Spectral Differences Between Normal and Atherosclerotic Aorta

Ischemic heart disease associated with coronary artery atherosclerosis is a leading cause ofdeath in the world today. In addition to standard treatments such as balloon angioplasty, laser mediated angioplasty is being considered as a potential adjuvant or replacement. Nevertheless, experiments and clinical experience have demonstrated that laser angioplasty is associated with damage to normal vessel tissue, which can cause serious complications. To study the possibility of minimizing these effects by directing laser energy more specifically to atherosclerotic lesions, data concerning the spectral characteristics of normal and diseased artery are necessary. In the current study, the absorbance, reflection and fluorescence spectra of normal and atherosclerotic aortic wall tissue are defined, revealing that (i) spectral characteristics of atherosclerotic aorta wall samples are significantly differed from that of healthy vascular wall samples and (ii) based on a spectral analysis of vascular wall, it is possible to distinguish morphological types of atherosclerotic plaques (i.e., lipidic, calcified). The current study contributes to a more complete understanding of laser-tissue interactions that may, following more experimentation and technique development, result in an improvement of clinical laser angioplasty technique.

6111Optical coherence tomography derived predictors of restenosis after non-stenting coronary intervention with drug-coated balloon

Background One of the limitations of metallic stents including contemporary drug eluting stents lies in the permanent existence of metallic materials within the coronary arteries, which may lead to neoatherosclerosis and a long-term use of dual antiplatelet therapy. Some reports have recently suggested the efficacy and safety of non-stent strategy with drug-coated balloon (DCB) angioplasty in combination with debulking devices for de novo lesions. However, little is known about the potential risk of restenosis after percutaneous coronary intervention (PCI) with DCB. Purpose We sought to assess the predictive factors of restenosis by optical coherence tomography (OCT) after PCI with DCB instead of metallic stents. Methods We retrospectively investigated 49 de novo lesions in 38 patients treated by DCB without stent implantation in whom OCT was performed immediately after PCI and follow-up angiography was performed at median of 5.6 (3.7–6.9) months. OCT findings after PCI and the incidence of restenosis at follow-up angiography were evaluated. By means of OCT images, medial coronary dissection was defined as a dissection which reached the medial layer of the vessel, and major dissection was defined as a dissection with more than 60 degrees of the circumference of the vessel or more than 3mm in length. Restenosis was defined as more than 50% diameter stenosis evaluated by Quantitative Coronary Angiography. Results Restenosis was observed in 13 of 49 lesions (27%). In univariate logistic regression analysis, major dissection and medial dissection at the final OCT were associated with restenosis (Odds ratio [OR] 10.0; 95% confidence interval [CI] 2.5–52.6; p<0.01 and OR 5.8; 95% CI 1.5–25.1; p=0.01, respectively). Lesion preparation prior to DCB were performed with rotational atherectomy (n=9), orbital atherectomy (n=2), directional atherectomy (n=4), excimer laser angioplasty (n=17), scoring balloon angioplasty (n=13), or balloon angioplasty (n=4). OCT-defined major dissection remained a significant predictor for restenosis independent of debulking devices used for the preparation (OR 8.1; 95% CI 1.2–70.2; p=0.03). Conclusions Major dissection was associated with restenosis after non-stenting PCI with DCB. Stent implantation should be considered in cases of OCT-defined major dissection. Acknowledgement/Funding None