This document discusses the management of unprotected left main disease and chronic total occlusions (CTOs) in coronary artery disease, highlighting the evolving guidelines and the effectiveness of percutaneous coronary intervention (PCI) compared to coronary artery bypass grafting (CABG). It emphasizes that while CABG has traditionally been viewed as the superior option, data show that PCI can also be a viable alternative when performed by experienced operators. The document presents a detailed analysis of procedural outcomes for both approaches and advocates for the treatment of CTOs, stressing the importance of skilled interventional cardiologists to improve patient outcomes.

1. LEFT MAIN AND
CHRONIC TOTAL
OCCLUSIONS –
FORGET BYPASS!
DR. TAN CHONG HIOK

2. 2 VERY SPECIAL
SUBSETS IN CORONARY
ARTERY DISEASE
•Unprotected Left Main disease
•Chronic Total Occlustion (CTO)

3. UNPROTECTED LEFT MAIN
DISEASE
•Significant disease of Left Main in a person
who has not under gone CABG of the LAD
&/0r LCx

4. OVER THE YEARS
•Has be battle ground for Surgeons and
Interventionists
•The argument has always been CABG is
better
•But ‘Better’ is a relative term: Better than
What?

5. GUIDELINES HAVE EVOLVED
OVER THE YEARS
•From a firm Class III
•Now a Class IIa/IIb depending on the
situation
•Not based on a whim but trial data

6. EXCEL - EVALUATION OF XIENCE
VERSUS CORONARY ARTERY BYPASS
SURGERY FOR EFFECTIVENESS OF
LEFT MAIN REVASCULARIZATION
•1900 patients would provide 80% power to
show the noninferiority of PCI to CABG with
respect to the 3-year primary end point
N Engl J Med 2016; 375:2223-2235

7. PRIMARY AND SECONDARY END POINTS

8. Time to
Event
• K-M Time to first
event analysis
PCI
CABG

9. PCI CABG
Event (No.) Rate (%) Event Rate Hazard ratio
p
PCI = 12.6% CABG =
7.5%
PCI = 0.7% CABG =
5.4%!
It is not ZERO! Therefore it is not ‘Once and
For All!
Graft occlusion can present as myocardial
infarction!

10. OVER A 3 YEAR PERIOD - PCI VS
CABG
•There is no significant difference in hard end point
of death, stroke of MI
•As expected, PCI will result in more
revascularisation – but so what?! Just repeat the
PCI
•Importantly… CABG is NOT a ‘Once and For All’
procedure
• There is a 7.5% revascularisation rate AND 5.4%

11. GUESS WHAT IS THE METHOD OF
REVASCULARISATION FOR GRAFT
OCCLUSION?

12. THINGS TO NOTE
•The PCI were done in experience centres
•The use of IVUS was high at 77%
•Total procedure time was 83min for PCI vs
243min for CABG
•98% had internal mammary arterial graft –
very good CABG

13. PCI CABG
CABG ends up with more AF
May take 1 less anti-platelet
BUT end up taking additional anti-
arrhythmic AND anti-coagulation!

14. •Let me share my data
•Presented in PCR SingLive
2016

15. METHOD
•A retrospective analysis of 68 unprotected Left Main
PCI cases that were performed from 2007 to 2013
•Mean follow up period was 3 years (range = 3 to 7
years)

16. RESULTS
68 patients
45
electiv
e
11
acute
12
urgen
t
Check angiogram
was performed in
52.9% of cases

18. RESULTS
•Overall MACE rates: 11.8% (8 out of 68 cases)
•Death: 10.3%
•Target lesion revascularisation: 1.5%
•Elective PCI: 6.6%
•2 deaths (4.4%) out of 45 patients
•Death rate in EXCEL at 3 yrs up to 7.3%
•Of which one was sepsis, and one was sudden
death
•1 target lesion revascularisation (2.2%)

19. RESULTS
•Acute STEMI PCI: 42.5%
•5 deaths
•Acute LM occlusion cases (5 out of 11, 42.5%)
•Presented with cardiogenic shock

20. LET’S SEE SOME EXAMPLE
•87 year old gentleman
•Angina
•Not good condition for CABG

21. VERY CALCIFIED DISTAL
LM

22. TEAR IN LEFT MAIN

23. PROTECT LCX WITH
STENT

24. ROTABLATE LM THEN STENT

25. FINALLY

26. CONCLUSION
•LM stenting in the non-urgent setting is safe
and has low MACE rate at 3 years
•Needs to be done in experienced hands
•Use of IVUS is strongly advocated
•It is a viable alternative to CABG

27. CHRONIC TOTAL
OCCLUSION-
THE FINAL FRONTIER OF
PCI
DR. TAN CHONG HIOK
ASIA HEART AND VASCULAR CENTRE

28. CHRONIC TOTAL OCCLUSION

29. 15-30%
85%
CTO Non-CTO
Success
50%
Failur
e50%
Not tried
70%
WHAT’S THE BIG
DEAL?
Of those sent for
Angiogram
15-30% have a CTO
Only 30% of CTO will
undergo an attempt
Only half of which will
succeed

30. SO WHAT?...
•Although at present there is no randomised control
trial on treatment of CTO
•But…
•There are 3 possible benefit to opening a CTO
•Improvement in symptoms
•Improvement in LV function
•Improvement in survival

31. IMPROVEMENT IN SYMPTOMSCollateral coming LCx

32. WHEN 1 ROAD IS BLOCKED, ANOTHER
OPENS
Collateral
“Self
Bypass”
Self bypass
enters the
RCA
RCA filling
‘backwards’

33. SYMPTOM IMPROVEMENT
•If collaterals are insufficient to provide
adequate blood flow
•During physical stress
•Symptoms will be alleviated with
revascularisation of the CTO vessel

34. IMPROVE LV FUNCTION
•MRI studies have demonstrated improved
LV function 5 months after successful
opening of a CTO vessel
•The benefits were greater in patients with
viable myocardium supplied by the CTO.
•This is due to abolition of the chronic
ischaemia resulting in myocardial
hibernation

35. IMPROVED SURVIVAL An MI in RCA would have
resulted in 2 huge territories
being infarcted
RCA collateral suppling a
huge LAD territory

36. IMPROVED SURVIVAL
•Observational studies found that mortality
was significantly reduced in the successful
PCI group during an average follow-up of 6
years
•Several observational studies suggest that
the improvements in LV function may result
in improved long-term survival
•Granted that randomised studies are not
easy to conduct

37. IF THERE IS BENEFIT IN
REVASCULARISING CTO
•Why is it that not all doctors treat CTO?
•Technically very demanding
•It is considered as a ‘sub-specialty’ in
Interventional cardiology
•Techniques and devices used are quite
specific for CTO

38. WHAT’S SO DIFFICULT ABOUT CTO
PCI?
Left Circumflex
CTO
Start of the
occlusion
Path of occluded
vessel

39. UNABLE TO SEE THE PATH OF THE
WIRE
The wire can come out of
the vessel completely!
Approximate path
of vessel
Vessel downstream
Path of wire

40. WHAT HAPPENED TO THE WIRE?
CTO
Fortunately in the CTO segment, there
is no blood flow

41. FORTUNATELY NOT EVERY CTO IS
SO HARDENED – DEPENDS ON
CHRONICITY
Hard
(Proteogylyca
n-collagen)
Not so
hard
Softer

42. SUCCESS RATE DEPENDS ON CHRONICITY
OF CTO
•The longer the CTO remains, the higher the content of
fully organised proteoglycan-collagen -> Hard
•Shorter duration CTO will have larger quantity of softer
organising thrombus
•The shorter the duration of CTO, the higher the
success rate for PCI
•Average operator, if he dares to attempt all CTO, will
have a success rate of 50%

43. WHAT ELSE CAN GO WRONG
WITH INEXPERIENCE DOCTOR?When the CTO segment is
not correctly crossed by wire

44. NOT KNOW WHAT TO DO
SO PLACED A STENT

45. THERE IS A SMALL PERFORATION
ARTERY STILL COMPLETELY
BLOCKED

46. PUTTING A STENT IN SUB-INTIMAL SPACE
WILL COMPLETELY BLOCK UP THE LUMEN!
Lumen
occluded!
Game Over!

47. CTO INTERVENTION REQUIRES
GOOD UNDERSTANDING OF
ANATOMY
Wire is not in LAD. Will never go
in correct direction! Failed after 1
hour

48. MUST REALLY KNOW THE
ANATOMY
Take the small path
Success after 30min!

49. WHAT IF THE WIRE JUST WON’T
GO?

50. RETROGRADE APPROACH!
Find the collateral that is
supplying occluded vessel
Bring a wire down

51. WIRE COMES UP FROM BELOW

52. ROUND THE WORLD TRIP

53. HUH? HOW DOES THAT WORK?
ONE long
wire!

54. WHEN THE SMOKE CLEARS

55. COMPARE THE BEFORE AND
AFTER

56. CAN ALL DOCTORS DO THIS?
•No

57. WORLD WIDE
•Limited number of people have good
experience in this technique
•Many cardiologists know and seen
•Few have tried and succeeded
•In Singapore
•Only a handful have done it

58. SINGAPORE
•Over the last 15 years I have done more than
100 fully documented retro-grade cases –
highest case load locally
•Done and taught more than 500 cases of
ante-grade CTO

59. CASES HAVE BEEN PRESENTED IN
PRESTIGIOUS INTERNATIONAL CTO
CONFERENCES

60. PROCEDURAL SUCCESS RATE
• High dependent on volume
https://doi.org/10.1016/j.jcin.2014.08.014

62. CTO SUCCESS
RATE
50%50%
Success rate of General
Interventionist
Success
Failure
95%
5%
Success rate of world
Masters
Success
Failure
87%
13%
My Success Rate
Success
Failure

63. CONCLUSIONS
•Limited number of CTO operators
•Patients are not offered the option of PCI
•If PCI is attempted the failure rate is high
•They are often told there is no choice but By-Pass
operation
•But If there is only a CTO of RCA or LCx without LAD
involvement, it is not fair to send for CABG without 1st
attempting PCI

64. SOME PEOPLE WOULD SAY
•Go for By-Pass operation
•Just go for one procedure
•Can have full revscularisation
•It’s a once-for-all procedure
•No need for staged procedure
•Surgeons always say ‘I see all these people with
rings that get blocked up whom at the end all
come see me!’

65. •6 Days after discharged for By-Pass
•LIMA to LAD
•SVG to RCA
•SVG to OM
•Presented with Inferior Myocardial Infarction
•Acute ST elevation in inferior leads
50 YEAR OLD MAN

66. SVG TO OM OCCLUDED! - HERE IS LAD AND LIMA

67. OM GRAFT COMPLETELY BLOCKED!
RCA GRAFT OCCLUDED AT
ANASTAMOSIS

68. CTO JUST BEYOND
ANASTOMOSIS SITE!
After crossing the CTO and
ballooning
The Lesion can be seen
Finally after Stenting
Wasted operation!

69. CONCLUSION
• CTO’s are reasonably common
• Patients are often inadequately treated
• Failure rate for PCI is high
• Patients are not offered the option of 2nd opinion
• Some are sent for unnecessary bypass
• Even bypass is not a solution sometimes
• There is good chance of successful PCI if performed by
experienced operator who has done at least 100 cases of CTO
and is proficient in Retrograde approach

70. THANK YOU