Predictive Value of Coronary Calcium Scoring

Matthew Budoff, MD, FACC, FAHA

Associate Professor of Medicine

UCLA School of Medicine

Director, Cardiac CT

Harbor-UCLA Medical Center, Torrance, CAConflict of Interest: Speakers Bureau

General Electric

Prevalence of Conventional Risk Factors in Patients with Coronary Heart Disease Prevalence of Conventional Risk Factors in Patients with Coronary Heart Disease (N = 87,869)(N = 87,869)

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

No one is born with atherosclerosis

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

There is a gradual, silent build up over time

x x x x

xx

xx

x

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

Finally, acute event occurs

x x x x

xx

xx

x

xx

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

Sx onset -- Permanent damage

x x x x

xx

xx

x

xx

Time 11/3 - Angina

1/3 - Acute MI

1/3 - Sudden Death

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

x x x x

xx

xx

x

xx

1st Event

Realistic Goal – DELAY PROGRESSION

xx

xx

x

x x x x x x x

x

x xx x

x x

x x x x x x x x

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

x x x x

xx

xx

x

xx

1st Event

Prevention- Primary vs. Secondary

xx

xx

x

x x x x x x x

x

x xx x

x x

x x x x x x x xCARDIOLOGISTS

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

x x x x

xx

xx

x

xx

1st Event

Prevention- Primary vs. Secondary

xx

xx

x

x x x x x x x

x

x xx x

x x

x x x x x x x xPRIMARY CARE

Time

0 1 2 2x

A.S.

x

Coronary atherosclerotic burden –

x x x x

xx

xx

x

xx

1st Event

Concept -- EARLY 2 ry PREVENTION

xx

xx

x

x x x x x x x

x

x xx x

x x

xx x x

xx

xxThe Problem

begins HERE

NOT HERE

Potential Prognostic Potential of Cardiac CT

Use a calcium score to screen patients with moderate (intermediate) Framingham risk Positive CAC scans indicate incremental risk Alters therapeutic goal (LDL, BP, etc)

Identify patients who do not need further cardiac medication (scores of zero)

Consider serial imaging as ongoing management tool (progression)

Prediction of Cardiac Events in AsymptomaticPrediction of Cardiac Events in AsymptomaticPatients by EBTPatients by EBT

The St. Francis Heart Study, ACC 2003The St. Francis Heart Study, ACC 2003

SFHS 3SFHS 3

0.12

0.7

2

2.4

3.3

0

0.5

1

1.5

2

2.5

3

3.5

0 > 0 > 100 > 200 > 600

Baseline EBT Calcium ScoreBaseline EBT Calcium Score

An

nu

al E

ven

t R

ate

(%)

An

nu

al E

ven

t R

ate

(%)

Calcium Score >100 vs <100

Rel

ativ

e R

isk

9.5

AnyEvent

10.7

Cor.Event

9.9

MI/SCD

2.72 2

12.47

3.55

6.15

12.29

0

2

4

6

8

10

12

14

Rel

ativ

e R

isk

DM Smoke HTN <1010-100

101-400401-1000

>1000

EBT Coronary Calcium ScoreEBT Coronary Calcium Score

All Cause Mortality [NDR]All Cause Mortality [NDR]n = 10,377n = 10,377asymptomatic men and womenasymptomatic men and womenf/u = 5.0f/u = 5.0++3.5 yrs.3.5 yrs.

Shaw, Raggi et alRadiology 2003

EBT found to be independentand incremental to risk factors

All Cause Mortality in PatientsAll Cause Mortality in PatientsWithout Known CADWithout Known CAD

EBT 5 year All-Cause Mortality – Shaw et al

0.00 2.00 4.00 6.00 8.00 10.00 12.00

Time to Follow-up (Years)

0.75

0.80

0.85

0.90

0.95

1.00

0.00 1.00 2.00 3.00 4.00 5.00

Time to Follow-up (Years)

0.75

0.80

0.85

0.90

0.95

1.00

Near- and Long-Term Survival from 2 Cohorts – over 35,000 patients

n=10,377 n=25,257

99.4%

97.8%95.2%

90.4%

81.8%

99.4%

97.8%

94.5%

93.0%

76.9%

2=1503, p<0.0001, interaction p<o.0001

CAC Score (5 Yr Mortality = 1.2%) (12-Yr Mortality = 2.1%) Difference 0-10 99.4% 99.4% 0.0%11-100 97.8% 97.8% 0.0%101-400 95.2% 94.5% 0.7%401-1,000 90.4% 93.0% 0.6%>1,000 81.8% 76.9% 4.9%

Cooper Clinic Study - 10,782 Patients: 3.5 year follow-up

0

10

20

30

40

50

None 1--16 17--96 97--409 >409 None 1--16 17--96 97--409 >409

Ad

juste

d O

dd

s R

atio

Adjusted age, history of diabetes, hypertension, elevated cholesterol, over weight

44.3(22-87)

2.9(1.2-6.7)

5.2(2.4-11)

13.4(6.7-26.5)

Ref

All CHD (n=278)

Nonfatal MI & CHD Death

2.7(0.8-9.3)

6.0(2.1-17)

9.7(3.6-26)

21.1(7.8-57)

Ref

Taylor et al – PACC Study – JACC 2005

2000 patients, mean age 43 Coronary calcium was associated with an 11.8-fold

increased risk for incident coronary heart disease (CHD) (p 0.002) in a Cox model controlling for the Framingham risk score.

In young, asymptomatic men, the presence of coronary artery calcification provides substantial,

cost-effective, independent prognostic value in predicting incident CHD that is incremental to measured coronary risk factors.

Calcium Versus Framingham

RR of MI/SCD: EBT Score and hs-CRP

0

1

2

3

4

5

6

7

High CAC Med. CAC Low CACLow hs-CRP

High hs-CRP

Park et al.Circ. 2002;106-2073-2077

AHA – Circulation 2005Given the evolving literature since the last ACC/AHA

Expert Consensus statement (2000), current data indicate that CAD risk stratification is possible with CAC

measures.

Specifically, low CAC scores are associated with a low adverse event risk, and high CAC scores are associated

with a worse event-free survival.

This recommendation to measure atherosclerosis burden, in clinically selected intermediate–CAD risk

patients (eg, those with a 10% to 20% Framingham 10-year risk estimate) to refine clinical risk prediction and to

select patients for altered targets for lipid-lowering therapies.

RAGGI - ATVB

Arad et al. JACC 2005

In the largest study reported to date, multiple logistic regression, demonstrated only age (p 0.03), male gender (p 0.04), LDL cholesterol (p 0.01), HDL cholesterol (p 0.04), and two-year change in calcium score (p 0.0001) were significantly associated with subsequent CAD events.

Thus, increasing calcium scores were most strongly related to coronary events.

NOT PREDICTIVE: Baseline CAC, CRP

Potential Uses of Cardiac CT

Use a calcium score to screen patients with moderate (intermediate) Framingham risk Positive EBT scans indicate incremental risk Alters therapeutic goal (LDL, BP, etc)

Identify patients who do not need further cardiac evaluation (scores of zero)

Consider serial imaging as ongoing management tool (progression)

Improve compliance Non-invasive Angiography

Coronary Artery Scanning

SEVERECALCIFICATION

Percentage of individuals maintaining Statin therapy at 3.6 years according to various levels of baseline CAC

No CAC CAC 1-99 CAC 100-399 CAC>4000

10

20

30

40

50

60

70

80

90

100

44

63

75

90

EBT Coronary Calcium