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How Are Left Main and non Left How Are Left Main and non Left Main Bifurcations Unique: Main Bifurcations Unique:

Insights from ImagingInsights from ImagingInsights from ImagingInsights from Imaging

Akiko Maehara, MDAkiko Maehara, MD

Cardiovascular Research Foundation/Cardiovascular Research Foundation/Columbia University Medical CenterColumbia University Medical Center

New York City, NYNew York City, NY

Disclosure Statement of Financial InterestWithin the past 12 months, I or my spouse/partner have had a financial Interest /arrangement or affiliation with the organization(s) listed below

Affiliation/Financial Relationship CompanyGrant/ Research Support: Boston Scientific Corp.

Speaker Fee Volcano Corp.

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Plaque Distribution by IVUS (n=140)Plaque Distribution by IVUS (n=140)1/1,1,1LMCA (1/1)

1/0,1,1LMCA (1/0)

1/0,1,0LMCA (1/0)

LCX (1)LAD (1)

62% 14% 14%LCX (1)LAD (1) LCX (0)LAD (1)

0/1,1,1LMCA (0/1)

0/0,1,0LMCA (0/0)

0/0,1,1LMCA (0/0)

0/1,0,1LMCA (0/1)

4% 3% 2% 1%

In 90% plaque extends from LMCA-LAD

LCX (1)LAD (1) LCX (0)LAD (1) LCX (1)LAD (1) LCX (1)LAD (0)

Oviedo C et al. Circ Cardiovasc Interv 2010;3:105Oviedo C et al. Circ Cardiovasc Interv 2010;3:105--12.12.

Plaque Distribution LMCA Plaque Distribution LMCA vsvs LAD/D1LAD/D1Inclusion: angiographically significant bifurcation disease

90%

96%

Yakushiji @ CRF

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Plaque Composition in Plaque Composition in 256 Bifurcations256 Bifurcations

Han SH et al. Eurointervention 2010;6:313Han SH et al. Eurointervention 2010;6:313--320.320.

Necrotic Core (NC) & Dense Calcium (DC)

%NC and %DC were greater in the LAD (15.7%, 8.8%) than in the LM (11.8%, 4.5%) or LCX (10.9%, 4.5%) - p=0.002 &

p=0 0004 respectively

Plaque Composition in Each Vessel

15.7 56.2 19.4

24.411.8 56

LAD

LMNecrotic Corep=0.0004Dense Calciump=0.002Fibrous

p=0.0004, respectively.

10.9 57.2 27.5

0% 50% 100%

LCX

Fibrous p=0.7FibroFatty p=0.001

Oviedo @ CRF

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The distribution by vessel of the 168 eccentric plaques differed according to plaque type

(p=0.035)

Plaque Phenotype in Each Vessel

LAD

LM

TCFAThCFAPIT

0% 50% 100%

LCX

Oviedo @ CRF

Pre -PCI FinalCarina Carina ShiftShift

LMCA LCX

LCX

LAD

5

12.0

m2 )

5.4mm2 4.0mm225.0

m2 )

11.8mm2 9.6mm2

3.0

rina

1.22 1.47

p<0.001

MLA within LCX ostium EEM area at MLA EEM eccentricity

Carina Shift Carina Shift (n=23, LCX DS<50%)(n=23, LCX DS<50%)

2.0

4.0

6.0

8.0

10.0

MLA

with

in L

CX

ost

ium

(mm

5.0

10.0

15.0

20.0

EE

M a

rea

at th

e M

LA s

ite (m

m

1.0

1.5

2.0

2.5

ecce

ntric

ity in

dex

at L

CX

car

p=0.009 p=0.048

p

0pre post-stenting

0pre post-stenting

E

0.5pre post-stentingE

EM

p 0.009 p 0.048

78% showed a >10% reduction of MLA within LCX ostium after cross-over stenting

Kang et al. Circulation Cardiovasc Interv 2011;4:355Kang et al. Circulation Cardiovasc Interv 2011;4:355--6161

Pre -PCI FinalPlaque Plaque ShiftShift

LMCA LCX

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Carina & Plaque ShiftCarina & Plaque Shift-- 38 Pre & Post 3D Comparison 38 Pre & Post 3D Comparison --

1.1. Narrow LAD/LCX AngleNarrow LAD/LCX Angle22 Less Plaque Burden atLess Plaque Burden at2.2. Less Plaque Burden at Less Plaque Burden at

LCX LCX OstiumOstium3.3. 60% of 60% of LumenLumen Decrease Decrease

Due to Carina Shift Due to Carina Shift

Xiu & Choi et al @ CRF

20

30

40

20

30

40 BMSDistal

LMCA 55%

Distal LMCA:100%All SES

Crush

Location of Restenosis after LMCA StentingLocation of Restenosis after LMCA Stenting

LCX

0

10

20

40

0

10SES Cross-

Over

Distal LMCA:100%SES: 84%

SES PES

4 10

LCX Ostium

0

10

20

30 Crush/T

Cross-Over

ISR:9% ISR:29%

4 10

Pan. et al, Am Heart J 2007; 88: 153, Kim Am J Cardiol 2006; 97:1957-1601, He Y, AHA 2009

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Criteria for stent Criteria for stent underexpansionunderexpansion at the at the distal LMCA bifurcation (n=403)distal LMCA bifurcation (n=403)

98 1%

LCX ostium

90.2%

98.1%

4 Cardiac death2 Late stent thrombosis

Kang et al. Circulation Kang et al. Circulation CardiovascCardiovasc IntervInterv 2011; 4:5622011; 4:562--569569

SB Stent Underexpansion After CrushSB Stent Underexpansion After CrushFinal angiographic result

SB stent ostium

MV

SB distal stent

MVMV SBSB PP

MSA, mmMSA, mm22 6.56.5±±1.71.7 3.93.9±±1.01.0 <0.0001<0.0001

Stent expansion, % Stent expansion, % 92.192.1±±16.616.6 79.979.9±±12.312.3 0.020.02

MSA <4 mmMSA <4 mm22 10%10%(2/20)(2/20)

55% 55% (11/20)(11/20)

0.0070.007

MSA <5 mmMSA <5 mm22 20%20%(4/20)(4/20)

90%90%(18/20)(18/20)

<0.0001<0.0001

Costa et al. J Am Coll Cardiol. 2005;46:599-605

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The Optimal Cutoff Value of Post-Procedural MSA to Predict a Follow-up MLA ≥4mm2 After

Bifurcatoin T-Stenting

Hahn et al. J Am Coll Cardiol 2009;54:110-7

AUC=0.81 (95%CH=0.64-0.99)

AUC=0.88 (95%CH=0.80-0.95)

Take Home MessageTake Home Message1.1. 90% of plaque distribution is LAD dominant in the 90% of plaque distribution is LAD dominant in the

LMCA, LAD/D1 bifurcation, no matter the angiographic LMCA, LAD/D1 bifurcation, no matter the angiographic appearance.appearance.

22 I LMCA bif ti d d th l iI LMCA bif ti d d th l i2.2. In LMCA bifurcations, advanced atherosclerosis In LMCA bifurcations, advanced atherosclerosis ((fibroatheromafibroatheroma, calcification) is more in the proximal , calcification) is more in the proximal LAD than LMCA or LCX. However, in nonLAD than LMCA or LCX. However, in non--LM bifurcation LM bifurcation lesions, the proximal segment had more plaque than lesions, the proximal segment had more plaque than the distal segment.the distal segment.

3.3. In LMCA lesions, carina shift is related to the narrow In LMCA lesions, carina shift is related to the narrow angle of LAD/LCX and minimum plaque at LCXangle of LAD/LCX and minimum plaque at LCX ostiumostium..angle of LAD/LCX and minimum plaque at LCX angle of LAD/LCX and minimum plaque at LCX ostiumostium..

4.4. The main difference between LMCA and LAD/D1 The main difference between LMCA and LAD/D1 bifurcation are 1) size of vessel and 2) angle which may bifurcation are 1) size of vessel and 2) angle which may relate to different mechanism of lumen compromise at relate to different mechanism of lumen compromise at side branch side branch ostiumostium and acute outcome (=minimum and acute outcome (=minimum lumen area).lumen area).