Abstract 4612: Angioscopic Evidence of Homogeneous Neointimal Coverage Following Bioabsorbable Polymer Based Drug-eluting Stent in Patients
Background- Adverse effects of stent polymer on the arterial repair following drug-eluting stents (DES) have been recognized in several pathological studies. We sought to investigate the arterial repair by angioscopy following DES implantation with and without bioabsorbable polymer.
Methods- Angioscopy was performed 9±2 months after 12 bioabsorable polymer based paclitaxel-eluting stents (BA-PES, CoStar) and 17 durable polymer based PES (DP-PES, TAXUS Express2) implanted for de novo lesion in the native coronary artery. Heterogeneity of the neointimal coverage (NIC) as well as the dominant grade was examined. NIC was defined as: grade 0=fully visible struts; grade 1=struts bulged into the lumen, but covered; grade 2=embedded, but translucent struts; grade 3=invisible struts. NIC was defined heterogeneous when difference in the grades equal to or greater than one was present. Existence of thrombus was also explored.
Results- In-stent late loss (0.36±0.13 versus 0.42±0.45mm, p=0.6), and dominant NIC grade (grade 0 to 3=0%, 25%, 8%, 67% versus 12%, 23%, 12%, 53%, p=0.6) were similar between BA- and DP-PES. BA-PES showed more homogeneous neointimal coverage than DP-PES (Figure⇓, p=0.045). Thrombi tended to be less in BA-PES than in DP-PES (17% versus 41%, p=0.23). All thrombi were red, subclinical, and were detected at the site of grade 0–1.
Conclusions- In spite of the similar late loss and NIC grade, NIC was more homogeneous in BA-PES with a trend toward less thrombus adhesion. Bioabsorable polymer may have an advantage of competent arterial repair.