Coronary artery calcium detected by electron beam tomography (EBT) establishes a diagnosis of coronary atherosclerosis, as there are no false positive calcium measurements. The amount of calcium seen on EBT correlates directly with the actual amount of coronary plaque measured by intravascular ultrasound and histopathology. Studies have also shown that a higher coronary artery calcium score on EBT is associated with greater risk of future myocardial infarction, sudden cardiac death, or ischemia over follow-up periods of 3-6 years.

1. EBT and Coronary Artery CalciumEBT and Coronary Artery Calcium
 Coronary Artery CalciumCoronary Artery Calcium ISIS AtherosclerosisAtherosclerosis
 There areThere are NONO false positive calcium measuresfalse positive calcium measures
by EBT [i.e. ALL calcium is plaque]by EBT [i.e. ALL calcium is plaque]
 Establishes a diagnosis ofEstablishes a diagnosis of
coronary atherosclerosiscoronary atherosclerosis

2. Coronary Calcium Area by EBT andCoronary Calcium Area by EBT and
Coronary Artery Plaque AreaCoronary Artery Plaque Area
0
2
4
6
8
10
12
14
16
0 2 4 6 8
Square Root Sum of Calcium Areas
SquareRootSumof
PlaqueAreas
Rumberger, Circ 1995:92:2157-62
n = 38n = 38
r = 0.90r = 0.90
p < .001p < .001

3. No. of coronary segments/pt. with plaques (IVUS)
0 1 2 3 4 5 6 7
No. of calcified
coronary
segments/pt.
(EBCT)
0
1
2
3
4
5
6
7
Y = -0.67 + (0.90 * X)
r = 0.86
p < 0.0001 N = 40 patients
total of 222 coronary
segments examined
Acute Coronary Syndrome and Non-Obstructive CADAcute Coronary Syndrome and Non-Obstructive CAD
# of segments with EBT calcium vs. # of segments with any plaque# of segments with EBT calcium vs. # of segments with any plaque
Schmermund et alSchmermund et al
AJC 1998; 81:AJC 1998; 81:
141-146141-146

4. EBT and Coronary Artery CalciumEBT and Coronary Artery Calcium
 Define the extent of disease? YESDefine the extent of disease? YES
 The amount of calciumThe amount of calcium correlates DIRECTLYcorrelates DIRECTLY toto
the amount of measurable coronary disease by:the amount of measurable coronary disease by:
1) direct histopathologic comparison1) direct histopathologic comparison
2) with intravascular ultrasound2) with intravascular ultrasound

5. Electron Beam TomographyElectron Beam Tomography
Hn x-factor
(Agatston Scoring)
130-199 1
200-299 2
300-399 3
>400 4
Area = 15 mmArea = 15 mm22
Volume = 12 mmVolume = 12 mm33
x10x10-3-3
Agatston (area) ScoreAgatston (area) Score
vs. Volume Scorevs. Volume Score
Area = 8 mmArea = 8 mm22
Volume = 6 mmVolume = 6 mm33
x10x10-3-3
Agatston (area) ScoreAgatston (area) Score
vs. Volume Scorevs. Volume Score
Total Score =Total Score = ΣΣ

6. ““Risk” of MI, SCD or Ischemia:Risk” of MI, SCD or Ischemia:
initially asymptomatic adultsinitially asymptomatic adults
2.7
6.9
14.3
19.7 20.2
0
5
10
15
20
25
30
'1-49 >50 >80 >160 >600
Arad: JACC 2000;36:1253-60
EBCT Calcium ScoreEBCT Calcium Score
Agatston: Circ 1997
OddsRatioOddsRatio
3-6 yr. f/u3-6 yr. f/u
n = 367n = 367
3.5 yr. f/u3.5 yr. f/u
n = 1177n = 1177

7. ““Risk” of MI, SCD or Ischemia:Risk” of MI, SCD or Ischemia:
initially asymptomatic adultsinitially asymptomatic adults
2.7
6.9
14.3
19.7 20.2
0
5
10
15
20
25
30
'1-49 >50 >80 >160 >600
Arad: JACC 2000;36:1253-60
EBCT Calcium ScoreEBCT Calcium Score
Agatston: Circ 1997
OddsRatioOddsRatio
3-6 yr. f/u3-6 yr. f/u
n = 367n = 367
3.5 yr. f/u3.5 yr. f/u
n = 1177n = 1177