Plaque type and composition as evaluated non-invasively by MSCT angiography and invasively by VH IVUS in relation to the degree of stenosis
- J E van Velzen1,2,
- J D Schuijf1,
- F R de Graaf1,
- G Nucifora1,
- G Pundziute1,3,
- J W Jukema1,2,
- M J Schalij1,
- L J Kroft4,
- A de Roos4,
- J H C Reiber4,
- E E van der Wall1,2,
- J J Bax1
- 1Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands
- 2The Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands
- 3Department of Cardiology, Kaunas University of Medicine, Kaunas, Lithuania
- 4Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
- Correspondence to Dr J J Bax, Department of Cardiology, Leiden University Medical Centre, Postal zone: C5-P, PO Box 9600, 2333 ZA Leiden, The Netherlands; j.j.bax{at}lumc.nl
- Accepted 8 September 2009
- Published Online First 20 October 2009
Abstract
Background: Imaging of coronary plaques has traditionally focused on evaluating degree of stenosis, as the risk for adverse cardiac events increases with stenosis severity. However, the relation between plaque composition and severity of stenosis remains largely unknown.
Objective: To assess plaque composition (non-invasively by multislice computed tomography (MSCT) angiography and invasively by virtual histology intravascular ultrasound (VH IVUS)) in relation to degree of stenosis.
Methods: 78 patients underwent MSCT (identifying three plaque types; non-calcified, calcified, mixed) followed by invasive coronary angiography and VH IVUS. VH IVUS evaluated plaque burden, minimal lumen area and plaque composition (fibrotic, fibro-fatty, necrotic core, dense calcium) and plaques were classified as fibrocalcific, fibroatheroma, thin-capped fibroatheroma (TCFA), pathological intimal thickening. For each plaque, percentage stenosis was evaluated by quantitative coronary angiography. Significant stenosis was defined >50% stenosis.
Results: Overall, 43 plaques (19%) corresponded to significant stenosis. Of the 227 plaques analysed, 70 were non-calcified plaques (31%), 96 mixed (42%) and 61 calcified (27%) on MSCT. Plaque types on MSCT were equally distributed among significant and non-significant stenoses. VH IVUS identified that plaques with significant stenosis had higher plaque burden (67% (11%) vs 53% (12%), p<0.05) and smaller minimal lumen area (4.6 (3.8–6.8) mm2 vs 7.3 (5.4–10.5) mm2, p<0.05). Interestingly, no differences were observed in percentage fibrotic, fibro-fatty, necrotic core and dense calcium. Non-significant stenoses were more frequently classified as pathological intimal thickening (46 (25%) vs 3 (7%), p<0.05), although TCFA (more vulnerable plaque) was distributed equally (p = 0.18).
Conclusion: No evident association exists between the degree of stenosis and plaque composition or vulnerability, as evaluated non-invasively by MSCT and invasively by VH IVUS.
Footnotes
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Funding JEvV is supported by the Netherlands Heart Foundation (The Hague, The Netherlands), grant no 2007B223. FRdG is co-supported by the Dutch Technology Foundation STW (Utrecht, The Netherlands), Applied Science Division of NWO and the Technology Program of the Ministry of Economic Affairs, grant no 10084. GP has a training fellowship grant from European Society of Cardiology. MJS has research grants from Boston Scientific (Natick, USA), Medtronic (Minneapolis, United States) and Biotronik (Berlin, Germany). JJB has research grants from Medtronic (Minneapolis, United States), Boston Scientific (Natick, United States), BMS medical imaging (New York, United States), St Jude Medical (St Paul, United States), GE Healthcare (Chalfont St Giles, United Kingdom), Biotronik (Berlin, Germany), and Edwards Lifesciences (Irvine, United States).
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Competing interests None declared.
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Provenance and Peer review Not commissioned; externally peer reviewed.
