Localization of in-stent neoatherosclerosis in relation to curvatures and bifurcations after stenting

In-stent neoatherosclerosis (ISNA) is a final common pathway of late-stent failure. However, distribution of ISNA has been little reported. This study was to evaluate the localization of ISNA in relation to curvatures and bifurcations after stent implantation using optical coherence tomography (OCT).

We retrospectively selected patients who underwent OCT examination ≥12 months after stent (sirolimus-eluting stents, SES) implantation. A stent curvature was defined if the angulation of the stent segment was >29°. Distribution of ISNA in relation to stent curvature and bifurcation was evaluated.

Totally, 331 patients were enrolled. The mean follow-up time was 15 months. Forty-one (12.3%) patients were found with ISNA. OCT results showed that stents with ISNA had thicker neointima (mean neointima thickness: 0.16 vs. 0.08 mm, P<0.001) compared to patients without ISNA. Segments with angulation >29° had a higher prevalence of ISNA compared with to angulation ≤29° [18 (18.4%) vs. 23 (9.9%), P=0.032]. ISNA was more frequently located at the "inner curvature" than the "outer curvature" (77.8% vs. 22.2%, P=0.018). If ISNA occurred in a branch, it was more often on the opposite side of the branch compared with the same side of the branch [21 (77.8%) vs. 6 (22.2%), P=0.004].

Localization of ISNA is related to vessel curvatures and bifurcations. ISNA occurs more often on the inner curvature and the opposite side of the branch.