This document discusses evidence for performing PCI on chronic total occlusions (CTOs). It summarizes several studies that found: 1. Successful CTO-PCI was associated with improved angina symptoms, quality of life, and left ventricular function compared to failed CTO-PCI or medical therapy alone. 2. A study using PET imaging found that successful single-vessel CTO-PCI resulted in increased blood flow and coronary flow reserve in remote myocardium supplied by non-target arteries. 3. Guidelines generally support CTO-PCI for reducing ischemia when performed by experienced operators, though some trials found no benefit of routine CTO-PCI over medical therapy alone on cardiovascular outcomes.

1. Another Indication for
Chronic Total Occlusion PCI !!!
Bilal Hussain

2. Chronic Total Occlusion
Clinical Definition
Complete coronary arterial obstruction with TIMI flow 0 for longer than
3 months

3. CTO Prevalence and Treatment
CTO
18.4%
Patients with Coronary
Artery Disease
N = 14,439
Attempted
CTO-‐PCI
10%
Non-‐CTO
PCI
20%
Medical
Therapy
44%
CABG
26%
Treatment of Patients
with CTOs
N = 1,697
Feferetal.JACC2012.

4. Variability in Current Treatment
CTO-PCI attempt rate varied among hospitals
from 1% to 16%
*p <0.001;**p =NS;°p<0.001
Feferetal.JACC2012.
CTO treatment strategies in 3 Canadian centers

5. PCI Utilization Disproportionately Low in CTOs
0%
10%
20%
30%
40%
50%
PCI
CABG
Med Rx
Christofferson et al. Am J Cardiol
2005.
BARI Registry Substudy
CTO
N=1,612
No CTO
N=1,475
CAD Treatment Strategies

6. Reason not bypassed:
Not intended to treat (n=12)
Diseased (n=11)
Inadequate conduit (n=2)
Too small (n=19)
Unable to find (n=1)
Other (n=36)
CABG is Not Always an Option
SYNTAX CTO Substudy
Bypassed
68%
Not
Bypassed
32%
266 CTO patients randomized
to receive CABG
Serruys P, CRT 2009 [modified]; courtesy Prof Serruys and the SYNTAX investigators

7. Percutaneous recanalization of Chronic Total occlusions
Most challenging procedure in the Cardiac Cath Lab
Technically difficult to treat
Time intensive
Complex procedure
Significant contrast load
Complications
Historic success rate ~ 50%
Success rates now - > 90%
COST !!!!!
PCI for Chronic Total Occlusion

8. Clinical Indications
why open a chronically occluded coronary artery?
• Symptom control
– Angina
– CHF
– Fatigue
• Improve LV function
– Regional
– Global
• Survival
– Improved tolerance of MI
– Complete revascularization
– Ischemic Risk

9. CTO-PCI
Brief Review of literature and Guidelines

10. Impact of CTO revascularization
on Quality of Life
Significant improvement in physical limitation, anginal
episodes, and treatment satisfaction in successful vs. failed
patients

11. CTO Recanalization and Angina Control
Series Successful Follow-up Asymptomatic
PCI (n) (months) (%)
Olivari 2016 248 12 88.7
Berger 2013 139 6 87
Stewart 2007 45 12 68
Ivanhoe 1999 264 36 69
Ruocco 1993 160 24 69
Bell 1991 234 32 76

12. Long Term LV Function
Improvement with CTO PCI
Kirschbaum SW et al. American Journal of Cardiology2008
Early and late effects of
percutaneous
revascularization for
chronic total coronary
occlusion on left ventricular
(LV) function and volumes
Magnetic resonance
imaging was performed in
21 patients before and 5
months and 3 years after
recanalization
Global LV function and
volumes and segmental
wall thickening (SWT) were
quantified on cine images
A positive effect on LV remodeling and
ejection fraction was observed up to 3 years
after recanalization

13. Successful intervention was associated with a decrease in mortality
(95% confidence interval: 0.62 to 0.83; p < 0.001).
CTO = chronic total occlusion; PCI = percutaneous coronary intervention.
13,443 patients
14,439 CTO procedures
CTO PCI was successful in
10,199 cases (70.6%).
Follow-up of 2.65 years
successful PCI of at least 1
CTO associated with
improved survival
Complete revascularization
was associated with
improved survival
compared with partial or
failed revascularization
Mortality benefit with CTO PCI
George S, Cockburn J, Clayton TC, Ludman P, Cotton J, Spratt J, Redwood S, de Belder M, de Belder A, Hill J, Hoye A. Long-term follow-up of elective chronic total
coronary occlusion angioplasty: analysis from the UK Central Cardiac Audit Database. Journal of the American College of Cardiology. 2014 Jul 22;64(3):235-43.

14. Major Randomized Control
Trials on CTO-PCI

15. Routine CTO-PCI performed within 1 week
of primary PCI for STEMI does not result in
improved LV function or clinical outcomes
over an intermediate period of follow-up
Conservative
(n = 154)
CTO-PCI
(n = 150)
EXPLORE
LVEF at 4 months: CTO-PCI vs. conservative: 44.1%
vs. 44.8%, p = 0.6; LVEDV: 215.6 vs. 212.8 ml, p =
0.70
MACE at 4 months: 5.4% vs. 2.6%, p = 0.21
Periprocedural complications in CTO arm:
Dissections: 13, tamponade 1, emergency CABG/
stroke/death: 0
Trial design: Patients with STEMI treated with primary PCI and with evidence of noninfarct
artery chronic total occlusion (CTO) were randomized to CTO-PCI within 7 days or
conservative management. They were followed for 4 months.
Results
Conclusions
Final LVEF at 4 months
%
(p = 0.6)

16. 0
4
8
Ischemia-driven revascularization
EUROCTO
Results
• Angina frequency score (p = 0.003) and
the quality-of-life score (p = 0.007)
improved for PCI compared with OMT
(intention to treat)
• Major cardiovascular and
cerebrovascular events: 5.2% for PCI vs.
6.7% for OMT (p = 0.55)
• Ischemia-driven revascularization: 2.0%
for PCI vs. 6.7% for OMT (p = 0.04)
Trial design: Stable angina patients with a chronic total occlusion (CTO) were
randomized to PCI with a biolimus-eluting stent plus optimal medical therapy (OMT)
(n = 259) vs. OMT alone (n = 137).
Conclusions
Among patients with stable angina due to
CTO, PCI improved angina frequency and
quality of life
PCI OMT alone
%
(p = 0.04)
2.0
6.7

17. DECISION-CTO
Trial Description: Patients with ≥1 chronic total occlusion (CTO) were randomized to receive CTO-PCI
or optimal medical therapy (OMT). They were followed for 4 years.
• RESULTS
• Primary endpoint for CTO-PCI + OMT vs. OMT, MACE
at 4 years: 22.3% vs. 22.4%, p for noninferiority =
0.014, p for superiority = 0.86
• Death at 4 years: 3.6% vs. 5.3%, p = 0.3, MI: 11.3% vs.
8.5%, p = 0.14, any
revascularization: 11.0% vs. 10.6%, p = 0.55
• QOL measures, including SAQ for angina, were similar
CONCLUSIONS
Routine CTO-PCI + OMT is not superior to OMT alone
in reducing CV outcomes among patients with ≥1 CTO
Lee SW, et al. Circulation 2019;139:1674-83
OMT
(n = 398)
CTO-PCI
(n = 417)
22.3 22.4
0
25
50
Primary endpoint
%

18. The 2012 ACCF/AHA/SCAI Guideline for
Percutaneous Coronary Intervention
CTO PCI is indicated in patients with clinical indications and suitable
anatomy when performed by operators with appropriate expertise
(Class IIa, Level of Evidence [LOE] B)
The 2014 European Society of Cardiology and
European Association for Cardio-Thoracic Surgery
Guidelines
CTO PCI is to be considered in patients with expected ischemia
reduction in a corresponding myocardial territory and/or for angina
relief (Class IIa, LOE B)
An initial anterograde approach and consideration of a retrograde
approach if this fails or a primary retrograde approach in selected
patients (Class IIb, LOE C)

19. The ACC/AATS/AHA/ASE/ASNC/SCAI/SCCT/STS
2017 Appropriate Use Criteria for Coronary
Revascularization in Patients With Stable Ischemic
Heart Disease
The separate criteria for CTO lesions was eliminated from the 2012
guidelines
Indications for revascularization in SIHD are determined irrespective
of whether the lesion is a CTO.The indication for revascularization of a
coronary artery lesion, whether CTO or severe stenosis, is based on
symptoms, the extent of antianginal medications, and the risk of
ischemia

20. EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society
of Cardiology. 2021 Dec 6.

21. The study aimed to evaluate the intrinsic effect
of CTO percutaneous coronary intervention
(PCI) on changes in absolute perfusion in
remote myocardium
AIM OF THE STUDY

22. A total of 164 patients who underwent serial [15O]H2
O positron emission tomography (PET) perfusion
imaging at baseline and three months after successful
single-vessel CTO PCI were included to evaluate
changes in hyperaemic myocardial blood flow (hMBF)
and coronary flow reserve (CFR) in remote
myocardium supplied by both non-target coronary
arteries
METHODS OF THE STUDY

23. BASELINE CHARACTERISTICS

25. RESULTS
CTO revascularisation resulted in an increase in remote myocardial perfusion
The quantitative improvement in hMBF and CFR in the CTO territory was
independently associated with the absolute perfusion increase in remote myocardial
regions

26. Provides tissue level evidence of improved perfusion in remote
myocardium supplied by donor arteries after CTO PCI

27. CRITIQUE
Small single-centre experience
Soft indication for CTO PCI
Study centered on treating lesions rather than patients
Patients with lesions with TIMI I flow included as CTO patients
Invasive pressure measurements not performed in the CTO and
collateral donor arteries

28. Conclusion
• CTO is associated with symptoms of angina, but also often with
dyspnea, fatigue
– Patients minimize symptoms
– Often inappropriately labeled asymptomatic
• CTO PCI is for symptoms improvement once drugs have failed
• Tissue level evidence of absolute improvement in perfusion does rally
the cause of CTO PCI but will such data change the approach of non
CTO operators towards CTO PCI is debatable
• For the non believers, is it too little, too late ??