Longitudinal Neointimal Distribution Pattern After Everolimus-Eluting Stent Implantation: Insights From Optical Coherence Tomography Study

Background/purpose: Everolimus-eluting stents (EES) are established as latest generation drug eluting stents. However, optical coherence tomography (OCT) assessment of neointimal distribution after EES implantation is lacking. We aimed to assess the longitudinal neointimal distribution pattern after EES implantation using OCT.

Methods: Data from 3 prospective studies (HEAL-EES, REVER and RESERVOIR), including patients with EES implantation and OCT follow-up study, were merged. Analyzed stents were divided into 3 segments of equal length (distal, medial, proximal). Longitudinal neointimal distribution patterns were compared between the 3 segments using generalized estimating equation. Neointimal thickness (NIT), neointimal area obstruction, and uncovered or malapposed struts were analyzed.

Results: In total, 86 patients (92 lesions) were analyzed. Time of OCT follow-up was 9.0 ± 1.5 months. NIT was 101.7 ± 65.4 μm and neointimal obstruction area was 12.2 ± 7.6%. The number of assessed struts was the same in all three segments. NIT tended to be higher at the medial segment (108.8 ± 71.1 μm) compared to distal (103.0 ± 63.4 μm) and proximal (93.3 ± 61.1 μm) (p = 0.076). Neointimal area obstruction was significantly different between the 3 segments (12.4 ± 7.5% [distal], 13.1 ± 7.7% [medial], 11.1 ± 7.5% [proximal]; p = 0.037). In the proximal segment, there was a significantly higher frequency of uncovered struts compared to medial and distal segments (3.9% vs. 2.1% vs. 2.5%, p = 0.009). The distribution of malapposed struts was not significantly different.

Conclusions: Distribution of neointimal hyperplasia seems to be different between stent segments, being higher in the medial segment as compared to proximal and distal. Whether this may reflect a response to local pre-interventional plaque burden centrally covered by the stent should be confirmed in a future study.

Manuscript summary: As optical coherence tomography based assessment of neointimal distribution after everolimus-eluting stent implantation is lacking, we analyzed data of 86 patients (92 lesions) from 3 prospective trials to evaluate neointimal distribution in distal, medial and proximal stent segments. Neointimal hyperplasia seemed to be different between the three segments, with a higher burden in the medial stent segment. Whether this reflects a response to local pre-interventional plaque burden centrally covered by the stent should be confirmed in a future study.