Abstract 4184: Assessment of Heterogeneity of Strut-Level Neointima Hyperplasia After Stent Implantation by Optical Coherence Tomography
Background: Optical coherence tomography (OCT) permits a highly accurate NIH assessment at each strut level within a cross-section. The aim of this study is to evaluate heterogeneity of NIH among different stents.
Methods: Patients enrolled in ODESSA were assessed. ODESSA was a prospective randomized trial designed to evaluate strut coverage of overlapped (OLP) vs. non-OLP stent segments for the treatment of de-novo, native coronary artery stenosis with four different stent types: Sirolimus-eluting stent (SES); Paclitaxel-eluting stent (PES); Zotarolimus-eluting stent (ZES); and Liberte BMS (BMS). Distance between strut and lumen was measured in every 5 frames (0.3mm) along the stented segment to determine strut-level intimal thickness (SIT). Heterogeneity index (HI) was calculated as the difference of maximum SIT and minimal SIT at each cross-sectional image and divided by average SIT. Finally, average HI was compared among the four stent types for OLP and non-OLP segments.
Results: 53,047 struts from 6,968 cross-sections in 75 patients (SES 20, PES 22, ZES 22, BMS 11) were analyzed. HI was similar between stents in non-OLP segments (SES 1.50, PES 1.56, ZES 0.94, BMS 0.78, P=NS). In OLP segment, all stents demonstrated higher HI, i.e. heterogeneous SIT, than in non-OLP segment, except for PES. SES presented significantly higher HI at OLP segments than the other stent types (SES 3.86, PES 1.22, ZES 1.17, BMS 1.29, P=0.0018).
Conclusions: The heterogeneity of NIH as assessed by OCT-derived SIT is influenced by stent type and presence of two layers of stents. Further studies would be warranted whether heterogeneous distribution of NIH influences the safety of DES.