Abstract 4913: Difference of not only Magnitude but also Heterogeneity of Neointimal Coverage between Drug-Eluting Stent and Bare Metal Stent in Acute Myocardial Infarction

Abstract

Drug-eluting stent (DES) achieved significant reduced restenosis, however the safety of efficacy of DES in acute myocardial infarction (AMI) are still controversial. In this study, we compared angioscopic parameters between DES and bare metal stent (BMS) in patients with AMI. Eighty-seven consecutive patients who received DES or BMS for AMI were enrolled. At 6-month after AMI, coronary angiography was performed in all patients. We performed coronay angioscope (CAS) if the patients did not show significant in-stent restenosis (>50% stenosis). Using CAS, we evaluated the maximum and minimum grade of neointimal coverage within one stent using the following CAS score: 0: stent struts were exposed similary to right implantaiton, 1: stent were covered by very thin neointima, 2: struts were embedded but visible and 3: struts were fully embedded and invisible. We adopted minimium grade as the magnitude of neointimal coverage and calculated heterogeneity score as the following formula: (maximum grade) − (minimum grade). We compared CAS parameters including magnitude and heterogeneity score of neointimal coverage, visible thrombi and plaque color (white or yellow) aroud stent, and serum parameters including low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, hemoglobin A1c and high sensitive C-reactive protein (hs-CRP). Restnosis rate of DES (n=56) was significantly lower than that of BMS (n=31): 9% vs. 29%, p=0.03. In patients without restenosis, DES group revealed lower magnitude and higher heterogeneity score as compared to BMS group while there were no significant differences of the other parameters between the two groups (table ). Not only lower magnitude but also more heterogeneous propery of neointimal coverage were shown in DES as compared to in BMS at 6-month after AMI. These findings may be correlated with future cardiac evetns while restenosis rate is lower in DES than in BMS.