Hiroyuki Kyono1; Giulio Guagliumi2; Vasile Sirbu2; Noah Rosenthal3; Satoko Tahara3; Giuseppe Musumeci4; Luigi Fiocca4; Orazio Valsecchi4; Daniel Simon5; Hiram G Bezerra5; Marco A Costa5
    1 Univ Hosps Case Med Cntr， Cleveland， OH
    2 2) Azienda Ospedaliera Ospedali Riuniti di Bergamo， Bergamo， Italy
    3 Univ Hosps Case Med Cntr， Cleveland， OH
    4 2) Azienda Ospedaliera Ospedali Riuniti di Bergamo， Bergamo， Italy
    5 Univ Hosps Case Med Cntr， Cleveland， OH
    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.