Serial angioscopic evaluation of neointimal coverage and incidence of thrombus formation after Paclitaxel-eluting stent implantation: comparison between 6- and 18-month follow-up.

BACKGROUND: Long-term serial angioscopic follow-up data after paclitaxel-eluting stent (PES) implantation has not previously been published. The aim of this study is to compare the angioscopic parameters such as neointimal coverage grade and prevalence of red mural thrombus at 6- and 18-month follow-up after PES implantation. HYPOTHESIS: Neointimal formation continues to grow and prevalence of angioscopic thrombus formation becomes low over time after PES implantation.
METHODS: We retrospectively enrolled 17 patients with 19 stents who underwent both 6- and 18-month follow-up coronary angioscopy after PES implantation. We evaluated the minimum and maximum neointimal coverage grade within 1 stent using coronary angioscopy by classifying neointimal coverage grade into 4 categories. Neointimal coverage grade and incidence of angioscopic red mural thrombus were compared between 6- and 18-month follow-up groups.
RESULTS: Minimum neointimal coverage grade at 18 months become lower than that at the 6-month follow-up (0.95 ± 0.62 at 6 mo vs 0.58 ± 0.51 at 18 mo, P = 0.035), whereas maximum grade was not significantly different (2.16 ± 0.83 at 6 mo vs 2.37 ± 0.76 at 18 mo, P = 0.248). High incidence of angioscopic red mural thrombus at 6 months was maintained even at 18-month follow-up (68% at 6 mo vs 84% at 18 mo, P = 0.224).
CONCLUSIONS: Long-term serial angioscopic follow-up demonstrated persistent high incidence of red mural thrombus formation at 18 months after PES implantation. 2011 Wiley Periodicals, Inc.