LAUSR

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 mm2; 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.