Vascular healing responses to paclitaxel coated balloons or everolimus eluting stents for the treatment of in-stent restenosis. Insights from optical coherence tomography.

Background: Treatment of in-stent restenosis (ISR) remains a significant challenge. Current options include repeat stenting or drug-coated balloons. However, there is a paucity of data regarding vascular healing after these strategies. We, aimed to compare optical coherence tomography (OCT)-based vessel healing after treatment with paclitaxel-coated balloons (PCB) or everolimus-eluting stents (EES).
Methods: An OCT substudy (baseline and 6-9 months) of patients from RIBS IV and RIBS V, two prospective multicenter, randomized controlled clinical trials comparing PCB vs. EES in patients with ISR was performed.
Results: Sixty-four patients were included (30 PCB and 34 EES). There were no differences in the baseline or angiographic characteristics between groups. Both groups had the same proportion of drug-eluting and bare-metal stent (BMS) ISR. Baseline OCT analysis did not show differences in the qualitative characteristics of the ISR nor the restenotic tissue burden. Follow-up OCT showed a larger mean lumen area in the EES group (6.03 ± 1.5 vs. 5.24 ± 1.3 mm 2 ; P  = 0.043) but no difference in angiographic restenosis ( P  = 0.66). Percentage tissue coverage was higher with PCB vs. EES (26 ± 13 vs. 19 ± 11%; P  = 0.031). EES-treated ISR more frequently had uncovered struts at follow-up [21 (72%) vs. 12 (44%); P  = 0.034]. Tissue covering struts more frequently had a high backscatter structure after PCB [21 (78%) vs. 16 (55%); P  = 0.07].
Conclusions: Compared with EES, ISR treated with PCB demonstrated more strut coverage with mainly high backscattering tissue. Larger OCT-defined neointimal proliferation in PCB-treated ISR did not translate into higher angiographic restenosis rates.
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