OCT - few basic facts

Dr Arindam Pande, Consultant Cardiologist,

Academic Coordinator: DNB Cardiology and PGDCC Training

Apollo Gleneagles Hospital, Kolkata

“OCT- few basic facts you must know”

OCT Imaging

Pre-InterventionAssessment

Stent Deployment

Complication and Post Procedural

Assessments

Intravascular OCT Imaging

1. How to acquire the image

2. Assess plaque composition3. Identify reference segments4. Choose stent size

5. Determine expansion/MSA6. Determine apposition7. Rule out geographical miss

8. Identify edge dissections9. Identify tissue protrusion10.Confirm procedural success

OCT Technology Console Ilumien, Ilumien Optis, OptisI integrated Rapid exchange (Rx) imaging catheter (Dragonfly) Flush Media Clearance Fast acquisition: 7.5 – 5.4cm pullback in 3.0 – 2.1sec

1. Image acquisition: Outside the Body

Imaging core

Imaging sheath

Optical Lens

1) Purge the catheter withflush media (3 drips)2)Connect the catheter tothe dock3)Set flush media injection

• Left coronary: 4cc/s, total 14• Right coronary: 3cc/s, total 12• Large vessel: 4cc/s, total 20• Manual injection: 16cc in 20cc

syringe*The key to adequate clearance is time not volume on automatic pullback.4.Select pullback length and image acquisition method.*Manual pullback is useful in small vessels, tight stenoses or very large vessels.

High-resolution pullback: 54 mm, 10 frames/mm 3.0 sec D1

LRP

LRP

Landing Zone

Long pullback : 75 mm, 5 frames/mm 2.1 sec

Pullback lengths

1. Image acquisition: Inside the body

1) Advance OCT catheter to region of interest on “Standby”

2) Engage guide catheter• Avoid sideholes• Administer IC NTG3) Enable “Live Image” and Inject

flush media to deliver NTG and ensure adequate blood clearance

*Do not waste contrast*Plan your angiographic view (avoidoverlap)4) Purge the OCT catheter*This minimizes signal dampening

Distal Marker

Lens Marker

Proximal Marker

1. Image acquisition: Inside the body5) Press enable on the OCT dock

or console to calibrate6) Cine - Enable - Inject

Proximal Marker

Lens Marker

Distal Marker

Region of Interest – Vessel Segment Imaged During Pullback

Markers20 mm apart

Pullback length: 5 cm

Lens

1. Co-registering

1) Select co-register2) Select a minimum of 3

points along the guidewire towards the guide.

*The co-registration is dependent on the lens

*Selecting more that 3 points is acceptable but not necessarily beneficial.

*If co-registration fails, select points starting just below the lens towards the guide.

Calcific• Rotablator

•High Pressure

Necrotic Core• CuttingBalloon

• HighPressure

2. Assess Plaque CompositionFibrous Fibro-Fatty

•BAS • BAS

LCX

Dx

LM

MLA 1.95 mm2

Ø = 1.56 mm, AS = 76.5%

LLeseisoionnlelnenggthth2

826mmmm

Area 8.29 mm2

Ø = 3.12 mmArea 8.32 mm2

Ø = 3.04 mm

Area 8.79 mm2

Ø = 3.25 mm

3. Identify Reference Segments1) Scroll reference vessel

markers to proximal and distal lesion edges.

2) Attempt to identify segment of vessel within 5mm with at least >180 degrees of visible EEL

3) Reposition reference scroll marker accordingly

Area 8.79 mm2 Ø = 3.55 mm

Lesion length 28 mm

LCX

LMDx

MLA 1.95 mm2

Ø = 1.56 mm, AS = 76.5%Area 8.32 mm2

Ø = 3.24 mm

Increasingly aggressive•Largest reference lumen (prox or dist)•Mid-wall•Media-to-media (typically discounted)

3. Choose Stent Length

How Big?

LumenMLD 3.0mmMSA (r2) = 7.07mm2

Mid-wallMWD 3.1mmMSA (r2) = 7.55mm2

External Elastic LaminaEELD 3.2mmMSA (r2) = 8.04mm2

3. Choose StentDiameter

OCT vs IVUS vs Histology

Kubo et al. iJACC 2013;6(10):1095-1104

Size Matters

de Feyter et al. Circulation 1999;100:1777-83

Final Minimum Stent Area (mm2)

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* ***

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5. Determine Expansion/MSA

1) Scroll reference vessel markers to distal stent edge and midpoint of stent.

2) Identify “automated measures”yellow box to determine MSA.

3) Identify respective “automated measures” reference blue box to determine residual area stenosis.

Distal Half

5. Determine Expansion/MSA

1) Scroll reference vessel markers to distal stent edge and midpoint of stent.

2) Identify “automated measures”yellow box to determine MSA.

3) Identify respective “automated measures” reference blue box to determine residual area stenosis.

Proximal Half

Lumen Area, Stent Area, Strut-LumenDistance

Strut-Vessel Wall Distance

Protruding Covered

MalapposedEmbedded

6. Determine AppositionMalapposition

Alloy Strut Polymer Total Thickness Embedded Contact Malapposed

Cypher 140 7 154 <80 80-160 >160Taxus 97 15 127 <65 65-130 >130Zotarolimus 91 8 107 <55 55-110 >110Everolimus 81 7 88* <54 50-100 >108

6. Determine Apposition

Major

Strut

MinorStrut

Lumen Area; 12.36mm2

Stent Area; 10.95mm2

Lumen Area; 5.47mm2

Stent Area; 4.32mm21mm

1mm

• Associated with stent underexpansion

• Not Associated with stent underexpansion

OCT

7. Rule out geographic miss

1) Peruse OCT longitudinalimage for geographic miss

Stented Segment

8. Identify Edge Dissections

Major Category1) >60° / >3mm2)Flow limiting (TIMI)3)Inadequate MLA

8. Identify Edge Dissections

LCX-post BVS implantation

LCX-post BVS implantation

LCX – OCT run

9. Identify Tissue Protrusion

Major

Minor

• Effective MLA<5.5mm2

Effective Lumen Area; 2.70 mm2

Protrusion Area/Stent Area ≥ 10%

Effective Lumen Area; 6.30 mm2

Protrusion Area/Stent Area < 10%

Tissue protrusion

Tissue protrusion

1mm

1mm

Effective MLA>5.5mm2

LAD – during BVS implantation

LAD – during BVS implantation

LAD – post aspiration

10. Confirm ProceduralSuccess

Adequate stent expansion: The MSA within the stented segment must be≥90% the mean proximal and distal reference lumen areas.Proximal Reference = 7.9mm2, Distal Reference = 7.1mm2 , mean = 7.45mm2

• Target =≥90% of 7.45mm2 = 6.70mm2

•Final MSA = 7.15mm2 (Adequate Stent Expansion Achieved)

OCT – ISR - BVS

Modality Advantages Disadvantages

IVUS - High tissue penetration- Good imaging of fiber, calcium- Plaque burden- LMCA- No flush required- Large installed base- Outcomes data- Operator Experience

- Cost- Slow- Inferior resolution- Difficult to resolve lipid, thrombus, stents,

dissections- Apposition- Dissection- Calcium shadowing- Virtual histology reliability

OCT - High resolution- < 3 second pullback- Non-occlusive- Follow-up for apposition, dissection- High sens/spec for lesion identification (lipid, calcium,

fiber, thrombus)- Low crossing profile- Bioabsorbable stents

- Lack of outcome data- LMCA- Poor tissue penetration- Ostial- Very tight lesions- Very large vessels- Adds contrast load

IVUS versus OCT

Very Tight Lesions Pre-dilation with 1.5-2.0mm balloon

Very Large Vessels Injection via Guideliner

Contrast Load

Obstacles to OCT

Visipaque Dextran-40

Thank You