Navigating the Coronary Circulation: Angiography vs IVUS Pearls and Pitfalls Philippe L. L’Allier, MD Montreal Heart Institute Tuesday, March 27, 2007 Philippe L. L’Allier, MD Montreal Heart Institute Tuesday, March 27, 2007

Angiography: the old friend 2D Longitudinal Lumen Imaging % Stenosis (QCA) “Normal” Reference Diameter

Angiography: the good and the bad Good  Extensively used > 60 years  Entire coronary anatomy, including small and distal vessels  Excellent PPV  Validated QCA  Helpful in clinical decision making Bad  Relative % stenosis  Reference segment assessment  Eccentricity  Post PTCA/dissections  Limited correlation with physiology

Quantitative coronary angiography Reference-catheter

Quantitative coronary angiography Edge detection

Quantitative coronary Angiography

Pitfall: lesion eccentricity

Vascular Remodelling (Glagov’s phenomenon)

IVUS Imaging 2D Cross-Sectional Imaging

IVUS: the good and the bad Good  Tomographic views  Vessel wall + lumen visualization  Excellent NPV+PPV  Validated quantitative software  Plaque characterization Bad  Need to instrument vessels  Limited to proximal segments  Cost  Not as well validated for clinical decision making  Limited correlation with physiology  Not always perpendicular to vessel axis

IVUS Imaging: Plaque Surface and Volume Longitudinal Plane Transverse Plane

IVUS 3D Reconstruction: %change atheroma volume ACC 2007: - ERASE - ILLUSTRATE

IVUS Pitfall : Imaging plane not perpendicular to vessel axis

Distal LMT

<6.0 mm2

Fibrous Soft Superficial Ca Deep calcification

Potentially unstable coronary lesion Echolucent

Conclusions Angio remains the most widely and conveniently used coronary imaging modality IVUS has helped better use/understand angiography Not IVUS vs Angio, more Angio ± IVUS Need to understand the pitfalls of each technique and use them appropriately