Self-Apposing Stents in Coronary Chronic Total Occlusions: A Pilot Study

Area of Science:

• Interventional Cardiology
• Biomaterials Science
• Vascular Biology

Background:

• Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is challenging, often associated with incomplete stent strut apposition and coverage.
• Self-apposing (SA) stents offer a potential solution to these issues compared to conventional balloon-expandable (BE) stents.

Purpose of the Study:

• To evaluate the 12-month angiographic and clinical outcomes of SA stents versus BE stents in CTO PCI.
• To compare stent strut malapposition and coverage between SA-DESs and BE-DESs.
• To assess the incidence of major adverse cardiovascular events (MACEs) at 12 months.

Main Methods:

• A pilot study comparing 20 patients treated with SA drug-eluting stents (DESs) against 20 matched controls treated with BE-DESs for CTO PCI.
• Clinical follow-up for 12 months, with coronary angiography and optical coherence tomography (OCT) at follow-up.
• Primary endpoints: stent strut malapposition and coverage. Secondary endpoint: composite MACEs at 12 months.

Main Results:

• The SA-DES group demonstrated significantly lower rates of malapposed struts (0% vs 4.5%) and uncovered struts (0.08% vs 8.2%) at 12 months.
• Despite improved stent coverage, the SA-DES group experienced a higher rate of MACEs (45% vs 15%), primarily driven by clinically-driven target lesion revascularisation.
• Both groups had a high prevalence of complex lesions and diabetes mellitus.

Conclusions:

• Self-apposing DESs in CTO PCI are associated with superior stent strut apposition and coverage compared to BE-DESs.
• However, SA-DESs in this context were linked to a significantly higher incidence of in-stent restenosis and MACEs.
• The findings suggest a potential trade-off between improved stent deployment and adverse clinical outcomes in complex CTO PCI.