1) The document discusses the relationship between carotid artery disease and coronary artery disease. Studies have found an association between carotid artery plaques and stenosis and adverse cardiac outcomes. 2) Measuring intima-media thickness (IMT) of the carotid arteries has been used as a surrogate for coronary artery atherosclerosis. However, atherosclerosis is non-uniform and different risk factors are associated with IMT increases in different carotid artery segments. 3) A recent study in young adults found that multiple coronary risk factors cause different morphological changes in carotid artery segments. Systolic blood pressure was most associated with common carotid IMT while age was most associated with carotid bulb IMT.

1. The Link Between Coronary and Carotid; How Strong Is It?
Provided by:
Jawahar L Mehta, M.D.,PhD
Anjan K Sinha, M.D.
Division of Cardiovascular Medicine
University of Arkansas for Medical Sciences, Little Rock, AR
VP Watch – November 20, 2002 - Volume 2, Issue 47
Editorial Slides

2.  Asymptomatic patients with cervical bruits
when followed prospectively by clinical and
Doppler examination had strikingly high
number of cardiac deaths. 1
 Ultrasonographically assessed carotid
arteriosclerosis is being used as a surrogate
measure for coronary arteriosclerosis. The
presence of any structural changes in the
common carotid arteries or carotid bulbs is
associated with higher risk of cardiovascular
events. 2-5
Is Carotid IMT surrogate for CAD

3.  Technically easier to measure common
carotid and carotid bifurcation.
 Most of the trials have used mean values
of Intima media thickness (IMT) measured
at common carotid, bifurcation and internal
carotid segments.
Is Carotid IMT surrogate for CAD

4. Arteriosclerosis in non uniform
• It is well known that plaques both in
coronary and extracoronary circulation are
non uniformly distributed.
• Under steady flow conditions plaques tend
to form in areas of low, rather than high,
shear stress, but indicate in addition that
marked oscillations in the direction of wall
shear may enhance atherogenesis. 6

5. Segment specific alterations
• Few clinical trials have selectively evaluated the
individual carotid segments.
 The patterns of differences in mean IMTamong
segments vary, depending on age, hypertension,BMI in
women, and coronary (case-control) status.
 Sex,postmenopausal status, LDL cholesterol, systolic
blood pressure,and history of myocardial infarction all
had statistically significant relationshipswith IMT that
were fairly homogeneous amongarterial sites. 7

6.  HultheJ,WikstrandJ,Emanuelsson H,WiklundO, deFeyterPJ,WendelhagI.
AtheroscleroticchangesinthecarotidarterybulbasmeasuredbyB-mode
ultrasoundare associatedwiththeextentofcoronary atherosclerosis. Stroke
1997;28:1189–1194.
 This was a small study.8
Segment specific alterations

7. • This study clearly demonstrate that Carotid
bifurcation stenosis is associated with
adverse cardiac outcome however it is small
study and includes older subjects.
• Study is not powered to evaluate the relative
significance of individual risk factors.8

8.  As reported in VP Watch of this week,
Urbina EM et al. show for the first time the
different morphological patterns observed in
carotid arteries with different risk factor profile.
Large population study including both blacks
and whites.Young adults are studied (all the
prior studies included middle aged to elderly).

9. Systolic blood pressure was the major
contributor to the explained variance of common
carotid IMT followed by race (black more than
white), age, LDL cholesterol, and HDL
cholesterol (inverse association), in that order.
Results

10.  Age was the major contributor for carotid bulb
IMT followed by systolic blood pressure, HDL
cholesterol (inverse association), LDL
cholesterol, race (black more than white), and
insulin level (inverse association).
 Gender (men more than women) and BMI
were the only contributors to the variance of
internal carotid IMT.
Results

11. Number of risk factors and segments involved
Urbina EM, Srinivasan
SR, Tang R, Bond MG, Kieltyka L,
Berenson GS.
Impact of multiple coronary risk
factors on the intima-media
thickness of different segments of
carotid artery in healthy young
adults (The Bogalusa Heart Study).
Am J Cardiol. 2002 Nov
1;90(9):953-8. 11

12. Conclusion:
 Multiple risk factors for coronary artery
disease cause different morphological
changes in carotid arteries.

13. Limitations:
 Carotid IMT observed in this study is less
than 1.0 mm. Prior epidemiological data
suggests that IMT > 1.0 mm has prognostic
value.
 Hypertension is prominent risk factor for both
carotid bifurcation as well as well as common
carotid changes. Hypertension is known to
cause medial hypertrophy and differences
may be due to different hemodynamic profiles
of the segments.

14. Questions:
• Would individual segment of carotid
artery involvement have different
prognostic value ?
• Should we only measure carotid
bifurcation IMT (has highest sensitivity
for combined risk factors) ?
• How will we define what is normal and
what is abnormal ?

15. Questions:
• Is one risk factor more important in a
particular individual than other since he or
she has demonstrated morphological
changes in their segmental carotid
arteries suggestive of specific risk factor ?
• Do therapeutic interventions selectively
change the morphology ?

16. 1) Chambers BR, Norris JW. Outcome in patients with asymptomatic neck bruits. N Engl J Med. 1986; 315:860-865.
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infarction: the Rotterdam Study. Circulation. 1997; 96:1432-1437.
3) Sinha AK, Eigenbrodt M, Mehta JL. Does carotid intima media thickness indicate coronary atherosclerosis? Curr Opin
Cardiol. 2002 Sep;17(5):526-530.
4) Salonen JT Salonen R Ultrasonographically assessed carotid morphology and the risk of coronary heart disease
Arterioscler Thromb 1991; 11:1245-1249
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with risk factors in the Cardiovascular Health Study. Am J Epidemiol 1994;139:1164-1179.
6) Ku DN, Giddens DP, Zarins CK, Glagov S. Pulsatile flow and atherosclerosis in the human carotid bifurcation. Positive
correlation between plaque location and low oscillating shear stress. Arteriosclerosis 1985;5:293–302.
7) Espeland MA, Tang R, Terry JG et al. Associations of risk factors with segment-specific intimal-medial thickness of the
extracranial carotid artery. Stroke 1999; 30:1049-1055.
8) Hulthe J, Wikstrand J, Emanuelsson H, Wiklund O, de Feyter PJ, Wendelhag I. Atherosclerotic changes in the carotid
artery bulb as measured by B-mode ultrasound are associated with the extent of coronary atherosclerosis. Stroke
1997;28:1189–1194.
9) Rosfors S, Hallerstam S, Jensen-Urstad K et al. Relationship between intima-media thickness in the common carotid
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blind, long-term trial. Circulation. 2002 Nov 5;106(19):2422-7.
11) Urbina EM, Srinivasan SR, Tang R, Bond MG, Kieltyka L, Berenson GS. Impact of multiple coronary risk factors on the
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Cardiol. 2002 Nov 1;90(9):953-8.
References