Different Nature Of The Inflammatory Reaction In Intracoronary Neo-Intimal Hyperplasia Between Sirolimus-Eluting Stents And Bare Metal Stents: An Optical Coherence Tomography Study

Background: It has been suggested that in a small number of autopsy cases, sirolimus-eluting stents (SES) provoked more sustained inflammatory changes in coronary neo-intimal hyperplasia (NIH) than bare metal stents (BMS). Normalized standard deviation using optical coherence tomography (NSD-OCT) has been recently suggested to correlate with the tissue accumulation of CD68 and macrophages in vulnerable plaque lesions in patients with acute coronary syndrome. However, it remains unknown whether NSD-OCT values in NIH in vivo are different between SES and BMS in patients with coronary artery disease. Objective: To compare post-stent inflammatory responses such as NSD-OCT values in NIH between patients with SES and BMS. Methods: Thirty-eight patients (14 BMS and 24 SES) underwent OCT during coronary angiography at their post-stent follow-up (mean 6–8 months after stent implantation). Region of interest (ROI) was determined as in NIH. NSD-OCT values in patients with SES were compared with those in patients with BMS. Moreover, high sensitive serum C-reactive protein (hsCRP) concentration was measured. Results: The NSD-OCT value was significantly higher in the SES group than in the BMS group (0.213 ± 0.004 vs. 0.198 ± 0.006, respectively; p Conclusions: Higher levels of NSD-OCT and hsCRP after SES implantation suggest sustained inflammatory changes in NIH, which may be prone to provoking late stent thrombosis after SES implantation.