Definitions of arterial remodeling in post mortem and Intravascular ultrasound research

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Definitions of arterial remodeling in post mortem
and Intravascular ultrasound research

• G. Pasterkamp
• Experimental Cardiology, UMC and Interuniversity
  cardiology Institute of the Netherlands, Utrecht,
  The Netherlands

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Glagov et al. New Engl J Med 19873161371-1375 Pa
sterkamp et al. Circulation 1995911444-1449
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Background

• In international literature, the modes of
  arterial geometrical remodeling are
  differentially defined resulting in different
  prevalence numbers.
• The current presentation will show and discuss
  the most widely used definitions

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L
R2
R3
R1

• L Lesion
• R1 most proximal site
• R2 proximal reference with normal lumen and
  least amount of plaque
• R3 distal reference with normal lumen and
  least amount of plaque

plaque
lumen
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Definition 1 Remodeling Index (RI) VA L / ( (VA
R2 VA R3)/2)

L
R2
R3
R1
plaque
lumen
Expansive remodeling when RI gt1.05 Intermediate
remodeling when RI gt0.95 or lt 1.05 Constrictive
remodeling when RI lt0.95 Smits et al. Heart
199982461-464 von Birgelen et al. J Am Coll
Cardiol 2001371864-1870. Schoenhagen et al.
Circulation 1999101598-603
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Definition 2 RI VA L / ( (VA R2 VA R3)/2)

L
R2
R3
R1
plaque
lumen
Expansive remodeling when RI gt1.0 Constrictive
remodeling when RI lt1.0 Dangas et al.
Circulation 1999993149-3154. Nakamura et al. J
Am Coll Cardiol. 2001 Jan37(1)63-9 Okura et
al. J Am Coll Cardiol 2001371031-1035.
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Definition 3

L
R2
R3
R1
plaque
lumen
Expansive remodeling when VA L gt VA R2 and VA L gt
VA R3 Constrictive remodeling when VA L lt VA R2
and VA L lt VA R3 Other values intermediate
remodeling Nishioka et al. J Am Coll Cardiol
1996271571-1576 Wexberg et al. J Am Coll
Cardiol 2000361860-1869.
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Definition 4

Upper limit of normal tapering over 10 mm never
exceeds 21 of vessel area reference
limit at 0.78
plaque
lumen
L
R2
R3
R1
Expansive/no remodeling when VA L / VA R2 gt 0.78
Constrictive remodeling when VA L / VA R2 lt 0.
78 Mintz et al Circulation 1997951791-1798.
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Definition 5 RI VA L / ( VA R1)

L
R2
R3
R1
plaque
lumen
Expansive remodeling when RI gt1.0 Constrictive
remodeling when RI lt1.0 Taylor et al. J Am Coll
Cardiol 1999 Sep34(3)760-7
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Definition 6RI VA L / VA R2 (site with least
amount of plaque

L
R2
R3
R1
plaque
lumen
Expansive remodeling when RI gt
1.05 Constrictive remodeling when RI lt
0.95 Other values intermediate
remodeling Pasterkamp et al. J Am Coll Cardiol
199526422-428. (Only applied peripheral
arteries)
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Remodeling definitions lead to large variations
in prevalence numbers.
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Which definition is best?

• All studies are cross-sectional
• The reference is not free of atherosclerotic
  disease
• The reference may have been remodeled in either
  direction
• We do not know which definition gives us the best
  estimate of the prevalence of the different
  remodeling modes.

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Which definitions make sense?

• Definitions 1-4 share the same receipt, only the
  tresholds differ.
• Definition 5 may be used in casuistic studies,
  but in larger studies on prevalence this
  definition should not be used (it will, by
  definition, approximate the 50 for each
  remodeling mode)
• Definition 6 can only be used in non tapering
  vessels.

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Conclusion

• The prevalence of constrictive and expansive
  remodeling differs widely in literature due to
  the application of different definitions.
• Without serial studies, there is no gold standard
  for the reference site.
• The definition of the remodeling modes merit
  careful consideration when prevalences are
  mentioned.