Coronary angiography and intravascular ultrasound

https://doi.org/10.1016/S0002-9149(01)01420-5Get rights and content

Abstract

Clinicians have long used the size of the lumen and the angiogram as a predictor of coronary events. However, cardiovascular disease is not a disease of the lumen but a disease of the vessel wall. In early stages, atherosclerosis outwardly remodels the external elastic membrane; only late in the disease process does luminal narrowing occur, enabling angiographic detection. This has profound implications for drug therapy, because approximately 70% of patients present with acute myocardial infarction (MI) or sudden death, not angina as the first symptom of coronary disease. Intravascular ultrasound (IVUS) can provide detailed images of the artery and is the only technique currently available that enables physicians to routinely visualize coronary plaques. Due to its sensitivity in measuring plaque volume and content, IVUS may be a useful surrogate marker to evaluate the atherosclerotic process in smaller numbers of patients than required for conventional clinical endpoint trials.

Section snippets

Ntravascular ultrasound and coronary remodeling

IVUS has been extraordinarily useful in teaching us about the atherosclerotic disease process. We have learned that the traditional model of the disease, in which the plaque develops in the vessel wall over many years, gradually narrowing the lumen to produce symptoms, is not accurate. A more accurate model of atherosclerosis was originally described by Glagov et al,3 who showed that coronary “remodeling” enables patients to develop large atherosclerotic plaques without reduction in lumen size

Intravascular ultrasound, angiography, and the assessment of atherosclerotic disease: trial results

To illustrate, Figure 2 shows a typical patient with disease of the right coronary. This patient had a 95% obstruction treated successfully with a stent. However, although the left coronary system appears normal angiographically, using IVUS, multiple large plaques were identified throughout the artery. Although the entire artery was diffusely atherosclerotic, the angiogram remained normal because the lumen size was not altered. Thus, ultrasound can be used to provide very detailed images of the

Conclusion

In summary, IVUS has great potential as a means to accurately assess the atherosclerotic disease process. IVUS has the ability to demonstrate changes in plaque volume and plaque vulnerability over a relatively short period of time, with fewer patients than required for large morbidity and mortality endpoint trials. In the future, for IVUS to become a widely accepted surrogate, there needs to be a clear correlation between plaque volume by IVUS and cardiovascular events. If this correlation can

Discussion

Michael Cressman:

How did you figure in the potential for heterogeneity of a response of atherosclerotic lesions into sample size calculations for these studies?

Steven Nissen, MD (Cleveland, Ohio):

We picked total volume as the primary endpoint, but prespecified a series of secondary endpoints. For example, we take rolling 10-slice segments, then take the segments with the least atherosclerotic plaque, and that represents a defined endpoint. We take the 10 slices with the greatest atherosclerotic

References (8)

  • W.C. Little et al.

    Can coronary angiography predict the site of a subsequent myocardial infarction in patients with mild-to-moderate coronary artery disease?

    Circulation

    (1988)
  • S.E. Nissen et al.

    Intravascular ultrasound assessment of lumen size and wall morphology in normal subjects and patients with coronary artery disease

    Circulation

    (1991)
  • S. Glagov et al.

    Compensatory enlargement of human atherosclerotic coronary arteries

    N Engl J Med

    (1987)
  • E.J. Topol et al.

    Our preoccupation with coronary luminologythe dissociation between clinical and angiographic findings in ischemic heart disease

    Circulation

    (1995)
There are more references available in the full text version of this article.

Cited by (0)

View full text