Author + information
- Yanping Cheng1,
- Qing Wang2,
- Laura Perkins3,
- Richard Rapoza3,
- Jenn McGregor1,
- Gerard Conditt1,
- Aloke Finn4,
- Greg Kaluza1 and
- Juan Granada1
The integration of the Absorb bioresorbable vascular scaffold (BVS) has never been tested in in-vivo models of atherosclerosis after the resorption process has been completed. We compared the long-term vascular healing of BVS to everolimus-eluting metallic stent (EES) in a familial hypercholesterolemic swine (FHS) model of spontaneous untreated atherosclerosis.
The FHS model displays a human-like vascular response to coronary stents. In this study, 20 weeks following initial balloon injury, BVS and EES were implanted in coronary segments of 11 FHS and investigated with imaging and histology at 2 (4 pigs: BVS=8, EES=5), 3 (4 pigs: BVS=8, EES=4) and 4 years (3 pigs: BVS=5, EES=3).
Compared to 1 year, BVS showed slower late lumen loss than EES (BVS 1.14±0.37 vs. EES 2.09±0.12, p=0.003) by angiography at 4 years. By OCT, there was no significant change in the lumen area in BVS (4.96±0.74mm vs. 4 year 5.04±0.97mm, p=0.97) while the lumen area was significantly decreased in EES (8.11±1.18mm vs. 4 year 5.30±0.38 mm, p=0.03). BVS struts were not visible in OCT or IVUS and barely discerned as regions of dense fibrous tissue in histology at 4 years. There was no difference in % diameter stenosis by QCA or total plaque area stenosis by IVUS (2 years: BVS 53.8±8.3% vs. EES 53.0±11.6%, p=0.90; 3 years: BVS 61.2±19.0% vs. EES 56.3±22.0%, p=0.72; 4 years: 62.7±18.0% vs. EES 67.7±1.2%, p=0.57) between two devices at all time points. Consistent with imaging findings, histomorphometry showed no increase in area stenosis in BVS from 2 to 4 years (2 years: 69.0±7.9% vs. 3 years: 73.0±15.7%, p=0.53; BVS 3 years vs. 4 years: 70.6±25.0%, p=0.83) and in EES from 2 to 3 years (2 years: 57.2±11.4 vs. 3 years: 50.1±5.3%, p=0.36). However, there was a significant increase in EES area stenosis from 3 to 4 years (4 years: 70.7±5.9%, p=0.01) consistent with the increased late lumen loss in EES implanted vessels.
In presence of untreated atherosclerosis, BVS demonstrates comparable long-term vascular healing and antirestenotic efficacy to EES, with lower late lumen loss at 4 years thanks to favorable remodeling not attainable in the EES-caged segments.
CORONARY: Bioresorbable Vascular Scaffolds