Quantified frequency-domain optical coherence tomography analysis for the thin-high signals on restenotic tissue after paclitaxel-coated balloon angioplasty

Thin-high signals (THS), detectable by optical coherence tomography (OCT), represent the paclitaxel coverage of in-stent restenotic tissue. This study was conducted to assess the relationship between THS and angiographic outcomes by means of quantified post-procedural frequency-domain OCT (FD-OCT) analysis. From January 2014 to July 2016, 41 patients underwent FD-OCT-guided percutaneous coronary intervention using paclitaxel-coated balloon (PCB) to prevent in-stent restenosis. Of these, we retrospectively enrolled 32 patients (38 lesions) who underwent a 6- to 9-month follow-up angiogram. THS were assessed quantitatively, as THS length and lumen perimeter length were measured using semi-automated software; %THS was calculated by the following formula; total THS area/lumen perimeter area × 100. THS were detected in all 38 lesions that had undergone PCB angioplasty. THS and %THS were significantly higher in lesions without binary restenosis (3.34 ± 2.11 vs. 11.48 ± 8.53 mm², p = 0.001 and 1.49 ± 0.73 vs. 4.42 ± 2.71%, p = 0.001, respectively). Values for THS, which indicates the paclitaxel coverage on restenotic tissue, are associated with reducing restenosis after PCB for in-stent restenosis.