Webinar 10 | Assessment of Left Main Stenosis-Slides: Step-by-Step IVUS and OCT Imaging of LM, Dr. Valeria Paradies

Slides: Step-by-Step IVUS and OCT Imaging of LM, Dr. Valeria Paradies

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This presentation by Dr. Valeria Paradies focuses on the use of intravascular imaging modalities—primarily Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT)—for the evaluation and treatment of left main (LM) coronary artery stenoses, particularly ambiguous or intermediate lesions.

Key points include:

1. <strong>Limitations of Angiography:</strong> Sole angiography may lead to inappropriate treatment decisions in up to 32% of intermediate LM stenoses. IVUS and OCT provide more accurate assessment of lesion severity and morphology.

2. <strong>Imaging Guidance Improves Outcomes:</strong> Network meta-analyses of 19 trials (13,030 patients) show a 29% relative reduction in target lesion failure when PCI is guided by IVUS or OCT compared to angiography alone. OCT is effective in stent optimization by ensuring adequate lesion coverage, stent expansion (≥90% reference size), apposition, and avoidance of malapposition or deformation, improving clinical outcomes.

3. <strong>Diagnostic and Procedural Nuances:</strong> Small angular variations can affect measurements like minimum lumen area (MLA). Factors like patient body surface area, downstream vessel lesions, ostial locations, and the presence of thrombus influence functional assessment with fractional flow reserve (FFR).

4. <strong>Bifurcation Lesions Complexity:</strong> Bifurcation lesions are classified by Medina criteria. Detailed imaging helps identify complexities such as calcium burden, plaque morphology (lipidic vs fibrotic), bifurcation angles, and risks like carina shift post-PCI.

5. <strong>Clinical Trials:</strong> Recent major trials (ILUMIEN IV, OCTOBER, RENOVATE, OCTIVUS) confirm the superiority or non-inferiority of IVUS/OCT guidance over angiography in terms of major adverse cardiac events (MACE), with some showing significant benefit in specific endpoints like target lesion failure and restenosis.

6. <strong>Technical Insights:</strong> OCT imaging assists in optimal wire positioning, avoiding accidental abluminal rewiring that can cause stent deformation and increase MACE. Proper stent sizing and post-dilatation techniques like proximal optimization technique (POT) and culotte stenting are highlighted.

7. <strong>Case Example:</strong> A complex PCI case is illustrated with staged PCI, rotablation, and optimized bifurcation stenting showing the practical application of these imaging-guided strategies.

In summary, IVUS and OCT are essential for precise LM lesion evaluation and device optimization, improving prognostic outcomes beyond angiography alone, especially in complex bifurcation disease.

Keywords

Intravascular Ultrasound (IVUS)

Optical Coherence Tomography (OCT)

Left Main Coronary Artery Stenosis

Angiography Limitations

Percutaneous Coronary Intervention (PCI) Guidance

Bifurcation Lesions

Medina Classification

Stent Optimization

Fractional Flow Reserve (FFR)

Major Adverse Cardiac Events (MACE)