Courtesy of Dr. Carlos Fava.

Chronic Total Occlusions (CTO) are truly challenging and different technologies are being developed to treat them, but currently our most pressing questions about them are whether in-stent CTO present the same success rate as de novo CTO, and what their prognosis is.

The present trial analyzed 899 CTO: 111(12.3%) were in-stent CTO and (IS-CTO) and 788 de novo CTO.

Both cohorts had similar characteristics, except for higher rates of AMI and PCI in the IS-CTO group.

There were no differences in angiographic characteristics, treated vessel, J-CTO (1.88±1.24) or PROGRESS-CTO scores (1.04±0.88). The IS-CTO cohort presented lower moderate/severe calcification and bifurcation distal to occlusion, more often >20 mm occlusion, and less adequate area for stent implantation.

There was a lower tendency to use the transradial approach in IS-CTO. Antegrade wire escalation was more frequent (59.0% of IS-CTO and 48.1% of de novo CTO p=0.08). The retrograde, dissection and re-entry techniques were less frequent in de novo CTO.

Second generation DES were preferred in both cohorts. Technical success was 87%, and procedural success, 86%.

90% of patients were followed up at 471 days (354-872). MACE was superior in the IS-CTO group (20.8% vs. 13.9% p=0.07), mainly driven by TVR (16.7% vs. 9.4% p=0.03), with no difference in death or MI related to the treated vessel.

IS-CTO was an independent predictor of MACE, with >2 fold increase at follow up.

Conclusion

Procedural success in IS-CTO was high and had similar results to those of de novo CTO. However, IS-CTO was independently associated with higher MACE driven by TVL at follow up.

Comment

It is worth noting that, in a program with a high number of CTO cases, more than 10% are in-stent CTO, which, compared to de novo CTO, have higher MACE rate at the expense of higher ischemia driven TLR.

In addition, IS-CTO required more use of crossing devices (this study used CrossBoss), which certainly increased costs.

We should bear in mind that, even though cohorts were similar, IS-CTO cohort presented more prior AMI and PCI. These data may negatively affect long term prognosis.

Courtesy of Dr. Carlos Fava.

Original Title: Procedural and long-Term Outcomes of Percutaneous Coronary Intervention for In-Stent Chronic Total Occlusion.

Reference: Lorenzo Azzalini, et al. J Am Coll Cardiol Intv 2017; 10:892-902.

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