From drug eluting stents to bioresorbable scaffolds; to new horizons in PCI

ABSTRACT

Drug eluting stents and particularly the fully bioresorbable drug-eluting scaffolds herald a new era in percutaneous treatment of coronary artery disease. There has been tremendous progress in drug eluting stents with fully biodegradable coating polymers and polymer-free devices with reservoir technology planting the anti-proliferative drug. Despite significant decreases in in-stent restenosis rates with drug eluting stents, limitations still remain before we are able to develop fully bioresorbable scaffolds. Enhanced mechanical flexibility that provides superior conformability to the vessel wall, resumption of the vasoreactivity in the follow-up period and improving visualization on non-invasive imaging modalities are some of the supremacies of the fully bioresorbable scaffolds. In this review, we aim to give a general view on the latest developments in metallic drug eluting stents and fully bioresorbable scaffolds.

KEYWORDS:

• Drug eluting stents
• fully bioresorbable scaffold
• durable polymer
• biodegradable polymer
• polymer-free drug eluting stent
• anti-proliferative drug

Acknowledgments

We would like to thank the investigators who have contributed to the progression of the field with their invaluable efforts.

Financial and competing interests disclosure

E. Tenekecioglu has a research grant from TUBITAK (The Scientific and Technological Research Council of Turkey). P.W. Serruys and Y. Onuma are members of Advisory Board of Abbott Vascular. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Key issues

• The second-generation DES with a more biocompatible DP-based coating diminished late ST compared to the first-generation DES. Up to 1-year BP-DESs are superior to DP-DES for mortality, cardiac death, MI, TLR, and other adverse events; however, long-term studies are needed to confirm efficacy and safety of BP-DES.

• Out of polylactide (PLLA), some other materials, poly(desaminotyrosil-tyrosine ethyl ester) carbonate, polycaprolactone, salicylic acid, and some metals, like magnesium and iron, have been investigated in manufacturing of the BRS.

• The introduction of BRS has afforded crucial advantages over metallic devices, such as absence of metallic structure enabling the vessel to expand due to positive vessel remodeling, recovery of vasomotor functions after resorption of the polymer struts, avoidance of the chronic inflammation, and accordingly, reduction of that reduces the risk of neoatherosclerosis, avoidance of interference with magnetic resonance, and computed tomography coronary imaging.

• Igaki–Tamai scaffold is the only BRS with a CE mark approval for peripheral interventions.

• ABSORB II randomized trial was the first study that compared Absorb BVS and a metallic EES (XIENCE V).

• At nominal pressure, the largest available Absorb BVS is 3.5 mm, and vessels >4.0 mm should not be treated with Absorb BVS to avoid malapposition and possible strut disruptions.

• During the implantation of the Absorb BVS, D_max measurement is preferred over the interpolated reference vessel diameter measurement to minimize oversizing of the scaffold.

• The data support that the Absorb BVS use in complex lesions such as bifurcation lesions requiring two-stent technique, chronic total occlusion, left main lesions, or coronary bypass graft is limited.