumen and to measure the area of the vessel lumen versus the area of an adjacent,apparently normal segment, which are not possible using QCA."

    Clinical Value of MDCT in the Diagnosis of Coronary Artery Disease in Patients with a Low Pretest Likelihood of Significant Disease
    Nikolaou K et al.
    AJR 2006;186:1659-1668.
  • Opinion

    - False positive coronary CTA is less of a practical issue that false negative coronary CTA. The lack of false negative is especially critical
  • "Sensitivity, specificity, and the negative predictive value (NPV) of 64-MDCT per patient were 97%, 79%, and 96%, respectively. Per segment, 923 of 1,020 coronary artery segments were assessable (90%). For the detection of stenoses of more than 50% and more than 75% per segment, 64-MDCT showed a sensitivity of 82% and 86%, respectively. Per segment, specificity and NPV were as high as 95% and 97%, respectively."

    Accuracy of 64-MDCT in the diagnosis of ischemic heart disease
    Nikolaou K et al
    AJR 2006 July; 187(1):111-117.
  • "Significant stenosis was defined as a diameter reduction of > 50%. Of 966 segments, 884 (92%) were assessable. Compared with ICAG, the sensitivity of CTA to diagnose significant stenosis was 90%, specificity 94%, positive predictive value (PPV) 89% and negative predictive value (NPV) 95%."

    Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population: comparison with conventional invasive angiography.
    Ehara M et al.
    Circ J 2006 May; 70(5):564-571.
  • "On 64-MDCT, 89% of coronary artery segments are assessible. Ten or more vessel segments are assessable in 94% of patients."

    Coronary CT Angiography with 64-MDCT: Assessment of Vessel Visibility
    Pannu HK,Jacobs JE,Lai S,Fishman EK
    AJR 2006; 187:119-128.
  • "In clinical routine, coronary CTA will primarily be used for risk stratification on a per patient basis. In the present study, coronary 64-MDCT showed a high diagnostic accuracy on both per patient and per segment analyses."

    Accuracy of 64-MDCT in the Diagnosis of Ischemic Heart Disease
    Nikolaou K et al.
    AJR 2006; 187:111-117.
  • "In conclusion, 64 MDCT coronary angiography provides a significantly increased spatial and temporal resolution compared with earlier MDCT systems. In a clinical setting, this technique may hold great promise for the reliable diagnosis or exclusion of significant CAD on a per patient basis and could give CTA an important role in the stratification of patients with both known and suspected CAD."

    Accuracy of 64-MDCT in the Diagnosis of Ischemic Heart Disease
    Nikolaou K et al.
    AJR 2006; 187:111-117.
  • "68 of 72 coronary CT angiograms (94%) were of diagnostic image quality. QCA showed significant CAD (i.e. one or more stenosis in >50%) in 57% (39/68) and nonsignificant disease or healthy CTA’s in 43% (29/68) of the patients. Sensitivity, specificity and the negative predictive value of 64 MDCT per patient were 97%, 79%, and 96% respectively."

    Accuracy of 64-MDCT in the Diagnosis of Ischemic Heart Disease
    Nikolaou K et al.
    AJR 2006; 187:111-117.
  • Plaque Attenuation Scoring

    - Predominantly lipid rich plaques; < 60HU
    - Intermediate plaques: 61-119 HU
    - Predominately calcified plaques: >120 HU
    - Reliability of Differentiating Human Coronary Plaque Morphology Using
    - Contrast Enhanced Multislice Spiral Computed Tomography
    Schroeder S et al.
    J Comput Assist Tomogr 2004;28:449-454
  • " The finding may have implications for the interpretation of calcification of atherosclerotic plaque in other vascular beds."

    Calcified Carotid Atherosclerotic Plaque Is Associated Less with Ischemic Symptoms Than Is Noncalcified Plaque on MIDST
    Nandalur KR et al.
    AJR 2005;184;295-298
  • " Image attenuation values vary by scanner and participant body size, producing calcium score differences that are not due to true calcium burden disparities. Use of calibration phantoms may improve the comparability of such measurements between persons scanned with different scanners and within persons over time."

    Measuring Coronary Calcium on CT images Adjusted for Attenuation Differences
    Nelson JC et al.
    Radiology 2005;235:404-414
  • " Micro CT provides quantitative information about plaque morphology equivalent to that provided with histomorphometric analysis. Micro CT is feasible for analysis of the coronary artery wall."

    Atherosclerotic Lesions at Micro CT: Feasibility for Analysis of Coronary Artery Wall in Autopsy Specimens
    Langheinrich AC et al.
    Radiology 2004; 231:675-681
  • " The absence of detectable calcium does not reliably exclude substantial coronary disease."

    Coronary Artery Stenosis: Detection with Calcium Scoring, CT Angiography, and Both Methods Combined
    Lau GT et al.
    Radiology 2005; 235:415-422
  • " The accuracy of sequential MDCT for coronary calcium quantification is sufficient in most cases for stratification of patient risk."

    Potential Clinical Impact of Variability in the Measurement of Coronary Artery Calcification with Sequential MDCT
    Halliburton SS et al.
    AJR 2005; 184:643-648
  • "Differences in coronary artery calcium measurements using EBT and MDCT are similar to interscan differences in CAC measurements previously reported for EBT or for other MDCT scanners individually."

    Concordance of Coronary Artery Calcium Estimates Between MDCT and Electron Beam Tomography Daniell AL et al. AJR 2005; 185:1542-1545
  • "Electron beam and multidetector row CT scanners have equivalent reproducibility for measuring coronary artery calcium. Calcium volumes and interpolated volume scores are slightly more reproducible than Agatston scores."

    Coronary Calcium Measurements: effect of CT Scanner Type and Calcium Measure on Rescan reproducibility-MESA Study Detrano RC et al. Radiology 2005; 236:477-484
  • "MDCT is a promising tool for coronary calcium scoring; however, more studies are needed comparing EBCT and MDCT, especially at lower coronary artery calcium levels."

    Electron beam CT versus helical CT scans for assessing coronary calcifications: Current utility and future directions
    Nasir K, Budoff M, Post WS, Fishman EK, Mahesh M, Lima JA, Blumenthal RS
    Am Heart J 2003; 146:969-977.
  • "For a true exclusion of coronary artery calcifications, different reconstruction intervals have to be evaluated."

    Different Reconstruction Intervals for Exclusion of Coronary Artery Calcifications by Retrospectively Gated MDCT
    Sandstede JJW et al.
    AJR 2006; 186:193-197(4 slice MDCT).
  • "Whereas in the present study 69-77% of patients with a low pretest probability for the presence of CAD had a calcium score of 0 at one reconstruction interval at least, in only 42% of the patients could coronary artery calcification be excluded after evaluation of all reconstructions at 50%,60%,70%, and 80% of the R-R interval."

    Different Reconstruction Intervals for Exclusion of Coronary Artery Calcifications by Retrospectively Gated MDCT
    Sandstede JJW et al.
    AJR 2006; 186:193-197(4 slice MDCT).
  • "Electron-beam and multi-detector row CT scanners have equivalent reproducibility for measuring coronary artery calcium. Calcium volumes and interpolated volume scores are slightly more reproducible than Agaston scores. Reproducibility is lower for scans with misregistrations or motion artifacts."

    Coronary Calcium measurements: Effect of CT Scanner Type and Calcium Measure on Rescan Reproducibility-MESA Study
    Detrano RC et al.
    Radiology 2005; 236:477-484.
  • Factoid

    - A zero coronary calcification score is associated with a high negative predictive value (nearly 100%) for excluding hemodynamically relevant CAD. The score must be 0 not 1,2 or 3 Agaston units.
All images on this site are © 2013 Elliot K. Fishman, MD.