Dr. Pavankumar P RasalkarSenior resident

Dept of CardiologyPGIMER, Chandigarh

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

• 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

• 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

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

Exclusion criteria: 1) Previous CABG; 2) History of cardiogenic shock or CPR3) 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

• 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

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

• 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.

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

• 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

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

• 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

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

THANK YOU