Calcified and Complex Coronary Lesions: Avoiding Stent Regret

Imaging to Guide PCI Decisions: Angiography, IVUS, or OCT

Arnold Seto, MD, MPAChief of Cardiology

Long Beach VA Medical CenterAssociate Clinical Professor,

University of California, Irvine

Disclosures

• Speaker’s Bureau: Terumo, Jannsen, Acist, Philips, Boston Sci

• Research funding: Acist, Philips

A brief true story:

So how do you want to fix this?

It’s a Type A lesion, focal, no Ca++, concentric. Primary stenting has been shown to save time, $, and may reduce periprocedure MI, no-reflow

I don’t know… let’s balloon it first

A brief true story:

AHA! See! I knew it!

Yessir.NC balloon high pressure -> Same resultAngiosculpt -> Same resultFlexotome -> Full dilation

What did we learn today?

When not to stent

• Unable to dilate/expand• Stent underexpansion

• Stent malapposition

• Small vessel

• Thrombus/Aneurysm

• Tortuosity

Stent underexpansion

• Failure to deploy the stent to desired/specified diameter (usually 90% of distal reference vessel)• Sometimes visible by fluoro (esp. StentBoost)• Often focal• Definitely imaged by IVUS/OCT

• Causes• Low pressure inflation• Compliant/Semicompliant balloon w/o NC postdil• High plaque burden• Eccentric lesions• Calcification• Prior stent

Basic reasons to use IVUS and OCT

Pre-PCI

• Lesion assessment

• Lesion length

• Stent sizing

• Calcification

Post-PCI

• Stent expansion

• Stent apposition

• Edge dissection

• Detect residual disease

The Korean Journal of Internal Medicine 2012;27(1):30-38.

IVUS ≠ Functional Assessment

• IVUS MLA has a modest correlation with FFR <0.80 except in the left main

• IVUS for non-LM lesion significance removed from 2018 ESC guidelines and 2017 AUC

Waksman, JACC 2013 61:917-23

FIRST study

350 patients10 sites

Best IVUS cutoff MLA <2.4mm2 <2.7 < 3.6

• Sizing Variability: – Sizing accuracy can vary by 0.3 mm depending on imaging modality used

– Recognize the risk of under/over-estimating vessel size by visual estimation

* Margin of error estimates based on resolution for each imaging modality: Resolution of OCT and IVUS: Bezerra, H.G., J Am Coll Cardiol.: Cardiovasc Interv. 2009; 2: 1035. Resolution of QCA: Dahm, J. and van Buuren, F. Int J Vasc Med. 2012. Offset and variability of visual estimate: data on file at Abbott Vascular.

Actual Size OCT IVUS QCA Visual Estimate

Over-Estimates Under-Estimates

Inter/Intra-ObserverVariabilityMost Accurate

Margin of Error*

3.0 mm 3.1 mm3.0 mm 2.8 mm 2.7 – 3.3 mm

Sizing by QCA/IVUS/OCT

IVUS vs OCT sizing European Heart Journal, May 2018 https://doi.org/10.1093/eurheartj/ehy285Most practical IVUS/OCT sizing criteria:

1) Mean distal lumen diameter with upsizing 0-0.25mm

2) Mean distal external elastic membanewith downsizing 0.25mm

Tip: Use Rotational Catheters to cross

Source: Boston Scientific

Crossing Force required

Same 3.5F crossing profile, but very different stiffness at distal end

When to use which IVUS catheter

Rotational

• Tortuosity

• Bifurcation

• Small caliber vessel

• Need for stent length

Phased-Array

• Larger straight vessel

• CTO (Short Tip)

• Short distal target

• When you are in a rush

Most common IVUS applications benefit from rotational catheter!

Phased Array vs Rotational vs HD IVUS

Phased Array 40MHz Rotational 40-45MHz HD IVUS 60 MHz

Freed, Safian Ch 12

Calcified Plaques

Calcium in OCT vs IVUS

• OCT and IVUS have similar accuracy for detecting calcium

• OCT has higher penetration of calcium, to detect thick calcium

• Degree of circumferential involvement and thickness that require atherectomy unclear

Bezerra, https://www.acc.org/latest-in-cardiology/articles/2016/06/13/10/01/intravascular-oct-in-pci

Case – LM Calcium

Case – LM Calcium

Case – LM Calcium

Case – LAD Calcium

Case – LAD Calcium

Goals of imaging post-PCI

The Korean Journal of Internal Medicine 2012;27(1):30-38.

Goal: 90% of distal reference lumen area or 80% of average reference lumen area

Pascal Motreff, and Geraud Souteyrand JIMG 2009;2:245-246

American College of Cardiology Foundation

56 yo man, 6 months after successful DES with angiographically good result.

Underexpansion “y” found at OCT associated with restenosis

Author Name (Year)

MACE

IVUS guidance (n=12,499 pts) was associated with:

▪ Larger stents ▪ Larger post-procedural MLD▪ More stents ▪ Longer stents

▪ Significant lower rates of:▪ MACE (OR 0.74, p<0.001) ▪ Death (OR 0.61, p<0.001)▪ MI (OR 0.57, p<0.001)▪ ST (OR 0.59, p<0.001)▪ TLR (OR 0.81, p=0.046)

Ahn JM, et al. Am J Cardiol. 2014;113:1338-47

Meta-analysis of outcomes after IVUS vs angiographic-guided DES implantation (n=26,503 pts from 3 RCT and 14 observational studies)

0.01 100

Favors CAGFavors IVUS

0.1 1 10

Odd Ratio and 95% CI

Ahn JM et al. (2013)

Ahn SG et al. (2013)

Chen SL et al. (2012)

Chieffo A et al. (2013)

Claessen BE et al. (2011)

Hur SH et al. (2012)

Jakabcin J et al. (2010)

Kim JS et al. (2011)

Kim JS et al. (2013)

Kim SH et al. (2010)

Park KW et al. (2012)

Park SJ et al. (2009)

Roy P et al. (2008)

Witzenbichler B et al. (2013)

Yoon YW et al. (2013)

Youn YJ et al. (2011)

Random Effect Model

0.000

0.006

0.190

0.186

0.057

0.091

0.820

0.577

0.171

0.015

0.155

0.006

0.322

0.000

0.789

0.202

<0.001

p-Value

Secondary Outcomes

Even

ts (

%)

Hong SJ, et al. JAMA. 2015;314(20):. doi:10.1001/jama.2015.15454700 673 660 643 624

700 671 665 654 641

Number at risk:

Angiographyarm

IVUS arm

Pati

ents

Wit

h P

rim

ary

End

po

int

Even

t (M

AC

E, %

)

0

5

10

Time Since Randomization (Months)

0 3 6 9 12

2.9%

5.8%

IVUS-guided PCI

Angiography-guided PCI

IVUS-XPL: Clinical Outcomes at 1 YearIVUS-guidance Led to 50% Reduction in MACE,Driven by Reduction in TLR

Primary Outcome: MACE(Cardiac Death, Target-lesion MI,

Ischemia-driven TLR)

HR 0.48 (95% CI, 0.28-0.83)P=0.007

0.40.0

2.5

0.30.7

0.1

5.0

0.3

0

2

4

6

8

10

CardiacDeath

MI TLR ST

P=0.48 P=0.32 P=0.02 P=1.00

All P-values calculated by log-rank

Angiography-guided PCIIVUS-guided PCI

Ultimate Trial

• 1448 patients• IVUS vs angio-guided PCI• 12 month f/u• Composite of

Death/MI/TVR• 2.9% IVUS vs 5.4% Angio

Target vessel failure

Zhang JACC 2018

Stent Malapposition

• Stent expanded adequately, but not well apposed to wall

• Causes• Late thrombus resolution

• Positive remodeling

• Inadequate post-dilatation

• Undersized stent

• Large vessel/aneurysm

Circulation 2007;115:2426-2434

Stent Malappositionwell-tolerated?

Prati JACC Cardiovasc Imaging. 2015 Nov;8(11):1297

Illumien III

Results

Ali Z, Lancet 2016; 388:2618-28

Illumien III

OCT-guided PCI:

Conclusions from Ilumien III

• Superior to angio-guided but noninferior to IVUS-guided PCI for achieving stent expansion.

• Resulted in:

Fewest untreated major dissections and areas of major stent malapposition

More contrast use than IVUS (220 vs 190ml)

• Only use OCT when cine would be necessary anyway

Clinical outcomes pending Ilumien IV (3,650 pts)

IVUS vs OCTEuropean Heart Journal, May 2018 https://doi.org/10.1093/eurheartj/ehy285

Summary

• Angiography is inadequate to diagnose calcium and detect stent underexpansion/malapposition/dissection

• IVUS and OCT both provide imaging to guide your interventions and avoid stent regret