ΓΕΡΑΣΙΜΟΣ ΓΑΒΡΙΕΛΑΤΟΣ MD, MSc, FESC

Επιμελητής Α΄, Επεμβατικός ΚαρδιολόγοςΓΝΑ Η ΕΛΠΙΣ

Ποια είναι η καλύτερη απεικονιστική μέθοδος για τηνόσο στελέχους;

• LMCA disease found in 5-8% of angiograms1

• LMCA supplies on average 75% of myocardium2

• LMCA medically managed (CASS registry 70’s) = 50% mortality at 3 years!3

• LMCA revascularization is an area of ongoing diagnostic and strategy dilemma –

NOBLE / EXCEL

WHY LEFT MAIN?

1. G. Kassimis et al. Cardiovascular Revascularization Medicine (2017) 2. Leaman DM, et al Circulation 1981;63:285–99. 3. Bing et

al. Percutaneous Transcatheter Assessment of the Left Main JACC: Cardiovascular Interventions Vol. 8 , No 1 2 ,2015: 1529-39

ΣΤΕΦΑΝΙΟΓΡΑΦΙΑΠΡΟΚΕΙΤΑΙ ΓΙΑ ΑΥΛΟΓΡΑΦΙΑ 2 ΔΙΑΣΤΑΣΕΩΝ ΟΠΟΥ ΔΕΝ ΑΠΕΙΚΟΝΙΖΕΙ ΟΥΤΕ ΤΗΝ ΜΟΡΦΟΛΟΓΙΑ ΤΗΣ ΠΛΑΚΑΣ

ΟΥΤΕ ΤΗΝ ΙΣΧΑΙΜΙΑ ΛΟΓΟ Δ/ΧΗΣ ΤΗΣ ΣΤΕΦΑΝΙΑΙΑΣ ΑΙΜΑΤΩΣΗΣ

ΠΩΣ ΘΑ ΕΙΜΑΣΤΕ ΣΙΓΟΥΡΟΙ ΟΤΙ ΑΥΤΟ ΠΟΥ

ΒΛΕΠΟΥΜΕ

ΔΕΝ ΕΙΝΑΙ ΕΠΙΚIΝΔYΝΟ;

ANGIOGRAPHIC ASSEMENT

• Angiographic cut-off of ≥50% diameter stenosis (equivalent to ≥75% area stenosis) has been used to indicate hemodynamic significance in LM

• LIMITATIONS:

• short vessel segment,

• lack of a reference vessel,

• eccentricity,

• remodeling,

• potential for missed ostial disease due to deep catheter placement,

• overlapping daughter branches,

• frequent foreshortening

• HARD to delineate the PLAQUE distribution at the bifurcation carina

Intravascular Ultrasound

-IVUS is the standard of care, in use > 20 years

• Available in most cath labs

• Data supports improved clinical events post-PCI:

– reduced incidence of death, MACE, and stent

thrombosis

• Advantages of IVUS:

– Pre-intervention imaging

• possible in almost all patients without pre-dilation

– Penetration to the adventitia

• allows mid-wall or true vessel stent sizing

– IVUS predictors of stent failure are well established

IVUS studies to assess the significance

of LMS lesions

Left main intermediate lesions (30-60% stenosis)

• 55 pts with moderate left main stenosis, an MLA

• Cut-off value of 5.9 mm2 (sensitivity of 93% and specificity of 95%) and a minimal lumen diameter of <2.8 mm (sensitivity of 93% and specificity of 98%) best correlated with FFR <0.75.

Jasti V, Circulation 2004;110:2831– 6.

• 354 patients with intermediate left main stenoses, an MLA value >6.0 mm2 identified patients at low risk for adverse events with deferred revascularization.

de la Torre Hernandez. J Am Coll Cardiol 2011;58:351– 8

IVUS ΠΑΡΑΜΕΤΡΟΙ ΚΑΙ FFR<0.75 ΣΕΝΟΣΟ ΤΟΥ ΣΤΕΛΕΧΟΥΣ

Conclusions: In isolated LM disease, an IVUS-derived MLA <4.8 mm2 is a useful

criterion for predicting FFR 0.80.

Kang SJ, et al. J Am Coll Cardiol Intv 2011;4:1168–74)

IVUS criteria for a “significant” LMCA stenosis

IVUS or/and FFR

Coronary angiography demonstrates tandem lesions of the proximal LAD artery and distal LMCA

Repeat coronary angiography 2 years later shows

a patent stent in the LAD (A), but the LMCA appears significantly stenosed (B). FFR was 0.84, indicating that the LMCA stenosis is not

hemodynamically significant (C).

(Anatol J Cardiol 2017; 17: 258-68)

PLOS ONE | https://doi.org/10.1371/journal.pone.0179756 June 22, 2017

Post-PCI IVUS

•A minimal stent area (MSA) <8 mm2 in the proximal LMS, <7 mm2 in the LMS bifurcation, <6 mm2 in ostialLAD and <5 mm2 in ostial LCx were associated with stent underexpansion, increased instent restenosis rate at 9 months and increased MACE rate at 2-year follow-up

S.J. Park, Y.H. Kim, D.W. Park, et al Circulation: Cardiovascular Interventions 2 (2009) 167–177.

S.J. Kang, J.M. Ahn, H. Song, et al., Circulation: Cardiovascular Interventions 4 (2011) 562–569.

S.J. Kang, G.S. Mintz, J.H. Oh, et al Catheterization and Cardiovascular Interventions 82 (2013) 737–745.

X.F. Gao, J. Kan, Y.J. Zhang, et al Patient Preference and Adherence 8 (2014) 1299–1309.

•Separate IVUS pullbacks of the LAD and LCx are advised to accurately measure the MLA or MSA, because LCx ostial measurements cannot be reliable assessed obliquely from the LAD to LMS

C. Oviedo, A. Maehara, G.S. Mintz, et al American Journal of Cardiology 105 (2010) 948–954.

OCT optical analogue of IVUS

Clinical Use of OCT

• OCT is a light-based imaging modality that can provide

high resolution in vivo images of the coronary artery (axial

resolution 10–20 μm).

• OCT can be used to:

– Assess atherosclertotic plaque and visualise thrombus

– Evaluate lumen area with automated measurements

– Aid in stent placement

– Assess stent apposition and tissue coverage

LMCA Imaged With Angiography, OCT, and IVUS 1

Year Following Implantation of a DES

Plaque rapture

•Rapture/ dissection of a thin cap

fibroatheroma in the distal left main, with a

second fibrous cap discontinuity in ostial LAD.

•Features of high risk in non culprit segment of

vessel.

OCT for LMS post-PCI

• Assess stent expansion.

• Detected malapposition can be corrected

• In distal LMCA stenting, OCT can be used to

measure the length of the proximal segment for

sizing of the post-dilatation balloon.

• Verify that the guidewire recrosses into the side

branch through a distal stent cell to ensure optimal

scaffolding and a minimal metal carina.

• 3D evaluation of the Cx ostium for the treatment of

distal LMCA bifurcation lesions.

OCT-Pre➢Distribution of plaque including the extent of calcified plaque, to assess the thickness of calcium plaques which may affect the lesion preparation strategy.

➢Dissections resulting from predilatation are also readily detected by OCT and therefore, can be taken into account when assessing the required stent length.

➢Assessment of reference diameters for stent sizing using OCT is in general performed by assessing lumen diameter at the most healthy looking segments

➢OCT may be used to assess stent expansion.

➢Detected malapposition can be corrected to ensure fast intimal coverage of the stent if warranted.

➢obtaining information in patients with stented LMSstenosis about carina or plaque shift and side branchcompromise .

➢identifying ‘‘floating struts’’ at the side branch ostiumwhich can be a good place for neointimal hyperplasia

OCT-Post

OCT limitations at LMS assessment

• Τhe need to flush the lumen to achieve a blood-free field: requires the selection and positioning of a guide catheter precisely at the ostium to allow an adequate flush of the lumen during pullback.

• It offers greater spatial resolution (15 mm vs. 100 mm) at the cost of tissue penetration (2.0 mm vs. 10 mm) which limits assessment of plaque burden

Concept of Fractional Flow Reserve

Measurements

FFR IN LMS DISEASE

OBSERVATIONAL DATA:

Pooled Analysis of 6 LM-FFR deferral studies

(525 patients with mean follow up of 26 months)

Is the LMCA different?

- consequence of plaque rupture greater- larger proportion of myocardium subtended- Does measuring into LAD vs Cx differ (Yes if downstream resistance to flow)

CHALLENGES?

ØTechnical considerations

•Pressure damping, need to disengage guide

•Achieving adequate hyperemia only possible with IV adenosine

ØSerial Disease

•Downstream non-contiguous disease in both branches (LAD and LCx)

•Disease non-contiguous disease in only one branch. In this case safe to use disease-

free side-branch to isolate ‘true’ significance of proximal lesion, especially if LM FFRmeasured when diseased branch doesn’t have FFR<0.45

LAD LCX

Measure FFR towards

both LAD and LCx

+ w +LAD AND LCx

F R > 0.80

LAD -OR LCx

FFR <0.80

LAD AND LCx

FFR < 0.80

Disoordant FFRresult

LMCA not

significant

'

OMT CABG or PCIBe guided by FFR w llback troce

Pa tients for PCI:

Perform FFR pull back, treat largest step up, repeat pullback until

FFR > 0.80. If pullback equivalent, be guided by IVUS of

LMCA, using MLA > 6.0 as cut -off

FFR Limitations

• There is a lack of randomized data confirming the long-term safety of this approach.

• In most of the reported studies the method of revascularization was surgical with only few patients treated using PCI.

• It remains debatable in LMS disease as to whether an FFR of 0.75 versus an FFR of 0.80 should be regarded as the appropriate ischaemic threshold.

• At least 50% to 60% of LMS lesions involve the distal bifurcation, often with significant involvement of the ostia of LAD and LCX coronary artery, which may impact on the accuracy of the measured FFR values.

• An FFR assessment across the LMS is influenced by the presence of stenoses within distal coronary segments as well as the amount of functional myocardium supplied by these stenosed segments individually. Significant stenosis within the LAD or LCX territories may erroneously increase the FFR measured across the LMS stenosis.

Ποιο είναι το «σημαντικό»? Λειτουργικά,

απεικονιστικά ή και τα δυο?

Conclusion

Isolated Ambiguous Left main Stenosis:

Patient for PCI – IVUS (to confirm indications and guide left main intervention)

Ostial LM stenosis – IVUS ± FFR

Establishing diagnosis and optimising stent deployment, OCT has the advantage of better resolution.

Ambiguous Left main Stenosis with concomittant LAD and or LCX significant disease:

Use IVUS to assess left main disease (to choose optimal revascularization strategy –CABG vs. PCI)

Use FFR to confirm ischemia

A comparison of cardiovascular magnetic resonance and single photon emission

computed tomography (SPECT) perfusion imaging in left main stem or equivalent

coronary artery disease: a CE-MARC substudy

Foley et al. Journal of Cardiovascular Magnetic Resonance (2017) 19:84

27 ασθενείς με σοβαρή νόσο LMSστην GANG υποβλήθηκαν σε CMR & SPECT

Η CMR εμφάνισε μεγαλύτερη ευαισθησία και ειδικότητα (78%&85% αντίστοιχα ) σε σχέση με το SPECT

Ποια είναι η εμπειρία σας στην απεικόνιση της νόσου του κυρίως στελέχους;

ΕΥΧΑΡΙΣΤΩ !