Abstract 4756: Evaluation of the Peri-strut Low Intensity Area Following Sirolimus- and Paclitaxel-Eluting Stents Implantation: Insights From an Optical Coherence Tomography Study in Humans

Abstract

Background: In previous pathological studies, paclitaxel-eluting stents (PES) showed greater fibrin deposition around stent struts, while sirolimus-eluting stent (SES) showed predominance of inflammatory cells with less fibrin deposition than PES. However, there are limited in-vivo data clarifying those qualitative differences in the process of vascular healing after 1st-generation drug-eluting stents (DES) implantation. A recent animal study has shown that peri-strut low intensity area (PLIA) seen in optical coherence tomography (OCT) imaging might represent the process of hyaluronic acid and proteoglycan replacing fibrin. Methods: A total of 60 patients who underwent 6-month follow-up OCT after SES (n=34) and PES (n=26) implantation were enrolled. PLIA was defined as a region around stent struts with a homogenous lower intensity appearance than surrounding tissue on OCT images without significant signal attenuation (Figure ). To evaluate longitudinal extent of PLIA, %PLIA was calculated for each lesion as follows: stent length with PLIA/entire stent length × 100. Results: PLIA was identified by OCT in 19 lesions in SES and 22 lesions in PES. PES showed a higher incidence of PLIA (85% vs. 56%; p=0.03, respectively) with a greater %PLIA than SES (43.0±25.6% vs. 27.8±23.1%; p=0.05, respectively). There was a positive correlation between average neointimal thickness and %PLIA in SES, while only a weak correlation was observed in PES (Figure ). Conclusions: PES showed a higher incidence of PLIA with a greater longitudinal extent of PLIA than SES. The presence and extent of PLIA appeared to be associated with neointimal proliferation after 1st-generation DES implantation.