What does coronary calcium
Dr. Jayanth H. K. MD.
Department of Radiology
How to calculate cardiovascular risk?
• Do you know your own CV risk? If you do not
go to this site below to calculate.
• Framingham CV risk calculator uses age,
gender, total cholesterol, HDL cholesterol,
smoking history, systolic BP and if on
medications for hypertension.
What is the science behind coronary
artery calcium (CAC)?
• CAC is pathognomonic for coronary artery
• Multiple studies have validated the risk of CV
event increases linearly with high CAC scores.
• CAC scoring is the most powerful predictor of
subclinical atherosclerosis and it is underused
Who should get coronary calcium
• Guidelines for coronary calcium scoring by
2010 ACCF task force.
• Intermediate cardiovascular risk and
asymptomatic adults- Class IIA.
• Low to intermediate risk and asymptomatic
• Low risk and asymptomatic-class III.
• Asymptomatic adults with diabetes, 40 years
of age and older- Class IIA.
History of looking for CAC.
• Chest radiographs
• Cardiac catheterization
• MI as you all know is a silent killer.
• 50% or more of these occur in individuals who
have no clue they are at risk of sudden cardiac
• CAC score gives added benefit to traditional
CV risk calculators
• Scan time 5-15 seconds
• No contrast
• Score is calculated on a workstation with
Coronary Calcium Score
• 0 none
• 1-99 mild
• 100-400 moderate
• >400 severe
• CAC score correlates linearly with risk of CV
events and obstructive CAD
• Input your age, select your gender and
race/ethnicity, input (optionally) your
observed calcium score and click “Calculate”
• This will convert the raw CAC score into a
relative risk percentile
• No Indian race but chinese is there?
What does CAC score “0” mean?
• One may still have noncalcified atherosclerotic
• Multiple studies have shown only a 0.11 %
annual event rate and 1.1% 10 year risk in
asymptomatic patients with 0 CAC scores.
Correlation with obstructive disease
and symptomatic patients
• CAC presence indicates coronary
• Amount of CAC only weakly correlates with
degree of luminal narrowing
• Likelihood of obstructive CAD certainly
increases with increasing CAC scores
CAC score relative risks from MESA
• 0 reference
• 1-100 3.61
• 101-300 7.73
• >300 9.67
• Similar prognostic value of CAC scoring has
been shown to be excellent in multiple large
• Easily to do and fairly highly reproducible
• Identify at CV risk individuals earlier
• If CAC present patient may be more compliant
• Identify low risk patient who doesn’t need a
• Cost effective
• More testing
• About 1mSv.
• Background per year 3 mSv.
• Mammogram 0.6 mSv.
• CXR 0.04- 0.06 mSv.
• Head CT 1-2 mSv.
• Chest CT 5-7mSv.
• Coronary catheterisation 3-5 mSv
Comparison to other biomarkers
• CAC scoring is superior to HS-CRP in predicting
• CAC was more predictive of coronary disease
than was carotid IMT
• CAC scoring is a well validated risk assessment
tool that represents a major advance in
screening for CAD
• The evidence is sound and physicians must be
made aware on the ways to incorporate this
screening tool into clinical practice
• More research is needed on CAC progression
and regression using various treatments for
1. There is calcified coronary plaque. Total calcium score = 235. The
highest density of these calcifications are at the bifurcation of the
left main into LAD and circumflex coronary artery.
2. Based on the MESA study, the calcium score is 67 percentile for age
3. The 5-year risk of cardiac events is estimated to be 78 % based on
this calcium score.
4. Recommendations: Follow up with primary care provider. Primary
prevention for atherosclerotic cardiovascular disease as indicated by
• 5. Subsequent stress echocardiogram showed no functional stenosis.
• No data available to get repeat CAC scores
after starting treatment
• 1. Detrano R, Guerci AD, Carr JJ et-al. Coronary
calcium as a predictor of coronary events in
four racial or ethnic groups. N. Engl. J. Med.
2008;358 (13): 1336-45.
• 2. http://cvdrisk.nhlbi.nih.gov/
• 3. 2010 ACCF/AHA Guideline for Assessment
of Cardiovascular Risk in Asymptomatic
• 4. Agatston AS, Janowitz WR, Hildner FJ et-al.
Quantification of coronary artery calcium
using ultrafast computed tomography. J. Am.
Coll. Cardiol. 1990;15 (4): 827-32.
• 5. Problem solving in Cardiovascular imaging
by Suhny Abbara and Sanjeva P.Kalva.