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.