OCT Made Easy

Hiram G. Bezerra, Guilherme F. Attizzani, Marco A. Costa, Hiram G. Bezerra, Guilherme F. Attizzani, Marco A. Costa

• Publisher: CRC Press
• Year: 2017
• eBook ISBN: 9781351667685
• Topic: Medicine
• Subtopic: Cardiology

This book, written by premier authors in the field of OCT intravascular imaging, covers the best practices for using OCT to provide high resolution cross-sectional viewing for atherosclerotic plaque assessment, stent strut coverage and apposition, assessment in stent restenosis evaluation, and PCI guide and optimization. Fully illustrated thorughout in a handy, cath-lab side handbook supplemented by online movie clips, OCT Made Easy includes case studies, angiography, CT correlations, and simple techniques for getting the best image.

1Optical coherence tomography imaging for stent planning

Daniel Chamié and Emile Mehanna

1.1Introduction

Since its introduction in 1977, percutaneous coronary intervention (PCI) has undergone continued and profound advancements. The evolution of coronary devices, operator’s experience, interventional techniques, and adjunctive pharmacotherapy dramatically reduced the risks of early complications and improved long-term outcomes, elevating PCI to the predominant modality of invasive treatment of coronary artery disease (CAD) and one of the most frequently performed therapeutic interventions in medicine.1

Although coronary angiography is the mainstay imaging modality to assess the presence, extent, and severity of CAD, and to guide PCI procedures, intravascular imaging has played a fundamental role during PCI maturation and evolution. Visual estimation of the planar silhouette of the contrast-filled luminogram may be insufficient for accurate diagnosis of CAD severity and extension, and oftentimes does not allow accurate planning and optimization of PCI. By providing higher-resolution tomographic images of the entire circumference of the vessel wall, intracoronary imaging may overcome these limitations.

In the mid-1990s—when coronary stents were plagued by elevated rates of acute or subacute thrombosis, and oral anticoagulants were part of the adjunctive pharmacotherapy with its associated hemorrhagic complications—Colombo et al.2 demonstrated that despite an optimal angiographic result (<20% residual stenosis), only 30% of the stents implanted in 420 lesions were adequately expanded by intravascular ultrasound (IVUS). After IVUS-guided high-pressure balloon postdilatation, full expansion and complete stent apposition were achieved in 96% of the patients. This strategy resulted in very low rates of acute (0.6%) and subacute (0.3%) stent thrombosis, eliminating the need for systemic anticoagulants, and consolidating the widespread use of coronary stents for the percutaneous treatment of CAD in the years to come.

Over the last two decades, IVUS guidance helped reduce the rates of restenosis and repeat revascularization after bare-metal stents—but not myocardial infarction (MI) and mortality. Despite the absence of adequately powered randomized trials to demonstrate whether routine IVUS guidance improves clinical outcomes after drug-eluting stent (DES) implantation, four contemporary meta-analyses suggest that IVUS guidance can reduce stent thrombosis, MI, repeat revascularization, and mortality when compared with angiographic DES guidance alone.3–6

Despite these benefits, and after more than 20 years of clinical use, IVUS has been used in less than 20% of PCI procedures.7

More recently introduced, optical coherence tomography (OCT) uses near-infrared light to generate cross-sectional images of the coronary arteries. Near-infrared light has a shorter wavelength and higher frequency than ultrasound, thus providing images with 10-fold higher resolution than those provided by IVUS. The faster and safe acquisition of longitudinal sequences of sharp and detailed images, along with ease of use and interpretation, leverages OCT as an attractive imaging modality with the potential to guide and optimize PCI, which ultimately may translate into improved clinical outcomes.

In this chapter, we discuss the usefulness of OCT in planning and guiding coronary stenting, using a practical, case-oriented approach, whenever applicable.

1.2General outline

Although at first sight the term stent planning may be viewed as a synonym for stent guidance, the two concepts are not always applied interchangeably. When it comes to the use of adjunctive intravascular imaging with the intention to guide coronary interventions, it is common practice to perform PCI based on angiography, and only execute intravascular imaging at the end of the procedure, to check the “final” PCI result. Although this approach offers the opportunity to optimize PCI, the planning strategy has been overlooked and restricted to the inherent limitations of angiography. As so, it is our opinion that the use of intravascular imaging for stent planning carries a much broader role, and intravascular imaging pre-PCI should not be underestimated.

Intravascular OCT pre-PCI allows accurate quantification of stenosis severity and extension, and characterization of the underlying plaque components and morphometry, helps locate adequate landing zones for the stent to be implanted, and provides accurate vessel sizing for selection of the stent length and diameter. It also allows up-front anticipation of the need for balloon postdilatation and the type and size of the balloon to be used. In other words, stent optimization can also be planned based on pre-PCI OCT imaging. After a satisfactory angiographic result has been achieved, post-PCI OCT can be performed to check on the procedure results, and judge whether further iterations are still needed.

Based on the concepts outlined above, we give pre-PCI imaging equal or higher importance than post-PCI imaging. As so, this chapter is presented according to the following structure:

• Preintervention OCT imaging
  • Basic nomenclature and definitions
  • Assessment of coronary stenosis severity
  • Assessment of lesion morphology, composition, and morphometry
  • Vessel measurements for stent sizing
• Postintervention OCT imaging
  • Verification and optimization of stent expansion
  • Verification and optimization of stent apposition
  • Assessment...

Table of contents

• Cover
• Half Title Page
• Title Page
• Copyright Page
• Contents
• Contributors
• Chapter 1 Optical coherence tomography imaging for stent planning
• Chapter 2 OCT imaging for assessment of plaque modification
• Chapter 3 OCT for plaque modification
• Chapter 4 OCT for stent optimization
• Chapter 5 OCT for left main assessment
• Chapter 6 Optical coherence tomography for late stent failure
• Chapter 7 OCT assessment in spontaneous coronary artery dissection
• Chapter 8 Optical coherence tomography assessment for cardiac allograft vasculopathy after heart transplantation
• Chapter 9 OCT assessment out of the coronary arteries
• Chapter 10 Optical coherence tomography for the assessment of bioresorbable vascular scaffolds
• Chapter 11 ILUMIEN OPTIS Mobile and OPTIS Integrated Technology Overview
• Chapter 12 Terumo OFDI system
• Chapter 13 OCT imaging acquisition
• Appendix: Intravascular Bioresorbable Vascular Scaffold Optimization Technique
• Index