Optical Coherence Tomography Tissue Coverage and Characterization with Grey-Scale Signal Intensity Analysis After Bifurcation Stenting with a New Generation Bioabsorbable Polymer Drug-Eluting Stent

Abstract

Bifurcation stenting is thought to be associated with delayed healing and a subsequent risk of stent failure. The aim of this study was to further evaluate healing of thin-strut bioabsorbable polymer everolimus-eluting stents (EES) post bifurcation stenting by optical coherence tomography (OCT) including grey-scale signal intensity (GSI) analysis. Patients undergoing bifurcation stenting with a planned two-stent approach using EES with OCT follow-up at 3-6 months post-stenting were included in this study. Morphometric analysis of contiguous cross-sections was performed at 1 mm longitudinal intervals within the stented segment. GSI analysis of neointimal regions of interest (ROI) overlying stent struts was performed for each of these cross-sections. Tissue coverage was classified as mature or immature. Data on a total of 31 lesions (17 cases) was available at a median of 168 days post stenting. Mean length of stented segments was 27.7 ± 16.6 mm. The mean minimum stent area was 6.50 ± 2.71 mm2 while the mean stent area was 8.69 ± 3.08 mm2. Amongst a total of 847 assessed frames, 9716 struts were visible. Overall strut coverage was 95.9%; 0.3% of struts were malapposed. The mean thickness of neointimal coverage was 100.95 ± 42.03 μm and the mean percentage area stenosis was 9.03 ± 7.80%. A total of 53.79% of ROIs were classified as mature. After implantation of EES in bifurcation lesions, rates of uncovered and malapposed struts were low. GSI analysis showed that more than half of neointimal areas analyzed were classified as mature in keeping with advanced vessel healing.