Section 1
Correlating Calcium Score and Atherosclerotic Plaque

These two articles demonstrate the intimate relationship between the amount of calcium in the coronaries as measured with EBCT and the amount of atherosclerotic plaque as measured by traditional pathologic staining methods. In effect, the calcium score measures the total plaque burden in the artery walls, which is the best predictor of future risk for coronary events.

Section 2
Correlating Electron Beam CT with Angiographic and Myocardial Perfusion Abnormalities

These three articles show how EBCT compares with other modalities used in the diagnosis of coronary heart disease (CHD). The first article demonstrates that a simple equation using the calcium scores in the left anterior descending and the circumflex arteries plus two other risk factors can very accurately predict the presence or absence of left main or three vessel disease in patients with symptoms suggestive of CHD.

Section 3
The Prognostic Value of EBCT

The following two articles demonstrate the power of EBCT to predict future cardiovascular events. The first article shows that a calcium score over 160 confers a 20 to 35-fold increase in risk, while the second paper was able to show that patients in the highest age-sex matched quartile of calcium scores had a 59-fold increase in risk compared with those in the lowest quartile. This suggests that the rate of progression of calcium scores is a more powerful predictor than the absolute scores. Patients with mild to moderate scores, but whose scores are above the 50th percentile for their age and sex, should receive aggressive risk factor modification.

Section 4
Using EBCT to Track Progression or Regression of Coronary Atherosclerosis

EBCT is the only noninvasive test that can be used to assess response to therapeutic interventions aimed at shrinking coronary plaque. The first article describes a 12-15 month study showing that statin treatment results in stabilization and even shrinkage of plaque burden, while no statin treatment can result in a 50% increase in plaque burden. The second article found that patients whose scores increase over a 12-36 month study period experience a 10-fold increase in risk of coronary events when compared to patients whose scores remain stabilized.