Arslan Shaukat Profile picture
Aug 26, 2018 13 tweets 10 min read Twitter logo Read on Twitter
Another #FITSurvivalGuide tweetorial. This time on #intracoronary imaging w/ focus on IVUS and OCT
➡️ Rationale for use
➡️ Tech basics
➡️ Uses
➡️ Data
➡️ Images (high-yield)
@z_alirhayim @Almanfi_Cardio @AntoniousAttall @abashirMD @Babar_Basir
Why use them?
- Cor angio limited by: 2D view of 3D artery, diffuse dx, foreshortening, angulations, Ca++, eccentricity, vessel overlap, contrast streaming
- Angio alone ➡️ undetected edge complications, suboptimal stent exp in 15-20% ➡️ adverse events @cardiojaydoc02
IVUS tech: US reflected from vessel wall
➡️ 2 types: Rotational; Phased-array
➡️Rotational: 40-45 MHz, 3.2 Fr, 5 Fr guide, Rx, better near field resolution
➡️Phased-array: 20 MHz, 3.5 Fr, 5 Fr guide, Rx, more trackable
➡️Co-registration with angio now available
➡️ Uses near infrared 🔦, principles of US
➡️ 2.4-2.8 Fr
➡️ Imaging core at distal tip at 90 degrees to vessel, Rx, automated pullback, co-registration
➡️ Cannot penetrate blood cells - needs contrast flush
➡️ 10 x ⬆️ resolution but less imaging depth vs. IVUS
IVUS uses: ✅ lumen and vessel 📏, extent/severity of dx, remodeling, plaque burden, Ca
Non-LM lesions: Correlation with FFR modest (~60%), variable cutoffs, ❌ recommended to decide PCI vs not.
IVUS-XPL trial – 1400 pts with ≥ 28 mm lesions: ⬇️ TLR
IVUS in LM – 💯
❓ with Cor angio: short, Ca++, diffuse dx, bifurcation, ostial
✅ Can defer PCI if MLA ≥ 6 mm2 (if <, consider FFR)
➡️ EXCEL subanalysis: ⬇️ MSA : ⬆️ MACE, death, MI, ST at 3 yrs
➡️ Meta-analysis of 4592: ⬇️ MACE, death, MI and ST.
Pre-PCI: reference lumen, lesion📏 (stent📏), landing zone, Ca++ (?atherectomy), large thrombus (?thrombectomy), dissection (?SCAD)
Post-PCI: detect comps, suboptimal stent deployment/expansion/apposition, edge dissections, incomplete lesion coverage, tissue protrusion, thrombus
IVUS + PCI: ⬇️ MACE (mainly ⬇️ TLR), ⬇️ ST (1st and 2nd gen DES)
2nd gen DES: ⬇️ MACE, ⬇️ MI
✅ BMS, 1st + 2nd gen, ✅✅ longer lesions.
But, IVUS used in ~20% in USA
Best to use when: ❓underexpansion, long, ❓reference size, Ca, LM, complex anatomy, CTOs.
OCT uses: incomplete stent expansion, stent fracture, incomplete coverage
Better than IVUS for:
Plaque type
🧐 thrombus and type (red - RBCs/white - plt)
Small stent malappositions
Edge dissections
Tissue prolapse
Neo-intima formation and characteristics
But ❓clinical and long-term implications of findings
Other uses of OCT:
-🧐 culprit in ACS (thrombus, plaque rupture, erosion, Ca nodules, SCAD, embolic)
- Stent surveillance: neointima, neoatherosclerosis, mechanism of ST
- IVUS better for plaque burden (⬆️depth)
OCT + PCI: Plaque type (fibrous/lipid vs Ca) ➡️ lesion prep (atherectomy vs. 🎈)
Ca area correlates with stent underexpansion
PCI optimization:
-co-registration (stent edge landing zones, stent 📏)
-targeted post-dil of underexpanded stent segments
-“❌ contrast” PCI in CKD
⬇️ data
⬇️ MLA thresholds
⬇️ studies of clinical outcomes vs FFR, esp in LM
- MLA correlation with FFR modest
- TCFAs ➡️ peri-PCI MI (ILUMIEN – ⬇️ peri-PCI MI with OCT)
- ILUMIEN 3: 450 patients (1:1:1) OCT non-inferior to IVUS and Cor angio
- ACC/AHA: ❓
Future: ILUMIEN IV: OCT vs angio, clinical outcomes, 2500 patients (high clinical or angiographic risk). Primary outcome: TVF
Barriers to use:
➡️ availability
➡️ 💰
➡️ ❌ reimbursement
➡️ adequate training
➡️ ⏲️
➡️ contrast
But, "a picture is worth 1000 words"!

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Arslan Shaukat

Arslan Shaukat Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!


0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy


3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!