Left Main disease and anomalies.

1. LEFT MAIN DISEASE
Raviraj Kadam

2. Introduction
• Significant unprotected left main coronary artery (ULMCA) disease occurs in 5–7% of
pts undergoing CAG.
• ULMCA disease treated medically have a 3-year mortality rate of 50%.

3. Gross anatomy
Origin
It is a branch of the ascending aorta, with its normal origin in the left aortic sinus, just superior to
the aortic valve.
Course
LMCA runs for 5-10 mm as it passes to the left and posterior to the pulmonary trunk before
bifurcating. Diameter is 4-4.5mm.
Branches
left anterior descending artery (LAD)
left circumflex artery (LCx)

5. Why left main is important?
• supplying 75% of the left ventricular (LV) cardiac mass with right dominant type or balanced type
and 100% in the case of left dominant type.
• severe LMCA disease will reduce flow to a large portion of the myocardium.
• divided into three anatomic regions-ostium or origin of the LMCA from the aorta, a mid-portion,
and the distal portion.
• Atherosclerotic lesions tend to form at specific regions of the coronary vasculature where flow is
disturbed, particularly in area of low shear stress.
• LMCA bifurcation, intimal atherosclerosis is accelerated primarily in area of low shear stress in the
lateral wall close to the LAD and LCx bifurcation

6. LMCA: Conical Shape by FD-‐OCT
Fujino et al, JACC CV Intv 2013

7. Etiology
 Atherosclerosis(significant shear stress)
 Nonatherosclerotic
 Syphilis aortitis
 Giant cell arteritis
 Takayasudisease
 Calcific diseases
 Valvereplacement
 Mediastinal irradiation,
 High angulated takeoff
 Coronary Anomalies
 Compression
https://www.medpagetoday.com/cardiology/pci/40986

8. Atherosclerosis Prevalence
https://slideplayer.com/slide/11116749/

9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4086336/

10. High Takeoff Coronary Ostia
Above Sinuses of Valsalva
Kimbiris D., et al. Circulation 58:606-15, 1978
&
www.ncbi.nlm.nih.gov/pmc/articles/PMC34232
80/.

11. Left Coronary Arising From PA
Bland-White-Garland Syndrome
Blood flows from the RCA via collaterals to
the left coronary artery, and then into
the pulmonary artery.
Am J Case Rep. 2013; 14: 370–372 & https://academic.oup.com/europace/article/12/9/1338/529188

12. Left Main Arising from Right
Coronary Sinus
Subtypes:
– Anterior free-wall course
– Retro-aortic course
– Inter-arterial- incidence 1:12,500
[Accounts for 60% of anomalous left
main from right coronary sinus (2.8%
overall coronary anomalies).
Recognized association with ischemic
symptoms and sudden death >50%]

13. Left Main from Right Sinus
Anterior Course
The left main trunk arises ectopically from the right sinus of
Valsalva and passes epicardially across the RV outflow tract.
Kimbiris D., et al. Circulation 58:606-15, 1978.

14. Anomalous Left Coronaries
Retro-Aortic Circumflex, Anterior LAD
The LAD and circumflex branches arise from the right sinus of Valsalva.The
LAD passes epicardially across the RVOT, and the LCX passes behind the aorta.

15. Anomalous Left Main
Inter-Arterial
The left main trunk arises ectopically from the right sinus
of Valsalva and passes between the aorta and pulmonary
artery.
https://www.amjmed.com/article/S0002-9343(17)31024-0/fulltext

16. Anatomic lesion complexity
• meta-analysis of various trials shows ULMCA identified distal lesion as the
most significant predictor of repeated revascularization and overall MACE.
• Some reports suggest that results in the case of ‘simple’ bifurcation lesions
treated with a one- stent approach are more favorable when compared with
‘complex’bifurcation lesions treated with a two-stent approach.
• because of the extensive plaque burden, patients with distal ULMCA disease
approached with two-stent techniques showed a TLR rate as high as 25% with
restenosis.
• (A collaborative systematic review and meta-analysis on 1278 patients undergoing percutaneous drug-eluting stenting for
unprotected left main coronary artery disease. Am Heart J 2008;155:274–283.)

17. Role of FFR in intermediate LMCA stenosis
• FFR measurement for intermediate LMCA evaluation should be required, especially in cases of ostial and
shaft LMCA disease.
• FFR measurement could avoid unnecessary LMCA stenting or bypass surgery.
• FFR of intermediate LMCA stenosis tends to be under- or overestimated because of additional disease in
LAD and left circumflex artery LCX.
https://www.radcliffecardiology.com/articles/use-fractional-
flow-reserve-left-main-coronary-artery-lesion-assessment

18. Result of IVUS
• MAIN-COMPARE registry reported that IVUS guidance was associated with improved 3-year
mortality compared with a conventional angiography-guided procedure.
• Pts receiving DES, IVUS-guided PCI associated with a significantly lower 3-year incidence of
mortality compared with angio-guided PCI (4.7% IVUS vs. 16% angiography).
interventions.onlinejacc.org/content/6/7/654

19. Ostial and mid vessel lesions

21. Journal of the Saudi Heart Association
Volume 27, Issue 4, October 2015, Pages 272-276

22. • Percutaneous coronary intervention could be considered in-
• elderly patients
• patients with small left circumflex artery
• patients without any complex additional lesions (low or intermediate
SYNTAX score)
• non-diabetic patients
• poor surgical candidates
• distal coronary disease unfavourable to CABG
• high surgical risk (high EuroSCORE)
• co-morbidity (chronic obstructive lung disease)
• emergency clinical situation, i.e. acute LM occlusion

23. • CABG-
• patients with heavy calcified LM disease
• reduced LV function
• diabetic patients particularly with insulin-dependent diabetes
• MVD suitable for CABG (particularly with low EuroSCORE).
• distal LM bifurcation lesion with reduced LV function or with occluded RCA or with
additional
complex lesions on the other coronary vessels (high SYNTAX score)

26. Conclusion
• Stenting of ULMCA stenosis can be performed with good results in carefully selected patients.
• Patient selection is crucial and must be based on medical–surgical consultation (Heart Team
concept) and ethics of information.
• Stenting of non-distal LM can be achieved without major technical difficulties and with good
immediate- and long-term results
• Stenting of distal LM lesion is a true technical challenge.
• For the UPLM bifurcation, single stent strategies are still preferred and should yield acceptable
results for >80% of cases.
• FFR & IVUS guidance should be considered and may improve clinical outcomes.

27. ???????????
Pete Maravich
(June 22, 1947 – January 5, 1988)

28. THANK YOU