Abstract 4725: Comparative Analysis of Vascular Responses Following Stent Implantation in the Lesion Wth Acute Coronary Syndrome Between Paclitaxel-Eluting and Bare-Metal Stent Using Optical Coherence Tomography
Background: Safety and feasibility of drug-eluting stent in the lesion with acute coronary syndrome (ACS) is still controversial. Optical coherence tomography (OCT) is a high-resolution intravascular imaging modality, which is expected to visualize microscopic vascular response to coronary intervention. The purpose of this study is to evaluate the difference of vascular responses following stent implantation in the ACS lesions between paclitaxel-eluting stent (PES) and bare-metal stent (BMS) using OCT.
Method: Fifty-eight ACS patients who were treated with either PES or BMS (33PESs and 25 BMSs) underwent OCT at 3 months follow-up, and 38 of them (20PESs and 18BMSs) also had 9 months follow-up OCT. Every observed stent struts were analyzed at intervals of 1mm. Neointimal coverage of struts, stent apposition, neointimal thickness (NIT), and the presence of thrombus were evaluated.
Result: At 3 months, frequencies of exposed-struts/stent and of incompletely-apposed-struts/stent were 7.87±9.45 % and 2.35±4.67% in PESs, 3.12±5.1 6 % and 0.7±1.46% in BMSs (p=0.055, p=0.126, respectively). Mean thickness of neointima was 0.13±0.07 mm in PESs and 0.35±0.18mm in BMSs (p<0.001). Thrombus was detected in 7 PESs (21.2%) and in 5 BMSs (20.0%; p=0.910). At 9 months, frequencies of exposed-struts/stent and of incompletely-apposed-struts/stent were 3.72±3.45% and 0.54±0.88% in PESs, 0.93±1.55% and 0.04±0.10% in BMSs (p=0.053, p=0.135, respectively). Mean thickness of neointima was 0.24±0.14mm in PESs and 0.43±0.13mm in BMSs (p<0.001). Thrombus was detected in 3 PESs (15.0%) and in 2 BMS (11.117%) (p=0.72).
Conclusion: A nonsignificant trend for more frequent exposed-strut was observed in PESs than in BMSs; however, frequencies of incomplete stent apposition and incidence of intracoronary thrombus were not different between PESs and BMSs at both 3 and 9 months follow up. Neointimal growth was suppressed more strongly by PESs than by BMSs. These data would suggest feasibility and efficacy of PES for the ACS lesions.