This document summarizes a study comparing long-term survival outcomes of revascularization versus medical therapy alone in patients with at least one chronic total occlusion and well-developed collateral circulation. The study found that among 738 patients in a registry with Rentrop grade 3 collaterals, revascularization plus medical therapy significantly decreased the risks of cardiac death, all-cause death, and major adverse cardiac events compared to medical therapy alone. Therefore, the study concludes that revascularization may be recommended as the initial treatment for these patients.

1. Dr. Pavankumar P Rasalkar
Senior resident
Dept of Cardiology
PGIMER, Chandigarh

2. INTRODUCTION
• Studies have reported the benefits of
revascularization: PCI and CABG in pts with coronary
chronic total occlusion (CTO)
• CABG , widely performed in pts with multiple CTOs,
multivessel CAD, or diabetes
• The surgical outcomes in pts with CTOs have
improved
• Due to better perioperative management and
increased surgical experience

3. • Success rate of PCI in pts with CTO has increased due
to improvements in device technology: drug-eluting
stents, dedicated guidewires, and microcatheters
• A high frequency of failed PCI, perioperative
mortality, and potentially lethal complications is seen
in pts with CTO
• Clinicians are more likely to treat pts with CTO and
abundant distal collateral flow with medical therapy
alone

4. • No studies have compared the long-term clinical
outcomes of pts with CTO and well-developed collateral
circulation who undergo medical therapy versus those
who undergo revascularization
• This study aimed to compare the long-term survival
outcomes a/w revascularization versus medical therapy
in pts with at least 1 CTO and well-developed collateral
circulation

5. METHODS
Between March 2003 and February 2012, 2,024
consecutive patients were enrolled in the
retrospective Samsung Medical Center CTO registry.
Inclusion Criteria:
1. At least 1 CTO detected on diagnostic coronary
angiography;
2. Symptomatic angina and/or a positive functional
ischemia study

6. Exclusion criteria:
1) Previous CABG;
2) History of cardiogenic shock or CPR
3) ST-segment elevation AMI during the last 48 h
• Out of 2,024 pts included in the registry, 738 pts had
Rentrop grade 3 collateral flow and were included in
the final analysis
• Revascularization of CTOs was accomplished by
CABG or PCI with drug-eluting stent based on the pt’s
and physician’s preference

7. • Primary outcome was cardiac death during follow-up
• Secondary outcomes were all-cause death, MI,
repeat revascularization, and major adverse cardiac
event (MACE).
STATISTICAL ANALYSIS:
• Continuous variables were compared using the
Student t test or the Wilcoxon rank-sum test
• Categorical data was tested using the Fisher exact
test or the chi-square test as appropriate.
• Cumulative event rates were estimated by the
Kaplan-Meier method

14. Discussion
• Several studies have shown a survival benefit
in patients with CTO who undergo successful
PCI compared with those who undergo failed
procedures, suggesting that survival depends
on procedural success
• However, these results are limited in their
application, as it is difficult to predict the
success of an intervention

15. • In contrast this study evaluated the clinical outcomes
of overall treatment strategies (including medical
therapy, CABG, successful PCI, or failed PCI, and so
on) using an intent-to-treat analysis of a large,
dedicated registry
• Results would be helpful when making a clinical
decision in real-world practice.

16. PERSISTENT MYOCARDIAL ISCHEMIA
DESPITE ABUNDANT COLLATERAL
CIRCULATION
• Hansen reported that distal collateralization led to
greatly improved survival and freedom from MI in
patients with ischemic heart disease
• Many clinicians recommend medical therapy alone in
order to avoid procedural complications

17. • Studies have reported a weak relationship
between visualized collaterals and cardiac events
• ?Coronary steal
• Well developed collateral circulation may not
protect the myocardium
• This study supported this finding

18. LIMITATIONS
• Nonrandomized, retrospective, observational study
• Retrospective nature : could not identify the
alteration of medical therapy in study patients
during follow-up
• Rentrop classification : reflects collaterals visualized
by angiography and may not reflect their functional
capabilities or physiologic consequences

19. • A high prevalence of multivessel disease, may not be
generalized to populations with less severe disease
• Did not routinely evaluate the amount of viable
myocardium or ischemia of study patients using
functional ischemia testing

20. CONCLUSIONS
• Patients with CTO and well-developed collateral
circulation, revascularization with medical therapy
significantly decreased the long-term risk of cardiac
death, all-cause death, and MACE compared with
treatment with medical therapy alone
• Revascularization may be recommended as an initial
treatment
• A large scale randomized trial is needed to confirm
these findings

21. THANK YOU