Purpose
Coronary CT Angiography is an accurate and feasible diagnostic tool to identify and to assess Coronary Artery Disease,
with a sensitivity about 99%1.
As other CT exam,
also Coronary CT Angiography is based on contrast administration which permits an optimal study of coronary lumen and coronary wall.
Coronary opacification depends on contrast geometry,
time of acquisition and,
overall,
coronary flow2. On this principle,
some studies have demonstrated how Corrected Coronary Opacification (CCO) changes across coronary stenoses are predictive of abnormal resting coronary blood flow.
In...
Methods and Materials
We retrospectively analyzed 41 patients (15 woman; 26 man; mean age 70±8) who had undergone cardiac CT and stress CMR,
with presence of 53 calcified plaques.
Evidence of stress myocardial perfusion imaging by CMR was compared with attenuation values in coronary lumen (CCO).
The CCO difference across the plaque were measured proximally and distally to the plaque,
in an axial plane,
and normalized to the descending aorta on the same slice.
Results
A total of 53 well-calcified plaques were assessed.
18 plaques showed a low CCO difference value (0.062)(fig.
1),
with negative Stress and LGE image.
20 plaques showed intermediate CCO difference value (0.20; r:0.7530; value near 0,184 as reported in literature) associated with reversible perfusion alteration under stress,
but negative LGE image (p-value:0.0012)(fig.2; fig.3).
The remaining 15 plaques showed high CCO difference value (mean value of 0.364; r:0.8152),
including chronic stenosis and collateral opacification,
and were associated with irreversible perfusion alterations and myocardial scar (p-value: 0.0002)(fig.4;...
Conclusion
Stress myocardial perfusion imaging by CMR and CCO analysis by cardiac-CT,
offers interesting similar information about hemodynamic significance of calcified plaques not properly evaluable by standard methods of analysis.
Increase of CCO difference values correlate with significant stenoses.
Therefore,
CCO is an highly promising technique for a prior assessment of coronary stenosis due to well-calcified plaques,
allowing to avoid “more-expensive” and complex systems of data analysis (like CT-FFR) or other not-invasive test studies.
The linear correlation shows that as CCO difference value increase as correlate...
References
1.
2013 ESC guidelines on the management of stable coronary artery disease The Task Force on the management of stable coronary artery disease of the European Society of Cardiology.
European Heart Journal (2013) 34,
2949–3003 doi:10.1093/eurheartj/eht296
2.
Can difference in Corrected Coronary Opacification measured with Computed Tomography predict resting coronary artery flow? Chow et al.
Journal of the American College of Cardiology.
Vol.
57,
No.
11,
2011