The impact of tissue characterization for in-stent restenosis with optical coherence tomography during excimer laser coronary angioplasty

Abstract

We aimed to evaluate the impact of tissue characterization for in-stent restenosis (ISR) with optical computed tomography (OCT) during excimer laser coronary angioplasty (ELCA) in the drug-eluting stent (DES) era. The effect of ELCA for ISR according to differences in tissue characteristics is unclear. Fifty-three ISR lesions (7 bare metal stents and 46 drug-eluting stents) were treated with an ELCA catheter. After ELCA, balloon dilatation with either the scoring or non-compliant balloons was conducted. The procedure was completed by applying a drug-coated balloon. Tissue characterization and lumen measurement with OCT were performed thrice: (1) before percutaneous coronary intervention (PCI), (2) after ELCA, and (3) and after the procedure. Lesions were categorized into the homogenous, layered, and mixed groups. Follow-up angiograms were conducted 6-12 months after PCI. No significant differences in minimal lumen area (MLA) were observed before PCI. A significant difference was observed in MLA after ELCA among the three groups (homogeneous group: 1.75 ± 0.84 mm, layered group: 1.72 ± 0.45 mm, mixed group: 2.24 ± 0.70 mm, P = 0.048). Final MLA was larger in the mixed group than in the homogeneous group (P = 0.028). No significant difference was observed in binary restenosis in the follow-up angiogram (homogeneous group 55.5%, layered group 33.3%, mixed group 33.3%; P = 0.311) and the target lesion revascularization rate (homogeneous 30.0%, layered 23.8%, mixed 25.0%; P = 0.923). Tissue characterization by OCT may predict the efficacy of ELCA and balloon angioplasty for ISR during the acute phase.

How should we treat “undilatable” coronary stents?

“…In another study with 42 patients with ISR, Miyazaki et al 13 compared ELCA+scoring balloon+DEB vs scoring balloon+DEB and found similar long-term angiographic and clinical results. Hashimoto et al 14 used OCT to characterise the underlying tissue in 53 ISR lesions treated with ELCA+DEB and found that the minimal lumen area after ablation was larger in mixed lesions than in those with a homogeneous pattern. Alternatively, Ishihara et al 15 compared results of 47 ISR lesions treated with ELCA+DEB with 161 ISR lesions treated with DEB only.…”