Comparisons of early vascular reactions in biodegradable and durable polymer-based drug-eluting stents in the porcine coronary artery

Abstract

Current drug-eluting stents have abluminal polymer coating; however, thrombus formation in these compared with that in uniformly coated stents remains controversial. We evaluated thrombus formation and early endothelialization after using abluminal biodegradable polymer-coated sirolimus- (BP-SES), and everolimus-eluting stents (BP-EES) versus a durable polymer-coated everolimus-eluting stent (DP-EES) in an in vivo setting. BP-SES, BP-EES, and DP-EES (n = 6 each) were implanted in coronary arteries of 12 mini-pigs that were then sacrificed after 7 and 10 days. Stents were stained with hematoxylin and eosin, and a combined Verhoeff and Masson trichrome stain. Areas of fibrin deposition were digitally detected and measured with off-line morphometric software. Stents were investigated for re-endothelialization by transmission electron microscopy. At 7 days, histological analysis revealed the lowest area of fibrin deposition in BP-SES (BP-SES vs. BP-EES vs. DP-EES; 0.10 ± 0.06 mm2 vs. 0.15 ± 0.07 mm2 vs. 0.19 ± 0.06 mm2, p = 0.0004). At 10 days, the area of fibrin deposition was significantly greater in DP-EES (0.13 ± 0.04 mm2 vs. 0.14 ± 0.05 mm2 vs. 0.19 ± 0.08 mm2, p = 0.007). Endothelial cells in BP-SES demonstrated a significantly greater number of tight junctions than those in DP-EES according to by transmission electron microscopy for both days (p<0.05). Various parameters, including an inflammatory reaction and neointimal formation, were comparable among the groups at 7 and 10 days. An abluminal biodegradable polymer-coated SES showed the least fibrin deposition and greatest endothelial cell recovery at an early stage following implantation in the coronary arteries of mini-pigs.

A serial optical frequency-domain imaging study of early and late vascular responses to bioresorbable-polymer sirolimus-eluting stents for the treatment of acute myocardial infarction and stable coronary artery disease patients: results of the MECHANISM-ULTIMASTER study

“…Moreover, experimental data that validated the neointima after dual-polymer (DP)-EES and BP-SES implantation revealed that the number of cell tight junctions in the neointima after BP-SES implantation was significantly higher than that after DP-EES implantation. As a result, the authors concluded that the stability and robustness of the neointima was higher after BP-SES implantation [12]. The risk of a hypersensitive reaction caused by the remaining polymer is recognized as a major problem [2,4,5].…”

Magnesium Bioresorbable Scaffold (BRS) Magmaris vs Biodegradable Polymer DES Ultimaster in NSTE-ACS Population—12-Month Clinical Outcome

“…In recently conducted studies Ultimaster has demonstrated good overall device performance, in the ACS cohort [ 19 ]. These favorable ACS-related outcomes might be linked to the presence of biodegradable polymer, which intensifies the alleviation of vascular inflammation and accelerates endothelial maturation, which is crucial in these high-risk patients [ 20 ]. Considering that in our study the rates of 1-year composite endpoints-TLR in the Ultimaster arm were lower than previously described [ 21 ] (5.4% vs 7.9%), we might assume that the Magmaris might demonstrate the outcomes compared to the ones observed in the new-generation DES devices.…”

A novel polymer-free everolimus-eluting stent with a nitrogen-doped titanium dioxide film inhibits restenosis and thrombosis in a swine coronary model

“…However, DP-DES may induce stent thrombosis through local hypersensitivity reactions and inflammation caused by polymer persistence [ 4 , 5 ]. To overcome this limitation, new-generation DES, including biodegradable polymer DES (BP-DES) and polymer-free DES, have been developed [ 6 , 7 ].…”