This document summarizes a post-mortem study examining the prevalence of inflammatory cells in non-ruptured atherosclerotic plaques. The study found that moderate or heavy staining for macrophages was present in 45% of femoral artery cross-sections and 84% of femoral arteries had at least one cross-section with moderate/heavy inflammation. There was no observed relationship between the degree of inflammation in the left and right coronary arteries within individuals, indicating the level of local inflammation is locally determined with little predictive value for other arteries.

1. The prevalence of inflammatory cells
in non ruptured atherosclerotic
plaques
G. Pasterkamp
Experimental Cardiology, UMC and
Interuniversity cardiology Institute of the
Netherlands, Utrecht, The Netherlands
Published in part in :
Arterioscl Thromb and Vasc Biol 1999;19:54-58.

2. Background
Plaque rupture and subsequent plaque
thrombosis is found to be associated
with the presence of inflammatory cells.
Davies et al. Br Heart J 1985;53:363-373
Van der Wal et al. Circulation 1994;89:36-44
Moreno et al. Circulation 1994;90:775-778

3. Plaque rupture

4. Question
Is the presence of inflammatory cells
A- specific for plaque rupture or
B- a commonly observed phenomenon in
atherosclerotic lesions?
What is the prevalence of moderate/heavy local
inflammation in non ruptured atherosclerotic
lesions?

5. Post mortem study:
• Atherosclerotic femoral (n=50) and coronary
arteries (n=74) from patients that did not die
of cardiovascular disease.
• In each artery, 4-6 non ruptured cross-
sections revealing atherosclerosis were
studied for the presence of macrophages (CD
68) and T-lymphocytes (CD45RO).

6. positive negative

7. positive negative

8. Femoral artery
45% of all cross-sections revealed
moderate or heavy staining for
macrophages in the cap or shoulder of
non ruptured plaques.

9. Question
If one would randomly stain 5-6 cross-
sections obtained from an
atherosclerotic artery for inflammatory
cells, how often would at least one
cross-section reveal moderate to heavy
staining for inflammatory cells?

10. positive negative

11. positive negative

12. Femoral arteries
In 84% of all femoral arteries at least one
cross-section revealed moderate or
haevy staining for macrophages or T-
lymphocytes in cap or shoulder of the
non ruptured athertosclerotic plaque.

13. Question
If one would find many cross-sections with
inflammation in one coronary artery: would
that be predictive for the occurrence of
plaque inflammation in another coronary
artery?
Right and left coronary arteries were compared
within the individual (next slide)

14. -= no staining, + = moderate staining, ++ = heavy staining,
No relation was observed between the degree of
staining for inflammatory cells between the left and right
coronary artery.
Left coronary artery
Right coronary artery - + ++
- 3 4 0
+ 2 11 2
++ 0 3 0

15. Conclusion
• The presence of inflammatory cells is a
common phenomenon in non ruptured
atherosclerotic lesions.
• The degree of local inflammation is
locally determined and has no/low
predictive value for the presence of
inflammation in other arteries.
(Pasterkamp et al. ATVB 1999, Vink et al JACC 2001)

16. Discussion
• Considering these results: what is the
predictive value of local inflammation for
the occurrence of plaque rupture?
• Visualization of the vulnerable plaque
when inflammation is used as marker:
– Specificity for local plaque rupture or
predictive value for plaque rupture may be
disappointing.